A Paleozoological Perspective on White-Tailed Deer (<Emphasis Type="Italic">Odocoileus virginianus texana</Emphasis>) Population Density and Body Size in Central Texas

Archaeological and paleontological datasets are used in conservation to add time-depth to ecology. In central Texas, several top carnivores including prehistoric Native American hunters have been extirpated or have had their historic ranges restricted, which has resulted in pest-level white-tailed deer (Odocoileus virginianus texana) populations in some areas. Differences in body size of deer between prehistory and modernity are expected, given that a lack of predation likely has increased intraspecific competition for forage among deer, resulting in smaller body size today. In fact, modern deer from settings without harvest pressure are significantly smaller than those from harvested areas and from prehistoric deer. From a natural history perspective, this research highlights potential evolutionary causes and effects of top-predator removal on deer populations and related components of biological communities in central Texas.     

Deer predation on leaf miners via leaf abscission

The evergreen oak Quercus gilva Blume sheds leaves containing mines of the leaf miner Stigmella sp. (Lepidoptera: Nepticulidae) earlier than leaves with no mines in early spring in Nara, central Japan. The eclosion rates of the leaf miner in abscised and retained leaves were compared in the laboratory to clarify the effects of leaf abscission on leaf miner survival in the absence of deer. The leaf miner eclosed successfully from both fallen leaves and leaves retained on trees. However, sika deer (Cervus nippon centralis Kishida) feed on the fallen mined leaves. Field observations showed that deer consume many fallen leaves under Q. gilva trees, suggesting considerable mortality of leaf miners due to deer predation via leaf abscission. This is a previously unreported relationship between a leaf miner and a mammalian herbivore via leaf abscission.     

梅花鹿养殖场抗生素抗性基因分布特征

梅花鹿养殖是近年来我国南方地区出现的新兴养殖业.为探究梅花鹿养殖对养殖环境抗生素抗性基因的影响,采用高通量荧光定量PCR研究了抗生素抗性基因在养殖场区对照土壤、梅花鹿新鲜粪便、梅花鹿粪便堆肥产物和施用堆肥菜地土壤中的分布、丰度和多样性.结果表明,抗性基因的绝对丰度梅花鹿粪便堆肥产物梅花鹿新鲜粪便施用堆肥菜地土壤养殖场区对照土壤,抗生素抗性基因在4种环境样品中具有不同分布格局;梅花鹿养殖场环境中抗性基因丰度与可移动基因元件丰度显著相关(P0.05),表明可移动基因元件可能加快了抗性基因的水平转移过程,促进了抗性基因的迁移、传播和富集,加剧了养殖环境抗生素抗性基因污染.     

Are faecal hormone levels linked to winter progression,diet quality and social rank in young ungulates ? An experiment with white-tailed deer (<Emphasis Type="Italic">Odocoileus virginianus</Emphasis>) fawns

Hormones play a central role in the physiology and behaviour of animals. The recent development of noninvasive techniques has increased information on physical and social states of individuals through hormone measurements. The relationships among hormones, life history traits and behaviours are, however, still poorly known. For the first time, we evaluated natural winter glucocorticoid and testosterone levels in young ungulates in relation to winter progression, diet quality and social rank. Overwinter, levels of glucocorticoid and testosterone decreased, possibly due to the decline of fawns’ body mass. The relationships between hormone levels and diet quality were surprising: Fawns fed the control diet presented higher glucocorticoid and lower testosterone levels then fawns fed the poor diet, suggesting that control fawns faced a higher nutritional stress than those on the poor diet. Similarly to other studies on social mammals, we found no relationship between faecal glucocorticoid levels and social rank, suggesting that social stress was similar for dominant and subordinate fawns during winter. Testosterone levels were not correlated to social rank as found previously in groups of individuals forming stable social hierarchies and maintaining stable dominance relationships. The simultaneous suppression of glucocorticoid and testosterone levels suggests for the first time that young ungulates present a hormonal strategy to prevent fast depletion of limited proteins and fat resources during winter.     

冶勒自然保护区林麝对生境选择研究

1995年在相岭山系的冕宁冶勒自然保护区,采用作者新近提出的临时空间样方法,以Vanderloeg和Scavia选择指数对林麝对生境的选择进行了研究,结果表明7～8月份,林麝喜欢活动于竹子密度不大（n＝0～15m     

中国茸鹿品种(品系)的随机扩增多态DNA(RAPD)研究

采用随机扩增多态ＤＮＡ技术研究了５个茸鹿品种（品系）７５个个体的遗传变异关系。在所使用的４１个引物中,有４０个引物扩增出多态谱带,共检测到３９５条扩增片段,其中２５９条（６５．６％）出现变异,用Ｓｈａｋｎｎｏｎ指数计算了５个品种（品系）的遗传变异及其遗传变异在群体内和群体间的分布。利用Ｎｅｉ氏片段共享度计算了７５个个体间的遗传距离,用ＵＰＧＭＡ聚类法构建了７５个个体的系统发育树状图,反映５个茸鹿品     

Seasonality of Cs in roe deer from Austria and Germany

Empirical data on the ¹³⁷Cs activity concentration in meat of roe deer (Capreolus capreolus) roaming in 3 spruce forest areas and one peat bog area are presented and compared. They cover time series of nearly 20 years after a spike contamination in 1986 originating from Chernobyl. A model is presented which considers three soil compartments to describe the change of the availability of ¹³⁷Cs with time.     

A patch use model to separate effects of foraging costs on giving-up densities: an experiment with white-tailed deer (<Emphasis Type="Italic">Odocoileus virginianus</Emphasis>)

The giving-up density of food (GUD), the amount of food remaining in a patch when a forager ceases foraging there, can be used to compare the costs of foraging in different food patches. But, to draw inferences from GUDs, specific effects of foraging costs (predation risk, metabolic and missed opportunities costs) on GUDs have to be identified. As high predation risk, high metabolic costs and abundant food all should produce high GUDs, this does not allow us to infer directly the quality of a habitat. In order to separate the effect of each foraging cost, we developed an optimal foraging model based on food supplementation. We illustrate the use of our model in a study where we assessed the impact of a power line right-of-way in a white-tailed deer (Odocoileus virginianus) winter yard by determining whether the negative effects of cover loss outweigh the positive effects of browse regeneration.     

Eld’s Deer Translocated to Human-Inhabited Areas Become Nocturnal

As human populations expand and nonhuman animals decline, understanding the interactions between people and wildlife is essential. For endangered species, appreciating the effect of human disturbance can be important for their conservation. However, a human disturbance angle is often absent from ecological research, despite growing evidence of the negative impact of nonfatal human interference. Here, we monitored Hainan Eld’s deer living within a reserve and translocated animals living amongst villagers. We show that translocated deer deviated from a crepuscular activity pattern and became increasingly nocturnal, and most active when villagers were not. It appears that translocated deer adapted over time to human disturbance and this pattern is similar to that of other species during periods of hunting. People do not pose an actual threat to Eld’s deer, but their presence triggered a response akin to predator avoidance and may be interfering with broader aspects of their biology and conservation.     

A Natural Experiment on the Impact of Overabundant Deer on Forest Invertebrates

Abstract:  In large parts of North America and Europe, deer overabundance threatens forest plant diversity. Few researchers have examined its effects on invertebrate assemblages. In a natural experiment on Haida Gwaii (British Columbia, Canada), where Sitka black-tailed deer ( Odocoileus hemionus sitkensis ) were introduced, we compared islands with no deer, with deer for fewer than 20 years, and with deer for more than 50 years. We sampled invertebrates in three habitat categories: forest edge vegetation below the browse line, forest interior vegetation below the browse line, and forest interior litter. In forest edge vegetation, invertebrate abundance and species density decreased with increasing length of browsing history. In forest interior vegetation, decrease was significant only on islands with more than 50 years of browsing. Insect abundance in the vegetation decreased eightfold and species density sixfold on islands browsed for more than 50 years compared with islands without deer. Primary consumers were most affected. Invertebrates from the litter showed little or no variation related to browsing history. We attributed the difference between vegetation-dwelling and litter-dwelling invertebrates to differences in the effect of browsing on their habitat. In the layer below the browse line deer progressively removed the habitat. The extent of litter habitat was not affected, but its quality changed. We recommend more attention be given to the effect of overabundant ungulates on forest invertebrate conservation with a focus on edge and understory vegetation in addition to litter habitat.