Igor L. Kaefer

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• PhD
• Professor at Federal University of Amazonas

We studied the reproductive biology of an invasive population of the bullfrog Litho-bates catesbeianus by analyzing individuals captured in the central Rio Grande do Sul state, southern Brazil. Specimens were collected during 12 field trips held from May 2002 to June 2003. We analyzed gonad development stages in 216 individuals to evaluate the fecu...

Phylogeographic perspectives incorporating multiple classes of characters, especially those relating to sexual signals, are promising for the elucidation of recent evolutionary mechanisms driving speciation. Here, forest frogs were used as a model system to access distinct stages in the process of evolutionary differentiation. We studied 280 indivi...

Here we describe a new species of the toad genus Amazophrynella (Bufonidae) from the south margin of the Amazon River in Santarém, state of Pará, Brazilian Amazonia. The new species can be diagnosed by (1) medium body size for the genus: adult females 19.5-20.4 mm SVL, adult males 13.0-14.5 mm SVL; (2) snout acuminate in lateral view; (3) Finger I...

We investigated 1) the role of area per se in explaining anuran species richness on reservoir forest islands, after controlling for several confounding factors. We also assessed 2) how sampling design affects the inferential power of island species–area relationships (ISARs) aiming to 3) provide guidelines to yield reliable estimates of area‐induce...

Soundscape studies are increasingly used to capture landscape‐scale ecological patterns. Yet, several aspects of soundscape diversity remain unexplored. Although some processes influencing acoustic niche usage may operate in the 24‐hr temporal domain, most acoustic indices only capture the diversity of sounds co‐occurring in sound files at a specif...

Amphibian declines, linked to climate change and disease, pose a global challenge, yet their primary drivers remain debated. We investigated the historical decline of Brazilian amphibians by assessing the influence of climate change, extreme weather events, and the chytrid fungus Batrachochytrium dendrobatidis (Bd). Our analysis encompassed 90 amph...

Haemosporidians constitute a monophyletic group of vector-borne parasites that infect a wide range of vertebrate hosts, including Neotropical lizards. The remarkable diversity of these host-parasite associations and inadequate research on certain parasite groups have resulted in controversial haemosporidian taxonomy. Herein, we rediscover erythrocy...

Amazonia holds global significance due to its essential role in climate regulation and its high biological diversity. However, in recent decades, the region has faced serious threats to its forest structure and rich biodiversity. Human activities, including habitat alterations, pollution, introduction of invasive species, pathogens, and accelerated...

Amazonia continuously reveals outstanding biotic diversity and endemism, but our comprehension regarding their underlying processes has been impaired by knowledge gaps on cryptic taxonomic diversity. Here, we clarified the diversity and historical biogeography of nurse-frogs typical from Brazilian Southwestern Amazonia, the Allobates tinae species...

The lack of synthesized information regarding biodiversity is a major problem among researchers, leading to a pervasive cycle where ecologists make field campaigns to collect information that already exists and yet has not been made available for a broader audience. This problem leads to long-lasting effects in public policies such as spending mone...

The lack of synthesized information regarding biodiversity is a major problem among researchers, leading to a pervasive cycle where ecologists make field campaigns to collect information that already exists and yet has not been made available for a broader audience. This problem leads to long-lasting effects in public policies such as spending mone...

The lack of synthesized information regarding biodiversity is a major problem among researchers, leading to a pervasive cycle where ecologists make field campaigns to collect information that already exists and yet has not been made available for a broader audience. This problem leads to long-lasting effects in public policies such as spending mone...

Knowledge on the ecology of many Amazonian anuran species is still incipient, especially when it comes to resource partitioning. Here, we studied dietary variation of four Pristimantis species (P. chiastonotus, P. crepitaculus, P. gutturalis and P. zeuctotylus) from Eastern Brazilian Amazonia during the rainy and dry seasons. From 226 stomach cont...

Adelphobates contains three species, and the inaccurate identification of A. quinquevittatus and the scarcity of records of A. castaneoticus complicate inference of their distributions; the latter species occurs in sympatry with A. galactonotus. Our objective was to revise the distributions of Adelphobates by compiling data and modeling habitat sui...

We reported anomalies in three anuran species belonging to two families: Craugastoridae (Pristimantis gutturalis and P. chiastonotus), and Bufonidae (Rhinella castaneotica). All records were found in two conservation units, a well-preserved and protected area of the Amazonian rainforest in the state of Amapa, eastern Amazon. The anomalies detected...

Differentiation in resource use by sympatric species reduces competition and allows coexistence. Constraints imposed both by evolutionary history and current ecological interactions strongly influence the coexistence of distinct anuran species. In this context, we analyzed the dietary habits of two sympatric frogs in a Batesian mimicry system, Amee...

Identifying risk areas for envenomation by animals is relevant for public health, such as strategic distribution of antivenoms. Coral snakes are highly diverse in the Amazon, inhabit natural and human-modified environments, and the outcome of the cases tends to be serious and potentially lethal due to their neurotoxic venom. By integrating species'...

In submitting conference proceedings to the 1st International Symposium on Research in Venomous Animals, Manaus, Brazil, 2–5 May 2023, the volume editors of the proceedings certify to the publisher that all abstracts published in this volume have been subjected to peer review, performed by a scientific committee administered by the volume editors [...

Investigating parallel roles of geography and environmental heterogeneity in diversification provides insights on how neutral and selective forces drive evolution of biological systems. Here, we investigate whether geographic and climatic distances explain either genetic or phenotypic variation in Blue-crowned Manakins (Lepidothrix coronata), a pol...

The Amazon represents the world’s greatest biodiversity and covers different countries in South America, including Brazil with the largest area. The interaction between the resident population of this area and its ecosystem is responsible for an intense exposure to venomous animals, which are considered an important health issue in the region. Ther...

We use integrative taxonomy to formally describe a candidate species of nurse frog of the genus Allobates from southwestern Brazilian Amazonia. The new species nests within a clade that has been defined historically as A. gasconi, but it has an 8.8-11.0% genetic distance for 16S to samples from the type locality of A. gasconi. The new species diffe...

Aim Distinguishing ecological and evolutionary processes that structure assemblages can provide a comprehensive vision of the variation in species turnover in heterogeneous regions. However, the causes of spatial variation in organism assemblies in most of the Amazon still require further studies. In view of this, our objective was to determine the...

Herein, we report three new separate cases of human envenomations by Micrurus hemprichii for the Amazon, which is a biome where envenomations by Micrurus are seldom reported. Two women were bitten after stepping on the snakes and one man was bitten while handling the animal. All cases occurred in the peridomicile, in rural areas. The first case evo...

Phyllomedusa bicolor (Phyllomedusidae), popularly known as the kambô in Brazil, is a tree frog that is widely distributed in South American countries and is known for producing a skin secretion that is rich in bioactive peptides, which are often used in indigenous rituals. The biological effects of the skin secretion were observed in the first stud...

Early detection of predators is fundamental for the survival of the prey. Predator detection can occur by perception of the chemical substances released by predators or injured conspecifics, granting prey the opportunity to avoid the attack. However, overreacting to cues can generate false alarm reactions that result in fruitless energetic costs. G...

Aim: The main focus of this chapter is to provide a brief overview on global patterns of diversity and conservation of wetlands herpetofauna and discuss both ecological and morphological adaptations that facilitate life in such environments. By treating Amazonian wetland amphibians and reptiles as our case studies, we examine their level of specif...

1. Soundscape studies are increasingly common to capture landscape-scale ecological patterns. Yet, several aspects of soundscape diversity quantification remain unexplored. Although some processes influencing acoustic niche usage may operate in the 24h domain, most acoustic indices only capture the diversity of sounds co-occurring in sound files at...

Reptiles and amphibians are exceptional hosts for different ectoparasites, including mites and ticks. In this study, we investigated tick infestations on reptiles and amphibians trapped in Central Amazonia, and also assessed the presence of rickettsial infections in the collected ticks. From September 2016 to September 2019, 385 reptiles (350 lizar...

Anti-predator mechanisms play a key role in the survival of any animal in nature. Anurans exhibit a great diversity of defensive behaviours and interact with the widest range of predators of any vertebrates. However, there are few systematic and experi- mental studies of anuran defensive behaviours, which are generally opportunistic. Here, we deplo...

Due to the importance of camouflage to avoid detection by predators, predation pressure can cause coupled evolution of skin colour and preference for substrate colour. Individuals can choose regions where the background makes their skin colour less noticeable (crypsis) or where it accentuates warning coloration (aposematism). In such scenario, indi...

Sexual selection predicts evolution of secondary sexual traits favoring mating. Here, we address the within population variation in courtship display behavior among male White-throated Manakins, Corapipo gutturalis, from Central Amazonia. We repeatedly quantified the courtship display elements used by 16 males over multiple days and specifically te...

In poison frogs (Dendrobatoidea), usually the males are territorial, care for terrestrial nests and later transport their offspring to waterbodies where they complete larval development. In some species, mothers care for their offspring or may exhibit flexible care to compensate for father absence. We conducted a multi-season field experiment with...

A região do interflúvio dos rios Purus e Madeira é ambientalmente diversa e lar de espécies de plantas e animais ainda desconhecidos pela humanidade, principalmente as mais pequenas, que são difíceis de enxergar. Para descobrir essas espécies, é preciso atenção e cuidado. Foi assim que, em 2018, o grupo de pesquisadores do qual faço parte encontrou...

Geographical and environmental distances influence the divergence of characters among biological populations, especially on a macro spatial scale, making it difficult to interpret the individual contribution of these predictor variables in the process of population differentiation. Anurans are excellent models for multi-character evolutionary studi...

A contentious aspect in dendrobatoid frog behaviour is the recognition of the predominant factor—if any—driving male mating success. This is probably related to an extensive correlation among different male quality predictors. Here, we investigated the diurnal and territorial nurse frog Allobates subfolionidificans by means of a field study during...

Aim: The main focus of this chapter is to provide a brief overview on global patterns of diversity and conservation of wetlands herpetofauna and discuss both ecological and morphological adaptations that facilitate life in such environments. By treating Amazonian wetland amphibians and reptiles as our case studies, we examine their level of specifi...

The increasing urbanization of the Amazonian biome has promoted the creation of several forest fragments surrounded by an urban matrix, but the relationship of animal assemblages to the urban environment, especially in forest fragments, is poorly known. Here we aimed to 1) determine the composition of the squamate fauna of the largest urban forest...

Blood samples from 72 Ameiva ameiva lizards from Central Amazonian upland forests were collected, and thin smears of 40 (55.5%) animals were positive for gamonts of Hepatozoon with a mean level of intensity of infection of 14 parasites/2000 blood erythrocytes (0.73%). The gametocytes were found attached with host cells’ nuclei, and their dimensions...

Blood samples from 330 lizards of 19 species were collected to investigate the occurrence of haemoparasites. Samplings were performed in areas of upland (terra-fi rme) forest adjacent to Manaus municipality, Amazonas, Brazil. Blood parasites were detected in 220 (66%) lizards of 12 species and comprised four major groups: Apicomplexa (including hae...

Envenomation by coral snakes represents a little known burden in Brazilian Amazonia. So far, details on clinical and epidemiological aspects remain obscure in the region. We gathered data from medical charts and from the scientific collection of snakes from Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, finding 26 cases of envenomation...

Defensive behaviours are a prime strategy for animal survivorship. However, the diversity of defence displays still needs systematic studies, since most reports are based on opportunistic field observations. In this study, we explore the defensive behaviour of the cane toad, Rhinella marina, collecting data from 173 individuals. As a result, here w...

Investigating the role of historical and ecological factors structuring assemblages is relevant to understand mechanisms and processes affecting biodiversity across heterogeneous habitats. Considering that community assembly often involves scale-dependent processes, different spatial scales may reveal distinct factors structuring assemblages. In th...

The American bullfrog Lithobates catesbeianus has a natural distribution in North America, but was spread by human activities in different regions around the world. It is listed as the most invasive amphibian species, affecting terrestrial and aquatic ecosystems and the community of native species. In addition, the American bullfrog is extensively...

Bothrops atrox snakes are mostly endemic of the Amazon rainforest and is certainly the South American pit viper responsible for most of the snakebites in the region. The composition of B. atrox venom is significantly known and has been used to trace the relevance of the venom phenotype for snake biology and for the impacts in the clinics of human p...

Snakes are a diverse group of terrestrial vertebrates of the order Squamata. Despite that, in the Amazonian biome, information about distribution and identification of snakes is limited when compared to other groups. Additionally, in Amazonia there is a sampling bias towards areas geographically close to urban centers and more densely populated are...

While intraspecific variation in aposematic signals can be selected for by different predatory responses, their evolution is also contingent on other processes shaping genetic variation. We evaluate the relative contributions of selection, geographic isolation, and random genetic drift to the evolution of aposematic color polymorphism in the poison...

Coral snakes constitute a relatively diverse and little known group of venomous snakes. So far, data for this kind of snakebite in the Amazon region are based only on case reports. This study takes advantage of novel data from the Brazilian Health Ministry database from 2010 to 2015 and presents a review of the cases reported in the literature rega...

Here we report the local extinction of Scinax caldarum, an endemic tree frog species of the Brazilian Atlantic Forest. We also report a reduction of the geographic range of this species to less than 15 % of the area in which it occurred 27 years earlier. We consider the excessive use of agrochemicals to be the main factor explaining the decline, in...

Introduction: Snake venom composition shows significant inter- and intra-species variation. In the case of the viperid species Bothrops atrox, responsible for the majority of snakebites in the Amazon region, geographical and ontogenetic variables affect venom composition, with ecological and medical implications. Previous studies had shown that ven...

Here we present data on the identity and geographic distribution of lizard taxa in the Purus-Madeira interfluve, along the road BR-319 in Brazilian Amazonia. We sampled 10 modules located at least 40 kilometres from each other. Data collection was performed through active search on vegetation and leaf-litter along 250 m-long transects, and by occa...

Detecting ecological patterns is highly dependent on the spatial scale of the analysis. However, the importance of scale has been poorly explored when testing environmental influences and estimating niche overlap between animal species. In this study, we tested the hypotheses that: 1) environmental influences on species distribution at different ge...

ABSTRACT The pitviper Bothrops atrox is a widely distributed and medically important snake in Amazonia. Given that the reproductive and feeding biology of snakes varies geographically, we aimed to characterize the natural history of individuals from the central and southwestern portions of the biome. We analyzed museum-preserved specimens collected...

The use of lizards as model organisms in ecological studies is based on their success in occupying a great diversity of habitats, and some species are closely tied to the environment, which is disadvantaged by the legislation of several countries concerning land use. Our aim was to relate lizard species distribution patterns in rainforest environme...

Most species of Amazonian snakes have wide geographic distributions. However, local environmental factors influence the formation of assemblages in different localities. In this study, we investigated the composition of the assemblage and the effect of environmental variables on the distribution of the species inhabiting an upland forest in the Exp...

The spatial distribution of biodiversity and related processes is the core of Biogeography. Amazonia is the world's most diverse rainforest and the primary source of diversity to several Neotropical regions. The origins of such diversity continue to be an unresolved question in evolutionary biology. Among many competing hypotheses to explain the...

Abstract. Allobates paleovarzensis is a diurnal leaf-litter anuran of the Dendrobatoidea superfamily inhabiting Amazonian forests. Based on behavioral field observations, conducted between 2008–2017 at three localities, we describe the courtship, mating, parental care behavior and territoriality of the species. Vocal activity is more intense in the...

We describe a new small species of Scinax from the rain forests on the interfluve between Purus and Madeira Rivers, Brazilian Amazonia. The new species is diagnosed by snout–vent length 20.2−22.5 mm in males; a yellowish-bronze dorsum showing small spots along the body and limbs; a red stripe horizontally extended on the medial portion of the iris;...

Nota curto a cerca do primeiro registro de comportamento de combate para perereca-de-vidro (Vitreorana uranoscopa) feito em Cascavel, Paraná, Brasil

The genus Scinax is one of the most specious genera of treefrogs of the family Hylidae. Despite the high number of potential new species of Scinax revealed in recent studies, the rate of species descriptions for Amazonia has been low in the last decade. A potential cause of this low rate may be the existence of morphologically cryptic species. Desc...

Species of Scinax occurring in Amazonia

Sampling methods for the environmental variables

Morphometric measurements of Scinax ruberoculatus sp. nov. from Purus-Madeira Rivers Interfluve, State of Amazonas, Brazil Abbreviations: (INPA-H) Herpetological Section of the Zoological Collection of the Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil, (RAPELD) sampling sites, (M) male, (F) female, (SVL) snout-vent length, (HL) head l...

Specimens examined for morphological comparisons Abbreviations: (AM) Highway at State of Amazonas, Brazil; (PDBFF) Projeto Dinâmica Biológica de Fragmentos Florestais (a project in Brazil focused on dynamics of forest fragments), (km) kilometre; (INPA-H) Herpetological Section of the Zoological Collection of the Instituto Nacional de Pesquisas da A...

Principal Components resulting from the Principal Component Analyses conducted for the SVL and 15 morphometric ratios from all individuals of Scinax ruberoculatus sp. nov. (males and females) Abbreviations: (PC) Principal Component, (SVL) snout-vent length, (HL) head length, (HW) head width, (ED) horizontal eye diameter, (UEW) upper eyelid width, (...

In polygamous mating systems, it is most often males that compete for the opposite sex, using strategies to provide access to as many females as possible. Females, on the other hand, constitute the sex that exerts the choice and so require a means of accessing the quality of a potential partner in comparison to its competitors. A common challenge i...

[This corrects the article DOI: 10.3897/zookeys.687.13221.].

In our recent work on the description of the new species of Pristimantis (De Oliveira et al. 2017), some errors that can impair your complete understanding were not noticed in the text. Corrections are as follows

A new tree frog species of the genus Scinax from the interfluve between the Purus and Madeira rivers, Brazilian Amazonia, is described and illustrated. The new species is diagnosed by medium body size, snout truncate in dorsal view, ulnar and tarsal tubercles absent, nuptial pads poorly developed, skin on dorsum shagreen, dorsum light brown with da...

A new tree frog species of the genus Scinax from the interfluve between the Purus and Madeira rivers, Brazilian Amazonia, is described and illustrated. The new species is diagnosed by medium body size, snout truncate in dorsal view, ulnar and tarsal tubercles absent, nuptial pads poorly developed, skin on dorsum shagreen, dorsum light brown with da...

Citation: Oliveira EA de, Rodrigues LR, Kaefer IL, Pinto KC, Hernández-Ruz EJ (2017) A new species of Pristimantis from eastern Brazilian Amazonia (Anura, Craugastoridae) ZooKeys 687: 101–129. https://doi. Abstract.. In this study a new species of Pristimantis (Anura: Craugastoridae) of the P. conspicillatus species group is described. Pristimantis...

Allobates subfolionidificans is a vulnerable and endemic leaf-litter frog from the state of Acre, Brazilian Amazonia. We monitored a population of A. subfolionidificans through regular censuses and mark-recapture of 181 individuals during an entire breeding season to characterize its reproductive behavior. The space use of A. subfolionidificans ind...