What happens to translocated game birds that 'disappear'?

The ultimate goal of most translocation efforts is to create a self-sustaining wild population of a species deliberately moved from one part of their range to another. As follow-up of a translocation attempt is often difficult, causes for failure are relatively unknown. Dispersal away from the release site is one potential source of failure because it decreases the likelihood of the released population establishing itself post-translocation. In this study, we used chukar Alectoris chukar as a surrogate for translocated game birds in order to conduct a large-scale experimental study. We observed that these desert-adapted birds demonstrate a strong fidelity for specific water sources. We also report the propensity for the translocated individuals to either disperse and return to their original water source site or remain at the release site. During two field seasons, we observed opposing behaviors such that the proportion of individuals returning to the capture site, versus those remaining at the release site, shifted between years. We analyzed this change between the years as well as within the years to assess the potential underlying causes such as translocated distance, differences in rainfall between seasons and water source type. We concluded that homing behavior was strong in this non-migratory bird species and that strength of this homing behavior varied, potentially due to conditions surrounding the limiting resource, water availability. The large-scale, original data presented here may help to explain why some releases result in a successfully established population while other releases result in widely dispersed individuals.     

SHIFTS IN BILATERAL ASYMMETRY WITHIN A DISTRIBUTION RANGE: THE CASE OF THE CHUKAR PARTRIDGE

Abstract Three major types of bilateral asymmetry (fluctuating asymmetry, directional asymmetry, and antisymmetry) have long been recognized in the literature. Little, however, is known about transitions between asymmetry types, especially in natural populations. It is often assumed that directional asymmetry and antisymmetry have a larger genetic basis than fluctuating asymmetry. This leads many scientists to exclude traits or populations showing either directional asymmetry or antisymmetry from developmental instability studies, focusing attention on fluctuating asymmetry alone. This procedure may bias the findings and thus our understanding of patterns of bilateral asymmetry and the factors influencing it. To examine changes in bilateral asymmetry across the distribution range of a species, I studied the length of the third toe in 11 chukar partridge (Alectoris chukar) populations across a steep environmental gradient of 320 km within the species' range in Israel. This trait was selected due to its adaptive value in the chukar, a species that spends much of its activity walking, and due to its high measurement repeatability. Moving from the core toward the very extreme periphery of the range, the following four trends are detected: (1) the expression of the directional asymmetry component significantly increases; (2) the frequency of symmetrical individuals in the population significantly decreases, with a sharp decline at the steepest part of the climatic and environmental gradient studied, within the Mediterranean‐desert ecotone; (3) mean asymmetry levels, as estimated using the unsigned difference between the right and left toe, significantly increases; and (4) the range of asymmetry increases such that the most asymmetrical individuals originate from the very edge of the range. These findings provide primary evidence that substantial shifts in asymmetry may occur across short geographical distances within a species' distribution range. They show a continuum between asymmetry types and support the notion that all three types of asymmetry can reflect developmental instability. Further studies of developmental instability should be designed so that they enable detection of transitions between asymmetry types across natural populations. Such a procedure may partly resolve some of the contradictions seen in the literature regarding the relationship between bilateral asymmetry and environmental stress.     

Introgression of chukar genes into a reintroduced red-legged partridge (Alectoris rufa) population in central Italy

Insight regarding the genetic origin and composition of the studied population of the red-legged partridge (Alectoris rufa) is likely to provide general and critical information for the appropriate management and possible conservation of the species. The reintroduced population of red-legged partridges living in Pianosa Island (National Park Tuscany Archipelago) has proven to be sustainable: captive-bred individuals, morphologically assigned to the taxon A. rufa, were released to the island approximately 20 years ago, establishing an apparently well-adapted population. We have investigated this population by means of 10 microsatellite loci in order to shed light on its genetic structure. Considering that A. rufa is known to crossbreed with A. chukar, the Pianosa Island population was compared at the molecular level with a red-legged partridge breeding stock (Aulla, MS) as well as with a population of pure A. chukar. Our results indicate that the red-legged partridge population from Pianosa, morphologically identified as A. rufa, is actually partly introgressed with A. chukar, questioning its genetic purity and the possible use of this population as a starting stock for future reintroductions elsewhere.     

陇东黄土高原石鸡的分子系统地理结构

本文运用聚合链式反应和直接测序的方法测定陇东黄土高原 8个石鸡 (Alectorischukar)地理种群 78个样本的mtDNA控制区 4 91bp ,建立其分子系统地理结构。 78个样本共发现 2 4个变异位点 ,2 5种单倍型。 8个地理种群共享单倍型C1 ,6个种群共享单倍型C2 ,种群间有一定的基因交流。 8个地理种群的 2 5种单倍型在NJ树中相互混杂 ,没有形成独立的地理结构 ,但聚成两个分支。单倍型网络图显示 2 5种单倍型聚成两个星状的集群 ,分别以单倍型C1和C2为中心。这两个群间的遗传差异显著。陇东黄土高原石鸡的系统地理结构属于“系统发生连续 ,具有部分空间隔离”的地理格局。这种地理格局是更新世冰川、泥石流和人类活动共同作用的结果     

六盘山地区石鸡和大石鸡间的渐渗杂交

在六盘山地区发现鹑类的两种鸟类石鸡和大石鸡进行杂交,本实验采用PCR和RFLP的方法,分析了六盘山西侧20个大石鸡和东侧36个石鸡的mtDNA基因,发现宁夏海原5个和甘肃庄浪8个的大石鸡具有石鸡的基因型,说明这可能是雌性石鸡与雄性大石鸡杂交的结果,在六盘山东侧石鸡种群中没有发现大石鸡的基因型,其基因是从石鸡到大石鸡的单向流动。杂交后代的形态与大石鸡相似且体型比双亲都大。这种渐渗杂交可能是杂交个体与雄性大石鸡回交的结果。根据分子钟推测,这种不对称的基因流动,可能是由于冰期隔离后次级相遇形成的。杂交种可与雄性大石鸡回交。虽然还需要加大样本量来进一步研究这种不对称基因流动,但是持续的渐渗杂交会导致大石鸡基因的灭绝     

基于线粒体DNA控制区的石鸡华北亚种的种群历史动态研究

隶属于鸟纲鸡形目雉科的石鸡是一个多型种,在我国已有7个亚种被报道,其中石鸡华北亚种是我国的特有鸟。用石鸡华北亚种(Alectoris chukar pubescens)12个地理种群112个样本的线粒体DNA控制区(mt DNA CR)1154 bp序列的信息研究了石鸡华北亚种的种群历史动态。112个样本中共发现28个变异位点,定义了29种单倍型,其中12个地理种群的50个样本共享单倍型H1,8个地理种群的16个样本共享单倍型H4。地理种群间存在较大的基因流,且种群间没有由于地理距离产生隔离的证据。负的Tajima(D=-1.336,P0.05)和Fu(Fs=-1.720,P0.05)统计检验值及错配分布的单峰模式都支持石鸡华北亚种经历了种群扩张。石鸡华北亚种大部分种群的错配分布与种群过去的扩张相一致,扩张发生在晚更新世中期的第五寒冷期(0.027—0.06 Ma)。推测其扩张的原因可能为:1)更新世期间我国北方地区没有发生大规模的冰川,2)青藏高原的隆升使我国北方干旱化和荒漠化加剧利于石鸡种群的扩散。武都(WD)位于东洋界,而石鸡是典型的古北界的鸟种,表明WD种群可能是石鸡在东洋界的一个建群种,因此需要给予充分的关注。     

Sixteen new polymorphic microsatellite markers isolated for red‐legged partridge (Alectoris rufa) and related species

We developed and tested 16 new polymorphic microsatellite markers for the red‐legged partridge (Alectoris rufa): four dinucleotide, two trinucleotide, eight tetranucleotide and two pentanucleotide repeat loci. The number of alleles per locus ranged from two to 21, observed heterozygosity was from 0.03 to 1.00 and expected heterozygosity was comprised between 0.18 and 0.91. Cross‐specific amplification in others members of the Phasianidae family highlighted the potential usefulness of these molecular markers for the study of related species.