The grey hamster, Nothocricetulus migratorius, is among the most widely distributed cricetid rodents in the Palearctic, yet its evolutionary history across the Iranian Plateau—an important biogeographic link between western and central Asia—has remained poorly understood. Here, we present the first comprehensive phylogeographic assessment of the grey hamster across the Iranian plateau by integrating newly generated mitochondrial cytochrome b (cytb) sequences from the previously unsampled southern margin of its distribution with all publicly available genetic data. Bayesian phylogenetic analyses recovered four geographically structured mitochondrial lineages: Western, Eastern, Qurama and a previously unrecognized Southern lineage confined to the Hazaran Mountains of southern Iran. Divergence-time analyses estimated the TMRCA of N. migratorius at approximately 292 ka, while the three previously recognized lineages showed broadly contemporaneous lineage-specific TMRCA estimates of 141–179 ka. The node separating the Western and Southern lineages was dated to approximately 228 ka, whereas the sampled Southern haplotypes showed a much more recent TMRCA of approximately 14 ka, consistent with recent demographic isolation or contraction in the Hazaran Mountains. The Western and Eastern lineages show clear geographic association on the Iranian Plateau and likely reflect two independent colonization routes from western and central Asia, despite approaching one another in the Alborz Mountains without sharing mitochondrial haplotypes. The newly identified Southern lineage highlights the evolutionary importance of the central Iranian massifs and raises the possibility that these mountainous regions provided localized refugial habitats during Quaternary climatic oscillations. Our results reveal previously unrecognized evolutionary diversity at the southern periphery of the species’ range and support the Iranian Plateau as an important biogeographic crossroads where historical isolation, dispersal, and climatic change have shaped the diversification of Palearctic small mammals.
The use of different food resources is often associated with divergence in feeding morphology. Dietary composition may be shaped by local fauna and flora as well as by phylogenetic history. This study focused on the dietary composition of the large Japanese field mouse, Apodemus speciosus, on the Izu Islands to examine the relationships between diet, morphology, and evolutionary history. We employed DNA metabarcoding of faecal samples to target the mitochondrial and chloroplast gene regions. Within the island system, populations represent three combinations of morphotypes and phylogenetic positions: island morphotype–island phylogeny (Niijima, Shikine, and Miyake), island morphotype–mainland phylogeny (Oshima), and mainland morphotype–mainland phylogeny (Kozu). Dietary composition differed substantially between the mainland and Izu Island populations, suggesting that the colonisation of island environments is associated with a broad dietary shift. However, within the Izu Islands, dietary similarity did not correspond to the current morphotype. Despite their contrasting morphotypes, the Oshima and Kozu populations showed similar dietary compositions. As both populations belong to the mainland phylogenetic clade, their colonisation histories may partly explain their dietary similarities. These findings suggest that both island environments and phylogenetic history contribute to dietary differences in these species.
While dietary niche partitioning is considered the primary long-term mechanism preventing competition among sympatric carnivores, coexistence, particularly in fragmented landscapes, depends strongly on resource partitioning across spatial and temporal dimensions. In the highly threatened Atlantic Forest, understanding felid time partitioning is essential for elucidating mechanisms reducing intraguild interactions. We investigated temporal niche partitioning among jaguars (Panthera onca), pumas (Puma concolor), and ocelots (Leopardus pardalis) in Rio Doce State Park, a major Atlantic Forest remnant. Using a three-year camera-trap survey (6,618 trap-nights), we obtained 11,078 independent records of mammal species. We modeled daily activity patterns using non-parametric circular kernel-density functions and quantified temporal interactions among predators and between predators and their potential prey using coefficients of overlap. Jaguars and pumas exhibited flexible cathemeral activity with crepuscular peaks, whereas ocelots were strictly nocturnal. Temporal overlap among the three felids was moderate (Δ = 0.67–0.75), indicating temporal segregation consistent with reduced encounter probability between dominant and subordinate predators. Jaguars and ocelots showed no sex-specific differences in activity patterns; in contrast, pumas exhibited marked sexual segregation, with males primarily crepuscular and nocturnal and females extending activity into diurnal hours. Predator activity patterns closely tracked prey availability: jaguars and pumas showed high temporal overlap (Δ > 0.77) with large prey such as capybaras and brocket deer, whereas ocelots synchronized primarily with small mammals (opossums and rodents). Our results demonstrate that temporal partitioning, mediated by both interspecific interactions and prey activity, facilitates coexistence among sympatric felids. The diurnal activity of female pumas likely represents a strategy to reduce intraspecific risk, highlighting Neotropical felid behavioral plasticity and the importance of protected areas.
Neotropical otters Lontra annectens and Lontra longicaudis, including the subspecies L. l. longicaudis and L. l. enudris, are apex predators in freshwater ecosystems across the Neotropics; however, their populations are increasingly vulnerable to habitat fragmentation and anthropogenic disturbance. Understanding their genetic diversity and population structure is therefore important for conservation strategies. We investigated mitochondrial genetic diversity and population structure of Lontra annectens in the Peñas Blancas River Basin (PBRB), Costa Rica, using three mitochondrial markers (D-loop, ND5, and ATP8/ATP6) obtained non-invasively from fecal samples. Phylogenetic and haplotype-network analyses positioned Costa Rican haplotypes within the northern evolutionary lineage currently recognized as L. annectens, clustering with haplotypes from Mexico and Colombia. Population genetic analyses revealed no statistically significant mitochondrial differentiation among the Peñas Blancas, Burro, and Fortuna tributaries (FST = 0.067, P = 0.062), with most genetic variation occurring within tributaries. The Fortuna River had fewer haplotypes and polymorphic sites than the other tributary samples, although fewer samples were available from this river. Differences in mitochondrial diversity among tributaries, together with the basin’s hydrological configuration, suggest that the Peñas Blancas River may help maintain connectivity within the river network; however, this hypothesis requires confirmation using biparentally inherited molecular markers and ecological data. Overall, our findings suggest that the otter populations in this river network were historically connected, emphasizing the importance of conserving riparian corridors to prevent genetic isolation. This study provides the first mitochondrial assessment of genetic diversity, phylogenetic relationships, and population structure of Lontra annectens in the Peñas Blancas River Basin and establishes an important baseline for future non-invasive genetic monitoring and conservation planning in Costa Rica.
The European wildcat (Felis silvestris) has been widely persecuted in Western Europe until the end of the nineteenth century. During the past few decades, the populations of this species have extended their range in most West European countries. Because of the species’ elusiveness, the study of its populations is a difficult endeavour over the scale of a whole country. The present study assesses the biases and usefulness of national-scale citizen science data to estimate and predict the distribution of the European wildcat in France. The oldest observations (before 1980) seem to be biased as having been contributed by a small number of observers. Another potential bias identified here is the habitat where wildcats were observed which seems to be influenced by their accessibility to observers. Overall, after considering these biases, the analyses with the MaxEnt and MaxLike frameworks found that altitude, temperature seasonality, and broadleaved forest cover are significant predictors of the probabilities of wildcat presence in France. Herbaceous cover, needleleaved forest cover, and urban areas are the most important variables with a negative effect on those probabilities. These results confirm the importance of mosaic-structured habitats where wildcats are likely to find food and shelters. The maps of predicted probabilities of wildcat presence from these models are consistent with the map of recent observations. The results from the present study point to the importance of the Jura Mountains for conservation, as well as some perspectives to improve the impact of citizen science data.
