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1.
Hubei Shishou Milu National Nature Reserve is an ideal place to restore the wild population of Père David's deer (Elaphurus davidianus). Understanding foraging ecology and diet composition is essential for assessing population development or establishing long-term effective conservation measures for endangered species. However, little is known about the diet composition of Père David's deer and its diet selection mechanism. In this study, we used stable isotope technology to investigate the diet composition of Père David's deer according to various tissues (i.e., fur, muscle, liver, heart, and feces) and seasons, and evaluated the correlation between the nutrient composition of plants and diet composition. Bayesian isotope analysis showed that the autumn and winter diet estimated by fur and fecal samples indicated a diet dominated by C3 grasses (42.7%–57.2%, mean), while the summer diet estimated by muscle and liver samples was dominated by C3 forbs (30.9%–41.6%, mean). The Pearson correlation test indicated that the contribution of winter diet composition reflected by fur and fecal samples was associated with correlations with crude protein (r = .666, p < .01) and soluble sugars (r = .695, p < .01). The results indicated that crude protein and soluble sugars were important factors influencing the winter diet selection of Père David's deer. In the context of the current reintroduction facing many challenges, such as habitat fragmentation, wetland degradation, and human disturbance, comprehensively evaluating the diet selection mechanism of Père David's deer under different resource specificities and temporal changes should be considered in the future.  相似文献   

2.
2017年12月至2018年3月在江苏盐城湿地珍禽国家级自然保护区,利用粪便显微组织学分析技术结合野外直接观察法对麋鹿(Elaphurus davidianus)冬季食性和食物营养成分进行了分析。野外调查在7条样线上共收集228堆麋鹿粪便,组成14个复合样本进行分析。结果表明,麋鹿冬季食物来源于14科51种植物,其中,芦苇(Phragmites australis,23.09%)和互花米草(Spartina alterniflora,17.58%)为最主要食物,其次为盐地碱蓬(Suaeda salsa,6.50%)、白茅(Imperata cylindrica,5.36%)、獐毛(Aeluropus sinensis,4.90%)、苇状羊茅(Festucas arundinacea,3.83%)、扁秆藨草(Scirpus planiculmis,3.45%)、碱蓬(Suaeda glauca,3.27%)、碱茅(Puccinellia distans,3.12%)、黑麦草(Lolium perenne,2.60%)和茵陈蒿(Artemisia capillaris,2.60%)。麋鹿冬季食物以草本植物为主(96.73%),极少采食木本植物枝叶(3.27%)。被啃食植物中粗蛋白含量基本满足麋鹿越冬营养需求。  相似文献   

3.
麋鹿作为中国特有的鹿科动物,经历129年的保护努力,种群数量恢复到10000多头。因近亲繁殖严重,表面上看已无灭绝危险,但仍存在巨大隐忧。通过对麋鹿种群变迁、灭绝、重引入、恢复现状及四大种群(乌邦寺、南海子、大丰、石首野化种群)的发展趋势进行追踪分析,探究近千年来困扰麋鹿种群发展壮大的多重因素,提出种群保护与栖息地保护并重、强化疫病监测等保护对策,为麋鹿及其它大型陆生濒危哺乳动物突破种群发展瓶颈提供借鉴。  相似文献   

4.
Prevalence of disease in wildlife populations, which is necessary for developing disease models and conducting epidemiologic analyses, is often understudied. Laboratory tests used to screen for diseases in wildlife populations often are validated only for domestic animals. Consequently, the use of these tests for wildlife populations may lead to inaccurate estimates of disease prevalence. We demonstrate the use of Bayesian latent class analysis (LCA) in determining the specificity and sensitivity of a competitive enzyme‐linked immunosorbent assay (cELISA; VMRD®, Inc.) serologic test used to identify exposure to Neospora caninum (hereafter N. caninum) in three wildlife populations in southeastern Ohio, USA. True prevalence of N. caninum exposure in these populations was estimated to range from 0.1% to 3.1% in American bison (Bison bison), 51.0% to 53.8% in Père David's deer (Elaphurus davidianus), and 40.0% to 45.9% in white‐tailed deer (Odocoileus virginianus). The accuracy of the cELISA in American bison and Père David's deer was estimated to be close to the 96% sensitivity and 99% specificity reported by the manufacturer. Sensitivity in white‐tailed deer, however, ranged from 78.9% to 99.9%. Apparent prevalence of N. caninum from the test results is not equal to the true prevalence in white‐tailed deer and Père David's deer populations. Even when these species inhabit the same community, the true prevalence in the two deer populations differed from the true prevalence in the American bison population. Variances in prevalence for some species suggest differences in the epidemiology of N. caninum for these colocated populations. Bayesian LCA methods could be used as in this example to overcome some of the constraints on validating tests in wildlife species. The ability to accurately evaluate disease status and prevalence in a population improves our understanding of the epidemiology of multihost pathogen systems at the community level.  相似文献   

5.
Since 1985, China has established three breeding herds of Père David’s deer: the Beijing Père David’s Deer Park (39°07′N, 116°03′E), the Dafeng Père David’s Deer Nature Reserve (33°05′N, 120°49′E) and Shishou (Tianezhou) Père David’s Deer Nature Reserve (29°49′N, 112°33′E), through reintroductions of about 30–40 founders. Since establishment, all three populations have grown steadily. However, genetic backgrounds in those populations are still unknown. We studied the genetic diversity in Père David’s deer and genetic consequences of population relocations in China. We revealed that genetic diversity was extremely low in Père David’s deer populations in China. Only a single mtDNA D-loop haplotype was found in the deer, furthermore, only five polymorphic microsatellite loci were screened out from 84 pairs of species-transferred primers. Genetic makeup in the three Père David’s deer populations were significantly different (P < 0.01). H E and allelic richness in the Tianezhou population were the highest (0.54, 2.60, n = 31), Beijing population (0.52, 2.4, n = 125) showed the second highest measures, while the Dafeng population (0.46, 2.39, n = 39) measured lowest. Our results suggest that effective management of a species of low genetic diversity like the Père David’s deer should consider the genetic background of each founder to make sure genetic variations are preserved in both source population and relocated population. Now, the Tianezhou population is the most appropriate source population in China when establishing new Père David deer populations in the wild.
Zhigang JiangEmail:
  相似文献   

6.
We conducted an experiment in the Beijing Milu Park to study the social behavior of male Père David's deer, and related social behavior to social position and serum testosterone level of the stags during rut. We classified the stags into three rank classes according to their rutting behavior: ‘harem master’, ‘challenger’ and ‘bachelor’. We monitored the behaviors of four ‘harem masters’, five ‘challengers’ and five ‘bachelors’, and analyzed serum testosterone levels in blood samples of those 14 stags using radioimmunoassay. We defined the effectiveness value, E = A/T, to assess the effectiveness of herding or mating attempts made by stags (‘T’ represents the frequency of herding or mating attempts made by a stag and ‘A’ represents the frequency of herding or mating attempts accepted by hinds). We found that: (1) the ‘harem masters’ and the ‘challengers’ displayed more frequent rut and locomotive behaviors but fewer ingestion behaviors than the ‘bachelors’; (2) serum testosterone levels in the ‘harem masters’ and the ‘challengers’ were higher than that in the ‘bachelors’; (3) effectiveness value of herding attempts differed significantly between the three types of stags, being highest in the ‘harem masters’ and the lowest in the ‘bachelors’; and (4) effectiveness value of mating attempts was significantly greater for the ‘harem masters’ than for the ‘challengers’. We conclude that: (1) reproductive behavior of the Père David's deer stags is strongly associated with social rank; (2) social roles of Père David's deer stags during the rut are related to the testosterone secretion; and (3) rank class affects the mating opportunity of the stags.  相似文献   

7.
The population of the Père David's deer or milu (Elaphurus davidianus), which was discovered in China by Père Armand David in 1866, has grown from five, or even merely three individuals, imported from China to approximately 5000 during a time-span of 140 years. We tried to find out more about the origin of the 18 individuals which formed the original herd of the 11th Duke of Bedford at Woburn Abbey. His breeding-group was the only safeguard for this species between the years 1900 and 1946. Of the 18 individuals three were offspring of Berlin Zoo, three originated from Cologne Zoo and probably all the rest came from the Jardin d‘Acclimatation in Paris. The origin of the breeding herd at the Jardin d‘Acclimatation is not clear. The first individuals either came from Berlin Zoo or were imported directly from China in the years between 1876 and 1886. In Berlin Zoo's breeding records there is a remarkable gap for the years 1879 and 1880. If they came from Berlin Zoo, the imported male and two females would be the sole founders of the herd, and if the Jardin d‘Acclimatation had done an own import, then there would be at least five founders. At Berlin Zoo at least 18 milu calves were born between the years 1878 and 1895. The final destinations of most of these could be traced in literature. Some of them are not quite conclusive yet. We sketched the development of the worldwide zoo-stock of Père David's deer, the return to China and the re-settlement in the original habitat in newly established reserves and finally even outside the reserves. After centuries the milu has again gained the status of a free-living species thanks to the efforts of several zoological gardens, the Dukes of Bedford and the Chinese conservation authorities.  相似文献   

8.
Li C  Yang X  Ding Y  Zhang L  Fang H  Tang S  Jiang Z 《PloS one》2011,6(8):e23623
Whether prey retains antipredator behavior after a long period of predator relaxation is an important question in predator-prey evolution. Père David''s deer have been raised in enclosures for more than 1200 years and this isolation provides an opportunity to study whether Père David''s deer still respond to the cues of their ancestral predators or to novel predators. We played back the sounds of crows (familiar sound) and domestic dogs (familiar non-predators), of tigers and wolves (ancestral predators), and of lions (potential naïve predator) to Père David''s deer in paddocks, and blank sounds to the control group, and videoed the behavior of the deer during the experiment. We also showed life-size photo models of dog, leopard, bear, tiger, wolf, and lion to the deer and video taped their responses after seeing these models. Père David''s deer stared at and approached the hidden loudspeaker when they heard the roars of tiger or lion. The deer listened to tiger roars longer, approached to tiger roars more and spent more time staring at the tiger model. The stags were also found to forage less in the trials of tiger roars than that of other sound playbacks. Additionally, it took longer for the deer to restore their normal behavior after they heard tiger roars, which was longer than that after the trial of other sound playbacks. Moreover, the deer were only found to walk away after hearing the sounds of tiger and wolf. Therefore, the tiger was probably the main predator for Père David''s deer in ancient time. Our study implies that Père David''s deer still retain the memories of the acoustic and visual cues of their ancestral predators in spite of the long term isolation from natural habitat.  相似文献   

9.
Culicoides spp. biting midges (Diptera: Ceratopogonidae) are vectors of pathogens that have a significant economic impact on the livestock industry. White‐tailed deer (Odocoileus virginianus), a farmed species in the U.S.A., are susceptible to two Culicoides spp. borne orbiviruses: bluetongue virus and epizootic haemorrhagic disease virus. Elucidating host–vector interactions is an integral step in studying disease transmission. This study investigated the host range of Culicoides spp. present on a big game preserve in Florida on which a variety of Cervidae and Bovidae freely roam. Culicoides were captured with Centers for Disease Control and Prevention (CDC) miniature light traps run twice weekly on the preserve for 18 consecutive months (July 2015–December 2016). Host preference was quantified through forage ratios, based upon PCR‐based bloodmeal analysis of Culicoides spp. and overall animal relative abundance on the preserve. Culicoides stellifer preferentially fed on Cervus spp. and fallow deer (Dama dama) and displayed a relative avoidance of Bovidae and white‐tailed deer. Culicoides debilipalpis preferred white‐tailed deer and avoided all Bovidae. Culicoides pallidicornis and Culicoides biguttatus showed preferences for white‐tailed deer and Père David's deer (Elaphurus davidianus), respectively. These results add to current knowledge of preferred hosts of Florida Culicoides spp. and have implications for the spread of orbiviruses. Copyright © 2018 John Wiley & Sons, Ltd.  相似文献   

10.
麋鹿鹿角生长周期及影响因子   总被引:1,自引:0,他引:1  
2013年8月至2014年8月,使用望远镜(SWAROVSKI 8×42 WB)和照相机(Canon 550D 70×300)观察北京南海子59只雄性麋鹿茸的生长和角脱落周期,发现麋鹿角总体趋势呈随着年龄的减少,脱角日期越迟,且等级序位高或者鹿王较年老个体先脱落。收集2012年12月至2014年2月两年度麋鹿自然脱落的角,研究表明,个体而言,左右角脱角顺序差异明显,同一天脱落两角者占17.0%,左角先脱落者占34.1%,右角先脱落者占48.8%,重量重和重量轻的角先脱落的个体各占41.5%,个体成对的左右角脱落时间间隔短,平均为1.98d;群体而言,角重量与脱角时间呈显著负相关,总体呈现角重的个体角先脱落,但不是角最重的个体角第一个脱落。2013年6月至2014年5月,对北京南海子、湖北石首、江苏大丰、天津七里海、浙江慈溪、浙江临安、海南海口、河北滦河上游、辽阳千山等9个地区麋鹿种群麋鹿角脱落起止时间进行调查,研究表明野生种群脱角时间比圈养种群早;迁入热带地区海南的麋鹿仍有规律的角周期;同一栖息地不同年份角周期存在差异,不同栖息地间麋鹿角周期存在差异;脱角起始时间与海拔、经度、纬度、年平均气温、圈养情况和气候类型等影响因子不存在统计学上显著的相关性,但光周期和激素直接主导和调节着角周期,年龄大小、角重量、营养以及与营养相关的能量、种群密度、物候等环境因子均影响角周期。  相似文献   

11.
湖北石首麋鹿昼间活动时间分配   总被引:2,自引:1,他引:1  
为探讨性别、年龄和季节对麋鹿(Elaphurus davidianus)行为的影响,2006年9月-2007年10月,作者采用焦点取样法和瞬时记录法,将麋鹿昼间活动归为采食、饮水、运动、休息、警觉、其他行为等六大类型,每月6-8 d对湖北石首麋鹿国家级自然保护区麋鹿种群的昼间活动时间分配进行了跟踪观察.结果表明:麋鹿有晨、昏两个采食高峰和一个午间休息期,各种行为类型所占比例依次是:休息53.40%(±5.59%)、采食22.36(±8.34%)、运动11.23%(±0.63%)、警觉5.03%(±1.76%)、其他行为4.42%(±2.06%),饮水2.65%(±0.74%).不同季节,时间分配变化明显.非参数Kruskal Wallis H检验结果显示(n=120),季节、年龄和性别显著影响麋鹿的活动时间分配.除运动行为(x2=16.856,df=3,P>0.05)和饮水行为(x2=7.667,df=3,P>0.05)无显著差异外,采食(x2=15.657,df=3,P<0.01)、休息(x2=13.173,df=3,P<0.01)、警觉(x2 =13.887,df=3,P<0.01)和其他行为(x2=16.317,df=3,P<0.01)在不同季节所占时间百分比均有极显著差异.对不同性别年龄组的活动时间分配采用两个独立样本的Mann-Whitney U检验,各性别-年龄组间的运动行为所占时间比例有极显著差异(P<0.01),雄鹿与雌鹿之间的警觉行为有极显著差异(P<0.01),雄鹿花较多时间用于警觉.幼鹿与成年鹿及亚成年鹿之间的采食行为时间有极显著差异(P<0.01).不同性别、年龄组在不同季节的昼间活动时间分配的差异采用方差(ANOVA)分析后发现:所有年龄组,夏季与冬季饮水、春季与夏季警觉均存在显著性差异(P<0.01);成体和亚成体麋鹿,春季与冬季警觉、夏季与冬季运动均存在显著性差异(P<0.01).  相似文献   

12.
本文在2014—2016年三个冬季(12月—翌年2月)收集了北京南海子麋鹿苑半散放麋鹿自然脱落的角,并观察和记录了2015—2017年发情期(5—9月)群主更替和2016—2018年产仔期(3—7月)麋鹿幼仔出生情况,结合2014—2018年年平均气温、季平均气温、月平均气温、年降雨量、雨季开始时间、种群密度等环境因子,对鹿角脱落、群主更替、产仔等繁殖特征的年节律及其环境影响因子进行了研究。结果表明:1)麋鹿鹿角脱落、群主更替、产仔的年节律均存在年际差异。2)鹿角脱落时间为12月开始,1月下旬或2月上旬结束。3)发情期为5月下旬或6月上旬开始,9月上旬结束;2015—2017年发情期时间有延长的趋势。4)产仔期为3月中旬或4月中旬开始,5月下旬或7月下旬结束。5)麋鹿鹿角脱落、群主更替、产仔的年节律存在明显的同步关系,其中鹿角脱落开始时间、鹿角脱落高峰期、鹿角脱落结束时间、第一次发情期开始时间、群主更替高峰期、产仔期开始时间、产仔高峰期、产仔期结束时间与前一年度比较均出现同步提前的现象。6)鹿角脱落年节律存在随着12月平均气温升高而提前的现象;产仔期开始时间和产仔高峰期存在随着前一年9月平均气温的升高而提前的现象。7)鹿角脱落年节律表现出随着年降雨量的增多而提前的现象;第一次发情期开始时间、群主更替高峰期的年节律表现出随着前一年度年降雨量的增多而提前的现象。8)麋鹿鹿角脱落、群主更替、产仔的年节律均不存在随着种群密度升高或降低而提前或延迟的现象。麋鹿繁殖特征的年节律是一个复杂的过程,受气候、营养、种群密度、纬度等环境因子的影响。  相似文献   

13.
To learn the seasonal home range pattern and its role in the ecological adaptation of rewild Père David’s deer, we took the investigation from spring to winter in three-collared females that released into the coastal wetlands of the Yellow Sea, China. Using GPS collars, minimum convex polygons and fixed kernel estimation, we recorded the movement and estimated the home ranges of the deer. The results showed that the collared deer inhabited only 42.85% of the coastal wetland habitat that had been designated for them. The home ranges were larger during winter and spring than in autumn and summer. In summer and autumn, the collared deer remained in the reserve, which was dominated by spartina grass. In the spring and winter, they were lured by the green leaves of wheat in the farmlands outside the reserve but were then driven back by people. Home range patterns reflected the seasonality of the availability of food resources and human activity. In addition to the frequently utilized habitats, much larger wetland areas are required for such deer. As the population density increases gradually, more available space will be needed to meet the fundamental needs of the seasonal dispersal of rewild Père David’s deer.  相似文献   

14.
Data for this study came from breeding records of 27 Père David's (Elaphurus davidianus) hinds maintained in large pastures and from estrous records of four hand-reared nulliparous hinds. The mean estrous cycle length ranged from 17.5 to 19.6 days. Standing estrus resembled that of other cervids, except that a low, moaning vocalization was given in response to contact, and activity (as measured by pedometers) did not increase. Mean gestation length was 183.38 ± SD 6.11 days (n = 21), and nearly all females conceived in the second and third years. The median interbirth interval was 362 days. The median birth date was April 8, and 80% of the births occurred over a 9.5-week period. Multiparous hinds gave birth an average of 20.5 days earlier in the season than primiparous hinds. There was no dimorphism in birth weight. The results are discussed in light of comparative data for other species.  相似文献   

15.
The pattern of LH secretion and response to exogenous GnRH was determined on 5 occasions during seasonal anoestrus of the Père David's deer hind. LH pulse frequency was low (3.3 +/- 0.6 pulses/18 h) in early anoestrus (February), increased significantly in mid-anoestrus (April; 8.4 +/- 1.4 pulses/18 h) and thereafter declined slightly in late anoestrus (June; 6.3 +/- 0.25 pulses/18 h). Mean LH concentrations also showed significant changes during anoestrus with higher levels in mid-anoestrus (April; 0.85 +/- 0.12 ng/ml) when compared with other times (0.53 +/- 0.05, 0.60 +/- 0.10, 0.68 +/- 0.06 and 0.71 +/- 0.05 ng/ml for February, March, May and June, respectively). LH pulse amplitude showed no significant changes during the study. The LH response to intravenous injections of 2 micrograms GnRH was lowest in early anoestrus (February), increased significantly in mid-anoestrus (April) and remained high through late anoestrus. The response during the luteal phase was similar to that seen during late anoestrus. These results indicate that seasonal anoestrus in the Père David's deer hind is not a uniform state but is characterized by an early period of 'deep' anoestrus.  相似文献   

16.
Zebras, as prey species, attend to the behavior of nearby conspecifics and heterospecifics when making decisions to flee from predators. Plains zebras (Equus quagga) and Grevy's zebras (E. grevyi) frequently form mixed‐species groups in zones where their ranges overlap in Kenya. Although anecdotal observations suggest that Plains zebras are more flighty around humans than Grevy's zebras are, this has not been empirically confirmed, and relatively little is known about how they may influence each other's flight behavior. We addressed these questions by examining the flight initiation distances (FIDs) of Plains and Grevy's zebras in single‐species and mixed‐species groups from an approaching human. One target individual per group was approached steadily on foot, with start distance, alert distance, and FID recorded from this target. Using start distance and alert distance separately as covariates, 22 Plains zebras in single‐species groups exhibited a significantly longer mean FID than 15 Grevy's zebras in single‐species groups. The FIDs of 7 Plains zebras and 5 Grevy's zebras tested in mixed‐species groups were virtually equivalent and intermediate to those of Plains and Grevy's zebras in single‐species groups, suggesting a bidirectional moderating influence of heterospecifics on risk assessment. This effect was most pronounced for Plains zebras in mixed‐species groups that exhibited an FID that was significantly shorter than that of Plains zebras in single‐species groups. Our findings underscore the importance of recognizing that related equids may be differently impacted by anthropogenic stress.  相似文献   

17.
In predator-prey encounters, many factors influence risk perceptionby prey and their decision to flee. Previous studies indicatethat prey take flight at longer distances when they detect predatorsat longer distances and when the predator's behavior indicatesthe increased likelihood of attack. We examined the flight decisionsof Columbian black-tailed deer (Odocoileus hemionus columbianus)using an approaching human whose speed, directness of approach,directness of gaze, and simulated gun carrying varied. Deerfled at greater distances when approached more quickly and directly,and there was a concave-down quadratic trend in the relationshipbetween the distances at which the predator began its approachand at which the deer became alert (alert distance [AD]), indicatingthat deer have a zone of awareness beyond which there is a delayin detecting an approaching predator. Time spent assessing theapproacher (assessment time) was shorter during faster approachesand was positively related with AD. Deer fled at longer distancesand had shorter assessment times when they were already alertto the predator at the initiation of approach. Males fled atshorter distances than females when approached during the gun-holdingcondition, and males had shorter assessment times than femaleswhen the approacher averted his gaze. Such sex differences inrisk assessment might reflect male motivation during the matingseason as well as exposure to human hunting. We suggest thatrisk assessment is affected the by the predator's behavior,the state of awareness of the prey, and the distance at whichthey detect the predator.  相似文献   

18.
Interspecies hybrids between Père David's deer (Elaphurus davidianus) and red deer (Cervus elaphus) have proved to be a powerful resource in the search for quantitative trait loci (QTL) in deer. Several regions of the genome with significant effects on live weight and growth rates in backcross hybrids were detected. These include putative QTL for 6-month live weight (LOD 3.90) on linkage group 12, for 14-month live weight (LOD 3.19) on linkage group 1, three putative QTL for growth rate from 3 to 6 months (LOD 4.19 on linkage group 12, LOD 3.92 on linkage group 12, and LOD 3.34 on linkage group 5). In addition, linkage groups 20 and 1 appear to be associated with live weight traits between 9 and 16 months. The variance in traits explained by these QTL ranged between 5.3% and 11.2%. Allele substitution with Père David's alleles at different loci had both positive and negative effects on live weights and growth rates.  相似文献   

19.
Sika deerCervus nippon Temminck, 1838 observability and flight behaviour were studied in an area with a high level of human disturbance (Tanzawa Mts, Japan). Deer observation rate was positively affected by habitat-related food conditions, while it was negatively correlated with the number of tourists in the study area. Flight frequency in April-September was lower than in October-February. It was also influenced by period of day, behaviour of investigator and deer group size. Group composition, deer activity and habitat condition had no effect on flight frequency. Thus, only 317 (48%) of the deer groups encountered were caused to flee and among them as many as 86% fled for a distance shorter than 40 m. It was concluded that deer in Tanzawa Mts learned to tolerate people, what is known for the populations which are unhunted or under low hunting pressure.  相似文献   

20.
In this paper, we investigate the relationship between early detection of predators and predator avoidance in white-tailed deer ( Odocoileus virginianus ) and mule deer ( O. hemionus ), two closely related species that differ in their habitat preferences and in their anti-predator behavior. We used observations of coyotes ( Canis latrans ) hunting deer to test whether the distance at which white-tails and mule deer alerted to coyotes was related to their vulnerability to predation. Coyote encounters with both species were more likely to escalate when deer alerted at shorter distances. However, coyote encounters with mule deer progressed further than encounters with white-tails that alerted at the same distance, and this was not due to species differences in group size or habitat. We then conducted an experiment in which a person approached groups of deer to compare the detection abilities and the form of alert response for white-tails and mule deer, and for age groups within each species. Mule deer alerted to the approacher at longer distances than white-tails, even after controlling for variables that were potentially confounding. Adult females of both species alerted sooner than conspecific juveniles. Mule deer almost always looked directly at the approacher as their initial response, whereas white-tails were more likely to flee or to look in another direction with no indication that they pinpointed the approacher during the trial. Mule deer may have evolved the ability to detect predators earlier than white-tails as an adaptation to their more open habitats, or because they need more time to coordinate subsequent anti-predator defenses.  相似文献   

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