How does a tigress balance the opposing constraints of raising cubs?

Mammal Research - The persistence of wildlife populations largely depends on females successfully rearing young through the earliest, most vulnerable period. During this period, mothers must...     

Maternal genomic variability of the wild boar (Sus scrofa) reveals the uniqueness of East‐Caucasian and Central Italian populations

The phylogeography of the European wild boar was mainly determined by postglacial recolonization patterns from Mediterranean refugia after the last ice age. Here we present the first analysis of SNP polymorphism within the complete mtDNA genome of West Russian (n = 8), European (n = 64), and North African (n = 5) wild boar. Our analyses provided evidence of unique lineages in the East‐Caucasian (Dagestan) region and in Central Italy. A phylogenetic analysis revealed that these lineages are basal to the other European mtDNA sequences. We also show close connection between the Western Siberian and Eastern European populations. Also, the North African samples were clustered with the Iberian population. Phylogenetic trees and migration modeling revealed a high proximity of Dagestan sequences to those of Central Italy and suggested possible gene flow between Western Asia and Southern Europe which was not directly related to Northern and Central European lineages. Our results support the presence of old maternal lineages in two Southern glacial refugia (i.e., Caucasus and the Italian peninsula), as a legacy of an ancient wave of colonization of Southern Europe from an Eastern origin.     

Interspecific Relationships between the Amur Tiger (Panthera tigris altaica) and Brown (Ursus arctos) and Asiatic Black (Ursus thibetanus) Bears

Biology Bulletin - During the years 1992–2013, we studied the relationship between Amur tigers and brown and Asiatic black bears in the Sikhote-Alin Nature Reserve and surrounding areas in...     

Home ranges of brown bears on the Kamchatka peninsula and Sakhalin Island

Territorial activity was studied using satellite tracking of four brown bears (Ursus arctos) in Kamchatka in 2005–2006 and three brown bears on Sakhalin in 2011–2012. The size of annual home ranges was 6.09–27.58 km² for females and 153.12 km² for males. The size of the nuclear zone of the annual home ranges did not exceed 1.68 km². Seasonal home ranges were largest in August-September and smallest in May. The home ranges of two females in Kamchatka were significantly overlapped, the lesser degree of overlap was noted for two females on Sakhalin. The nature of the use of the study area by bears, essentially depends on the seasonal distribution of food, in particular salmon.     

Genomic patterns in the widespread Eurasian lynx shaped by Late Quaternary climatic fluctuations and anthropogenic impacts

Disentangling the contribution of long‐term evolutionary processes and recent anthropogenic impacts to current genetic patterns of wildlife species is key to assessing genetic risks and designing conservation strategies. Here, we used 80 whole nuclear genomes and 96 mitogenomes from populations of the Eurasian lynx covering a range of conservation statuses, climatic zones and subspecies across Eurasia to infer the demographic history, reconstruct genetic patterns, and discuss the influence of long‐term isolation and/or more recent human‐driven changes. Our results show that Eurasian lynx populations shared a common history until 100,000 years ago, when Asian and European populations started to diverge and both entered a period of continuous and widespread decline, with western populations, except Kirov, maintaining lower effective sizes than eastern populations. Population declines and increased isolation in more recent times probably drove the genetic differentiation between geographically and ecologically close westernmost European populations. By contrast, and despite the wide range of habitats covered, populations are quite homogeneous genetically across the Asian range, showing a pattern of isolation by distance and providing little genetic support for the several proposed subspecies. Mitogenomic and nuclear divergences and population declines starting during the Late Pleistocene can be mostly attributed to climatic fluctuations and early human influence, but the widespread and sustained decline since the Holocene is more probably the consequence of anthropogenic impacts which intensified in recent centuries, especially in western Europe. Genetic erosion in isolated European populations and lack of evidence for long‐term isolation argue for the restoration of lost population connectivity.     

The seasonal sensitivity of brown bear denning phenology in response to climatic variability

Background

For brown bears (Ursus arctos), hibernation is a critical part of the annual life cycle because energy savings during hibernation can be crucial for overwintering, and females give birth to cubs at that time. For hibernation to be a useful strategy, timing is critical. However, environmental conditions vary greatly, which might have a negative effect on the functionality of the evolved biological time-keeping. Here, we used a long-term dataset (69 years) on brown bear denning phenology recorded in 12 Russian protected areas and quantified the phenological responses to variation in temperature and snow depth. Previous studies analyzing the relationship between climate and denning behavior did not consider that the brown bear response to variation in climatic factors might vary through a period preceding den entry and exit. We hypothesized that there is a seasonal sensitivity pattern of bear denning phenology in response to variation in climatic conditions, such that the effect of climatic variability will be pronounced only when it occurs close to den exit and entry dates.

Results

We found that brown bears are most sensitive to climatic variations around the observed first den exit and last entry dates, such that an increase/decrease in temperature in the periods closer to the first den exit and last entry dates have a greater influence on the denning dates than in other periods.

Conclusions

Our study shows that climatic factors are modulating brown bear hibernation phenology and provide a further structuring of this modulation. The sensitivity of brown bears to changes in climatic factors during hibernation might affect their ability to cope with global climate change. Therefore, understanding these processes will be essential for informed management of biodiversity in a changing world.

     

Coat Polymorphism in Eurasian Lynx: Adaptation to Environment or Phylogeographic Legacy?

Journal of Mammalian Evolution - We studied the relationship between the variability and contemporary distribution of pelage phenotypes in one of most widely distributed felid species and an array...     

Fleas (Siphonaptera) of Carnivores (Mammalia,Carnivora) of the Russian Far East

Entomological Review - Ten flea species were collected in 2012–2017 from 6 species of carnivores in Primorsky Territory and Sakhalin Province of Russia. The most complete collections of fleas...     

Spatial variation in the density and vulnerability of preferred prey in the landscape shape patterns of Amur tiger habitat use

Theoretical and empirical research suggests that carnivore distributions are largely determined by prey availability. Availability depends not only on prey density but also on prey accessibility which is affected, in part, by the configuration of landscape attributes that make prey vulnerable to predation. Exactly how spatial variation in these processes shape patterns of carnivore habitat use at the home range scale remains poorly understood. We examined the influence of prey density (negative binomial resource selection function) and vulnerability (kill site resource selection function), mapped separately for each of three species of primary prey, on habitat use patterns within the home range for Amur tigers Panthera tigris altaica in Far East Russia over 20 winters. We developed spatially‐explicit mixed linear regression models to assess these patterns and found that models with parameters for specific primary prey were more robust than models with composite parameters for all primary prey species. This emphasizes the importance of evaluating predation dynamics at a species‐specific level. We also found that Amur tigers used habitat within the home range where red deer Cervus elaphus and wild boar Sus scrofa were dense. These two species were clearly preferred by tigers accounting for 72% (201 of the 278) of the tiger kills detected. The effect of red deer density however, was modulated by the vulnerability of red deer in the landscape. Amur tigers tended to establish their home ranges on habitat where red deer were most vulnerable to predation, but would use habitat where red deer were dense in the peripheral regions of their home ranges. This suggests that tigers may utilize two separate strategies for acquiring prey. As the configuration of resource patches within the home range influences carnivore survival and reproduction, our analysis has implications for tiger conservation that extend beyond our improved understanding of tiger‐prey ecology.     

Cranometric Variability in Brown Bears of the Russian Far East

Morphometric analysis of 282 skulls of the brown bear Ursus arctos from the Far Eastern part of the range was carried out. The presence of two morphological clusters for both males and females is shown. Samples from two clusters were compared with their geographical location and subspecies. It was found that one cluster or another had no specific reference to the particular region or subspecies of a particular cluster, only the superiority of one over the other in a cluster of different subspecies and regions was changed. A comparison with the spread of brown bear genetic lines in the Far East of Russia is made. It was noted that the precise distribution of a particular cluster to a specific genetic line of haplotypes was not found.