Late Pleistocene climate changes have deeply impacted the range dynamics of temperate species. While the genetic legacy of these dynamics has been widely investigated, little is known about their phenotypic consequences. Anti-predatory strategies offer intriguing opportunities to study phenotypic evolution in response to dispersal dynamics since the ability to avoid predation can be pivotal for populations colonising new environments. Here we investigated the spatial differentiation of background colour matching strategies along a Late Pleistocene range expansion route of a temperate species, the Tyrrhenian tree frog Hyla sarda. Using common-garden experiments, we tested whether individuals from the source area (Sardinia) and individuals from the newly founded area (Corsica) differ in two components of the camouflage strategy: colour change abilities and background choice behaviour. We found a remarkable spatial structure in both colour change abilities and background choice behaviour, across the expansion range. Tree frogs from the source area displayed higher colour change abilities and a more pronounced preference for a greener background, with respect to tree frogs from the newly colonised area. Our results support the intriguing hypothesis that Late Pleistocene biogeographic history might be an overlooked major player in shaping current spatial patterns of phenotypic traits variation across animal populations. 

Spatial differentiation of background matching strategies along a Late Pleistocene range expansion route

Korean Leopard Cat (Prionailurus bengalensis) population with low genetic diversity is distinct from Southeast Asian populations

Abstract Variation in coat colour within mammal species is of enduring interest, likely because of its potential to be either adaptive or maladaptive. Coat colour in the genus Lynx tends to be stable, with little variation within species compared to that of other felids. Canada lynx (Lynx canadensis) have coats that typically are silver grayish in winter and reddish brown in summer with dark spots, and black hairs on the tips of their tails and ears. A rare pallid colourmorph is occasionally observed, suggestive of partial albinism. Here, I report the first record of a melanistic Canada lynx. The individual was photographed during summer in the Yukon (Canada). It had a black coat containing whitish gray guard hairs throughout, as well as whitish gray hairs in the facial ruff and the rostrum and dorsal regions. There are only a small number of records of coat colour polymorphisms in the genus Lynx. The adaptive significance of melanism in lynx is unknown, but the loss of camouflage when hunting during winter is likely maladaptive.

https://www.degruyter.com/document/doi/10.1515/mammalia-2022-0025/pdf

Paint it black: first record of melanism in Canada lynx (Lynx canadensis)

Predation on ungulates exposes large predators to conflicts with farmers and hunters if they kill livestock and shared game species. Therefore, it is crucial to know the drivers of predation on large prey, understand how they differ from predation on smaller prey and reveal general large-scale patterns. We tested three hypotheses in the global Eurasian lynx Lynx lynx population: 1) consumption of ungulates and hares increases with their densities, 2) effects of predictors on ungulate and hare predation differ between continents, latitudes, longitudes and landscapes, 3) effects of predictors are generally applicable regardless of study materials (scats, carcasses and intestinal tracts). We collected information from 70 publications, including data from 174 study cases (107 from Europe and 67 from Asia) and 114 sites in 30 countries, mainly Russia (73 cases and 46 sites). Linear regression of logit-transformed data and logistic regression were used to test the hypotheses. We found that ungulates made up more than half of the lynx diet in areas containing at least 570 individual ungulates/100 km2 and/or located south of 56°N. Predominance of ungulates in the diet could be related to the higher availability of the main medium-sized ungulate prey species, and to the presence of (mixed) broadleaf deciduous forests with open spaces providing optimal hunting conditions. No significant effects on hare consumption by lynx were revealed, possibly because of a small sample size of hare density data from lynx habitats, fluctuations and instability of hares as a food resource, declines of some hare populations and separation in habitat use by lynx and hares. We conclude that the Eurasian lynx is an adaptable predator, not a lagomorph specialist; throughout its range, the lynx takes ungulates according to their availability. The use of practical nonlethal interventions is important to limit the availability of domestic ungulates (livestock and game) for predation by lynx, and to promote human-lynx coexistence. 

Patterns of predation by the Eurasian lynx
 Lynx lynx
 throughout its range: ecological and conservation implications

We studied the relationship between the variability and contemporary distribution of pelage phenotypes in one of most widely distributed felid species and an array of environmental and demographic conditions. We collected 672 photographic georeferenced records of the Eurasian lynx throughout Eurasia. We assigned each lynx coat to one of five phenotypes. Then we fitted the coat patterns to different environmental and anthropogenic variables, as well as the effective geographic distances from inferred glacial refugia. A majority of lynx were either of the large spotted (41.5%) or unspotted (uniform, 36.2%) phenotype. The remaining patterns (rosettes, small spots and pseudo-rosettes) were represented in 11.0%, 7.4%, and 3.9% of samples, respectively. Although various environmental variables greatly affected lynx distribution and habitat suitability, it was the effect of least-cost distances from locations of the inferred refugia during the Last Glacial Maximum that explained the distribution of lynx coat patterns the best. Whereas the occurrence of lynx phenotypes with large spots was explained by the proximity to refugia located in the Caucasus/Middle East, the uniform phenotype was associated with refugia in the Far East and Central Asia. Despite the widely accepted hypothesis of adaptive functionality of coat patterns in mammals and exceptionally high phenotypic polymorphism in Eurasian lynx, we did not find well-defined signs of habitat matching in the coat pattern of this species. Instead, we showed how the global patterns of morphological variability in this large mammal and its environmental adaptations may have been shaped by past climatic change.

Alim B. Pkhitikov

Papers

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