Marta B Manser

• Professor
• Professor at University of Zurich

Animal populations in arid environments, where extreme temperatures and erratic rainfall are normal, are particularly vulnerable to climate change. While numerous studies have examined the effects of temperature and rainfall on the breeding success and survival of arid‐zone species, the mechanistic pathways linking climate variation to demography r...

In many pair-living vertebrates, females commonly mate outside the pair bond, but when and why they do so is unclear. This behavior may stem from females seeking ‘good genes’ or ‘compatible genes’ from extra-pair mates superior to or less related than their partner. Variation in female ability to acquire extra-pair copulations, however, may also in...

In arid habitats, recent increases in summer temperatures associated with global warming are adversely affecting many animal populations. However, annual rainfall also varies widely in many of these areas, and we do not yet fully understand the relative impact of variation in temperature and rainfall on the demography of arid-zone species. Here, we...

Diverse information encoding systems, including human language, the vocal and gestural systems of non-human animals and the structure of DNA and proteins, have been found to conform to ‘Menzerath’s Law’—a negative relationship between the number of units composing a sequence, and the size of those units. Here, we test for the presence of Menzerath’...

Social animals often face a trade-off between the costs of foraging competition among group members and the benefits of protection from predators offered by group living. The spatial position of an individual in relation to the other group members during foraging can mediate the effects of this trade-off as individuals at the front or edge may have...

Supplementary material for our paper "Dominance loss and tenure maintenance in Kalahari meerkats", published in Behavioral Ecology Volume 34, Issue 6, pages 979–991. https://doi.org/10.1093/beheco/arad066

Bioacoustic research provides invaluable insights into the behavior, ecology, and conservation of animals. Most bioacoustic datasets consist of long recordings where events of interest, such as vocalizations, are exceedingly rare. Analyzing these datasets poses a monumental challenge to researchers, where deep learning techniques have emerged as a...

To benefit from group living, individuals need to maintain cohesion and coordinate their activities. Effective communication thus becomes critical, facilitating rapid coordination of behaviours and reducing consensus costs when group members have differing needs and information. In many bird and mammal species, collective decisions rely on acoustic...

Animal vocal communication research traditionally focuses on acoustic and contextual features of calls, yet substantial information is also contained in response selectivity and timing during vocalization events. By examining the spatiotemporal structure of vocal interactions, we can distinguish between ‘broadcast’ and ‘exchange’ signalling modes,...

Automated acoustic analysis is increasingly used in animal communication studies, and determining caller identity is a key element for many investigations. However, variability in feature extraction and classification methods limits the comparability of results across species and studies, constraining conclusions we can draw about the ecology and e...

In many social species, both the acquisition of dominance and the duration that individuals maintain their status are important determinants of breeding tenure and lifetime reproductive success. However, few studies have yet examined the extent and causes of variation in dominance tenure and the duration of breeding lifespans. Here, we investigate...

Climate change and climate‐driven increases in infectious disease threaten wildlife populations globally. Gut microbial responses are predicted to either buffer or exacerbate the negative impacts of these twin pressures on host populations. However, examples that document how gut microbial communities respond to long‐term shifts in climate and asso...

In some mammals, and particularly in cooperative breeding ones, successive bouts of reproduction can overlap so that a female is often pregnant while still nurturing dependent young from her previous litter. Such an overlap requires females to divide their energetic budget between two reproductive activities, and pregnancy costs would consequently...

Audio playbacks are a common experimental tool in vocal communication research. However, low directionality of sound makes it hard to control the audience exposed to the stimuli. Parametric speakers offer a solution for transmitting directional audible signals by using ultrasonic carrier waves. The targeted transmission of vocal signals offers exci...

Investigations of collective movement and animal communication have often followed distinct, though complementary, trajectories. Both subfields are deeply concerned with how information flows between individuals and shapes subsequent behaviour. Collective movement has largely focused on the dynamics of passive, cue‐mediated group coordination, whil...

Inter-individual differences in gut microbiota composition are hypothesized to generate variation in host fitness—a premise for the evolution of host–gut microbe symbioses. However, recent evidence suggests that gut microbial communities are highly dynamic, challenging the notion that individuals harbour unique gut microbial phenotypes. Leveraging...

Infections with Tuberculosis (TB)‐causing agents of the Mycobacterium tuberculosis complex threaten human, livestock, and wildlife health globally due to the high capacity to cross trans‐species boundaries. Tuberculosis is a cryptic disease characterized by prolonged, sometimes lifelong subclinical infections, complicating disease monitoring. Conse...

In animals, large variation for vocal individuality between and within call types exist, yet we know little on what level selection is taking place. Identifying the selection pressures causing this variation in individuality will provide insight into the evolutionary relationships between cognitive and behavioral processes and communication systems...

Climate change and climate-driven increases in infectious disease threaten wildlife populations globally. Yet, their combined long-term effects on gut microbial communities remain unknown. Over the past two decades, wild meerkats inhabiting the Kalahari have experienced rapid climate change paired with increasing tuberculosis (TB) disease prevalenc...

A critical feature of language is that the form of words need not bear any perceptual similarity to their function-these relationships can be 'arbitrary'. The capacity to process these arbitrary form-function associations facilitates the enormous expressive power of language. However, the evolutionary roots of our capacity for arbitrariness, i.e. t...

Background: The manual detection, analysis and classification of animal vocalizations in acoustic recordings is laborious and requires expert knowledge. Hence, there is a need for objective, generalizable methods that detect underlying patterns in these data, categorize sounds into distinct groups and quantify similarities between them. Among all c...

The rate of adaptive evolution, the contribution of selection to genetic changes that increase mean fitness, is determined by the additive genetic variance in individual relative fitness. To date, there are few robust estimates of this parameter for natural populations, and it is therefore unclear whether adaptive evolution can play a meaningful ro...

Infections with Tuberculosis (TB)-causing agents of the Mycobacterium tuberculosis complex threaten human, livestock, and wildlife health globally due to the high capacity to cross trans-species boundaries. Tuberculosis is a cryptic disease characterized by prolonged, sometimes lifelong subclinical infections, complicating disease monitoring. Conse...

Acoustic signals degrade and attenuate as they propagate through the environment, thus transmitting information with lower efficiency. The acoustic adaptation hypothesis (AAH) states that selection should shape the vocalizations of a species to maximize transmission through their habitat. A specific prediction of the AAH is that vocalizations will...

Inter-individual differences in gut microbiota composition are hypothesized to generate variation in host fitness – a premise for the evolution of host-gut microbe symbioses. However, recent evidence suggests that gut microbial communities are highly dynamic, challenging the notion that individuals harbour unique and stable gut microbial phenotypes...

Tuberculosis (TB) is an increasing threat to wildlife, yet tracking its spread is challenging because infections often appear to be asymptomatic, and diagnostic tools such as blood tests can be invasive and resource intensive. Our understanding of TB biology in wildlife is therefore limited to a small number of well-studied species. Testing of feca...

One important but understudied way in which climate change may impact the fitness of individuals and populations is by altering the prevalence of infectious disease outbreaks. This is especially true in social species where endemic diseases are widespread. Here we use 22 years of demographic data from wild meerkats (Suricata suricatta) in the Kalah...

Vocal emission requires coordination with the respiratory system. Monitoring the increase in laryngeal pressure, needed for vocal production, allows detection of transitions from quiet respiration to vocalization-supporting respiration. Characterization of these transitions could be used to identify preparation for vocal emission and to examine the...

During group movements, many socially living and group-foraging animals produce contact calls. Contact calls typically function to coordinate and maintain cohesion among group members by providing receivers with information on the callers' location or movement-related motivation. Previous work suggests that meerkats, Suricata suricatta, also produc...

In most socially structured populations, the formation of new groups depends on the survival and reproduction of dispersing individuals. Quantifying vital rates in dispersers, however, is difficult because of the logistic challenges of following wide-ranging animals. Here, using data from free-ranging meerkats (Suricata suricatta), we estimate surv...

The manual detection, analysis, and classification of animal vocalizations in acoustic recordings is laborious and requires expert knowledge. Hence, there is a need for objective, generalizable methods that detect underlying patterns in these data, categorize sounds into distinct groups, and quantify similarities between them. Among all computation...

Circadian rhythms in gut microbiota composition are crucial for metabolic function, yet the extent to which they govern microbial dynamics compared to seasonal and lifetime processes remains unknown. Here, we investigate gut bacterial dynamics in wild meerkats (Suricata suricatta) over a 20-year period to compare diurnal, seasonal, and lifetime pro...

In many social vertebrates, variation in group persistence exerts an important effect on individual fitness and population demography. However, few studies have been able to investigate the failure of groups or the causes of the variation in their longevity. We use data from a long-term study of cooperatively breeding meerkats, Suricata suricatta,...

In some mammals that breed cooperatively, nonbreeding female helpers nurse offspring born to the breeding female in their group, a process known as allonursing. Previous laboratory studies have suggested that primiparous and multiparous females (those that have successfully given birth once or more, respectively) are more likely to contribute to al...

The ability of dispersing individuals to adjust their behaviour to changing conditions is instrumental in overcoming challenges and reducing dispersal costs, consequently increasing overall dispersal success. Understanding how dispersers' behaviour and physiology change during the dispersal process, and how they differ from resident individuals, ca...

In many cooperatively breeding mammals, an unrelated dominant pair monopolizes reproduction in the social group while subordinates help to raise their offspring. In Kalahari meerkats (Suricata suricatta), dominant males are usually immigrants while dominant females are natal animals that have not left the group where they were born. However, in aro...

Increased vulnerability to predation results in young individuals of many species experiencing higher predation pressure than adults. Consequently, the production of antipredator-related calls by young can differ from that of the same vocalizations given by adults. Sentinel behaviour is a coordinated vigilance behaviour, where one individual climbs...

Animal‐borne accelerometers have been used across more than 120 species to infer biologically significant information such as energy expenditure and broad behavioural categories. While the accelerometer's high sensitivity to movement and fast response times present the unprecedented opportunity to resolve fine‐scale behaviour, leveraging this oppor...

Communication plays a vital role in the social lives of many species and varies greatly in complexity. One possible way to increase communicative complexity is by combining signals into longer sequences, which has been proposed as a mechanism allowing species with a limited repertoire to increase their communicative output. In mammals, most studies...

Background: The ability to recombine smaller units to produce infinite structures of higher-order phrases is unique to human language, yet evidence of animals to combine multiple acoustic units into meaningful combinations increases constantly. Despite increasing evidence for meaningful call combinations across contexts, little attention has been...

The efficiency of communication between animals is determined by the perception range of signals. With changes in the environment, signal transmission between a sender and a receiver can be influenced both directly, where the signal’s propagation quality itself is affected, and indirectly where the senders or receivers’ behaviour is impaired, impac...

The efficiency of communication between animals is determined by the perception range of signals. With changes in the environment, signal transmission between a sender and a receiver can be influenced both directly, where the signal’s propagation quality itself is affected, and indirectly where the senders or receivers’ behaviour is impaired, impac...

Across many taxa, individuals learn how to detect, recognise and respond to predators via social learning. Learning to recognise and interpret predator cues is essential in the accurate assessment of risk. Cues can come directly from a predator's presence (visual, acoustic) or from secondary predator cues (SPCs, such as hair/feathers, urine or faec...

The assessment of current risk is essential in informing defensive behaviours. Many animals use cues left behind by predators, known as secondary predator cues (SPCs), to assess risk and respond appropriately. However, meerkats, Suricata suricatta, exhibit seemingly unique mobbing-like responses to these cues. The benefit of this high-intensity rec...

Mechanical constraints imposed by anatomical adaptations are a ubiquitous feature of animal sound production. They can give rise to ‘vocal predispositions’ (i.e., acoustic structures strictly determined by vocal anatomy). Such predispositions are crucial to the investigation of the cognitive and evolutionary processes underlying acoustic communicat...

Researchers studying mammals have frequently interpreted earlier or faster rates of ageing in males as resulting from polygyny and the associated higher costs of reproductive competition. Yet, few studies conducted on wild populations have compared sex‐specific senescence trajectories outside of polygynous species, making it difficult to make gener...

Violent conflicts between groups have been observed among many species of group living mammals and can have important fitness consequences, with individuals being injured or killed and with losing groups surrendering territory. Here, we explore between-group conflict among meerkats (Suricata suricatta), a highly social and cooperatively breeding mo...

Territoriality and stable home ranges are a common space‐use pattern among animals. These ranges provide its inhabitants with important resources and thus favourable territories are associated with an increased fitness. While the role of territory quality and changes of territory ownership have often been investigated, the changes of territorial bo...

Cooperative breeding often evolved in harsh and arid habitats characterized by high levels of environmental uncertainty. Most forms of cooperative behavior have energetic costs and previous studies have shown that the contributions of individuals to alloparental provisioning are conditional on their food intake. However, the effect of naturally occ...

Choosing suitable sleeping sites is a common challenge faced by animals across a range of taxa, with important implications for the space usage patterns of individuals, groups, and ultimately populations. A range of factors may affect these decisions, including access to resources nearby, shelter from the elements, safety from predators, territoria...

The majority of carnivore species are described as solitary, but little is known about their social organization and interactions with conspecifics. We investigated the spatial organization and social interactions as well as relatedness of slender mongooses (Galerella sanguinea) living in the southern Kalahari. This is a little studied small carniv...

Dispersal is a key process influencing the dynamics of socially and spatially structured populations. Dispersal success is determined by the state of individuals at emigration and the costs incurred after emigration. However, quantification of such costs is often difficult, due to logistical constraints of following wide-ranging individuals. We inv...

Body mass and fGCM data collected on wild meerkats in the field. R codes for model 1a (body mass in emigrants, returners, and residents), model 1b (fGCM in emigrants, returners, and residents), model 2a (emigrant body mass during dispersal stages), and model 2b (emigrant fGCM during dispersal stages).

Coordination is a fundamental aspect of social living, underlying processes ranging from the maintenance of group cohesion to the avoidance of competition. Coordination can manifest as synchronization, where individuals perform the same action at the same time but can also take the form of anti-synchronization or turn-taking. Turn-taking has mainly...

To maximise foraging opportunities while simultaneously avoiding predation, group-living animals can obtain personal information on food availability and predation risk and/or rely on social information provided by group members. Although mainly associated with low costs of information acquisition, social information has the potential to be irrelev...

Language is inherently combinatorial, and parallels of this combinatorial capacity are found in non-human systems, with animals combining sounds and calls into larger meaningful structures. However, further analogue examples are central in unveiling the diversity, distribution and evolutionary drivers of combinatoriality. Here, we provide evidence...

Group-living animals need to trade off the benefits and the costs of close proximity to conspecifics. Benefits can be increased, and costs reduced by preferentially choosing specific locations within a group best adjusted to an individual’s needs or by associating with specific group members and/or avoiding others. We investigated the spatial struc...

Evolang 12, 16.-19.04.2018, Torun, Poland. Link to presentation: https://sabrinaengesser.weebly.com/20180417_evolang-torun_pieds-recruitmentcries_web_video.html

Social animal groups often make consensus decisions about when to return to a sleeping site after a day of foraging. These decisions can depend on extrinsic as well as intrinsic factors, and can range from unshared to shared. Here we investigated how decisions of meerkats, Suricata suricatta, to return to their burrows are coordinated, whether they...

Angiostronglyus vasorum is a cardiopulmonary nematode infecting mainly canids such as dogs (Canis familiaris) and foxes (Vulpes vulpes). Natural infections have also been reported in mustelids and red pandas (Ailurus fulgens fulgens). We report the occurrence of natural A. vasorum infections in a group of captive meerkats (Suricata suricatta), hous...

In cooperative breeders, aggression from dominant breeders directed at subordinates may raise subordinate stress hormone (glucocorticoid) concentrations. This may benefit dominants by suppressing subordinate reproduction but it is uncertain whether aggression from dominants can elevate subordinate cooperative behaviour, or how resulting changes in...

Many species produce alarm calls in response to predator threats. Whilst these can be general alert calls, some are urgency-based, indicating perceived threat level, some are predator-specific, indicating the predator type present, and some encode information about both urgency level and predator type. Predator-specific calls given to a narrow rang...

Olfaction is a central aspect of mammalian communication, providing information about individual attributes such as identity, sex, group membership or genetic quality. Yet, the chemical underpinnings of olfactory cues remain little understood, one of the reasons being the difficulty in obtaining high quality samples for chemical analysis. In this s...

In animals, signaling behavior is often context-dependent, with variation in the probability of emitting certain signals dependent upon fitness advantages. Senders may adjust signaling rate depending on receiver identity, presence of audiences, or noise masking the signal, all of which can affect the benefits and costs of signal production. In the...

It is well established that animal vocalizations can encode information regarding a sender’s identity, sex, age, body size, social rank and group membership. However, the association between physiological parameters, particularly stress hormone levels, and vocal behavior is still not well understood. The cooperatively breeding African meerkats (Sur...

Correlation of individual mean close call duration per season, and individual median fGCM level per season. (reproductive (black, dashed line) and non-reproductive season (white, black line)). (TIF)

Correlation of individual mean IPI close call duration per and individual median fGCM level per season. (reproductive (black, dashed line) and non-reproductive season (white, black line)). (TIF)

P-values for post-hoc Tukey tests run for factors with significant (or significant trend) effects. (PDF)

Pearson correlation test for structural close call parameters in relation to fGCM levels. rep = reproductive season, nonrep = non-reproductive season. (TIF)

Ethogram with recorded activities. All behaviors were mutually exclusive. (With permission adjusted from Engesser, 2011.) (TIF)

Demographic group composition of 9 sampled groups during the reproductive andnon-reproductive season. Focal individuals are marked in bold. The first 2 individuals listed per group are the dominant individuals. F: Female, M: Male. (PDF)

Sample dates for data collection of focal individuals. (PDF)

Individual median close call rate, GCs level, dry fecal weight, mean body weight and close call rate and dry fecal weight range. rep: reproductive season, nonrep: non-reproductive season; SUB: subordinate, DOM: dominant; F: female, M: male. (PDF)

Correlation of individual mean pulse close call duration per and individual median fGCM level per season. (reproductive (black, dashed line) and non-reproductive season (white, black line)). (TIF)

Correlation of individual mean F0 per and individual median fGCM level per season for the reproductive (black, dashed line) and non-reproductive season (white, black line). (TIF)

Deception, the use of false signals to modify the behaviour of the receiver, occurs in low frequencies even in stable signalling systems. For example, it can be advantageous for subordinate individuals to deceive in competitive situations. We investigated in a three-way choice task whether dogs are able to mislead a human competitor, i.e. if they a...

Group coordination, when ‘on the move’ or when visibility is low, is a challenge faced by many social living animals. While some animals manage to maintain cohesion solely through visual contact, the mechanism of group cohesion through other modes of communication, a necessity when visual contact is reduced, is not yet understood. Meerkats (Suricat...

Sentinel behaviour, a form of coordinated vigilance, occurs in a limited range of species, mostly in cooperative breeders. In some species sentinels confirm their presence vocally by giving a single sentinel call type, whereby the rate and subtle acoustic changes provide graded information on the variation of perceived predation risk. In contrast,...

Repertoire size, frequently determined by the number of discrete call types, has been used to assess vocal complexity in animals. However, species can also increase their communicative complexity by using graded signals or by combining individual calls. Animal call sequences can be divided into two main categories, each subdivided into two classes:...

Attending to the perception of others may help individuals gaining information from conspecifics, or help in competitive situations. Dogs (Canis familiaris) are attentive to humans' signals and their attentional state. We investigated whether dogs of different breed groups differ in their ability to pay attention to human's perception, first accord...

The mongoose family (Herpestidae) has provided a wealth of data on life history patterns and behavior of its more social species but little is known about the many solitary mongoose species. Here, we provide the 1st long-term data on life history patterns and the biology of the solitary slender mongoose (Galerella sanguinea) in the Kalahari Desert,...

Animals produce a variety of call sequences, from simple repetitions of the same acoustic unit to the combination of different, meaningful acoustic units resulting in a new meaning. On the example of several highly vocal mongoose species, including meerkats (Suricata suricatta), and banded mongoose (Mungos mungo) I identify the composition of diffe...

A number of diurnal species have been shown to use directional information from the sun to orientate. The use of the sun in this way has been suggested to occur in either a time-dependent (relying on specific positional information) or a time-compensated manner (a compass that adjusts itself over time with the shifts in the sun’s position). However...

Language's intentional nature has been highlighted as a crucial feature distinguishing it from other communication systems. Specifically, language is often thought to depend on highly structured intentional action and mutual mindreading by a communicator and recipient. Whilst similar abilities in animals can shed light on the evolution of intention...

For food caching to be adaptive, the benefits of recovery must outweigh the costs of storing an item. One of the costs to cachers is the risk of theft, and therefore, it is predicted that individuals may be sensitive to this theft and show various behavioural strategies to minimise it. In this study, we gave wild Cape ground squirrels (Xerus inauri...