Boreal predator co‐occurrences reveal shared use of seismic lines in a working landscape

Interspecific interactions are an integral aspect of ecosystem functioning that may be disrupted in an increasingly anthropocentric world. Industrial landscape change creates a novel playing field on which these interactions take place, and a key question for wildlife managers is whether and how species are able to coexist in such working landscapes. Using camera traps deployed in northern Alberta, we surveyed boreal predators to determine whether interspecific interactions affected occurrences of black bears (Ursus americanus), coyotes (Canis latrans), and lynx (Lynx canadensis) within a landscape disturbed by networks of seismic lines (corridors cut for seismic exploration of oil and gas reserves). We tested hypotheses of species interactions across one spatial‐only and two spatiotemporal (daily and weekly) scales. Specifically, we hypothesized that (1) predators avoid competition with the apex predator, gray wolf (Canis lupus), (2) they avoid competition with each other as intraguild competitors, and (3) they overlap with their prey. All three predators overlapped with wolves on at least one scale, although models at the daily and weekly scale had substantial unexplained variance. None of the predators showed avoidance of intraguild competitors or overlap with prey. These results show patterns in predator space use that are consistent with both facilitative interactions or shared responses to unmeasured ecological cues. Our study provides insight into how predator species use the working boreal landscape in relation to each other, and highlights that predator management may indirectly influence multiple species through their interactions.     

Electrical activity in rat cortico-limbic structures after single or repeated administration of lipopolysaccharide or staphylococcal enterotoxin B

Immune-to-brain communication is essential for an individual to aptly respond to challenging internal and external environments. However, the specificity by which the central nervous system detects or 'senses' peripheral immune challenges is still poorly understood. In contrast to post-mortem c-Fos mapping, we recorded neural activity in vivo in two specific cortico-limbic regions relevant for processing visceral inputs and associating it with other sensory signalling, the amygdala (Am) and the insular cortex (IC). Adult rats were implanted with deep-brain monopolar electrodes and electrical activity was monitored unilaterally before and after administration of two different immunogens, the T-cell-independent antigen lipopolysaccharide (LPS) or the T-cell-dependent antigen staphylococcal enterotoxin B (SEB). In addition, the neural activity of the same individuals was analysed after single as well as repeated antigen administration, the latter inducing attenuation of the immune response. Body temperature and circulating cytokine levels confirmed the biological activity of the antigens and the success of immunization and desensitization protocols. More importantly, the present data demonstrate that neural activity of the Am and IC is not only specific for the type of immune challenge (LPS versus SEB) but seems to be also sensitive to the different immune state (naive versus desensitization). This indicates that the forebrain expresses specific patterns of electrical activity related to the type of peripheral immune activation as well as to the intensity of the stimulation, substantiating associative learning paradigms employing antigens as unconditioned stimuli. Overall, our data support the view of an intensive immune-to-brain communication, which may have evolved to achieve the complex energetic balance necessary for mounting effective immunity and improved individual adaptability by cognitive functions.     

Molecular signaling during taste aversion learning

Behavioral and neural assessment tools have been used to identify cellular and molecular events that occur during taste aversion acquisition. Studies described here include an assessment of taste information processing and taste-illness association using fos-like immunoreactivity (FLI) to mark populations of cells that react strongly to the taste conditioned stimulus (CS), the illness unconditioned stimulus (US), or the pairing of CS and US. Exposure to a novel, but not a familiar, CS taste (saccharin) was found to induce robust increases in FLI in some, but not all, brain regions previously implicated in taste processing or taste aversion learning. Striking effects of taste novelty on FLI were found in central amygdala (CNA) and insular cortex (IC) but not in basolateral amygdala (BLA), pontine parabrachial nucleus (PBN), or nucleus of the solitary tract (NTS). Of those regions responding to taste novelty, only CNA showed significant elevations in FLI in response to the US, LiCl. In additional studies, FLI was examined after an effective training experience, novel CS-US pairing, and compared with an ineffective one, familiar CS-US pairing. After CS-US pairing, taste novelty modulated FLI in virtually all the regions previously implicated in conditioned taste aversion (CTA) learning, including PBN, CNA, BLA, IC, as well as NTS. Thus, a distributed and interdependent neural CTA circuit is mapped using this method, and the use of localized lesion and inactivation studies promises to further define the functional role of structures within this circuit.     

Middle Paleolithic human remains from the Gruta da Oliveira (Torres Novas), Portugal

Ongoing excavations in the Middle Paleolithic levels at the Gruta da Oliveira, Portugal have yielded four fragmentary human remains, a manual phalanx and an ulna from levels 9 and 10, and a humerus and a tibia from levels 18 and 19. The first two remains date to approximately 39 ka 14C BP ( approximately 43.5 ka cal BP), whereas the latter two derive from earlier in oxygen isotope stage 3. The preserved portions of the phalanx, humerus, and tibia align them morphologically with the Neandertals. In addition, the Oliveira 4 tibial diaphysis shows evidence of carnivore (probably canid) gnawing.     

中国云豹种群分布现状与关键栖息地信息更新

云豹(Neofelis nebulosa)是中国大型猫科动物中对森林生态系统依赖性最高的物种。中国作为云豹的主要分布区, 由于长期以来缺乏深入研究和有效保护, 在盗猎、森林采伐、土地利用变化等威胁因素的共同作用下, 云豹在中国的分布范围和种群数量近数十年来均大幅缩减, 其分布现状亟需全面评估。本研究系统检索和查阅了国内1950年以来的云豹标本、野外调查记录、地方志、新闻报道等直接证据, 整理了中国各省级行政区内云豹记录存在的年代; 基于2010-2020年国内55个地区的红外相机监测数据, 结合同期研究文献中记录的中国云豹确认分布位点, 校准了已发表的云豹栖息地适合度模型, 并在此基础上叠加保护地和行政区划图层, 根据2010-2020年间森林覆盖率的减量评估云豹栖息地适合度的变化, 以识别我国的云豹关键栖息地和保护优先区。结果显示, 1950-2009年, 我国的云南、西藏、四川、陕西、甘肃、重庆、贵州、广西、广东、海南、湖北、湖南、安徽、江西、浙江、福建以及台湾共17个省级行政区有云豹分布, 但其中12个迄今已超过20年无确凿记录, 且目前仅在云南省和西藏自治区仍有云豹记录延续。当前我国大陆地区云豹潜在栖息地总面积64,093 km², 分别位于9个连续的栖息地斑块中, 其中3个为跨境斑块。2010-2020年间, 我国境内共在5个自然保护区的10个样区记录到云豹, 全部位于西藏东南部以及云南西部和南部的2个跨境栖息地斑块(即“喜马拉雅-横断山脉西侧-若开山脉”和“无量山南麓-安南山脉”)的边缘。2010-2020年间, 这两个斑块在中国境内区域的年均森林覆盖率减量(0.84%)小于境外(1.57%)。从本研究的结果推断, 中国目前确认分布的云豹种群极有可能维持在跨境分布的生境中, 面临内部和跨境的双重挑战。相关保护地应有针对性地加强反盗猎执法, 并开展栖息地恢复工作以提升云豹栖息地质量与斑块连通性, 同时与周边分布区国家开展跨境保护合作, 为现有云豹种群的长期生存和发展提供必要基础。     

Identification of land predators of African Penguins Spheniscus demersus through post-mortem examination

The African Penguin Spheniscus demersus is an endangered seabird endemic to southern Africa, and killing sprees by terrestrial predators have been one of the main threats for its mainland colonies. The methods employed to manage predators may differ depending on the species involved, therefore the implementation of strategies to limit the impacts of predation relies on the correct identification of the culprit predator. We report and quantify the lesions seen in African Penguins killed by four species of terrestrial predators: Caracal Caracal caracal (52 kills), Leopard Panthera pardus (27 kills), Domestic Dog Canis lupus familiaris (10 kills), and Cape Grey Mongoose Galerella pulverulenta (4 kills). We discuss patterns of necropsy findings that can be used to identify the predator species involved. Traditional forensic methods are useful tools to direct species-specific management actions for the conservation of the African Penguin and other seabirds so that effective mitigating measures can be deployed quickly to prevent further losses. It should be borne in mind, however, that the age, size and previous hunting experience of the predator are likely to influence the pattern of lesions that will be observed, and not all carcasses will have hallmark lesions or recognisable bite marks.     

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.     

Late Pleistocene human remains from Wezmeh Cave, western Iran

Paleontological analysis of remains from Wezmeh Cave in western Iran have yielded a Holocene Chalcolithic archeological assemblage, a rich Late Pleistocene carnivore faunal assemblage, and an isolated unerupted human maxillary premolar (P(3) or possibly P(4)). Species representation and U-series dating of faunal teeth place the carnivore assemblage during oxygen isotope stages (OIS) 3 and 2, and noninvasive gamma spectrometry dating of the human premolar places it at least as old as early OIS 2. The human premolar crown morphology is not diagnostic of late archaic versus early modern human affinities, but its buccolingual diameter places it at the upper limits of Late Pleistocene human P(3) and P(4) dimensions and separate from a terminal Pleistocene regional sample. Wezmeh Cave therefore provides additional Paleolithic human remains from the Zagros Mountains and further documents Late Pleistocene human association with otherwise carnivore-dominated cave assemblages.     

Predator-prey size relationships in an African large-mammal food web

1. Size relationships are central in structuring trophic linkages within food webs, leading to suggestions that the dietary niche of smaller carnivores is nested within that of larger species. However, past analyses have not taken into account the differing selection shown by carnivores for specific size ranges of prey, nor the extent to which the greater carcass mass of larger prey outweighs the greater numerical representation of smaller prey species in the predator diet. Furthermore, the top-down impact that predation has on prey abundance cannot be assessed simply in terms of the number of predator species involved. 2. Records of found carcasses and cause of death assembled over 46 years in the Kruger National Park, South Africa, corrected for under-recording of smaller species, enabled a definitive assessment of size relationships between large mammalian carnivores and their ungulate prey. Five carnivore species were considered, including lion (Panthera leo), leopard (Panthera pardus), cheetah (Acinonyx jubatus), African wild dog (Lycaon pictus) and spotted hyena (Crocuta crocuta), and 22 herbivore prey species larger than 10 kg in adult body mass. 3. These carnivores selectively favoured prey species approximately half to twice their mass, within a total prey size range from an order of magnitude below to an order of magnitude above the body mass of the predator. The three smallest carnivores, i.e. leopard, cheetah and wild dog, showed high similarity in prey species favoured. Despite overlap in prey size range, each carnivore showed a distinct dietary preference. 4. Almost all mortality was through the agency of a predator for ungulate species up to the size of a giraffe (800-1200 kg). Ungulates larger than twice the mass of the predator contributed substantially to the dietary intake of lions, despite the low proportional mortality inflicted by predation on these species. Only for megaherbivores substantially exceeding 1000 kg in adult body mass did predation become a negligible cause of mortality. 5. Hence, the relative size of predators and prey had a pervasive structuring influence on biomass fluxes within this large-mammal food web. Nevertheless, the large carnivore assemblage was dominated overwhelmingly by the largest predator, which contributed the major share of animals killed across a wide size range.