Genotyping success of historical Eurasian lynx (Lynx lynx L.) samples

Historical samples, like tanned hides and trophy skulls, can be extremely important for genetic studies of endangered or elusive species. Selection of a sampling protocol that is likely to provide sufficient amount and quality of DNA with a minimum damage to the original specimen is often critical for a success of the study. We investigated microsatellite genotyping success of DNA isolated from three different types of Eurasian lynx historical samples. We analysed a total of 20 microsatellite loci in 106 historical samples from the endangered Dinaric lynx population, established from re-introduction of three pairs of lynx in 1973 from Slovakian Carpathians. Of the three tested sample types, turbinal bone and septum from the nasal cavity of the trophy skulls had the lowest percentage of samples successfully genotyped for all 20 microsatellite loci. Footpad samples, collected using a cork drill, exhibited better results in polymerase chain reaction amplification and genotyping than samples of footpad epidermis cut with a scalpel. We report simple and efficient sampling protocols, which could be widely applied for future studies utilizing historical samples.     

同胞侵犯对猞猁幼仔行为的影响

研究了非自由生活的4窝11只猞猁幼仔的玩耍行为、亲和及入侵关系的变化.观察到36-57日龄幼仔的同胞打斗行为,这些打斗减少了这些幼仔之间游戏性接触的频次.这个"打斗期"与游戏行为和食性的变化同步发生.打斗后,幼仔游戏性接触的非对称性以及同胞之间的偏爱更加清楚.这些打斗导致了不同窝的幼仔之间等级结构的建立.     

猞猁在云南省野外分布的首例影像记录

<正>猞猁(Lynx lynx Linnaeus, 1758)为食肉目(CARNIVORA)猫科(Felidae)猞猁属(Lynx)的中等体型哺乳动物,主要分布于欧洲、北亚、西亚及中亚地区(蒋志刚等,2015)。猞猁分布较广,数量多,为IUCN红色名录的无危物种(Least Concern, LC)(Breitenmoser et al., 2015)。亚洲地区的猞猁主要栖息在山地森林、无林裸岩地带、密集灌木丛和草原,分布海拔可达4 500 m (汪松,1998)。在中国,猞猁分布于东北、华北、西北和西南地区(高耀亭等,1987;王应祥,2003),野外种群数量较少,属于国家二级重点保护野生动物,     

Repetitive sequences in Eurasian lynx (Lynx lynx L.) mitochondrial DNA control region

Mitochondrial DNA (mtDNA) control region (CR) of numerous species is known to include up to five different repetitive sequences (RS1-RS5) that are found at various locations, involving motifs of different length and extensive length heteroplasmy. Two repetitive sequences (RS2 and RS3) on opposite sides of mtDNA central conserved region have been described in domestic cat (Felis catus) and some other felid species. However, the presence of repetitive sequence RS3 has not been detected in Eurasian lynx (Lynx lynx) yet. We analyzed mtDNA CR of 35 Eurasian lynx (L. lynx L.) samples to characterize repetitive sequences and to compare them with those found in other felid species. We confirmed the presence of 80 base pairs (bp) repetitive sequence (RS2) at the 5' end of the Eurasian lynx mtDNA CR L strand and for the first time we described RS3 repetitive sequence at its 3' end, consisting of an array of tandem repeats five to ten bp long. We found that felid species share similar RS3 repetitive pattern and fundamental repeat motif TACAC.     

Risk taking by Eurasian lynx (Lynx lynx) in a human-dominated landscape: effects of sex and reproductive status

This study aimed to test how the sex and reproductive status of Eurasian lynx influenced their use of 'attractive sinks'– habitats with high prey density and high mortality risks. Locations of 24 Eurasian lynx Lynx lynx were obtained by radio-telemetry in a mixed forest and agricultural habitat in south-eastern Norway. Roe deer, the major food source of lynx in the study area, occurred at higher densities closer to areas of human activity and infrastructure. Proximity of lynx locations to human activity and infrastructure was used as a risk index because the most common causes of death among Scandinavian lynx were of anthropogenic origin. This study shows that distances from lynx locations to human activity were significantly greater for females with newborn kittens than for males, but this decreased with kitten age. The data suggest that this response to human activity is influenced by the reproductive strategies of males and females, and might explain male-biased human-induced mortality in this study and in carnivores more generally.     

Long‐term changes in habitat selection and prey spectrum in a reintroduced Eurasian lynx (Lynx lynx) population in Switzerland

When wild‐caught Eurasian lynx (Lynx lynx) from the Slovak Carpathian Mountains were reintroduced to Central Switzerland in the early 1970s and spread through the north‐western Swiss Alps (NWA), they faced a largely unfamiliar landscape with strongly fragmented forests, high elevations, and intense human land use. For more than 30 years, radio‐collared lynx have been monitored during three different project periods (in the 1980s, 1990s, and 2010s). Our study explored, how lynx over generations have learned to adjust to the alpine environment. We predicted that (1) lynx nowadays select more strongly for open habitats, higher elevations, and steep slopes compared to the early stages of recolonization and that (2) consequently, there were significant changes in the Eurasian lynx’ prey spectrum. To test our predictions, we analyzed telemetry data (VHF, GPS) of 13 adult resident lynx in the NWA over 35 years, using Resource Selection Functions. Furthermore, we compared kills recorded from different individuals inhabiting the same region during three project periods. In general, lynx preferred forested areas, but over the years, they avoided open habitat less. Compared to the early stage of the recolonization, lynx in the most recent project period selected for higher elevations and the proportion of chamois in their prey spectrum surmounted that of roe deer. Potential driving factors for the observed changes could be increasing tolerance to human presence, intraspecific competition, or fitness benefits through exploitation of new resources. Long‐term studies like ours provide important insight into how animals can respond to sudden environmental changes, e.g., in the course of translocations into new areas or anthropogenic alterations of their habitats.     

Lynx (Lynx lynx) killing red foxes (Vulpes vulpes) in boreal Sweden – frequency and population effects

We studied the frequency and pattern of lynx Lynx lynx predation on red foxes Vulpes vulpes in boreal Sweden by the radio tracking of foxes and the snow tracking of lynx. We also assessed the population trend of red foxes after the re-establishment of lynx in the region, based on various population indices. Fifty per cent of recorded fox mortalities in the radio-tracking study (four of eight) were lynx kills. Adult-sized foxes killed by lynx during radio tracking were in normal condition and of prime age, and were killed after the assumed annual population bottleneck. Albeit based on a small number of kills, this pattern may suggest that lynx predation, at least to some extent, is additive to other mortality in foxes. The annual lynx predation rate was 14% on radio-tracked foxes and 4% on snow-tracked foxes. The population indices of foxes in the main study area decreased by about 10% annually during the study period. The population decrease could potentially be explained by lynx predation alone, but we acknowledge some alternative explanations. Our results point out the possibility that red fox populations can be significantly limited by allowing lynx populations to recover.     

Spatial density estimates of Eurasian lynx (Lynx lynx) in the French Jura and Vosges Mountains

Obtaining estimates of animal population density is a key step in providing sound conservation and management strategies for wildlife. For many large carnivores however, estimating density is difficult because these species are elusive and wide‐ranging. Here, we focus on providing the first density estimates of the Eurasian lynx (Lynx lynx) in the French Jura and Vosges mountains. We sampled a total of 413 camera trapping sites (with two cameras per site) between January 2011 and April 2016 in seven study areas across seven counties of the French Jura and Vosges mountains. We obtained 592 lynx detections over 19,035 trap days in the Jura mountains and 0 detection over 6,804 trap days in the Vosges mountains. Based on coat patterns, we identified a total number of 92 unique individuals from photographs, including 16 females, 13 males, and 63 individuals of unknown sex. Using spatial capture–recapture (SCR) models, we estimated abundance in the study areas between 5 (SE = 0.1) and 29 (0.2) lynx and density between 0.24 (SE = 0.02) and 0.91 (SE = 0.03) lynx per 100 km². We also provide a comparison with nonspatial density estimates and discuss the observed discrepancies. Our study is yet another example of the advantage of combining SCR methods and noninvasive sampling techniques to estimate density for elusive and wide‐ranging species, like large carnivores. While the estimated densities in the French Jura mountains are comparable to other lynx populations in Europe, the fact that we detected no lynx in the Vosges mountains is alarming. Connectivity should be encouraged between the French Jura mountains, the Vosges mountains, and the Palatinate Forest in Germany where a reintroduction program is currently ongoing. Our density estimates will help in setting a baseline conservation status for the lynx population in France.     

When carnivores collide: a review of studies exploring the competitive interactions between bobcats Lynx rufus and coyotes Canis latrans

1. Bobcats Lynx rufus and coyotes Canis latrans are two widespread mesopredators with a complex history of sympatry. The competitive interactions between these species are of interest to biologists due to the furbearer status of bobcats, the recent range expansion of coyotes, and the recolonisation of several parts of North America by bobcats following their extirpation. Although studies exploring the dynamics and competition between bobcats and coyotes span decades, there is a lack of understanding regarding what factors influence exploitative or interference competition, and what methodologies are conducive to identifying these types of competition.
2. We gathered a comprehensive list of research papers (n = 41) exploring bobcat–coyote competitive interactions in North America. From them, we collected the following: study site characteristics, number and types of research methods, number and types of metrics explored, history of sympatry of the two species at the study location, presence of apex predators, and documentation of interference and/or exploitative competition.
3. Using generalised linear models, we determined that interference competition between bobcats and coyotes was observed primarily in open habitat. However, habitat heterogeneity, the number of research methods and metrics used, presence of an apex predator, and history of sympatry could not be used to predict the occurrence of interference competition. Studies that included diet overlap were less likely to observe interference competition than studies that used other metrics to infer competition.
4. Competitive interactions between coyotes and bobcats are largely a function of prey availability. Our findings suggest that habitat type may be a surrogate for prey availability, which many researchers mention, but do not explicitly measure. Future studies investigating bobcat–coyote interactions should include the quantification of prey densities to gain a more comprehensive understanding of the system at large, and should avoid using solely diet or habitat overlap as metrics to assess competition.

     

Diet of Eurasian lynx, Lynx lynx, in the boreal forest of southeastern Norway: the relative importance of livestock and hares at low roe deer density

The year-round food habits of lynx were studied using radio-telemetry and snow-tracking in the boreal forest of southeastern Norway. The main objectives of the study were to clarify the importance of domestic sheep and small prey species in the diet of lynx in an area with a very low density of roe deer. During the period 1995–1999, we found 193 scats and 358 kills made by lynx. Our results indicate that roe deer were the most common prey species (contributing to 83 and 34% of the biomass consumed in winter and summer, respectively), although a wide range of other species were also found, including mountain hares, tetranoids, red foxes, domestic sheep, wild reindeer, and even moose. Most of the diet was obtained by predation, although we did document several cases of scavenging. Roe deer were more important in the diet in winter than in summer, perhaps because they were easier to locate in winter as they clustered around feeding sites. In summer, domestic sheep and small prey increased in importance. Despite the very low density of roe deer in this study area, lynx seemed to still specialise on them, although domestic sheep did constitute a significant amount to their diet, especially for males and yearlings. However, the contribution of sheep to summer diet was far from that expected if their relative density was considered.     

Description of Crenosoma vismani n. sp., parasitic in the lungs of Lynx lynx (L.) (Carnivora: Felidae), with identification key to the species of the genus Crenosoma Molin, 1861 (Nematoda: Crenosomatidae)

A new species of Crenosoma Molin, 1861 is described from the lungs of the Eurasian lynx, Lynx lynx (L.) (Carnivora: Felidae). Crenosoma vismani n. sp. differs from other species of the genus in the morphology of the male copulatory organs (two ventral rays originating from a common stem; three lateral rays with common stem; gubernaculum 79–92 μm long, well developed, spoon-shaped; spicules 232–253 μm long, slightly curved, with robust dorsal appendage) and a vulva with rounded, prominent vulvar cuticular appendage is located in middle region of body in females. An analysis of the morphology and life-cycle data for Crenosoma petrowi Morozov, 1939 from Ursus americanus Pallas indicate that this nematode should be described as a new species. The validity of Crenosoma schulzi Gagarin, 1958 is resurrected. A new identification key for the species of Crenosoma is provided. Published records of the genus Crenosoma from definitive hosts and patterns of host specificity are presented. Morphological data revealed that the genus Crenosoma should contain 15 species (14 with valid names) with different host specificity, ranging from oioxenous to euryxenous. However, a review of the current genetic data indicates that the actual number of Crenosoma spp. is greater, and the host range is still unknown, even in Europe.

     

The mechanistic basis for higher‐order interactions and non‐additivity in competitive communities

Motivated by both analytical tractability and empirical practicality, community ecologists have long treated the species pair as the fundamental unit of study. This notwithstanding, the challenge of understanding more complex systems has repeatedly generated interest in the role of so‐called higher‐order interactions (HOIs) imposed by species beyond the focal pair. Here we argue that HOIs – defined as non‐additive effects of density on per capita growth – are best interpreted as emergent properties of phenomenological models (e.g. Lotka–Volterra competition) rather than as distinct ‘ecological processes’ in their own right. Using simulations of consumer‐resource models, we explore the mechanisms and system properties that give rise to HOIs in observational data. We demonstrate that HOIs emerge under all but the most restrictive of assumptions, and that incorporating non‐additivity into phenomenological models improves the quantitative and qualitative accuracy of model predictions. Notably, we also observe that HOIs derive primarily from mechanisms and system properties that apply equally to single‐species or pairwise systems as they do to more diverse communities. Consequently, there exists a strong mandate for further recognition of non‐additive effects in both theoretical and empirical research.     

Effects of pH,humic substances and animal interactions on survival and physiological status of Asellus aquaticus L. and Gammarus pulex (L.)

Summary The mortality and physiological status (body water content) of Asellus aquaticus (Isopoda) and Gammarus pulex (Amphipoda) were measured after 25 days exposure in 20 natural streams with a pH range of 4.3–7.5 and a colour range of 8–280 mg Pt L^–1. In addition, the effects of keeping the animals as single species or together were studied. The response of Gammarus to low pH was an increased mortality and lower physiological status of surviving individuals in streams with a pH lower than 6.0. In Asellus the physiological status was correlated with pH, while the mortality was not pH dependent. The effects of humus on the physiological status of Asellus was significant when fitted to a second order polynomial function. The influence of humus can, however, be regarded as small relative to pH. The interactions between the species could be described as asymmetric under optimal conditions of high pH and low humus concentrations, where the presence of Gammarus decreased the survival and physiological status of Asellus. Acid stress did not seem to reverse the direction of this asymmetry, but the presence of Gammarus improved the physiological status of Asellus at pH lower than 6.0. Since the presence of Asellus did not increase the mortality or decrease the physiological status of Gammarus, this could be explained by Asellus feeding on Gammarus that died from physiological stress solely. This mechanism suggests that food quality, and thus effects of diffuse competition, can be important for the ability to withstand acid stress. The results, though, give no support for the hypothesis that competition from Asellus is important for the disappearance of Gammarus during the acidification of streams.