Effects of social and climatic factors on birth sex ratio in Macaca mulatta in Mount Taihangshan area

Sex allocation theory predicts the optimal investment to male and female offspring. However, a biased sex ratio requires explanations as to why the deviation occurs. Rhesus macaque (Macaca mulatta) is the most widely distributed nonhuman primate species and the Taihangshan macaque (Macaca mulatta tcheliensis) occupies the northern limit of all rhesus macaque natural populations worldwide. We observed one macaque troop (Wangwu‐1 [WW‐1]) inhabiting Taihangshan Macaque National Nature Reserve and recorded all birth events and the sex of newborn macaques from 2004 to 2013. Our aim was to apply the Trivers–Willard hypothesis to this free‐ranging rhesus macaque troop, and to understand the relationship between climatic parameters (precipitation and temperature) and birth sex ratio. We found that the total newborn macaques showed a female‐biased sex ratio at birth in the WW‐1 troop, but there were no significant biased birth sex ratios in all matriarchs and in high‐ranking and middle‐ranking matrilineal units. However, the low‐ranking macaque matrilineal unit was significantly female‐biased. Moreover, we found that the annual precipitation of the previous year was positively associated with the birth sex ratio, and there was an interactive effect of troop size and current winter temperature on the birth sex ratio. The underlying mechanisms for the effects of social and climatic factors on birth sex ratio could be complex, and we discuss several plausible explanations.     

Opposing offspring sex ratio variations with increasing age and weight in mouflon mothers (Ovis musimon).

There are two main theories explaining offspring sex biases in polygynous mammals. Trivers and Willard (1973) argue that mothers with greater reproductive resources should invest in the sex with the greater variance in reproductive success, usually sons. In contrast, because daughters in many polygynous mammals stay with their mother and compete with her for food, Local Resource Competition theory (e.g. Clark, 1978; Silk, 1983) predicts that the mothers with the greatest reproductive resources should invest in daughters. We investigated the strategy of sex allocation of a captive, outdoor population of 139 mouflon mothers, Ovis musimon, kept in a game state. A complex picture emerged in which, despite weight and body condition being correlated with age in female mouflons, mothers lambed more daughters with increasing age but also, within a given age, gave birth to more sons with increasing weight. Results may be useful in game management aimed at increasing the recruitment or quality of males in managed populations.     

Competitor densities,habitat, and weather: effects on interspecific interactions between wild deer species

There is a growing interest on the potential interplay between weather, habitat, and interspecific competition on population dynamics of wild herbivores. Favorable environmental conditions may buffer the negative effects of competition; conversely, competition may be expected to be stronger under harsh environmental conditions. We investigated relationships between competitor abundance, weather, and habitat cover on density and local distribution of a medium-sized herbivore, the roe deer Capreolus capreolus, as well as its spatial overlap with fallow deer Dama dama in a Mediterranean protected area. Over 11 years (2007–2017), roe deer density was not affected by spring–summer rainfall in the previous year and decreased with increasing density of fallow deer in the previous year. Hence, over the considered temporal scale, results supported a major role of competition over weather in influencing population trends of roe deer. At a finer spatial scale, roe deer occupancy was negatively affected by local abundance of fallow deer, especially in “poorer” habitats. We found a slight support for a positive effect of fallow deer density on interspecific spatial overlap. Moreover, fine-scale spatial overlap between deer species increased with decreasing rainfall in spring–summer. Fallow deer were introduced to our study area in historical times and their role as superior competitors over roe deer has been found also in other study areas. We suggest a potential role of harsh weather conditions during the growing season of vegetation (i.e. scarce rainfall) in triggering the potential for ecological overlap, emphasizing the negative effects of interspecific competition.     

Prevalence of Toxoplasma gondii antibodies in wild red deer, roe deer, moose, and reindeer from Norway

Serum samples from 4339 wild cervids collected in Norway were tested for antibodies against Toxoplasma gondii using the direct agglutination test. The association between seroprevalence and species, sex, age, and geographic region was investigated. Positive titers (> or =1:40) were found in 33.9% of 760 roe deer (Capreolus capreolus); 12.6% of 2142 moose (Alces alces); 7.7% of 571 red deer (Cervus elaphus); and 1.0% of 866 reindeer (Rangifer tarandus). The seroprevalences were significantly different between the species. There was a significant increase in prevalence with age in roe deer, moose, and red deer, except from yearling to adult in red deer. A significant age-sex interaction was found in moose, and the effect of age was most distinct for females. No association between seropositive animals and sex was found for roe deer and red deer. There were significant differences in prevalence between geographic regions in roe deer and male moose. A widespread exposure to T. gondii in Norwegian cervids is documented, and meat from Norwegian cervids, particularly roe deer, should be regarded a potential source of infection for humans.     

Prevalence of antibodies against Toxoplasma gondii in roe deer from Spain

Roe deer (Capreolus capreolus) is an important game animal in Spain. Sera from 278 roe deer from eight areas in mainland Spain were assayed for antibodies to Toxoplasma gondii by modified agglutination test (MAT). Titers of 1:25 or higher were found in 109 (39.2%) of 278 deer. No significant differences in antibody prevalence were found between sex or age categories. In contrast, significant differences in seroprevalence between locations were evident. Roe deer from the Northern coastal habitats (high humidity and roe deer density) had the highest prevalence, compared with low prevalence in Central Spain (arid areas and low roe deer density). There was a positive correlation between antibody prevalence and mean annual rainfall (r(s)=0.85, n=8, P<0.01). These findings have environmental and/or public health implications because venison can be an important meat source of T. gondii infections for humans and feral cats.     

Description of post‐implantation embryonic stages in European roe deer (Capreolus capreolus) after embryonic diapause

The embryonic stage of development is defined as the period between fertilization and the establishment of most of the organ systems by the end of this period. Development in this stage is rapid. In many mammalian species, particularly in humans, the interval between fertilization and implantation is exactly determined and continuous without intermission. However, European roe deer (Capreolus capreolus) embryos undergo a reversible retardation of development. This interesting reproduction strategy is called embryonic diapause (delayed implantation). After this period of embryonic arrest, development continues without further interruption. The aim of this study was to investigate embryonic development after diapause in European roe deer. Because of the embryonic diapause and the unknown date of fertilization, it was impossible to assign the embryos to a certain gestational age (days). This study describes normal stages of embryonic development mainly based on the external morphological traits of 56 well‐preserved post‐implantation roe deer embryos and attempts to assign the embryos to certain development stages. Carnegie stages of human embryos were used as an orientation for staging roe deer embryos. We observed a considerable range of variation of embryonic stages investigated until the end of January. We found post‐implantation stages of embryonic development already at the end of December and foetuses at the end of January. Moreover, assigning the embryos to a particular stage of development allows the comparison between pairs of twins and triplets. We showed that twins and triplets were always at the same development level, despite the discrepancy in inter‐twin and inter‐triplet size.     

Geographic segregation and evidence of density‐dependent changes in sex ratios in an abundant colonial waterbird

Demographic information, such as geographic segregation of sexes and sex ratio data, is needed to develop, model and evaluate conservation and management strategies for wildlife. A variety of physiological, behavioral and environmental factors can influence segregation of sexes and sex ratios, many of which originate with density‐dependent processes. Departure from 50:50 sex ratios of double‐crested cormorants (Phalacrocorax auritus) collected during control efforts in breeding and wintering areas across their eastern range of the USA were evaluated using using a Z‐test as well as Stouffer's weighted Z‐tests. In addition, a specifically‐designed randomization test was used to evaluate density‐dependent effects on primary sex ratios in cormorants from egg collections and colony nest count data over a 21‐year period. Cormorants collected from breeding colonies were strongly male‐biased, whereas cormorants collected from feeding flocks were slightly biased toward females. Cormorants were partly segregated by sex on the wintering grounds, with significantly more males found in areas with intensive channel catfish aquaculture. The null hypothesis that females produced a balanced sex ratio independent of number of nesting cormorants was rejected: more male embryos were produced during rapid population growth, whereas at maximum nesting number more female embryos were produced. Once populations stabilized, the sex ratio was more equal. This examination of sex ratios indicates that different management methods and locations result in sex‐biased culling of cormorants. Sex‐biased culling in cormorants could make population reduction efforts more efficient and reduce overall take. We suggest further research to examine density‐dependent effects on primary sex ratios documented here.     

两性异型红隼的子代性比研究

Fisher经典的性比分配理论预测:如果双亲繁殖雄性和雌性子代的代价相同,那么子代的性比应趋于平衡.然而,性比组成是长期进化的结果,常因不同因素的影响而出现偏离.文献报道猛禽由于存在不同形式的两性异型现象而导致子代性比常出现偏离,但子代性比偏离方向因种而异.本研究中我们对红隼(Falco tinnunculus)子代的性比组成进行了调查,目的是检验红隼子代性比是否受产卵日期、产卵顺序、卵重、出雏顺序或窝卵数影响.在窝水平上,红隼(雄性)的初级性比为47.0%,没有偏离0.5,但次级性比为40.8%,显著偏离0.5(p=0.029).在种群水平上,初级性比和次级性比都没有出现偏离.窝卵数和卵重影响红隼的次级性比组成,窝卵数越大,雄性后代数量越多,且发育为雄性后代的卵重较发育为雌性后代的重.初级性比和次级性比都受到产卵日期的影响,产卵越早,雄性后代比例越高.     

Prevalence of Cryptosporidium and Giardia in roe deer (Capreolus capreolus) and wild boars (Sus scrofa) in Galicia (NW, Spain)

Faecal samples from 224 roe deer (Capreolus capreolus) and 381 wild boars (Sus scrofa) shot during the 2008-2009 hunting season (August-January) in Galicia (NW Spain) were examined to determine the presence and intensity of infection by Cryptosporidium and Giardia. Analysis of a single sample from each of the roe deer revealed that the prevalence of cryptosporidiosis and giardiosis was 1.3% and 5.3% respectively. The prevalence of Giardia infection was significantly higher in juvenile female roe deer than in adult females, but no other significant differences were found in relation to age and sex. In wild boars, the prevalence of cryptosporidiosis and giardiosis was 7.6% and 1.3% respectively. The prevalence of Cryptosporidium infection was significantly higher in juvenile male wild boars than in adult males, but no other significant differences were found in relation to age or sex. In both groups of wild animals, the number of Cryptosporidium oocysts per gram of faeces (OPG) ranged from 5 to 200 and the number of Giardia cysts per gram of faeces (CPG) was between 5 and 47; there were no significant differences between the two groups with respect to number of infections. This is the first large study of Cryptosporidium and Giardia in roe deer and wild boars in hunting areas in Spain and the results demonstrate a low, but widespread prevalence of Cryptosporidium and Giardia in these animals.     

Prevalence of antibodies against Toxoplasma gondii and Neospora caninum in moose (Alces alces) and roe deer (Capreolus capreolus) in Sweden

Toxoplasma gondii and Neospora caninum are two coccidian parasites with a worldwide distribution. T. gondii is one of the more common parasitic zoonoses in the world and in young children and immunocompromised persons, infection can lead to severe disease and death. N. caninum is an important cause of abortions in cattle. Wildlife have been identified as reservoirs and transmitters for both parasites. The purpose of this study was to investigate the seroprevalences of T. gondii, and N. caninum in moose (Alces alces), and roe deer (Capreolus capreolus) in Sweden. Blood samples were collected from 417 moose during 2000-2005 and from 199 roe deer during 1990-2007. The samples were investigated for presence of antibodies by a T. gondii direct agglutination test and a N. caninum iscom ELISA. Because the iscom ELISA has not been validated for moose or roe deer, sera that gave a positive result were further investigated by immunoblot analysis to verify presence of antibodies. Antibodies to T. gondii were detected in 85 (20%) and 68 (34%) moose and roe deer sera, respectively. In moose the seroprevalence was higher in south and central Sweden than in the north, whereas there was no difference between the regions for roe deer. Adult moose and roe deer had higher odds of being seropositive than young animals but there were no difference in seroprevalence between males and females. One roe deer was positive by immunoblotting and was regarded as N. caninum positive, whereas all moose sera were negative. The results show that T. gondii infection is widely spread in the Swedish moose and roe deer populations. Precautions should therefore be taken when handling internal organs and carcasses of harvested cervids. Proper handling and cooking of game meat also is important to prevent toxoplasmosis in humans.     

Pneumocystis carinii Delano? & Delano?, 1912 found in lungs of freeliving animals in Denmark at autopsy

Stained imprints made from autopsy lung biopsies from hares, foxes, badgers, stone martens, one hedgehog, roe deer from Denmark and from caribou from Greenland were examined microscopically for Pneumocystis carinii. Pneumocysts were found in the lungs of 3 out of 28 hares, 3 out of 18 foxes and 1 out of 6 roe deer. This is the first report of Pneumocystis carinii in hares, foxes, and roe deer in Denmark. It seems to be the first report of Pneumocystis carinii in roe deer.     

Prevalence of Cryptosporidium and Giardia in free-ranging wild cervids in Norway

Faecal samples were collected from 1,190 wild cervids in Norway and analyzed for cysts/oocysts of the protozoan parasites Giardia and Cryptosporidium. Samples were from calves, yearlings and adults of moose (Alces alces), red deer (Cervus elaphus), roe deer (Capreolus capreolus) and reindeer (Rangifer tarandus) shot during the hunting season. Cryptosporidium was found in 15 (3.3%) of 455 moose, 1 (0.3%) of 289 red deer, 18 (6.2%) of 291 roe deer, but was not found in any of 155 reindeer. Giardia was found in 56 (12.3%) moose, 5 (1.7%) red deer, 45 (15.5%) roe deer and 11 (7.1%) reindeer. The calves had the highest prevalence of infection, but this was only statistically significant for Giardia in moose and for Cryptosporidium and Giardia in roe deer. Calves generally had the highest intensity of infection, but this difference was only statistically significant for calves with Giarda and the highest intensity of infection. Both Giardia and Cryptosporidium were found in samples from several geographical areas, indicating that these parasites are distributed among the cervid population in all parts of Norway, especially in moose and roe deer. This is the first published report of Cryptosporidium in moose and of Giardia in reindeer.     

Seroprevalence of Toxoplasma gondii in wild boar and deer in Brandenburg,Germany

Consumption of game in Germany has increased during the past 10 years. Wild boar (Sus scrofa), roe deer (Capreolus capreolus) and red deer (Cervus elaphus) are the most frequently hunted and consumed game animals in Germany, yet information on the occurrence of zoonotic pathogens in these animal species is scarce. To better estimate the public health risk emanating from handling and consumption of game, this study investigated seroprevalences of Toxoplasma gondii in game hunted in the German federal state of Brandenburg during two hunting seasons from 2017 to 2019. Toxoplasma gondii‐specific antibodies were detected in 24.4% (44/180, 95% CI: 18.4%–31.4%) of wild boar, 12.8% (16/125, 95% CI: 7.5%–20%) of roe deer and 6.4% (3/47, 95% CI: 1.3%–17.5%) of red deer using a commercial ELISA kit. Seroprevalences were similar in the two hunting seasons. Correlation between sex and seropositivity could not be observed. A rise in seroprevalence was seen with increasing age in all studied game species. Observed seroprevalences suggest that T. gondii is endemic in the sylvatic environment in the German federal state of Brandenburg and imply that game could represent a relevant source for human T. gondii infection.     

Evidence of Anaplasma infections in European roe deer (Capreolus capreolus) from southern Spain

Anaplasma spp. (Rickettsiales: Anaplasmataceae) are tick-borne pathogens of veterinary and human importance. The wildlife hosts for these pathogens are not well characterized and may play an important role in the epidemiology of the disease. The objective of this research was to study the infection with A. marginale, A. ovis and A. phagocytophilum in free-ranging European roe deer (Capreolus capreolus) from Cádiz, Andalucía, Spain. Of 17 roe deer tested, 14 (82%) and 5 (29%) had antibodies reactive to Anaplasma spp. and A. phagocytophilum by competitive ELISA and indirect immunofluorescent antibody testing, respectively. Polymerase chain reaction and sequence analysis of Anaplasma major surface protein 4 (msp4) gene was conducted on blood samples from all roe deer examined. Nine (53%) animals had evidence of infection with A. ovis and 3 (18%) were positive for A. phagocytophilum. Concurrent infections were not detected. Despite the presence of A. marginale infections in cattle in the study site (36% msp4 PCR-positive animals), none of the msp4 amplicons from roe deer corresponded to A. marginale sequences. A. ovis msp4 sequences were identical to a genotype previously identified in sheep in Sicily, Italy. Two different A. phagocytophilum genotypes were identified in infected roe deer. This is the first report of roe deer naturally infected with A. ovis. These results demonstrate that roe deer are infected with A. ovis and A. phagocytophilum in Spain and suggest that this species may be involved in the natural cycle of these pathogens in this region, thus acting as potential reservoir for transmission to domestic and wild animals.     

Cervids as sentinel‐species for tick‐borne encephalitis virus in Norway ‐ A serological study

Tick‐borne encephalitis virus (TBEV) is the causative agent of tick‐borne encephalitis (TBE). TBEV is one of the most important neurological pathogens transmitted by tick bites in Europe. The objectives of this study were to investigate the seroprevalence of TBE antibodies in cervids in Norway and the possible emergence of new foci, and furthermore to evaluate if cervids can function as sentinel animals for the distribution of TBEV in the country. Serum samples from 286 moose, 148 roe deer, 140 red deer and 83 reindeer from all over Norway were collected and screened for TBE immunoglobulin G (IgG) antibodies with a modified commercial enzyme‐linked immunosorbent assay (ELISA) and confirmed by TBEV serum neutralisation test (SNT). The overall seroprevalence against the TBEV complex in the cervid specimens from Norway was 4.6%. The highest number of seropositive cervids was found in south‐eastern Norway, but seropositive cervids were also detected in southern‐ and central Norway. Antibodies against TBEV detected by SNT were present in 9.4% of the moose samples, 1.4% in red deer, 0.7% in roe deer, and nil in reindeer. The majority of the positive samples in our study originated from areas where human cases of TBE have been reported in Norway. The study is the first comprehensive screening of cervid species in Norway for antibodies to TBEV, and shows that cervids are useful sentinel animals to indicate TBEV occurrence, as supplement to studies in ticks. Furthermore, the results indicate that TBEV might be spreading northwards in Norway. This information may be of relevance for public health considerations and supports previous findings of TBEV in ticks in Norway.     

Toxoplasma gondii and Neospora caninum in wildlife: common parasites in Belgian foxes and Cervidae?

Sera from Cervidae were tested for the presence of antibodies against Neospora caninum using ELISA; and against Toxoplasma gondii using SAG1-ELISA and a commercially available agglutination test. The T. gondii seroprevalence was 52% (38/73) in roe deer (Capreolus capreolus), 0% in bred fallow deer (0/4) (Dama dama) and red deer (0/7) (Cervus elaphus). We found 2.7% of the roe deer samples and none of the bred deer samples positive for N. caninum. Brain samples from wild roe deer, red deer and red foxes (Vulpes vulpes) were tested for the presence of T. gondii and N. caninum DNA using multiplex real-time PCR. We detected T. gondii in 18.8% (57/304) of the red foxes and in 1 of the 33 deer samples. N. caninum was found in 6.6% of the red foxes and in 2 roe deer samples. Twenty-six of the T. gondii positive DNA extracts from the red fox samples were genotyped. Twenty-five were type II and only one was found to be type III.     

黑龙江凉水国家级自然保护区西伯利亚狍的冬季食性

2011年11月~2012年1月,在黑龙江凉水国家级自然保护区,采用粪便显微组织学分析方法研究了西伯利亚狍的冬季食性,结果表明:西伯利亚狍冬季采食的植物类别共有17科25种,主要食物为粗茎鳞毛蕨、白桦、毛榛子、山杨和刺五加,可辨认的每种植物相对密度(RD)分别为36.01%、12.10%、7.24%、6.22%、6.07%,共占食物组成比例的65.29%。取食植物类别中,乔木植物所占比例最高,为47.76%,灌木次之,为14.94%,草本最少,为37.30%。计算出的Shannon-Wiener指数H'值为-3.25;均匀度指数J'值为-1.01;生态位宽度B值为7.12。     

Preliminary study on the feeding habits of roe deer (Capreolus capreolus) in the western Alps

Roe deer feeding habits were studied in the western Alps during the summer season using the faecal analysis method. The diet of cattle grazing in the same area was also investigated and the trophical niche overlap between the two species was determined. The roe deer diet was found very variable and mostly composed of dicotyledons, with Leguminosae and Cistaceae as prevalent species. Monocotyledons, mainly represented by Graminaceae, were consumed to a lesser extent. A significant preference was observed for Cistaceae and other dicotyledons whereas a significant refuse was observed for Graminaceae and Asteraceae. These data confirmed the roe deer's behaviour to select food with a better nutritive value. Despite the differences between the cattle and roe deer's diets, the trophical niche overlap was quite high. This can be explained by the homogeneity of the plants covering the whole area which probably limited food selection by the roe deer.     

Prevalence of Coxiella burnetti infection in wild and farmed ungulates

The aim of this study was to evaluate by serology and PCR analyses the prevalence of Coxiella burnetti infection in ungulates in Spain. Sera were collected from red deer (Cervus elaphus; n=116), roe deer (Capreolus capreolus; n=39), fallow deer (Dama dama; n=13) and cattle (n=79). Sera were tested for anti-C. burnetii antibody detection by means of an immunofluorescence antibody assay (IFA) and C. burnetii DNA was amplified by PCR in samples from ungulates that had antibodies to phase II antigens. Twenty-nine, 15 and 39 percent of the red deer, roe deer and cattle had antibodies against C. burnetii, respectively. None of the fallow deer sera tested positive. Seroprevalence was statistically higher in farmed than in wild red deer and higher in northern than in southern populations, whereas an inverse pattern was observed for the roe deer. Most of the seropositive animals had only anti-C. burnetii phase II antibodies, thus showing the acute nature of infections in the sampled ungulates. These results show that C. burnetii circulates in wild ungulates in Spain and suggest that they can act as pathogen reservoirs for both domestic animals and humans.     

人工养殖西伯利亚狍肠道微生物组成的雌雄差异

肠道微生物是一个复杂的生态系统,与宿主的健康、疾病以及其他因素有着密切的关系。目前,关于肠道菌群结构和功能的研究较多,但是对西伯利亚狍肠道菌群的研究还未见报道。西伯利亚狍(Capreolus pygargus)属于反刍动物,有独特的消化特性和微生物群来帮助它们适应高纤维的食物。本研究利用高通量测序技术在Illumina MiSeq平台上对14只狍肠道微生物进行16S rRNA基因分析。结果表明:个体样本中门类组成的差异,雌性个体JY3和雄性个体JY9除Firmicutes,Bacteroidetes,Proteobacteria这3类菌群外,其他门类菌群所占比例都很低。在科水平上,雌性个体中Ruminococcaceae在JY7和JY13肠道内含量相对较少,Bacteroidaceae在JY7,JY10和JY13中含量较高。雄性个体中Ruminococcaceae在JY11和JY14肠道内含量较少,Prevotellaceae在JY4中含量较少。在属水平上,雌性个体特有的菌属为Roseburia,Alloprevotella,Lachnospiraceae_incertae_sedis和Coprococcus;雄性个体特有的菌属为Fusobacterium,Succiniclasticum,Streptococcus和Clostridium sensu stricto。Alpha多样性分析表明,Ace指数范围2128.93—772.98,Chao1指数范围2128.89—785.27,Shannon指数范围5.44—3.78,Simpson指数范围0.07—0.01。在不同物种分类水平上,雌雄狍肠道内的优势菌群有些不同。PCoA(principal co-ordinates analysis)分析显示,狍样本几乎混在一起,没有明显差异。