Predator densities and white-tailed deer fawn survival

Predation is the dominant source of mortality for white-tailed deer (Odocoileus virginianus) <6 months old throughout North America. Yet, few white-tailed deer fawn survival studies have occurred in areas with 4 predator species or have considered concurrent densities of deer and predator species. We monitored survival and cause-specific mortality from birth to 6 months for 100 neonatal fawns during 2013–2015 in the Upper Peninsula of Michigan, USA, while simultaneously estimating population densities of deer, American black bear (Ursus americanus), coyote (Canis latrans), bobcat (Lynx rufus), and gray wolf (Canis lupus). We estimated fawn predation risk in response to sex, birth mass, and date of birth. Six-month fawn survival pooled among years was 36%, and fawn mortality risk was not related to birth mass, date of birth, or sex. Estimated mean annual deer and predator densities were 334 fawns/100 km², 25.9 black bear/100 km², 23.8 coyotes/100 km², 3.8 bobcat/100 km², and 2.8 wolves/100 km². Despite lower estimated per-individual kill rates, coyotes and black bears were the leading sources of fawn mortality because they had greater densities relative to bobcats and wolves. Our results indicate that the presence of more predator species in a system is not entirely additive in its effect on fawn survival. © The Wildlife Society, 2019     

Using spotlight observations to predict resource selection and abundance for white-tailed deer

Spotlight surveys for white-tailed deer (Odocoileus virginianus) can yield large presence-only datasets applicable to a variety of resource selection modeling procedures. By understanding how populations distribute according to a given resource for a reference area, density and abundance can be predicted across new areas assuming the relationship between habitat quality (measured by an index of selection) and species distribution are equivalent. Habitat-based density estimators have been applied to wildlife species and are useful for addressing conservation and management concerns. Although achieving reliable population estimates is a primary goal for spotlighting studies, presence-only models have yet to be applied to spotlight data for estimating habitat selection and abundance for deer. From 2012 to 2017, we conducted spring spotlight surveys in each of 99 counties in Iowa, USA, and collected spatial locations for 20,149 groups of deer (n = 71,323 individuals). We used a resource selection function (RSF) based on deer locations to predict the relative probability of use for deer at the population level and to estimate statewide abundance. The number of deer observed statewide increased significantly with increasing RSF value for all years and the mean RSF value along survey transects explained 59% of the variability in county-level deer counts, indicating that a functional response between habitat quality and deer distribution existed at landscape scales. We applied our RSF to a habitat-based density estimator (extrapolation) and zero-inflated Poisson (ZIP) and negative binomial (ZINB) count models to predict statewide abundance from spotlight counts. Population estimates for 2012 were variable, indicating that atypical weather conditions may affect spotlight counts and population estimates in some years. For 2013–2017, we predicted a mean population of 439,129 (95% CI ∼ ± 55,926), 440,360 (∼ ± 43,676), and 465,959 (∼ ± 51,242) deer across years for extrapolation, ZIP, and ZINB models, respectively. Estimates from all models were not significantly different than estimates from an existing deer population accounting model in Iowa for 2013 and 2016, and differed by <76,000 deer for all models from 2013–2017. Extrapolation and ZIP models performed similarly and differed by <2,897 deer across all years, whereas ZINB models showed inconsistencies in model convergence and precision of estimates. Our results indicate that presence-only models are capable of producing reliable and precise estimates of resource selection and abundance for deer at broad landscape scales in Iowa and provide a tool for estimating deer abundance in a spatially explicit manner. © 2019 The Wildlife Society.     

Spatial distribution and landscape associations of large-antlered deer

For more than a century, the Boone and Crockett Club has kept records of harvest locations for 38 categories of North American big game, which includes measurement details and sizes of enduring characteristics (e.g., antlers, skulls, horns). All white-tailed deer (Odocoileus virginianus) entered in the Club records (i.e., record deer) have large antlers because the measurements must meet or exceed a minimum size to qualify for entry. We used the records from the Club to test the hypothesis that the spatial distribution in the harvest of record deer was related to the number of antlered deer harvested, variations in land productivity, soil mineral content, and attributes of land cover for 9 states in the midwestern United States. We used a Bayesian theoretical framework to develop a spatial model that examined the influence of explanatory variables on the number of record deer harvested in each county. In our study area, 3,658 record deer were harvested in 692 of the 856 counties (80.8%). More record deer were harvested in counties that had more high-contrast edges, less contiguous land cover, and greater variation in soil productivity. These results provide information for managers and hunters to better understand the spatial distribution of record deer and factors that are correlated with their distribution. © 2019 The Wildlife Society.     

獐在吉林省的重新发现

獐(Hydropotes inermis)在历史上曾广泛分布于中国的辽东半岛、华北平原及长江两岸,在1949年以后的多篇文献中没有发现对吉林省獐分布的记载。2017年12月至2018年3月,利用红外相机于吉林省白山市(原浑江市)白山原麝国家级自然保护区拍摄到獐有效照片21张,有效视频时长总计600 s。在后续的野外调查中,研究者现场拍摄到獐幼崽活体及大量獐的活动痕迹,确认獐在吉林省重新发现。     

应用流式细胞术分析林麝外周血 CD4+、CD8+ T淋巴细胞

通过对圈养林麝(Moschusberezovskii)外周血淋巴细胞CD4~+、CD8~+亚群的检测,探讨林麝细胞免疫功能状态,并探索应用流式细胞仪分析其淋巴细胞亚群的方法,为研究林麝重大疾病的病理机制及诊断方法提供科学依据。本研究选取健康林麝和患呼吸道疾病林麝各5头,以双色流式细胞术检测其外周血淋巴细胞CD4~+、CD8~+亚群的含量,并进行比较。结果显示,羊源CD4、CD8的流式荧光抗体能够标记林麝细胞并有效检测;患病林麝与健康林麝相比,外周血CD4~+细胞含量无差异(P 0.05),CD8~+细胞含量则显著降低(P 0.01),CD4~+/CD8~+比值显著增高(P 0.01)。结果表明,患呼吸系统炎性疾病的林麝其外周血淋巴细胞CD8~+亚群变化显著,检测淋巴细胞亚群对林麝疾病的诊断有重要意义。     

Daily rhythm and seasonal pattern of lick use in sika deer (Cervus nippon) in China

Many ungulates are reported to use natural or artificial licks with seasonal patterns around the world. From December 2016 to August 2017, we used infrared camera to record the use of artificial licks in wild sika deer (Cervus nippon) in Zhejiang Qingliangfeng National Nature Reserve, China. We explored the daily rhythm, seasonal pattern and sex difference in lick utilization. In total, 12,043 videos and 22,901 pictures were collected. Our results showed that: (1) the lick visiting frequency was higher at night than that during daytime; (2) the difference in lick visiting frequency between females and males disappeared after taking into account of sex ratio; (3) the lick duration peaked in April during a year. These findings suggested that there were clear daily rhythm and seasonal pattern of lick use in sika deer. Seasonal change in lick use intensity was consistent with our prediction. These variations in lick use might be driven by both the physiological needs of the mineral elements in different life stages and the seasonal changes in climate and food. The reserve management authority should pay more attention to the supplement of licks in spring and summer to fulfill animal’s physiological needs.     

林麝源蜡样芽孢杆菌SCBCM001株的分离鉴定及全基因组序列分析

【背景】细菌性疾病是林麝规模化养殖的重要制约因素,蜡样芽孢杆菌曾在林麝化脓灶中检出,但是目前对林麝源蜡样芽孢杆菌的研究报道很少。【目的】对分离自病死林麝肝脏中的一株疑似蜡样芽孢杆菌进行分离鉴定和全基因组序列分析,为林麝相关疾病的防治奠定基础。【方法】将病原菌纯化培养后,对病原菌进行生化试验、药敏试验和小鼠致病性试验;并通过第3代单分子测序技术进行全基因组测序,根据测序结果进一步评估物种间的亲缘关系,并进行基因功能注释和遗传进化分析。【结果】该病原菌经平均核苷酸相似度分类和系统发育树分析属于蜡样芽孢杆菌群,生化结果符合蜡样芽孢杆菌的一般特征,将分离菌株命名为SCBCM001。该菌株对小鼠的半数致死量为8.3×107 CFU,对大多数β-内酰胺类、四环素和磺胺异噁唑耐药,对氨基糖苷类、头孢氨苄、头孢哌酮和亚胺培南等药物敏感;全基因组测序结果表明该菌株的染色体大小为5292570bp,GC含量为35.37%,多位点序列分型显示该菌株属于ST427序列类型。在菌株SCBCM001基因组内发现hblA、hblC、hblD、nheA、nheB、clo和cytK等多种毒力因子,同时菌株携带对β-内酰...     

Understanding the role of wild ruminants in anthelmintic resistance in livestock

Wild ruminants are susceptible to infection from generalist helminth species, which can also infect domestic ruminants. A better understanding is required of the conditions under which wild ruminants can act as a source of helminths (including anthelmintic-resistant genotypes) for domestic ruminants, and vice versa, with the added possibility that wildlife could act as refugia for drug-susceptible genotypes and hence buffer the spread and development of resistance. Helminth infections cause significant productivity losses in domestic ruminants and a growing resistance to all classes of anthelmintic drug escalates concerns around helminth infection in the livestock industry. Previous research demonstrates that drug-resistant strains of the pathogenic nematode Haemonchus contortus can be transmitted between wild and domestic ruminants, and that gastro-intestinal nematode infections are more intense in wild ruminants within areas of high livestock density. In this article, the factors likely to influence the role of wild ruminants in helminth infections and anthelmintic resistance in livestock are considered, including host population movement across heterogeneous landscapes, and the effects of climate and environment on parasite dynamics. Methods of predicting and validating suspected drivers of helminth transmission in this context are considered based on advances in predictive modelling and molecular tools.     

Parasitism of the deer ked,Lipoptena cervi,on the moose,Alces alces,in eastern Finland

The deer ked, Lipoptena cervi L. (Diptera: Hippoboscidae), is an ectoparasitic fly that spread to Finland in the early 1960s from the southeast across the Soviet border. It is currently a common parasite of the moose, Alces alces (Artiodactyla: Cervidae), in the southern part of the country and its area of distribution is gradually spreading to Finnish Lapland, where it will come into contact with another potential cervid host, the semi‐domesticated reindeer, Rangifer tarandus tarandus. The aim of this study was to determine the intensity of deer ked parasitism on the moose in eastern Finland. Whole skins of 23 moose were examined for the presence of deer keds, which were extracted and their total numbers estimated. The intensity of deer ked parasitism was correlated to the age, sex, skin area and anatomical region of the host. Bulls had the highest total number of keds (10616 ± 1375) and the highest deer ked density (35.7 ± 4.4 keds/dm² of skin). Cows had a higher total number of keds than calves (3549 ± 587 vs. 1730 ± 191), but ked densities on cows and calves were roughly equal (11.8 ± 1.7 vs. 9.4 ± 1.1 keds/dm² of skin). The density of keds was highest on the anterior back, followed by the posterior back, front limbs, abdomen, head and hind limbs. The sex ratio of deer keds was close to equal (male : female, 1.0 : 1.1). After they had consumed blood, male keds were heavier than females. As the total numbers and densities of deer keds were higher than reported previously on moose or for any other louse fly species, the effects of parasitism on the health of the host species should be determined.