Article

Scent‐Marking of Giant Otter in the Southern Pantanal, Brazil

January 2009
Ethology 115(3):210 - 216

DOI:10.1111/j.1439-0310.2008.01607.x

Authors:

Caroline Leuchtenberger

Instituto Federal Farroupilha

Guilherme Mourão

Brazilian Agricultural Research Corporation (EMBRAPA)

Giant otters live in social groups, consisting of a mating pair and one or two litters. Groups are territorial and mark their territories often with scent-marks. Our objectives were to evaluate the frequencies of marking and over-marking according to the social status of the individuals and to define the different postures used during the marking. We observed four groups, totaling 25 individuals (five alpha males, four alpha females, seven adult females, one adult male and eight juveniles) with group size ranging between four and 13 individuals. The study was conducted between July 2006 and July 2007 in the Vermelho River and in a stretch of the Miranda River, in the Southern Pantanal. We observed the groups for a total of 2006 min and recorded 95 events of marking totaling 84.9 min. Time spent marking varied between groups and ranged from 4.3 to 44.7 min. The alpha males marked more frequently (62% of marking events, 55 min) than the alpha females (17% of marking events, 13.6 min). Of the 59 events of scent-marking by the alpha males, 32 over-marked the marks of other individuals from the group. Of the 16 events of scent-marking of the alpha females, five over-marked that of other females from the same group. When scent-marking, alpha males used the ‘stepping’ posture most frequently (63%), then ‘fore-paw rubbing’ (24%), ‘latrine use’ (7%), and ‘body rubbing’ (6%). Alpha females used the ‘stepping’ posture most frequently (65%), then ‘latrine use’ (19%) and ‘fore-paw rubbing’ (12%), with only one event of ‘body rubbing’ observed during marking. Subordinate females used the ‘stepping’ posture (76%) and ‘latrine use’ (24%) during marking. Scent-marking can play many roles in mammals and for giant otters, and the main roles appear to be communication of social and sexual status and territorial defense.

Giant otter behaviour in a mega-hydroelectric reservoir, Central Amazon, Brazil

Article

Full-text available

Nov 2021
ANIM BIOL

We tracked thirteen giant otters from three different groups in the Balbina Hydroelectric Reservoir. One of them was a transient animal, while the others were living in groups of five and seven individuals. Travelling was the most frequent behaviour, both for the transient otter (>40%) and group otters (46%). Diurnal resting was the longest-lasting behaviour. Most giant otter behaviour in the reservoir showed little difference when compared with the behaviour of giant otters living in nondammed areas, indicating a significant degree of resilience of this species. However, otters in the reservoir spent more time travelling, probably because their territory sizes were much greater than the territories of giant otters in nondammed areas. The frequency of fishing was similar to what has been recorded elsewhere, suggesting that current fish density and availability in the reservoir is similar to what is observed in nondammed areas. Nevertheless, otters in Balbina spent more time fishing than those in nondammed areas, which alternatively could suggest that fish density in the reservoir was low and could be compensated by increasing the time spent fishing. The high frequency of intraspecific kleptoparasitism observed in this study (62%) is noteworthy, although virtually undocumented for this species. This is the first study of giant otter behaviour in a hydroelectric reservoir that can be used for the conservation of this endangered species in man-made lakes.

Sociality and signaling activity modulate information flow in river otter communication networks

Article

Nov 2020

Animal communication networks are built from interactions between senders and receivers of signals. The drivers of signaling decisions, which are the building blocks of such networks, are not well understood. Theory predicts that conditions which ensure information spread to the largest possible number of receivers should be favored. Several carnivores use latrine sites for visual, olfactory, and auditory signaling. We tested the hypotheses that signaling behavior at latrine sites is influenced by social structure and locally acquired information on the presence of conspecifics, using coastal river otters (Lontra canadensis), in Alaska. River otters exhibit a flexible social system of mostly males that communicate through scent marking at latrines. During scent marking, river otters also perform feet stomping, which may add a visual component to their signal. Using trail camera footage, we found that solitary otters were more likely to perform both sniffing and scent marking compared with otters in groups. Feet stomping was more intense for solitary otters but less pronounced during overmarking. Signalers demonstrated a greater tendency to scent mark when in smaller groups at highly active latrines, whereas feet stomping was more intense in recently visited sites. When in groups, scent-marking frequency increased when other individuals were signaling, suggesting a positive feedback, possibly driven by feet stomping. In concert, our results suggest that in river otters, scent-marking decisions minimize signal dilution by being performed in small groups and maximize the receivers through preferential signaling at latrines with higher, more recent activity. Because signaling decisions in social animals are linked to key life-history events such as mating and group membership shifts, understanding their individual and population-level drivers can be crucial.

Scent-Marking

Chapter

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Dec 2018

Caroline Leuchtenberger

Dancing to the message: African clawless otter scent marking behaviour

Article

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Sep 2017

Latrine use and behaviour at latrines have been studied in numerous otter species, but not African clawless otters, Aonyx capensis. We set up trail cameras at two latrines near Dullstroom, South Africa. On several occasions, we observed Aonyx capensis performing scent marking behaviours that included body rubbing on a bare patch of ground and deposition of anal secretions while “jiggle dancing”. Although body rubbing has been documented in this species, it has not been associated with scent marking, while “dancing” during scent marking has not been reported. Given the context of these observations, we speculate that the main function of scent marking behaviour in African clawless otters is likely related to inter-clan territorial marking.

Advances in the study of giant otter (Pteronura brasiliensis): ecology, behavior, and conservation: a review

Article

Full-text available

Dec 2015

Giant otters, once targeted by the pelt trade to near extinction, are now legally protected and have made a comeback in some parts of their range. Our state of knowledge about the behavior and ecology of this apex predator has increased substantially since the first studies in the 1970s but remains incomplete. Negative anthropogenic pressures and conflicts affecting giant otters are intensifying and now take many forms, from extensive habitat loss and degradation, pollution, ecotourism with heavy impacts, to gold mining. We review the corpus of giant otter field research and findings since 1980 and discuss new findings and our shortfall of knowledge and its implications for the long-term conservation of the species.

Vocal repertoire of the social giant otter

Article

Full-text available

Nov 2014
J ACOUST SOC AM

According to the "social intelligence hypothesis," species with complex social interactions have more sophisticated communication systems. Giant otters (Pteronura brasiliensis) live in groups with complex social interactions. It is likely that the vocal communication of giant otters is more sophisticated than previous studies suggest. The objectives of the current study were to describe the airborne vocal repertoire of giant otters in the Pantanal area of Brazil, to analyze call types within different behavioral contexts, and to correlate vocal complexity with level of sociability of mustelids to verify whether or not the result supports the social intelligence hypothesis. The behavior of nine giant otters groups was observed. Vocalizations recorded were acoustically and statistically analyzed to describe the species' repertoire. The repertoire was comprised by 15 sound types emitted in different behavioral contexts. The main behavioral contexts of each sound type were significantly associated with the acoustic variable ordination of different sound types. A strong correlation between vocal complexity and sociability was found for different species, suggesting that the communication systems observed in the family mustelidae support the social intelligence hypothesis.

Avaliação do risco de extinção da Ariranha Pteronura brasiliensis (Zimmermann, 1780) no Brasil

Article

Full-text available

Aug 2013

Ariranhas, Pteronura brasiliensis, são sociais, vivendo em grupos monogâmicos sob cooperação reprodutiva, o que restringe o tamanho populacional efetivo da espécie aos casais dominantes. Indivíduos tornam-se maduros a partir de dois anos de vida, sendo que fêmeas na natureza reproduzem até os 11 anos de idade aproximadamente e os machos podem reproduzir até os 15. Dessa forma, estima-se que o ciclo de três gerações da espécie represente um período aproximado de 20 anos. A espécie, que ocorria nos biomas Cerrado, Mata Atlântica, Pantanal e Amazônia, sofreu uma drástica redução populacional no passado devido principalmente à caça. Atualmente, há registros isolados no Cerrado e possivelmente na Mata Atlântica, no estado do Paraná, sendo que populações viáveis da espécie estão limitadas à Bacia Amazônica e ao Pantanal. Essas áreas, no entanto, serão diretamente impactadas pela destruição e fragmentação de áreas naturais, bem como pela construção de hidrelétricas de pequeno e grande porte em grande quantidade e num futuro próximo (prazo menor que 20 anos, ou três gerações da espécie), ocasionando uma representativa perda de habitat e provável alteração na comunidade de peixes, que são seu principal recurso alimentar (sub-critério Ac). Perdas populacionais também ocorrem devido a conflitos com pescadores e interferência da espécie na aqüicultura (sub-critério Ad). Desta forma, considera-se que a espécie sofrerá uma redução populacional de pelo menos 30% nos próximos 20 anos, o que justifica sua categorização como Vulnerável (VU), segundo o critério A3cd.

Latrine site selection by African clawless otters, Aonyx capensis, and their behavior during latrine visitations

Article

Full-text available

Feb 2024

The behavioural ecology of African clawless otters, Aonyx capensis

Thesis

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Jan 2024

Stephanie Nicolaides

Mustelid Communication

Chapter

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May 2022

Latrine site selection by African clawless otters, Aonyx capensis, and their behavior during latrine visitations

Article

Full-text available

Jan 2024
J MAMMAL

Latrine sites are used as areas for the deposition of scent-containing excretions and play important roles in intraspecific olfactory communication, territoriality, sexual attraction, and defense behaviors of many mammals. African clawless otters (Aonyx capensis) likely use latrine sites as primary areas for scent marking and scent communication but no studies to date have investigated their potential role or site selection. We assessed latrine site selection at 2 spatial scales (micro- and macroscale) and recorded behaviors via camera trap recordings. Thirty-eight latrine sites were identified and assessed at 2 locations in Mtunzini on the north coast of KwaZulu-Natal, South Africa (uMlalazi Nature Reserve and Zini Fish Farm) during the months of August to November 2021. Latrine sites were identified through several intensive surveys, while we characterized nonselected sites through a systematic sampling approach. Latrine and control sites were inventoried along a 52-m buffer around all water bodies in both study areas. At each site we measured a series of potential environmental predictors, including horizontal and vertical vegetation cover, surface slope, and averaged wind speeds for days classified as relatively wind-still and relatively windy. To assess the relative role of various environmental predictors, we used a binomial generalized linear model resource selection function to model both spatial scales of latrine site selection. The majority of latrine sites were located at the ecotone between 2 vegetation units or between a vegetation unit and a water source. At a macroscale, latrine sites were associated with areas containing little vegetative substrate cover and minimal canopy cover. The top-ranked models at the microscale also indicated that latrine sites were characterized as occurring in open areas with less canopy and horizontal cover and on flatter areas that are relatively protected against wind. The most common behaviors recorded at 3 latrine sites were the “jiggle dance” (42%) and sniffing (29%). We hypothesize that otters evaluate numerous environmental parameters to enhance the functionality of latrine sites. For example, sites with little vegetative cover may increase the conspicuousness of latrines to conspecifics, while areas exposed to less wind likely aid in the retention of scent. Ongoing research is characterizing the behaviors of otters around latrines and chemical signatures of latrine sites in an effort to facilitate interpretation of their social function to African clawless otters.

First report of myiasis caused by Cochliomyia hominivorax in free-ranging giant otter (Pteronura brasiliensis)

Article

Full-text available

Nov 2022
REV BRAS PARASITOL V

Giant otters are territorial semi-aquatic mammals. It is common to find several individuals exhibiting wounds and scars due to intraspecific conflicts. Myiasis is a parasitic infestation on living tissues of vertebrates caused by dipterous larvae, that usually develops in freshly open wounds and can seriously threaten the host’s health. Ectoparasites seem to be rare among giant otters and myiasis had not been recorded in this species until now. Here, is presented one record of myiasis in a free-ranging giant otter found dead in the Pantanal, Brazil. An ulcerative lesion was found in the frontoparietal region, from which 22 larvae were recovered and identified as Cochliomyia hominivorax. The low occurrence of ectoparasites in giant otters might reflect their semi-aquatic habits and their grooming behavior, which makes it difficult for parasites to remain on the skin. The injured otter probably got the larvae after an intraspecific fight. Agonistic encounters between groups of giant otters have been reported before and these fights can result in serious wounds or even death. It was hypothesized that the myiasis caused by C. hominivorax deteriorated the health of the infested giant otter, which prevented recovery and accelerated its death.

Mumm C.A.S., Knörnschild M. (2018) Mustelid Communication. In: Vonk J., Shackelford T. (eds) Encyclopedia of Animal Cognition and Behavior. Springer, Cham

Chapter

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Jan 2018

Territorial choruses of giant otter groups (Pteronura brasiliensis) encode information on group identity

Article

Full-text available

Oct 2017
PLOS ONE

Group living animals often engage in corporate territorial defence. Territorial group vocalizations can provide information about group identity, size and composition. Neighbouring groups may use this information to avoid unfavourable direct conflicts. Giant otters are highly social and territorial animals with an elaborate vocal repertoire. They produce long-range screams when they are alert or excited, i.e. in an alarm, isolation or begging context. Long-range screams are not only produced by one individual at a time (‘single screams’) but also by multiple group members simultaneously, resulting in a highly conspicuous ‘group chorus’. Wild giant otters regularly produce group choruses during interactions with predators, when they detect intruders in their territory or before group reunions after separation. Since single screams and especially group choruses probably contribute to the groups’ corporate territorial defence, we hypothesized that group identity is encoded in single screams and group choruses. We analysed vocalizations from five wild and three captive giant otter groups and found statistical evidence for a group signature in group choruses. Results for single screams were less conclusive, which might have been caused by the comparatively lower sample size. We suggest that giant otters may gain information on group identity by listening to group choruses. Group identity likely constitutes important social information for giant otters since territory boundaries of neighbouring groups can overlap and direct inter-group conflicts are severe. Therefore, group chorusing may contribute to the mutual avoidance of members from different groups.

Mix it and fix it: Functions of composite olfactory signals in ring-tailed lemurs

Article

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Apr 2016

Animals communicating via scent often deposit composite signals that incorporate odorants from multiple sources; however, the function of mixing chemical signals remains understudied. We tested both a ‘multiple-messages’ and a ‘fixative’ hypothesis of composite olfactory signalling, which, respectively, posit that mixing scents functions to increase information content or prolong signal longevity. Our subjects— adult, male ring-tailed lemurs (Lemur catta)—have a complex scent-marking repertoire, involving volatile antebrachial (A) secretions, deposited pure or after being mixed with a squalene-rich paste exuded from brachial (B) glands. Using behavioural bioassays, we examined recipient responses to odorants collected from conspecific strangers. We concurrently presented pure A, pure B and mixed A+B secretions, in fresh or decayed conditions. Lemurs preferentially responded to mixed over pure secretions, their interest increasing and shifting over time, from sniffing and countermarking fresh mixtures, to licking and countermarking decayed mixtures. Substituting synthetic squalene (S)—a well-known fixative— for B secretions did not replicate prior results: B secretions, which contain additional chemicals that probably encode salient information, were preferred over pure S. Whereas support for the ‘multiple-messages’ hypothesis underscores the unique contribution from each of an animal’s various secretions, support for the ‘fixative’ hypothesis highlights the synergistic benefits of composite signals.

Giant otter alarm calls as potential mechanisms for individual discrimination and sexual selection

Article

Full-text available

Mar 2016

Acoustic variation can convey identity information, facilitate social interactions among individuals and may be useful in identifying sex and group affiliation of senders. Giant otters live in highly cohesive groups with exclusive territories along water bodies defended by the entire group by means of acoustic and chemical signals. Snorts are harsh alarm calls, emitted in threat contexts, which commonly elicit the cohesion and the alert behaviour of the members of the group. The aim of this study was to determine whether giant otter snorts have potential to be used for individual discrimination. We tested this hypothesis by verifying if the acoustic characteristics of snorts vary between two study areas, among social groups and individuals, and between males and females. Snort acoustic variables did not differ significantly among study areas, but varied significantly among groups, individuals and between sexes, with higher discrimination between sexes. The frequency of formants (F1–F5) and formant dispersion (DF) potentially allow identity coding among groups, individuals and sexes. The stronger sex discrimination of snorts may be related to information on body size carried by formant frequencies and dispersion, indicating acoustic sexual dimorphism in giant otters. Acoustic differences among groups and individuals are more likely learned, since we did not find evidence for a genetic signal encoded in the snort variables measured. We conclude that the snorts carry information that could be used for individual or group recognition.

Territoriality of Giant Otter Groups in an Area with Seasonal Flooding

Article

Full-text available

May 2015
PLOS ONE

Territoriality carries costs and benefits, which are commonly affected by the spatial and tempo- ral abundance and predictability of food, and by intruder pressure. Giant otters ( Pteronura bra- siliensis ) live in groups that defend territories along river channels during the dry season using chemical signals, loud vocalizations and agonistic encounters. However, little is known about the territoriality of giant otters during the rainy season, when groups leave their dry season ter- ritories and follow fish dispersing into flooded areas. The objective of this study was to analyze long-term territoriality of giant otter groups in a seasonal environment. The linear extensions of the territories of 10 giant otter groups were determined based on locations of active dens, la- trines and scent marks in each season. Some groups overlapped the limits of neighboring ter- ritories. The total territory extent of giant otters was correlated with group size in both seasons. The extent of exclusive territories of giant otter groups was negatively related to the number of adults present in adjacent groups. Territory fidelity ranged from 0 to 100% between seasons. Some groups maintained their territory for long periods, which demanded constant effort in marking and re-establishing their territories during the wet season. These results indicate that the defense capacity of groups had an important role in the maintenance of giant otter territo- ries across seasons, which may also affect the reproductive success of alpha pairs.

The Vocal Repertoire of Adult and Neonate Giant Otters (Pteronura brasiliensis)

Article

Full-text available

Nov 2014
PLOS ONE

Animals use vocalizations to exchange information about external events, their own physical or motivational state, or about individuality and social affiliation. Infant babbling can enhance the development of the full adult vocal repertoire by providing ample opportunity for practice. Giant otters are very social and frequently vocalizing animals. They live in highly cohesive groups, generally including a reproductive pair and their offspring born in different years. This basic social structure may vary in the degree of relatedness of the group members. Individuals engage in shared group activities and different social roles and thus, the social organization of giant otters provides a basis for complex and long-term individual relationships. We recorded and analysed the vocalizations of adult and neonate giant otters from wild and captive groups. We classified the adult vocalizations according to their acoustic structure, and described their main behavioural context. Additionally, we present the first description of vocalizations uttered in babbling bouts of new born giant otters. We expected to find 1) a sophisticated vocal repertoire that would reflect the species' complex social organisation, 2) that giant otter vocalizations have a clear relationship between signal structure and function, and 3) that the vocal repertoire of new born giant otters would comprise age-specific vocalizations as well as precursors of the adult repertoire. We found a vocal repertoire with 22 distinct vocalization types produced by adults and 11 vocalization types within the babbling bouts of the neonates. A comparison within the otter subfamily suggests a relation between vocal and social complexity, with the giant otters being the socially and vocally most complex species.

High‐resolution drone imagery reveals drivers of fine‐scale giant otter habitat selection in the land‐water interface

Article

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Nov 2022

Neotropical freshwater habitats are particularly sensitive to degradation by human activity. Piscivorous semi‐aquatic freshwater megafauna inhabit both the terrestrial and aquatic mediums and thus may be good indicators of wetland habitat quality. However, the drivers of their space use at the terrestrial and aquatic landscape levels are not well understood. We studied the spatial behavior and habitat use of giant otters in Madre de Dios, Peru, inhabiting areas with variable levels of protection. We combined unmanned aerial vehicle (UAV) and satellite images to develop different terrestrial and water‐associated land cover variables. We tested the influence of these predictors on giant otter habitat use at multiple spatial scales, comparing used and available locations. Giant otters favored bank areas with dense forest canopy cover. In the aquatic medium, giant otters showed positive selection for open water and fallen logs and avoided floating vegetation. These findings may be explained by preference for optimal fish habitat to maximize foraging yield and bank areas that provide more cover from predators and higher quality denning locations. Variables developed from UAV images outperformed satellite‐derived variables. Despite recent signs of deforestation in lake banks in unprotected areas, spatial model predictions indicated that unprotected oxbow lakes did not differ in their habitat suitability from protected freshwater habitats. Management implications of our findings include identification of factors driving habitat suitability to guide policy and decisions regarding protection or restoration of oxbow lake ecosystems to support giant otter populations. In addition, we demonstrate that UAVs have value in complementing satellite‐derived images and providing a cost‐effective methodology to assess habitat quality for semi‐aquatic species at the land‐water interface.

Group Dynamics and Habitat Use of the Giant Otter, Pteronura brasiliensis (Zimmermann, 1780), in Seasonally Flooded Forest in the Araguaia River, Central Brazil: A 10-Years Study

Article

Full-text available

Jan 2022

We carried out monthly surveys of the giant otter population between 2010 and 2020 in a study area comprised of 1,500 hectares of igapó flooded forest with oxbow lakes in the Cantão region of central Brazil. We recorded 16-32 resident adults in the study area each year, distributed in 4-8 groups. Resident groups exhibited extensive home range overlap, with each group using several lakes and larger lakes used in rotation by up to six groups. Dens and campsites were also shared by multiple groups, but lakes were used by only one group at a time, and encounters between groups were very rare. Twenty-four adult otters were observed to join an existing group. Some individuals changed groups multiple times. Resident adult turnover was high. Each year an average of 36% of resident adults were new immigrants, and 72% of groups left the area within two years. Resident groups had, on average, one litter every three years, and annual cub production showed high variability and a negative correlation to the number of new immigrants in the area. No pairs of giant otters reproduced successfully during the study. Groups of three otters formed through the recruitment of an adult individual by an existing pair and reproduced as successfully as larger groups. Group dynamics and territorial behavior in the Cantão flooded forest ecosystem, where optimal giant otter habitat is continuous in all directions, were found to be different from that reported in areas composed of patchy (isolated oxbow lakes) or linear (rivers) habitat. This suggests that giant otter social and territorial behavior is plastic and adapts to the spatial characteristics of the habitat.

The Function of Carnivore Latrines: Review, Case Studies, and a Research Framework for Hypothesis Testing

Chapter

Aug 2022

Latrines are accumulations of two to several hundred faeces resulting from the repeated use of the same defecation sites by the same or several individuals. Many carnivores deposit their faeces in such dedicated latrine sites, which are often shared by several animals either from the same social group or from neighbouring territories. Although latrines are assumed to play an important role in olfactory communication, detailed knowledge of specific information exchange is still lacking. Four different categories of data are important in trying to understand the function of latrines in animal societies: (i) spatial distribution patterns; (ii) temporal usage patterns; (iii) individual visit and contribution patterns; and (iv) information content of the signal. While the spatial distribution of latrines in relation to territory boundaries, landmarks and resources has been studied in a variety of species, only a few studies concentrated on temporal variation in latrine usage. Even fewer studies provide insights into inter‐individual differences in visit and contribution patterns or the olfactory information content of latrines. In this review, we outline potential functional hypotheses for latrine use and develop a research framework for the study of latrine function. We then present three model species – European badger, Meles meles , meerkat, Suricata suricatta , and banded mongoose, Mungos mungo – for which we have detailed data for at least three of the four above‐mentioned categories, which we will use to test these hypotheses. Throughout the chapter, we review the different techniques used to collect these data in different species, discuss the limitations of using spatial data alone to test functional hypotheses, and highlight the value of a combined approach.

Turismo de observação de mamíferos no Pantanal

Article

Full-text available

Dec 2021

O turismo de observação de fauna é uma atividade que vem aumentando gradativamente em diversas regiões no mundo, principalmente em países com alta diversidade, como o Brasil. Essa atividade busca a observação em vida livre de espécies carismáticas, entre as quais se enquadram muitos mamíferos. No Brasil, a atividade ainda é pouco desenvolvida, contudo o Pantanal é o bioma com o maior potencial para a expansão e a consolidação desse tipo de turismo. O Pantanal é considerado uma savana brasileira, com abundância de fauna, havendo facilidade para observação de grandes vertebrados, como porcos-do-mato, capivaras, ariranhas e até mesmo onças-pintadas. O turismo de observação de fauna tem aumentado nos últimos anos neste bioma, principalmente na região norte, no Pantanal de Cuiabá, e ao sul, no Pantanal de Miranda e Aquidauana. Neste artigo, discutimos as características da atividade de observação de fauna no Pantanal, as principais espécies observadas, as leis e regras já estabelecidas, os problemas existentes, abordando também a importância do turismo como atividade econômica para o desenvolvimento sustentável desta região.

Observations of multiple reproductive females in groups of smooth‐coated otters

Article

Jan 2022

Smooth‐coated otters (Lutrogale perspicillata) inhabit waterways of India and Singapore. Smooth‐coated otters typically live in family groups, or “romps,” consisting of a single mating pair with adult‐sized, nonbreeding offspring. We note here the presence of multiple reproductive female otters within some romps, as well as the possible existence of simultaneous litters by different mothers. This finding has not been reported among L. perspicillata before. We address possible influences leading to multiple reproductive females (MRF) within romps of smooth‐coated otters, including inclusive fitness, incomplete suppression of reproduction and existing in an urban environment. The numerous observations of MRF warrant further investigation. Smooth‐coated otter pup and adults near the Singapore River in Singapore. Smooth‐coated otters live in groups, or “romps”, with a dominant breeding pair and one or more broods of offspring. We collate evidence from India and Singapore of multiple females with reproductive traits within romps, including females with simultaneous litters and multiple females lactating. We also include evidence of what may be infanticide by other adults within a romp. The Zouk romp, shown, had two lactating females in December 2020.

Conservation of Amazonian aquatic mammals

Article

Full-text available

Apr 2021

• Aquatic mammals worldwide are highly threatened in freshwater ecosystems where they are affected by direct human activities (e.g. hunting) as well as indirect human alteration of freshwater ecosystems (e.g. dams, mining activity). Although aquatic mammals of the Amazon Basin are experiencing many growing threats, little is known about the escalating impacts on them, current limitations in protection mechanisms, and possible strategies to ensure their conservation. This study synthesizes the available information on Amazonian aquatic mammals, including the ecological characteristics of these species, key threats, population status and conservation prospects. • Amazonian aquatic mammals comprise seven species – Inia geoffrensis, Inia boliviensis, Inia araguaiaensis, Sotalia fluviatilis, Trichechus inunguis, Pteronura brasiliensis and Lontra longicaudis – which are characterized by low reproductive rates and keystone ecosystem roles. These species are endangered mainly by biological resource use, natural ecosystem modifications, energy production and mining, and climate change. Although information is sparse, there is evidence that these threats are inducing population declines of Inia spp., and hindering the recovery of populations of P. brasiliensis. • Protection mechanisms for these species mostly include national and international laws and agreements, legislation governing environmental licensing and protected areas. Each of these protection mechanisms, however, has limited capacity to protect Amazonian aquatic mammals, largely because they are poorly enforced, lack transnational coordination or require population trend data that do not exist. • Reversing the current state of affairs for Amazonian aquatic mammals requires an integrated research and policy approach that, at a minimum, substantially increases the present capacity to monitor their population responses to human impacts, establishes effective enforcement of existing legislation and prevents further impacts from hydropower development. To implement such an approach, information on the ecology of these species is necessary to create public and scientific awareness.

Social organization of otters in relation to their ecology

Article

Full-text available

Mar 2021

Otter species are known to fluctuate intraspecifically from a solitary lifestyle to group-living arrangements. By examining what is known about habitat use and foraging style in otters of 13 different species, based on 93 studied sites, we assessed (1) the relationship between social habits and preferred habitats, (2) the relationship between species and prey preferences, and (3) the effect of predator avoidance on their social organization in order to assess the socio-ecological factors influencing otters. Females remain the core of their social stability. We show the major influence of habitats and feeding strategies (i.e. socio-ecology) of otters. The different species of solitary otters most often inhabit linear environments, such as freshwater ecosystems or wave-exposed marine coasts, and their habitat is often subject to disturbances that fragment their functional continuity. Social otters are more often found in extensive habitats with high plant cover, regular food resources and in areas with large predators compared to solitary species. The maintenance of regular resources and the fact that the main trophic resources are replenished rapidly might be determining factors driving sociality. Group-living and bachelor congregations among otters can also respond to pressure from large predators. This suggests that foraging, habitat use and the presence of large predators may be the drivers of sociality in otters. We conclude that most otters have a greater social potential than previously assumed, which is confirmed by their various vocalizations recently described.

New Scent Marking Behavior of Neotropical Otter (Lontra longicaudis) in the Eastern Brazilian Amazon

Article

Full-text available

Feb 2021

Scent marking behavior in mammals is related with both inter and intra-specific communication. Several otter species are known to communicate via scent marking, but a couple scent marking has not been documented in the Neotropical Otter (Lontra longicaudis). We obtained field observations of scent marking behavior in Neotropical Otters over two years using camera traps along waterways in the eastern Brazilian Amazon. Our results reveal the use of sandy substrates on islands and river margins for intra-specific communication between otters. Most records (62.5%) were from solitary adults. We document multiple independent records of adult otters digging to scent mark with urine and couple behavior of males urinating on top of female's fresh urine in newly dug shallow craters. We also demonstrate behavioral plasticity of this species evidenced by camera traps recording terrestrial activity during both day and night. Our results contribute to improve the knowledge of the behavior of this otter species in the wild and can potentially be applied to improve ex-situ welfare of captive otters.

Giant otter diet differs between habitats and from fisheries offtake in a large Neotropical floodplain

Article

Nov 2020
J MAMMAL

Giant otters Pteronura brasiliensis are semiaquatic mammals that mainly eat fish, the abundance of which is affected by seasonal flooding and habitat structure. The piscivorous habits of giant otters lead to negative human perception and conflicts with fisheries. We compared giant otter feeding habits between seasons and habitats in the Southern Pantanal, Brazil, by analyzing feces collected between September 2008 and June 2011.We investigated whether habitat and season affected P. brasiliensis diet composition and prey size. We calculated the frequency of occurrence, relative frequency, and overlap of fish species eaten by giant otters and caught by fishermen. The giant otters had a more diverse assemblage of fish prey than the offtake in the fisheries. We did not find strong seasonality in otter diets, but diet composition and prey size differed between rivers and lakes. The giant otter diet had higher overlap with the offtake of sport than with professional fishermen. Although the otters’ piscivorous diet often leads to negative perceptions by humans, the low overlap between otter diet and species taken in local fisheries suggests that otters have little effect on the commercial fishery. These results indicate that educational programs could be used to reduce perceived conflict between giant otters and fishermen.

Total mercury concentration in the fur of free-ranging giant otters in a large Neotropical floodplain

Article

Nov 2020

The giant otter, Pteronura brasiliensis, (Zimmermann, 1780), is a semiaquatic carnivore that feeds mainly on fish. Mercury has high toxicity and high potential for bioaccumulation in tissues and biomagnification in organisms through food chains. Thus, as a top predator in the trophic chain, the giant otter has the potential to accumulate mercury by biomagnification. The objective of the present study was to measure the total mercury concentration in giant otter fur samples from an area in the southern Brazilian Pantanal. Fur samples from 19 otters from different social groups were collected from captured animals or were sampled with biopsy darts. Total mercury determination was performed by cold steam spectrophotometry. Mercury concentrations found in the giant otter fur were 7.15 ± 3.41 μg·g-1 (2.01 to 12.06 μg·g-1) dry weight. The values are above to the upper limit found in fur samples of otter species not exposed to contamination sources, which typically range from 1 to 5 μg·g-1. The concentrations found in the study area indicate that even in the southern Pantanal, which is approximately 475 km from gold mining activity, mercury can be considered a threat for giant otters, as well as for riverside populations. It is also important to consider that other anthropogenic sources of mercury, such as pesticides used in agriculture, could affect this population.

Deciding when to intrude on a neighbour: quantifying behavioural mechanisms for temporary territory expansion

Article

Full-text available

Sep 2019
THEOR ECOL-NETH

Flexible territorial structures are common to a variety of animal populations. When resources are abundant, animals can maintain relatively fixed territory boundaries. However, if resources decline, animals may have to intrude temporarily into a neighbour’s territory to secure enough food for survival. Although such intrusions may be necessary, they take time away from foraging and can lead to costly conflicts, resulting in a behavioural trade-off. Here, we examine this trade-off using a spatially explicit, energy-based movement model inspired by observations of giant otters. We uncover conditions under which temporary neighbour intrusions are beneficial. We show that, under certain circumstances, this benefit is sufficient for allowing territorial groups to survive in perpetuity, when otherwise they would be forced to disperse or die. Our model also reveals plausible mechanisms behind a variety of observed phenomena, including the emergence of intermediate-sized territorial groups, territorial fission/fusion dynamics, and the employment of multiple methods for advertising territories (e.g. vocal and olfactory). Although we focus our modelling on giant otters, the behavioural mechanisms it describes are quite general, having been observed across a wide range of taxa, including birds, fish and mammals. Our model therefore serves as a general theoretical test-bed for understanding temporary territory expansion.

More than meets the eye: kinship and social organization in giant otters (Pteronura brasiliensis)

Article

Full-text available

Jan 2016
BEHAV ECOL SOCIOBIOL

Giant otters live in highly cooperative groups. Behavioral observations suggest that groups are composed of a dominant reproductive pair and their offspring of previous years. We combined genetic data and long-term ecological information to determine genetic relatedness within and between groups to verify that hypothesis. We genotyped 12 polymorphic loci of 50 otters from 13 groups and two transient individuals. The average relatedness within groups (r = 0.23) was high, but the degree of relatedness varied within the groups, including groups of unrelated individuals, contradicting the current social hypothesis of an exclusively parent-brood model. Negative correlations between kinship and distance between territories were higher in females, and on two occasions, dominant females were replaced by related subordinates of the same group. Solitary transients were males, suggesting a tendency of male-biased dispersal. These data, combined with long-term ecological and behavioral information, indicate that direct benefits, such as alloparental care, and acquisition, inheritance, and defense of high-quality territories may drive the evolution of group living of this endangered social carnivore.

Activity Patterns of giant Otters Recorded By Telemetry and Camera Traps

Article

Full-text available

May 2013

The giant otter (Pteronura brasiliensis) is a social species that defends territories along water bodies. Although some researchers have visually monitored otters during long periods at night, no nocturnal activity of the species has been recorded and giant otters are currently believed to be strictly diurnal. In this study, we present information about the activity patterns of groups of giant otters in the Brazilian Pantanal, using radio telemetry and camera trap data. We captured, implanted transmitters in, and monitored three male giant otters from different groups in the Miranda and the Vermelho Rivers between November 2009 and June 2011. The locations and behavior of the group were recorded at 30-min intervals from 05:00 to 19:00. Camera traps were positioned at the active dens and latrines of eight groups of giant otters in the Miranda, Vermelho and Negro Rivers between June 2010 and October 2011. The groups of giant otters were mostly crepuscular and diurnal, but 31% of the camera-trap recordings were nocturnal. Fishing was the most frequent (64%) behavior recorded by telemetry. Giant otters were recorded exiting the den mostly in the early morning (06:00) and entering the den at the end of the day (16:00 to 19:00). Nocturnal activity appeared to be associated with the need to defecate, prey availability nearby the den and predation risk.

Scent-Marking

Chapter

May 2022

Caroline Leuchtenberger

Mustelidae Cognition

Chapter

Feb 2018

Mustelidae Cognition

Chapter

May 2022

Group dynamics and habitat use of the Giant Otter, Pteronura brasiliensis (Zimmermann, 1780), in seasonally flooded forest in the Araguaia River, Central Brazil: A 10-years study

Preprint

Full-text available

Jan 2022

We carried out monthly surveys of the giant otter population between 2010 and 2020 in a study area comprised of 1,500 hectares of igapo flooded forest with oxbow lakes in the Cantao region of central Brazil. We recorded 16-32 resident adults in the study area each year, distributed in 4-8 groups. Resident groups exhibited extensive home range overlap, with each group using several lakes and larger lakes used in rotation by up to six groups. Dens and campsites were also shared by multiple groups, but lakes were used by only one group at a time, and encounters between groups were very rare. 24 adult otters were observed to join an existing group. Some individuals changed groups multiple times. Resident adult turnover was high. Each year an average of 36% of resident adults were new immigrants, and 72% of groups left the area within two years. Resident groups had, on average, one litter every three years, and annual cub production showed high variability and a negative correlation to the number of new immigrants in the area. No pairs of giant otters reproduced successfully during the study. Groups of three otters formed through the recruitment of an adult individual by an existing pair and reproduced as successfully as larger groups. Group dynamics and territorial behavior in the Cantao flooded forest ecosystem, where optimal giant otter habitat is continuous in all directions, were found to be different from that reported in areas composed of patchy (isolated oxbow lakes) or linear (rivers) habitat. This suggest that giant otter social and territorial behavior is plastic and adapts to the spatial characteristics of the habitat.

Social Structure of Marine Otters: Inter and Intraspecific Variation

Chapter

Jul 2021

Otters are a semiaquatic clade that stands out among carnivorans. Of 13 otter species, only three are known to cooperate, although most species exhibit some form of sociality. The observed variation in social structure among species, especially those in marine environments, makes this taxon suitable for studying the proximate and ultimate factors underpinning sociality. Here we review evidence for social behavior in otters with an emphasis on two species: the North American river otter (an inland and coastal generalist) and the sea otter (a marine specialist). In addition, we provide new information on a marine population of river otters in coastal Alaska using telemetry, camera traps, and social network analysis. Our results provide new insight into the contexts for river otter social behavior, confirm previous observations on individual variation in social behavior, and highlight differences between males and females. We additionally review the published data on sea otter social behavior. We discuss potential directions for hypothesis testing in otter social systems with an emphasis on drivers of individual variation in social behavior, especially potential insights from the fields of sociogenomics and proteomics.

Feeding behavior and trophic niche partitioning between co-existing river otter species

Article

Full-text available

Oct 2021
HYDROBIOLOGIA

Niche partitioning occurs among coexisting populations to reduce the effects of competitive exclusion among species of similar niche. The aim of the present study is to verify the trophic niche partitioning and feeding behavior between two mustelids, the Giant otter and the Neotropical otter, through the dry and rainy season hydrologic of the Lower Xingu River. Our results suggest that the diets of both mustelids are composed primarily of fish of the family Anostomidae (Headstanders). Despite extensive niche overlap, our results indicate partitioning is facilitated by differences in niche breadth, with potential implications for conservation of both species in the case of declines in prey abundance and diversity. Both species inhabit an area recently impacted by completion of the Belo Monte Hydropower Plant, resulting in large changes to the hydrologic regime. Thus, our results provide important information for conservation efforts regarding the feeding behavior and co-occurrence of both species, as well as providing a baseline for monitoring future health of these mustelid populations. The present study is the first to test the hypothesis of niche partitioning between these two mustelids outside a protected area in the Amazon.

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Article

Full-text available

Nov 2020
ECOLOGY

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non‐detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non‐governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer‐reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non‐detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio‐temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large‐scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data.

North American River Otter (Lontra canadensis)

Chapter

Full-text available

Jan 2018

The Global Otter Conservation Strategy (IUCN/SSC Otter Specialist Group)

Book

Full-text available

Dec 2018

The IUCN-SSC Otter Specialist Group has produced otter conservation programs since 1974. We have seen successes when otters returned to their former haunts but we are also witnessing the sharp acceleration of environmental threats that affect otters everywhere: pollution, deforestation, overpopulation, illegal trade, limited protection, and the escalating effects of climate change. As you read the Global Otter Conservation Strategy, you will notice the litany of similar threats for each species and the urgent need for programs that can stem the tide. We identify and discuss the significant factors that influence habitat quality and the presence of otters in each region where they occur. Some species have already been studied in great detail, like the Eurasian otter and sea otter, others hardly at all, like the Hairy-nosed otter. The goal of this Strategy is to be both aspirational and inspirational: for biologists to aspire to know more about otters and go do it, and to inspire foundations to fund their efforts. The future of otters depends on this.

Characterization of the behavior and reproductive endocrinology of giant river otters ( Pteronura brasiliensis ) in managed care

Article

Aug 2018

Propagation of giant river otters (GRO) in zoos is inconsistent: some pairs never reproduce while others are prolific in producing young but can be hindered by low cub survival. Developing effective breeding programs requires understanding normal reproductive parameters and behavior. Fecal samples were collected for 6–16 months from five breeding pairs, two individual females, and one female pair at seven zoos, and analyzed for fecal progesterone, estrogen, testosterone, and glucocorticoid (FGM) metabolites via enzyme immunoassay. Enclosure characteristics and management routines were recorded at six facilities where behavior was assessed over 1 week. Median fecal progestogens during pregnancy and pseudopregnancy were ∼2.5–3.8× greater than basal concentrations. Gestation lasted 66.5 ± 3.5 days (62–70 days); pseudopregnancies lasted 58 ± 11.6 days (41–69 days). Elevated progestogens indicate ovulation but cannot distinguish pregnancy from pseudopregnancy. Periodically sustained, elevated progestogens observed in two females housed without a male indicated spontaneous ovulation. Elevations in fecal estrogens were not associated with estrus, and seasonality in male testosterone was not observed. Wavering scream and contact call vocalizations among reproductively successful males and females, respectively, suggested the importance of social communication. Most facilities housing successful pairs had larger enclosures with more water than land area, vegetation, and limited public exposure. Baseline FGM were negatively correlated with enclosure size and percentage of water area (p < 0.05), and lower baseline FGM were associated with reproductive success (p < 0.05). These results suggest that housing GRO in spacious enclosures with open water and some insulation from disturbance might promote appropriate behavior, lower FGM, and reproduction.

Pteronura brasiliensis (Carnivora: Mustelidae)

Article

Sep 2017

Pteronura brasiliensis (Zimmermann, 1780), the giant otter, is the largest freshwater otter. Found in South America, it inhabits slow-moving rivers and creeks and feeds predominantly on fish. Extinct in the southern portions of its former range, P. brasiliensis is listed as "Endangered" by the International Union for Conservation of Nature and Natural Resources. Threats to P. brasiliensis include habitat destruction, illegal hunting, and disease.

Evaluating the responses of a territorial solitary carnivore to potential mates and competitors

Article

Full-text available

Jun 2016

Successful communication is critical to the fitness of individuals and maintenance of populations, but less is known regarding the social contexts and reactions to scent marking by other individuals in solitary carnivores, including pumas. We evaluated the responses of resident male pumas to visitation and scent marking by potential competitors (other male pumas) and potential mates (female pumas) by capturing and marking 46 pumas (Puma concolor), and documenting scent marking behaviours using motion-triggered video cameras. By comparing resident male puma visitation rates and communication behaviours in response to either male or female visitors, we found that their visitation and communication behaviours were best explained by the combination of visitation by both competitors and potential mates. Resident males returned to scent marking sites more quickly and increased their rate of flehmen response after visitation by a females, while they increased their rate of visitation and duration of visits in response to other males. Male pumas also visited less frequently in summer and autumn when female visitation rates were lower, but males created nearly twice as many scrapes during these visits. This study suggests that advertising for mates when scent marking may sometimes overshadow the importance of deterring competitors and claiming territory.

Jaguar mobbing by giant otter groups

Article

Full-text available

Feb 2016

Group-living in carnivores is mostly associated with cooperative hunting and anti-predator defense. Giant otters (Pteronura brasiliensis) live in monogamous and cooperative breeding groups, where mechanisms other than cooperative foraging may be driving group maintenance in the species. We herein describe three interactions between giant otters and jaguars (Panthera onca) observed in the wild, two of which involved groups of otters and one, a lone individual. In the two group instances, the otters mobbed the jaguar until it left the area. The mobbing behavior displayed in these instances likely reinforces the advantages of living in groups, reducing predation risk and promoting group cohesion, with resulting territorial and fitness benefits.

Capybara Scent Glands and Scent-Marking Behavior

Chapter

Full-text available

Mar 2013

Scent marking in mammals can convey a wide range of information (e.g., Brown 1979; Müller-Schwarze 1983; Brown and Macdonald 1985a, b; Arakawa et al. 2008), sometimes linked to agonistic behavior in ritualized contests over resources (e.g., Gosling 1990). Scent marks are used by some mammals to delineate territorial boundaries, as in Ethiopian wolves (Sillero-Zubiri and Macdonald 1998). They can also indicate group membership, as in matrilines of cats, Felis sylvestris catus(Passanisi and Macdonald 1990), individual identity, as in dwarf mongooses, Helogale undulate(Rasa 1973) or spotted hyenas, Crocuta crocuta(Drea et al. 2002) or social and sexual status as in giant otters, Pteronura brasiliensis(Leuchtenberger and Mourão 2008). Frequently, scent-marking behavior and the chemistry of the secretion are related to social dominance (e.g., Huck and Banks 1982; Novotny et al. 1990; Ryon and Brown 1990). The latter is especially true in rodents, where status signaling appears to be the most common function of scent marking (Roberts 2007). Scent glands are commonly sexually dimorphic. Capybaras are unusual among caviomorph rodents in having not only anal glands but also a nasal gland, both of which are sexually dimorphic (Macdonald et al. 1984; Macdonald 1985).

The Giant Otter Bibliography, updated February 2015

Article

Full-text available

Apr 2015

Originally published in the Otter Specialist Group Bulletin (Duplaix, Groenendijk, Schenck, Staib & Sykes-Gatz, 2003) and subsequently on http://www.giantotterresearch.com, the Giant otter bibliography strives to list nearly all published material on giant otters (Pteronura brasiliensis). This review presents an updated version of the list published in 2003. It is not meant to be exhaustive but to be a working tool for persons who are interested in giant otters and who do not have access to a large university library. It is interesting to note that the number of articles published per year averages about 25 to 30 per year, indicating that the research on giant otters continues at a steady rate. Many, but not all, of the more recent titles are available for download as PDF files on the www.giantotterresearch.com website and more will become available in the future. We encourage authors to send their articles to one of the authors for inclusion. We will continue to add new titles to the website in the future, so this should be considered a work in progress. The annotations for each entry in the blbliography, if needed, are short and general in nature (eg, giant otter status, giant otter in captivity, giant otter Red List) to allow for quick searches in the list. The www.giantotterresearch.com website also allows for searches according to specific areas of interest (for example, by country, in captivity, ecology and behavior, etc.). We welcome any questions, additions or corrections to this list: please e-mail the authors.

The Giant Otter Bibliography Updated – February 2015

Article

Full-text available

Apr 2015

Maintenance of familiarity and social bonding via communal latrine use in a solitary primate (Lepilemur leucopus)

Article

Full-text available

Dec 2014

Latrine use (i.e., the repeated use of specific defecation/urination sites) has been described for several mammals, including carnivores, ungulates, and primates. However, the functional significance of latrine use in primates has not been studied systematically yet. We, therefore, followed 14 radio-collared individuals of the pair-living white-footed sportive lemur (Lepilemur leucopus) for 1097 hours of continuous focal observations to investigate latrine distribution, seasonality of latrine use, as well as age and sex of users to test various hypotheses related to possible functions of latrine use, including territory demarcation, resource defense, signaling of reproductive state, social bonding, and mate defense. All individuals of a social unit exhibited communal use of latrines located in the core area of their territory, supporting the social boding hypothesis. Latrine use seems to facilitate familiarity and social bonding within social units via olfactory communication in this primate that lives in family units but exhibits low levels of spatial cohesion and direct social interactions. In addition, frequency of latrine visitation was higher during nights of perceived intruder pressure, supporting the mate defense hypothesis. However, animals did not react to experimentally introduced feces from neighboring or strange social units, indicating that urine may be the more important component of latrines than feces in this arboreal species. Based on a survey of latrine use and function in other mammals, we conclude that latrines facilitate communication particularly in nocturnal species with limited habitat visibility and in species where individuals are not permanently cohesive because they constitute predictable areas for information exchange. Electronic supplementary material The online version of this article (doi:10.1007/s00265-014-1810-z) contains supplementary material, which is available to authorized users.

Richness and composition of vertebrates in active and inactive latrines of Pteronura brasiliensis (Carnivora, Mustelidae) in the Eastern Amazon, Brazil

Article

Full-text available

Jul 2014
IHERINGIA SER ZOOL

This study aimed to evaluate the richness and composition of the medium and large sized vertebrates in active and inactive latrines of Giant otters [Pteronura brasiliensis (Gmelin, 1788)] in a Sustainable Use conservation unit in the Eastern Brazilian Amazon. The study was performed in 45 latrines along 230 km of the Falsino and Araguari rivers (0 degrees 55'N, 51 degrees 35'W) and from this total, 24 presented fresh feces of Giant otters while 21 presented only old feces. From July to November 2012 each latrine was continuously monitored with a camera trap set to operate for 24 hours. The effort resulted in 458.8 camera trap/days, with 247.5 camera trap/days in latrines with fresh feces and 211.3 camera trap/ days with old feces. From this effort we obtained photos from a total of 22 vertebrate species. Most species photographed at latrines were mammals (n = 13), followed by birds (n = 6) and reptiles (n = 3). The most frequently photographed species were paca [Cuniculus paca (Linnaeus, 1766), n = 21], ocelot [Leopardus pardalis (Linnaeus, 1758), n = 11], white-tipped dove (Leptotila verreauxi Bonaparte, 1855, n = 8), giant otter [Pteronura brasiliensis (Gmelin, 1788), n = 7], and tapir [Tapirus terrestris (Linnaeus, 1758), n = 6], that accounted for 55.8% of all records. Most records (69.5%) were obtained in latrines with fresh feces and the number of vertebrate species was greater (n = 19) than in latrines with old feces (n = 15). However, the dissimilarity between the vertebrate communities of latrines with fresh and old feces did not differ statistically. However, the mean visitation of vertebrates to latrines with fresh feces was slightly higher than with old feces, although this difference was only marginally significant. There was an increase in records of felids [Leopardus pardalis, Leopardus wiedii (Schinz, 1821), and Panthera onca (Linnaeus, 1758)] in latrines with old feces, but it was only marginally significant. Thus, the presence of fresh feces of giant otters seems to increase the records of vertebrates, being especially important for groups with similar trophic guild.

Space use by giant otter groups in the Brazilian Pantanal

Article

Apr 2013

Giant otters (Pteronura brasiliensis) live in groups that seem to abandon their territories during the flooding season. We studied the spatial ecology of giant otter groups during dry and wet seasons in the Vermelho and Miranda rivers in the Brazilian Pantanal. We monitored visually or by radiotelemetry 10 giant otter groups monthly from June 2009 to June 2011.We estimated home-range size for all groups with the following methods: linear river length, considering the extreme locations of each group, and fixed kernel. For the radiotracked groups, we also used the k-LoCoh method. Spatial fidelity and habitat selection of giant otter groups were analyzed seasonally. On the basis of k-LoCoh (98%) method, home-range sizes during the wet season (3.6—7.9 km 2 ) were 4 to 59 times larger than during the dry season (0.1—2.3 km 2 ). Home-range fidelity between seasons varied among giant otter groups from 0% to 87%, and 2 radiotagged groups shifted to flooded areas during the wet seasons. Giant otter groups were selective in relation to the composition of the landscape available during the dry seasons, when the river was used more intensively than other landscape features. However, they seemed to be less selective in positioning activity ranges during the wet season. During this season, giant otters were frequently observed fishing in the areas adjacent to the river, such as flooded forest, grassland, and swamps.

A reassessment of the function of scent marking in territories

Article

Full-text available

Jan 1982
Z Tierpsychol

Leonard Morris Gosling

The energetic costs and the risk of injury in agonistic encounters can be reduced by prior assessment of opponents: it will generally pay low quality animals to avoid combat with one of high quality. Following this principle it is suggested that territory owners scent mark their territories to provide intruders with a means of assessment. When the odour of a competitor, or of a scent mark it is seen to have made, matches that of scent marks encountered in the vicinity, then the competitor is probably the territory owner. Since owners are generally high qualitv animals, and assuming they have more to gain by retaining a territory than an intruder has in taking it over, it will pay the owner to escalate and the intruder to give up early. The advantage to owners in markinq may thus be that by allowing themselves to be identified they reduce the costs of territory defence. Published information on the behavior of territory owners and intruders is consistent with predictions from this hypothesis. The hypothesis offers an explanation for a number of poorly understood behaviours including 'self-anointing' and scent markinig during agonistic encounters.

Social Significance of Scent Marking in Capybaras

Article

Full-text available

May 1994

Capybaras, Hydrochaeris hydrochaeris, scent mark with a sebaceous snout gland and anal glands, either separately or in sequence. In the Venezuelan llanos, marking was observed 3,864 times. A minority of marks was associated with aggressive interaction, but most marks were deposited out of any obvious context. Males marked more often than females, and the majority of marks with the snout gland was followed by marks with anal glands. Rates of marking by individuals were associated with social rank and decreased with group size.

Observations on the Ecology and Behavior of the Giant river otter (Pteronura brasiliensis) in Suriname 1980

Article

Full-text available

Jan 1980
REV ECOL-TERRE VIE

Nicole Duplaix

L’écologie et le comportement de la Loutre géante du Brésil Pteronura brasiliensis ont été étudiés de juillet 1977 à mars 1978 au Suriname. L’espèce est diurne et grégaire, formant des groupes familiaux durables qui défendent certaines portions de leur domaine vital contre les incursions de leurs congénères. Pteronura brasiliensis est piscivore. Les modalités de reproduction et les déplacements saisonniers des poissons Characoides qui forment l’essentiel de son régime ont une influence profonde sur l’écologie de cette loutre. Pendant la saison des pluies, par exemple, les Pteronura suivent leurs proies dans la forêt inondée, abandonnant temporairement leurs «bivouacs » et tanières habituels. La reproduction a lieu d’août à octobre. Les jeunes loutres restent avec leurs parents quand naît la portée suivante, peut-être même jusqu’à leur propre maturité. Le répertoire comportemental de Pteronura brasiliensis est décrit et comparé avec celui des Lutra solitaires. Lutra enudris peut cohabiter avec Pteronura dans certains cours d’eau de Suriname. Ses mœurs solitaires, son activité surtout crépusculaire et la taille moyenne de ses proies, tout comme le fait qu’elle peut également habiter dans les marais côtiers et les petites rivières de la grande forêt, minimisent les chances d’une éventuelle compétition avec Pteronura.

Failures of reproductive suppression in dwarf mongooses

Article

Full-text available

Mar 1991
BEHAV ECOL

In many communally breeding species, only the dominant female normally breeds, while subordinates tolerate reproductive suppression (these are “despotic” species, in the terminology of Brown, 1987; Macdonald and Moehlman, 1983; Vehrencamp, 1983). Yet in many species for which reproductive suppression is the norm (across a wide variety of taxa), subordinates do occasionally breed. Because reproduction by subordinates is atypical for these species, it is often regarded as simple failure of the normal mechanisms of suppression. An alternate hypothesis is that subordinate pregnancies represent an evolutionary compromise between dominant and subordinate, in which dominants concede their monopoly on reproduction in order to retain helpers. We use data from a long-term study of dwarf mongooses (Helogale parvula) in Serengeti National Park, Tanzania, to test this hypothesis, using an inclusive fitness model adapted from one by Vehrencamp (1983). We find that the incidence of subordinate pregnancy closely matches that predicted by the model, suggesting that the mechanisms that underlie reproductive suppression in dwarf mongooses are finely adjusted to the social and demographic environment. [Behav Ecol 1991; 2: 7–15]

Scent matching modulates space use and agonistic behaviour between male snow voles, Chionomys nivalis

Article

Full-text available

Dec 2001

The ‘scent-matching’ hypothesis predicts that competitors could identify resource holders by investigating scent marks from a given area and matching these with the owner's odour when they meet. Previous studies on small rodents have supported the use of scent matching among males with mutually exclusive ranges. We designed an experiment to evaluate the potential role of scent matching in the snow vole, a species in which males have largely overlapping ranges but individually use specific locations within shared areas. Initial exploration of enclosures containing a choice between a scent-marked and an unmarked area established that males were more attracted to recently occupied areas. During a subsequent social encounter with either the donor of the scent marks present in the enclosure (matching opponent) or another male (nonmatching opponent), males were less aggressive towards matching than nonmatching opponents. Furthermore, during exploration of enclosures after encounters, males spent significantly less time at the scent-marked side after meeting a matching male but not after meeting another male. These results suggest that male snow voles may use scent matching to identify potential opponents and to respond differentially to occupied areas. By modifying their behaviour after assessing the identity of their opponents, males may be able to minimize current and prospective costly encounters with resource holders. Our findings show that the mechanism of scent matching is also compatible with spatial systems in which competing conspecifics possess overlapping ranges.

Notes on giant otter (Pteronura brasiliensis) behavior in the lake of Balbina hydroelectric power station, Amazonas, Brazil. The Latin American Journal of Aquatic Mammals, 2 (2): 127-129

Article

Full-text available

Dec 2003

Mustelid scent-marking in managed ecosystems: Implications for population management

Article

Full-text available

Dec 2001
MAMMAL REV

Scent-marking is the primary form of communication for mustelids and is important in understanding their sociobiology. In addition, mustelids interact with managed ecosystems or may themselves be managed. However, little is known about the scent-marking behaviour of most mustelids or the impact of management on this behaviour. Mustelids have a number of different scent mark types that can be used for several possible functions, creating a flexible system of varied scent-marking strategies both across and within species. We review the types of scent marks used by European mustelids in relation to their social systems and consider the various hypotheses proposed for their function. Scent-marking behaviour is not fixed for each species, but varies with habitat and population density. We use Badgers (Meles meles) as an example of mustelids acting as reservoirs of disease and Otters (Lutra lutra) as an example of a key conservation species, to demonstrate the applied importance of understanding natural patterns of mustelid scent-marking strategies and the impact of habitat and population management on them.

Changes in the behaviour of a male Eurasian badger: Evidence in favour of the anti-kleptogamy hypothesis?

Article

Full-text available

Dec 1999

We report a case of male badger Meles meles (Linnaeus, 1758) territorial expansion after the removal, by poaching activity, of a neighbouring male in an area of low badger density. The most plausible reason for the behaviour of this male is the gaining of the access to the females of the adjacent territory because: the male spent approximately half of his active time inside the new area, made a similar effort as the previous male in sleeping together with the new breeding female and did not use the summer-autumn feeding areas of the taken range. While considering that data have come from only one animal, it is discussed the key importance of female access against food resources and shelter when explaining male badger spatial behaviour, at least in low density populations.

Carter, S. K. and F. C. W. Rosas. Biology and conservation of the giant otter Pteronura brasiliensis. Mammal Rev

Article

Full-text available

Mar 1997
MAMMAL REV

The Giant Otter Pteronura brasiliensis (Zimmermann, 1780) is endemic to South America, distributed throughout the Orinoco, Amazon and La Plata River basins and numerous localities in the Guyanas. This otter is the largest member of the family Mustelidae, clearly distinguished from other South American otter species by morphological and behavioural characteristics. Large-scale pelt hunting in the 1950s and 1960s led to the classification of the species as ‘vulnerable’ by the World Conservation Union (IUCN, 1990). Habitat degradation and destruction now present the largest threat to remaining populations. The current distribution of the Giant Otter is presented, emphasizing recent information collected in the Amazon Basin. Morphology, systematics, habitat, behaviour, diet, predation, competition, reproduction, development and physiology are discussed. New data on habitat use and preference, behaviour and diet in northern Amazônia are included, and recommendations for future conservation measures are made. Because of the decimation of the Giant Otter in its southern distribution and the habitat destruction occurring in the remainder of its range, we recommend that this species be elevated to ‘endangered’ status in the IUCN Red Data Book.

Perspectives on over-marking: Is it good to be on top?

Article

Full-text available

May 2007

What we refer to as over-marking occurs when one individual places its scent mark on top of, touching, or adjacent to the scent mark of another individual, usually a conspecific. Over-marking frequently occurs among mammals that share common paths, trails, and runways. Despite its ubiquity among terrestrial mammals, we know little about how individuals respond to over-marks and the function(s) of over-marking. Studies on voles and golden hamsters indicate that after exploring an over-mark, individuals respond selectively to the mark of the top-scent donor relative to that of the bottom-scent donor. Thus, individuals may be able to focus their attention on a particular scent mark relevant at a particular time and in a particular context, neglecting other scent marks that are present. The function(s) of over-marking are examined within the framework of ten hypotheses. Several hypotheses are plausible. However, the bulk of the literature is consistent with hypotheses stating that over-marking serving a role in olfactory communication between opposite and same-sex conspecifics. Lastly, we postulate the costs and benefits that may be garnered by the top-scent donor of an over-mark.

Social organization in European small Mustelids

Article

Full-text available

Dec 1995
HYSTRIX

Erlinge Sam

Abstract A review of the social organization in the weasel (Mustela nivalis) and stoat (M. erminea) is made, based mainly on my earlier mark-recapture studies on weasels and stoats and radio-tracking studies on stoats. During the non-breeding season, from September to April, the small mustelids are organized in a territorial pattern; individuals of the same sex exploit exclusive areas. The extensive male territories often include one or several female ranges. The territories are probably delineated mainly by scent marking. During the breeding season the males increase their movement activity and extend their ranges. The territorial systems brake down and male ranges generally overlap considerably. Depending on their social status, males adopt different strategies, i.c. roaming or staying, in their attempts to obtain as many matings as possible. Prey abundance and distribution are considered to be the decisive factors determining female spacing behaviour throughout the year. The great amount of food required by females when rearing young makes it rewarding to defend and use restricted areas exclusively. In males there is a seasonal change in social organization resulting from a shift in decisive resources; i.e. priority is placed on procuring receptive females during the breeding and food during the non-breeding season. Riassunto Organizzazione sociale nei piccoli mustelidi europei - L'autore presenta un'analisi dell'organizzazione sociale della donnola (Mustela nivalis) e dell'ermellino (M. erminea), basata soprattutto sui suoi studi effettuati mediante i metodi di marcamento-ricattura per entrambe le specie e di radio-telemetria per l'ermellino. Durante la stagione non riproduttiva, da settembre ad aprile, i piccoli mustelidi sono organizzati secondo un modello territoriale: individui dello stesso sesso utilizzano aree esclusive. Gli ampi territori dei maschi spesso includono quello di una o più femmine. Probabilmente i territori sono delimitati principalmente con marcamenti odorosi (feci). Durante la stagione riproduttiva i maschi incrementano i loro movimenti e estendono le loro aree vitali. Il sistema territoriale non viene più mantenuto e le aree vitali dei maschi generalmente si sovrappongono notevolmente. In relazione al loro stato sociale, i maschi adottano differenti strategie: cioè, vagano o restano nella loro area vitale nel tentativo di avere più accoppiamenti possibile. La distribuzione e l'abbondanza delle prede sono considerati i fattori prioritari che determinano il comportamento spaziale delle femmine nell'arco dell'anno. L'elevata richiesta di cibo da parte delle femmine durante l'allevamento della prole si traduce nella difesa ed uso esclusivo di aree limitate. L'organizzazione sociale dei maschi varia stagionalmente in relazione al cambiamento delle risorse di "vitale importanza": durante la stagione riproduttiva diventa prioritario procurarsi femmine recettive, mentre durante quella non riproduttiva diventa fondamentale il cibo.

Intraspecific Agonism between Giant Otter Groups

Article

Full-text available

Oct 2004

In August 2002, we studied Giant Otters in the region of the Vermelho river, in the Brazilian Pantanal. During our research, we observed and filmed a particularly aggressive interaction between two groups of Giant Otters at the junctions of the rivers Vermelho and Miranda. This article reports the event and presents a sonogram of the very stereotypic vocalisations of the aggressor group.

Scent Marking (Pasting) in a Colony of Immature Spotted Hyenas (Crocuta crocuta ): A Developmental Study

Article

Full-text available

Mar 1991

Pasting, a stereotypic form of anal gland scent marking, was studied in 2 cohorts (N = 20) of captive spotted hyenas (Crocuta crocuta). A significant increment in the frequency of pasting occurred in both cohorts as the animals approached sexual maturity; however, gonadectomy during the early juvenile age period had no significant effects on subsequent pasting frequency. Dominant hyenas in both cohorts tended to scent-mark more frequently than subordinates during the late subadult period. Pasting was facilitated by the immediately preceding pasting activities of other hyenas, as has been reported to occur in nature, and olfactory investigation was the most common behavior preceding pasting.

Cannibalism among giant otters (Pteronura brasiliensis)

Article

Jan 2001
MAMMALIA

Otters: Ecology, behaviour and conservation

Article

Jan 2010

H. Kruuk

Hans Kruuk's previous Wild Otters was the first, and until now the only, book to cover both natural history and scientific research on behaviour and ecology of otters in Europe. The present book is a revision, rewrite, and update, now covering all species of otter in North America as well as Europe and elsewhere. Aimed at naturalists, scientists, and conservationists, in a personal style and with many illustrations, it describes the ecology and behaviour of some of the most charismatic and enigmatic mammals in our environment, as well as the research to understand their particular ecological problems. With over 650 references, there is up-to-date description of the most recent studies, including feeding ecology, foraging behaviour, relationships with prey species, and factors that limit populations, as well as social and breeding behaviour, molecular genetics, energetics, the problems of exposure to cold water, mortality, effects of pollution, and the serious, recent conservation problems. There are enchanting direct observations of the animals, as well as guidance about how and where to watch and study them, and what are the most serious questions facing researchers. From otters in the British and American lakes and rivers, to sea otters in the Pacific ocean, giant otters in the Amazon and other species in Africa and Asia, this book provides an enthusiastic, critical, and thorough approach to their fascinating existence, the science needed to understand it, and the threats to their survival.

Territoriality of the Otter Lutra lutra L

Article

Jan 1968

Sam Erlinge

Otters were studied by reading tracks and signs in fresh water habitats in Southern Sweden, in 1958-1966. 1. The populations in winter consisted of 30-40% resident territory holders, about the same proportion of temporary residents or transients and 25-38% young of the year. The rate of reproduction of otters is low. Most probably some females do not breed every year. The density of otters in the areas studied was one otter per 0.7-1.0 km2 area of water or one individual per 2-3 km length of lake shore, and one otter per 5 km length of a stream. 2. Otters display territorial behaviour which is shown by signal activity, dispersion pattern and movements of the otters. 3. The adult dog otters maintain territories which have an individual character, their size and location depending on the qualities of the dogs. The boundaries are overlapping zones where territorial conflicts occur continuously. 4. The females with cubs (family groups) exploit territories separately. The areas are probably fixed and situated within the dog otters' territories. Territorial conflicts between the family groups are rare, after the areas have been settled. 5. Otters - apart from territory-holding dog otters and females with cubs - behave as temporary residents (mainly during summer and winter) or transients. 6. Territorial behaviour primarily appears between individuals of the same sex. The behaviour has a pronounced individual character. The individuals behave according to their status in a hierarchic system. 7. The territories are primarily maintained by threatening signals. Avoidance plays a larger part than pursuits. 8. The territories of the family groups are feeding areas, securing the young access of food all the first year of their lives. The dog otters' territories primarily have sexual significance. /// Исследовали популяции выдр в пресноводных водоемах Южной Швеции в 1958-1966 гг. 1. Популяции выдр зимой состоят на 30-40% из постоянных обитателей участков, примерно того же количества временных и кочующих обитателей и 25-38% молодых особей, родившихся в том же году. Скорость размножения у выдр очень низка. Некоторые самки очевидно не приносят потомства ежегодно. Плотность популяций выдр в исследованных участках составляла І экз. 0,7-1,0 KM2 водной поверхности или Іэкз. на 2-3 погонных км берега озера либо на 5 погонных км берега реки. 2. Выдры имеют индивидуальные участки, что доказывается характером их распределения и передвижения. 3. Взрослые самцы занимают определенные территории, являющиеся их индивидуальными участками. Территории соседних участков перекрываются у границ, и здесь постоянно возникают конфликты. 4. Самки с детенышами (семьн) занимают отдельные территории, расположенные внути индивидуальных участков. После заселения участков территориальные конфликты между семьями возникают редко. 5. Остальные представители популяции (исключая упомянутых выше самцов и самок с детенышами) ведут себя как временные или кочующие посетители участков, особенно летом и зимой. 6. Территориальная приуроченность проявляется сначала у представителей одного пола. Поведение выдр в отношении территории носит индивидуальный характер и зависит от положения каждого животного в иерархической системе. 7. Выдры охраняют свои участки от других особей, применяя сигналы угрозы. 8. Территории семейных групп - это места, хорошо обеспеченные пищей, где имеется возможность прокормить детенышей в течение первого года их жизни. Выбор участков взрослыми самцами связан с их половой активностью.

The information in scent over-marks of golden hamsters

Article

Aug 1994

Although scent over-marking is a commonly observed behaviour among mammals, it has received little experimental attention. With regard to individual signatures, there are three types of information that might be obtained from such marks: (1) the scents might blend, thus creating a new odour quality but sacrificing individually distinctive information, (2) the scents might remain distinct, preserving individual identity information, or (3) the scent on top could mask the individual identity information in the bottom scent. These three possibilities were tested in golden hamsters for two scents (flank gland and vaginal secretions) that are deposited by hamsters using two distinct patterns of scent-marking behaviour. In an habituation paradigm, test animals were exposed on five successive trials to a simulated over-mark in which the scent from one individual was placed on top of scent from another individual. On the sixth (test) trial, males were exposed to two separate scents, one from a novel individual and the other from the individual that provided either the top or the bottom scent during the habituation trials. Results on the test trial were similar for both vaginal secretions (experiment 1) and flank gland scent (experiment 2). The novel scent was investigated more than the top scent, indicating that the top scent was familiar to the males, but the bottom scent and the novel scent were investigated equally, indicating that the bottom scent was not familiar. These results suggest that the distinctive information in the bottom scent was masked by that of the top scent; furthermore, they show that the other two possible phenomena (scents blending or remaining distinct) did not occur. This demonstration of scent masking may well be the first reported to date. The possible significance of over-marking in hamsters and other species is discussed, and it is suggested that the precision and thoroughness of covering one scent with another may relate to species differences in the information available in over-marks and therefore in the functions that such marks serve.

Why do river otters scent-mark? An experimental test of several hypotheses

Article

Oct 2004

We tested several alternative hypotheses about the function of scent marking by the North American river otter, Lontra canadensis. Otters may mark at latrine sites with spraints (faeces) to (1) signal species identity, (2) advertise their reproductive status, (3) establish and maintain territories, and (4) communicate social status and identity to group members. Olfactory preference tests were conducted at the Alaska Sealife Center in Seward, Alaska, on a group of 15 wild-caught male otters in February 1999. We found that male otters investigated otter scent more than sealion faeces. The male otters also showed a preference for male scent over the scent of anoestrous females. No preference for the scent of unfamiliar males, compared with the scent of familiar males, was observed, and no preference for the scent of close kin was detected. However, an investigation of dominant relationships of the captive otters showed that dominant males spent more time investigating male scent than did subordinate males. Thus, spraints deposited at latrine sites may function to communicate social status of males.

Meadow Voles (Microtus pennsylvanicus, Arvicolidae) Over‐mark and Adjacent‐mark the Scent Marks of Same‐sex Conspecifics

Article

Dec 2001
ETHOLOGY

Michael H Ferkin

Scent over-marking occurs when an animal deposits its scent mark on top of the scent mark of a conspecific; adjacent-marking occurs when an animal deposits its scent mark next to the scent mark of a conspecific. Given that male rodents usually scent mark more than females and that animals spend more time investigating the odor of the top-scent donor of an over-mark, I tested the following three hypotheses. First, male meadow voles deposit more scent marks than female meadow voles. Second, male meadow voles will deposit more over-marks and adjacent-marks in response to the scent marks of a same-sex conspecific than females would. Third, meadow voles spend more time investigating the odor of the second vole placed in the arena than that of the first vole placed in the arena. To test these hypotheses, two age-matched, like-sex conspecifics (first vole and second vole) were placed successively into an arena in which they were allowed to freely explore and scent mark for 15 min. The first hypothesis was not supported. The first and second vole, independently of sex, deposited a similar number of scent marks. The second hypothesis was also not supported by the data: more conspecific scent marks were over-marked by the second female than by the second male. The third hypothesis was supported by the data. After investigating a scented arena, males and females spent more time investigating the odor of the second vole than that of the first vole. Sex differences in scent-marking behaviors of meadow voles are unlike those reported for other species of rodents.

An observational study of scent-marking in coyotes, Canis latrans

Article

May 1981

Urination and defaecation patterns of free-ranging coyotes (Canis latrans) were studied in the Grand Teton National Park, Jackson, Wyoming, for two years. The vast majority of urinations by adult males and females were involved in ‘marking’, and differentiating between ‘marking’ and ‘elimination’ may not be necessary. Our results may be summarized as follows: (1) raised-leg urinations (RLU) performed by males were most frequently used in marking. (2) Females marked throughout the year using the squat (SQU) posture. (3) Snow tracking and reading snow sign resulted in a gross underestimate of the relative frequency of SQU's and a large overestimate in the relative frequency of defaecations (DEF) when compared to results obtained by direct observation. (4) There was sexual dimorphism for the contexts in which marking occurred. Overall, marking by males was associated with courtship and mating, with travelling, and with aggression. Marking by females was associated with the acquisition and possession of food and with the denning season. (5) Marking rates per coyote increased in groups larger than two animals. (6) RLU marking rates were greatest in areas of high intrusion when compared to denning areas and areas in which non-group members infrequently tresscent odours are important in orienting individuals in space but do not represent in and of themselves barriers to movement.

Scent-marking and territorial behaviour of Ethiopian wolves Canis simensis

Article

Jul 1998
J ZOOL

Scent-marking behaviour and inter-pack aggression were studied in wild Ethiopian wolf, Canis simensis, packs. Raised-leg urinations, followed by ground scratching, were the most frequently deposited scent-mark. Scent-marking rates were highest along or near territory boundaries, where distances between scent-marking sites were reduced and the proportion of multiple marks was increased, relative to other areas. Marking rates increased with wolf numbers during patrols but not during other activities. Although all adult members of a pack contributed to scent-marking, the dominant pair marked most frequently. Subadult males scent-marked occasionally but subadult females never did. Wolves vigorously over-marked neighbours' scent-marks. Most direct encounters between neighbouring wolves at territory borders were aggressive and involved repeated chases, and the larger group was most likely to win. Resident wolves were more tolerant of opposite-sex than same-sex neighbours. Resident wolves therefore signalled pack composition and status at home range borders by olfactory and auditory cues and by aggressive contests. Such signalling may reduce the occurrence of potentially costly inter-pack aggressive encounters at territory borders and provide information on reproductive status.

Adult Male Scent-Marking in Lemur catta and Eulemur fulvus rufus

Article

Jun 2002

Scent-marking and olfactory communication are used extensively by prosimians and can provide spatial and temporal records of group movement and behavior. We compare rates of male scent-marking in relation to reproductive seasons, male dominance rank, and habitat use in two related prosimians: Lemur catta and Eulemur fulvus rufus. We collected scent-marking data on adult male Lemur catta at Beza-Mahafaly Reserve (dry forest), and on Eulemur fulvus rufus at Ranomafana National Park (rainforest), Madagascar. In Lemur, rates of overall scent-marking differed significantly by reproductive season, with higher rates occurring in mating and lactation/migration periods, whereas in Eulemur, reproductive season did not appear to affect scent-marking rates. Dominance rank of male Lemur catta did not affect rates of scent-marking. Among male Eulemur fulvus, dominance relations were not apparent; however, 2 of the 5 focal males scent-marked somewhat more frequently during the mating season and also experienced greater mating success. In Lemur catta, higher rates of scent-marking in the mating season may relate to indirect reproductive competition during a period of high aggression, while such mating competition was not as marked in Eulemur fulvus. Furthermore, higher rates of marking in resident male Lemur catta during male migration may correlate with vigilance toward immigrating males. Greater overall scent-marking rates in ring-tailed lemurs may relate to extensive intergroup home range overlap and no area of exclusive use, whereas the red-fronted lemur groups tended to forage in areas of their home range where little-to-no intergroup overlap occurred.

Pantanal: A large South American wetland at a crossroads

Article

Apr 2005
ECOL ENG

The Pantanal, a large and still rather pristine wetland in the center of the South American continent, is becoming increasingly threatened by large development programs. Agroindustries and reservoirs for hydroelectric power generation in the catchment area modify discharge pattern and sediment load of the tributaries, plans for canalization of the Paraguay River (hidrovia) are putting in risk the natural flood regime of large areas inside the Pantanal, and attract industries with high potential for environmental pollution, economic pressure on the traditional cattle ranchers accelerates the transformation of natural vegetation into pasture, etc. These activities negatively affect habitat and species diversity and scenic beauty but also the hydrological buffer capacity of the Pantanal. The article summarizes the ecological conditions of the Pantanal, discusses commercial and non-commercial values of the area, describes constraints for the development of intensive agriculture and cattle ranching, and discusses development alternatives. Considering the low density of human population inside the Pantanal, it can be concluded that development pressure on the Pantanal arises mostly from pressure groups outside the area that will also mostly benefit from the economic return of the development projects. Low density of human population would still allow the application of economically viable and environmentally friendly development alternatives that maintain and sustainably manage one of the largest wetlands in the world.

Behavioural mechanisms of information transmission and reception by badgers, Meles meles, at latrines

Article

May 2002

We investigated the behavioural mechanisms by which European badgers receive and transmit information at shared defecation sites (latrines). We surveyed locations of 143 latrines to establish factors influencing latrine position, and monitored the behaviour of badgers at latrines. Badger latrines were significantly closer to tree trunks than were random samples, and were more likely to be associated with conifers than broadleafs. This may serve to protect scent marks from erosion. Latrines were also placed more closely to linear features than expected; linear features may channel the movements of badgers, promoting discovery of latrines. Within latrines, badgers differed in their placement of faeces and subcaudal scent marks. Faeces were placed in a subset of pits, which were used for several consecutive nights, then abandoned for another subset of pits. Subcaudal scent (squat) marks were positioned in prominent places, and there was no consistent tendency to overmark. Meetings were rare at latrines. Sniffing was the most common behaviour, and was focused on defecation sites. At least three distinct behaviours that appear to serve an information transfer function were observed: squat marking; defecation; and digging and scuffing. Squat marking and defecation were performed by all age and sex classes, and may have a role in cross-territorial communication. Digging and scuffing were associated with mating, and may communicate breeding condition. The wide range of marking behaviours, compounded by the lack of any clearly sex-limited behaviour at latrines, suggests a multiplicity of roles in the social lives of all age and sex classes of badgers. Copyright 2002 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour

Scent marking in Mammals

Article

Aug 1973

Roger P. Johnson

This paper reviews experimental and field studies on scent marking behaviour. The occurrence and effects of scent marking are considered in particular, and a number of areas for further research are made apparent. Marking behaviour in mammals is often stated to be ‘territorial’ or, more specifically, to play a role in territorial defence. In fact there is a shortage of evidence to support this view; many of the relevant observations are anecdotal or interpreted with preconceived notions of function in mind. While marking is clearly associated with aggressive behaviour in many species and may therefore be related in some way to territorial behaviour, its role in aggression is not understood. Moreover, there is evidence to support a number of other theories of function some of which are unrelated to territory. It seems that, as with any other mode of communication, scent marking has become adapted for use in a variety of contexts. It probably has more than one function in any one species and different functions in different species.

Latrine distribution and patterns of use by wild meerkats: implications for territory and mate defence

Article

Apr 2007

Many carnivores defend territories and deposit faeces and other scent-marks at specific latrine sites. The role of latrines in territory defence is well established, but evidence suggests at least a subsidiary role in mate defence. We investigated latrine function in cooperative meerkats, Suricata suricatta. By analyses spatial and temporal distribution of latrines we found patterns that might facilitate information transmission to a range of potential intruders. Each group usually shared one latrine with each known neighbouring group, which probably allowed efficient intergroup monitoring of surrounding land tenure. The remaining latrines were primarily concentrated in territorial core regions. As transient groups and prospecting males enter territories unpredictably, this distribution may maximise the likelihood of latrine discovery. In large meerkat territories, the chance of intruders missing widely spaced boundary scent-marks is high, and a core-marking strategy may the refore be more effective. Latrines were positioned close to refuge sites, which may further increase the likelihood of intercepting intruders, as prospectors are known to visit these sites regularly during intrusions. Although latrine use did not increase during periods when resident females were sexually receptive, it was significantly more likely during the peak period in general, and occurred at significantly greater rates during observation periods when prospecting males were encountered. As prospectors threaten resident male reproductive success, these results highlight the potential importance of latrines in mate defence.

Olfactory preferences in dogs: The response of male and female beagles to conspecific urine

Article

Sep 1977
Behav Biol

Ian Dunbar

In Experiment 1 male dogs were observed visiting either a tethered male or a tethered nonestrous female. The duration and frequency of visits and the parts of the stimulus animal that were investigated were recorded. In Experiment 2 male and female dogs were observed in a series of two-choice tests to determine their visiting preferences toward males and nonestrous and estrous females. In Experiment 3 similar two-choice olfactory tests were employed to demonstrate investigatory preferences for urine, feces, anal gland and vaginal secretions, saliva, and ear wax samples from the stimulus animals. The females were brought into artificial estrus with injections of estradiol benzoate, and changes were observed in their visiting and olfactory preferences and in their attractiveness to male dogs. Males spent less time visiting males than they spent visiting females, regardless of the physiological condition of the latter. However, the visiting time devoted to estrous females was longer than that spent with females not in heat. These preferences may be partially explained by the findings that male dogs find estrous urine and vaginal secretions more attractive than their nonestrous counterparts and that they prefer female urine and feces compared to corresponding samples from male dogs. Following the induction of artificial estrus, female subjects spent significantly more time investigating male dogs and male urine when compared to female dogs and female urine, respectively. Male dogs and to a lesser extent bitches urinated more frequently in the vicinity of the preferred animals and odor stimuli.

Scent-marking by coyotes, Canis latrans: The influence of social and ecological factors

Article

Dec 1997

We observed 49 coyotes, Canis latransfrom five resident packs for 2456 h and five transient coyotes for 51 h from January 1991 to June 1993 in the Lamar River Valley, Yellowstone National Park, Wyoming, U.S.A. During these observations we recorded 3042 urinations, 451 defecations, 446 ground scratches and 743 double-marks. The rate of scent-marking (via urination) was influenced by the social organization (resident versus transient) to which the coyote belonged, the social class (alpha, beta or pup) of the animal and the time of the year. Transient coyotes scent-marked at a lower rate than did members of a resident pack. Within the resident packs, alpha coyotes scent-marked at a higher rate than beta coyotes (adults and yearlings subordinant to alphas, but dominant over pups) and pups. Alpha coyotes increased their rate of marking during the breeding season; beta and pup coyotes performed scent-marks at a relatively constant rate throughout the year. There was no influence of social class or time of year on the rate of defecation. The rate of double-marking was highest among alpha coyotes with a peak during the breeding season. Alpha coyotes ground-scratched at a higher rate than did beta and pup coyotes. Alpha and beta coyotes scent-marked more than expected along the periphery of the territory compared to the interior; pups marked in the interior and edge in proportion to expected frequencies. Double-marking and ground-scratching were higher than expected along the periphery of the territory. The distribution of defecations was not different from expected along the edge versus the interior of the territory. Pack size did not influence the rate of scent-marking performed by individuals in the pack or by the alpha pair. We concluded that alpha coyotes were the primary members of the resident pack involved in scent-marking. The large coyote packs and the high rate of marking by the alpha pairs were parallel to the scent-marking behaviour displayed by wolves, C. lupusto a greater extent than previously reported. Scent-marks appear to provide internal information to the members of the resident pack (internal map of territory, breeding condition, reproductive synchrony) and enhance demarcation of territorial boundaries.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour

Proteins in urine scent marks of male house mice extend the longevity of olfactory signals

Article

Jun 1998

The binding of volatile semiochemicals to lipocalin proteins in many mammalian scent marks may provide a gradual release of volatile ligands, extending the life of airborne odour signals. We tested this by using menadione to displace semiochemical ligands from major urinary proteins (MUPs) in urine streaks obtained from adult male house mice, Mus domesticus, and assessed the responses of other males to these and to intact urine marks as they aged. Dominant male mice scent-mark their territories extensively with urine streaks; MUPs in these marks bind at least two semiochemically active molecules, 2-sec-butyl-4,5-dihydrothiazole (thiazole) and 2,3-dehydro-exo-brevicomin (brevicomin), associated with the males' aggressive status. Wild-caught males (N=24), housed in individual enclosures, were presented with two glass slides, behind mesh to prevent contact, on which 10 µl of both unfamiliar urine and 0.5 mg/ml menadione in ethanol had been streaked. On one slide the urine and menadione solution were mixed to displace ligands; on the other they were separate (intact urine). We carried out tests 0, 0.5, 1 or 24 h after deposition, and matched them to changes in the concentration of thiazole and brevicomin within the intact and displaced marks. Males were hesitant to approach intact urine up to 1 h old but, when ligands were displaced, or were reduced to low levels by natural evaporation from intact urine streaks aged 24 h, their approach was similar to that to water and to menadione controls. Ligands did not appear to cause any longer term avoidance and, after the first approach, investigation increased with the freshness of urine regardless of when the ligands were displaced. This is the first direct demonstration that proteins evince a slow release of olfactory signals from mammalian scent marks. The nature of their response suggests that, from a distance, mice may be unable to tell whether airborne signals emanate from scent marks or from the donor himself and we suggest that this may provide territory owners with a major advantage in defending their territories.Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.

Perspectives on over-marking: is it good to be on top? J. Ethol. 25, Scent-marking by coy-otes, Canis latrans: the influence of social and ecological factors A reassessment of the function of scent marking in territories

Jan 1982
89-118

M H Ferkin
A A Pierce
—
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Scent‐Marking of Giant Otter in the Southern Pantanal, Brazil

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