To avoid certain problems encountered with more-traditional and invasive methods in behavioral-ecology studies of mammalian predators, such as felids, molecular approaches have been employed to ...identify feces found in the field. However, this method requires a complete molecular biology laboratory, and usually also requires very fresh fecal samples to avoid DNA degradation. Both conditions are normally absent in the field. To address these difficulties, identification based on morphological characters (length, color, banding, scales and medullar patterns) of hairs found in feces could be employed as an alternative. In this study we constructed a morphological identification key for guard hairs of eight Neotropical felids (jaguar, oncilla, Geoffroy's cat, margay, ocelot, Pampas cat, puma and jaguarundi) and compared its efficiency to that of a molecular identification method, using the ATP6 region as a marker. For this molecular approach, we simulated some field conditions by postponing sample-conservation procedures. A blind test of the identification key obtained a nearly 70% overall success rate, which we considered equivalent to or better than the results of some molecular methods (probably due to DNA degradation) found in other studies. The jaguar, puma and jaguarundi could be unequivocally discriminated from any other Neotropical felid. On a scale ranging from inadequate to excellent, the key proved poor only for the margay, with only 30% of its hairs successfully identified using this key; and have intermediate success rates for the remaining species, the oncilla, Geoffroy's cat, ocelot and Pampas cat, were intermediate. Complementary information about the known distributions of felid populations may be necessary to substantially improve the results obtained with the key. Our own molecular results were even better, since all blind-tested samples were correctly identified. Part of these identifications were made from samples kept in suboptimal conditions, with some samples remaining outdoors for up to seven days, simulating conditions in the field. It appears that both methods can be used, depending on the available laboratory facilities and on the expected results.
Although considered an evolutionary force responsible for shaping ecosystems and biodiversity, fires’ natural cycle is being altered by human activities, increasing the odds of destructive megafire ...events. Here, we show that forest type modulates the responses of terrestrial mammals, from species to assemblage level, to a catastrophic megafire in the Brazilian Pantanal. We unraveled that mammalian richness was higher 1 year after fire passage compared to a pre-fire condition, which can be attributed to habitat modification caused by wildfires, attracting herbivores and open-area tolerant species. We observed changes in assemblage composition between burned/unburned sites, but no difference in mammalian richness or relative abundance. However, by partitioning the effects of burned area proportion per forest type (monospecific vs. polyspecific), we detected differential responses of mammals at several levels of organization, with pronounced declines in species richness and relative abundance in monospecific forests. Eighty-six percent of the species presented moderate to strong negative effects on their relative abundance, with an overall strong negative effect for the entire assemblage. Wildfires are predicted to be more frequent with climate and land use change, and if events analogous to Pantanal-2020 become recurrent, they might trigger regional beta diversity change, benefitting open-area tolerant species.
The progressive fragmentation and loss of habitats represent the main threats for endangered species, causing genetic consequences that may have potential implications for a population's long-term ...persistence. Large mammals are the most affected species among vertebrates. The giant armadillo Priodontes maximus is a large South American mammal threatened species, showing nocturnal, solitary and fossorial behavior, occurring at low population densities, and its population dynamics are still poorly known. In this study, we carried out the first assessment of genetic variability and population genetic structure of the species, using a panel of 15 polymorphic microsatellites developed by high-throughput genome sequencing. The spatial Bayesian clustering, Fst and Dest results indicated the presence of two genetic clusters (K = 2) in the study area. These results suggest a reduction in gene flow between individuals inhabiting the Brazilian savanna (Cerrado) and the Pantanal wetlands, with the increased human-driven habitat modifications possibly contributing for this scenario. A bottleneck signal was detected in both populations, and a subpopulation structuring in the Cerrado may also be reflecting consequences of the extensive habitat modifications. Findings from this study provide important and useful information for the future maintenance of genetic diversity and long-term conservation of this flagship species.
Environmental DNA (eDNA) and invertebrate‐derived DNA (iDNA) have been increasingly recognized as powerful tools for biodiversity assessment and conservation management. However, eDNA/iDNA efficiency ...for vertebrate diversity assessment remains uncertain, and comparisons to conventional methods are still rare. Through a meta‐analysis of previously published vertebrate diversity surveys, we compared the efficiency of eDNA/iDNA against conventional methods across several types of samplers, vertebrate groups, and locations (tropical vs. temperate zones). We also assess eDNA/iDNA efficiency to estimate relative abundance or biomass over different molecular methods (qPCR and metabarcoding) and type of experiment (in the laboratory or in the field). We showed that for water sampler, fish as a target species, and studies achieved in temperate zones, eDNA presents lower risk of not detecting a species or a site with a target species than conventional methods. These results show that eDNA is an efficient tool to assess fish diversity. Moreover, eDNA data presents positive correlation with fish abundance or biomass. However, such correlation was higher in laboratory experiments than in the field. For the other samplers, vertebrate groups, and in tropical zones we were not able to draw general conclusion, highlighting the urgency of conducting more comparative studies.
Context
Forest loss and fragmentation are rapidly expanding across the tropics. Although forest loss is a major driver of the current biodiversity crisis, the effect of fragmentation remains debated, ...particularly for forest-specialist species.
Objectives
We evaluated the univariate and combined effect of forest loss (percent of forest cover) and fragmentation (forest patch density) on populations of a forest-specialist primate, the black-fronted titi monkey (
Callicebus nigrifrons
), in the landscapes from a transitional zone between Atlantic Forest and Cerrado biomes.
Methods
We surveyed titi monkey density in 14 landscapes. Using a multiscale and multimodel inference approach, we tested the relative effect of each landscape variable assessed at their respective scales of effect on titi monkey density.
Results
Titi monkey density ranged from 0 to 12 groups/km
2
and was best predicted by the combined effect of forest cover and patch density. Density increased in forest patches embedded in more deforested and fragmented landscapes. Interestingly, the effect of forest patch density was consistently positive along the entire evaluated forest cover gradient (9–42%).
Conclusions
Our findings support that fragmentation per se can have positive effects on biodiversity, in this case, by increasing the likelihood that more individuals can be ‘rescued’ from deforestation and crowded in the remaining forest patches. Although the long-term consequences of living crowded in forest patches are unknown, a conservative approach for preserving this (and potentially other) forest-specialist species could be to promote forest restoration projects focused on increasing the number and/or size of forest patches in the landscape (i.e., reverse fragmentation).
In general, large mammal species with highly specialized feeding behavior and solitary habits are expected to suffer genetic consequences from habitat loss and fragmentation. To test this hypothesis, ...we analyzed the genetic diversity distribution of the threatened giant anteater inhabiting a human-modified landscape. We used 10 microsatellite loci to assess the genetic diversity and population structure of 107 giant anteaters sampled in the Brazilian Central-Western region. No genetic population structuring was observed in this region suggesting no gene flow restriction within the studied area. On the other hand, the moderate level of genetic diversity (Ho = 0.54), recent bottleneck detected and inbreeding (F
is
, 0.13;
p
≤ 0.001) signatures suggest potential impacts on the genetic variation of this Xenarthra. Additionally, a previous demographic reduction was suggested. Thus, considering the increased human-promoted impacts across the entire area of distribution of the giant anteater, our results can illustrate the potential effects of these disturbances on the genetic variation, allowing us to request the long-term conservation of this emblematic species.
Habitat loss and fragmentation are considered the major treats to worldwide biodiversity. Carnivores in particular can be more sensitive to landscape modification due to their low occurrence density ...and large home ranges. Population structuring of Puma concolor has been already reported as a consequence of extensive human activities in the North American continent. Here, we investigated the occurrence of fine-scale population structuring in the South American cougar population, contrasting two conservation areas immersed in a highly human-fragmented landscape dominated by the presence of sugar cane monoculture, roads, and urbanization, including a series of dams in the Tietê River which enlarges its water body. Seven microsatellites were amplified using non-invasive DNA obtained from fecal samples. We conducted genetic clustering analyses using Bayesian and factorial components. We also performed genetic differentiation analyses by fixation indices (Fst and Dest). Two genetic clusters represented by individuals from each area were found, indicating the occurrence of gene flow reduction between the areas. The intense human-induced landscape modification-which includes the Tietê River water body enlargement, imposing physical barriers to the movement of the individuals-could explain the gene flow reduction. Increasing connectivity among the preserved areas can mitigate such effects, and the creation of corridors or further management actions such as individual translocation to ensure gene flow in the highly-modified landscape may be essential for maintaining the genetic and demographic health of the species and its long-term persistence.
Abstract
European Hare (Lepus europaeus), like many invasive species, have declined in much of their native range but flourished in non-native regions (e.g. South America). Previous studies suggested ...that loss of farmland heterogeneity due to agricultural intensification is the main driver of the species decline in its native range in Europe. Yet, little is known about the role of spatial and temporal heterogeneity and land cover types as predictors of European Hare local abundance in Neotropical agricultural landscapes. We hypothesized that spatial and temporal heterogeneity, rather than land cover types, would be the most influential predictors of hare local abundance in intensively managed Neotropical agricultural landscapes. We sampled 55 sites embedded within agricultural-dominated landscapes from southeastern Brazil with camera traps and transect surveys. Sites were selected along an uncorrelated gradient of native vegetation cover and compositional heterogeneity. We estimated the relative abundance of European hares using an occupancy model that accounts for imperfect detection of species induced primarily by variation in local abundance. We found that land cover diversity, sugarcane, and savanna cover were the best predictors of European Hare relative abundance. Hare relative abundance estimates were low and did not vary dramatically among sites, suggesting that this invader has not yet attained high local density in our study region. European Hare attained the highest relative abundance in agricultural landscapes that locally combine higher compositional heterogeneity, including sugarcane crops, and little to no native savanna. Areas with these combined features may represent the most important nascent foci, fostering ongoing northward spread of this invasive species in the Neotropics.
The invasive European Hare is more likely to attain higher local abundance in areas that combine diverse land cover types, including sugarcane but little native savanna. Abundance estimates were low and did not vary dramatically among sites, suggesting European Hare have not yet attained high density in southeastern Brazil. Monitoring hare densities in agricultural landscapes with diverse land covers, containing sugarcane and little native savanna coverage, is advisable.
Over the past few years, insects have been used as samplers of vertebrate diversity by assessing the ingested‐derived DNA (iDNA), and dung beetles have been shown to be a good mammal sampler given ...their broad feeding preference, wide distribution and easy sampling. Here, we tested and optimized the use of iDNA from dung beetles to assess the mammal community by evaluating if some biological and methodological aspects affect the use of dung beetles as mammal species samplers. We collected 403 dung beetles from 60 pitfall traps. iDNA from each dung beetle was sequenced by metabarcoding using two mini‐barcodes (12SrRNA and 16SrRNA). We assessed whether dung beetles with different traits related to feeding, nesting and body size differed in the number of mammal species found in their iDNA. We also tested differences among four killing solutions in preserving the iDNA and compared the effectiveness of each mini barcode to recover mammals. We identified a total of 50 mammal OTUs (operational taxonomic unit), including terrestrial and arboreal species from 10 different orders. We found that at least one mammal‐matching sequence was obtained from 70% of the dung beetle specimens. The number of mammal OTUs obtained did not vary with dung beetle traits as well as between the killing solutions. The 16SrRNA mini‐barcode recovered a higher number of mammal OTUs than 12SrRNA, although both sets were partly non‐overlapping. Thus, the complete mammal diversity may not be achieved by using only one of them. This study refines the methodology for routine assessment of tropical mammal communities via dung beetle ‘samplers’ and its universal applicability independently of the species traits of local beetle communities.
Typically, males of polygamous mammals are responsible for population connectivity and gene flow via dispersal, whereas females, showing stronger philopatry, strengthen local population stability and ...growth. These expectations can be disrupted by human disturbances; however, this possibility has been poorly examined in wide‐ranging mammals that are important targets for conservation.
By reviewing philopatry and dispersal in felids, we aimed to evaluate: 1) whether the sex‐related patterns of philopatry and dispersal predicted for polygamous mammals are prevalent in felids, 2) possible major causes underlying each of these behaviours, and 3) if, and to what extent, anthropogenic disturbances can alter patterns of philopatry and dispersal in this animal lineage.
We synthesised the available literature (n = 55 papers) comprising 12 species. Puma concolor was the most‐studied species, followed by other large species. Both philopatry and dispersal were heterogeneously defined, depending on the study aim and the method employed (telemetry, camera trapping or molecular tools).
Most species followed the predicted philopatric and dispersal patterns, and most study areas (76%) were under some type of anthropogenic disturbance drivers. Philopatry was linked to females’ higher dependency on the quality and availability of resources, and to their social dynamics, higher reproductive success, inclusive fitness and demographic aspects of population. Dispersal was frequently linked to competition for mates and resources, and inbreeding avoidance. However, some plasticity was observed in both philopatry and dispersal, especially under the presence of anthropogenic drivers. For example, hunting can create open territories, increasing the number of philopatric females and opportunistic philopatric males. Habitat fragmentation can increase population isolation and male dispersal distance, and the presence of anthropogenic or natural barriers can result in unsuccessful dispersal attempts.
We postulate that human activities affect long‐term population persistence in the Felidae, via disruption of sex‐related patterns of spatial dynamics.
RESUMO EM PORTUGUÊS
Machos de mamíferos poligâmicos, geralmente, são responsáveis pela conectividade e fluxo gênico das populações via dispersão, enquanto as fêmeas, apresentando maior filopatria, fortalecem a estabilidade e o crescimento da população local. Essas expectativas podem ser interrompidas por perturbações antrópicas; no entanto, essa possibilidade tem sido pouco examinada em mamíferos de grande porte, que são alvos importantes para a conservação.
Ao revisar filopatria e dispersão em felinos, pretendemos avaliar: 1) se os padrões esperados de filopatria e dispersão relacionados ao sexo em mamíferos poligâmicos são prevalentes em felinos, 2) as principais possíveis causas para cada um desses comportamentos, e 3) se, e em que medida, perturbações antropogênicas podem alterar os padrões de filopatria e dispersão neste grupo de animais.
Sintetizamos a literatura disponível (n = 55 artigos) compreendendo 12 espécies. Puma concolor foi a espécie mais estudada, seguida por outras espécies de grande porte. Tanto filopatria quanto dispersão são definidos de forma heterogênea, dependendo do objetivo do estudo e do método empregado (telemetria, armadilhamento fotográfico ou ferramentas moleculares).
A maioria das espécies apresentou os padrões de filopatria e de dispersão esperados e a maioria das áreas de estudo (76%) estava sob algum tipo de perturbação antropogênica. Filopatria foi relacionada a maior dependência das fêmeas com a qualidade e disponibilidade de recursos, dinâmica social, maior sucesso reprodutivo, aptidão inclusiva e aspectos demográficos da população. A dispersão foi frequentemente associada a competição por parceiros e recursos, e fuga da endogamia. No entanto, alguma plasticidade foi observada tanto na filopatria quanto na dispersão, especialmente na presença de fatores antropogênicos. Por exemplo, a caça pode criar territórios vagos, aumentando o número de fêmeas filopátricas e machos filopátricos oportunistas. A fragmentação do habitat pode aumentar o isolamento da população e a distância de dispersão dos machos, e a presença de barreiras antropogênicas ou naturais pode resultar em tentativas de dispersão malsucedidas.
Postulamos que as atividades humanas afetam a persistência a longo prazo das populações de felinos, por meio da interrupção dos padrões relacionados ao sexo de dinâmica espacial.
Patterns of sex‐related philopatry and dispersal expected for felid species (on the left) and possible consequences of human drivers on these behaviours (on the right). Males are predominantly dispersers, responsible for population connectivity and gene flow, whereas females show stronger philopatry (tendency to remain close to or within the natal home range) and promote local population stability and growth. However, some extent of female dispersal is also expected. Human drivers, such as urbanisation, fragmentation and hunting, can cause long‐term population consequences for these species, by altering male and female behaviour. Dispersal of both sexes can be reduced, because of population isolation caused by urbanisation (e.g. roads that act as barriers) and hunting (the removal of individuals that increases the number of vacant territories near the natal area). Conversely, fragmentation (increased distance between natural populations but without barriers) can increase the dispersal distance of individuals. Felids can adapt to some level of human habitat modification, but it is important that populations are connected by undisturbed areas to ensure long‐term population persistence.
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