高山兀鹫繁殖期交配及筑巢行为初步观察

高山兀鹫(Gyps himalayensis)在海拔2 400~4 800 m的悬崖峭壁之上营巢,行为观测难度较大,资料匮缺。2013年至2015年,在天山采用样线调查法、问卷调查法,寻找到上百个巢穴。通过布设红外自动相机的方法,对高山兀鹫繁殖期巢内行为进行拍摄,同时结合焦点动物取样法和瞬时扫描法,对其交配及巢内行为进行观察和研究。共拍摄11万张照片,选出有效照片2 150张。对繁殖期行为进行了描述和定义,共7大类16种行为。根据照片逐一对比每种行为,统计各种行为拍摄张数及所占比例,其中,交配135张(6.3%),筑巢403张(18.7%),休息420张(19.5%),警戒375张(17.4%),保养335张(15.6%),运动200张(9.3%),其他282张(13.1%)。照片记录显示,交配行为从1月16日持续到3月2日,在一天的8:00~16:00时间段内,除9:00~10:00时没有记录到交配行为外,其余时间段内都有发生。交配行为次数(张数)在13:00~14:00时达到高峰,与气温同期达到高峰。交配过程持续8~15 s。筑巢期间,巢材由雌雄兀鹫运输,雌性负责将巢材放入巢中,整理、铺垫和修缮。筑巢行为在白天有三个高峰期,分别为11:00~12:00时、13:00~14:00时和15:00~16:00时。在每个高峰期后,往往出现一个短暂的低谷期。冬季食物短缺,照片显示雕鸮(Bubo bubo)、雪豹(Uncia uncia)等食肉动物进入巢内,对兀鹫繁殖造成干扰,甚至中断繁殖。作为高原健康指示物种,高山兀鹫生存状况不容乐观,急需加强保护。     

北热带石灰岩地区红耳鹎的繁殖生态和巢址选择

热带鸟类的生活史进化策略与温带鸟类的不同,而迄今国内对热带鸟类的研究却非常缺乏,红耳鹎(Pycnonotus jocosus)在我国北热带地区分布广泛,是较为理想的研究对象。2010年至2014年春夏季,对北热带石灰岩地区红耳鹎的繁殖生态和巢址选择进行了研究。采用系统搜寻法并根据亲鸟行为寻巢,应用方差分析和主成分分析对相关数据进行处理。结果显示,红耳鹎的产卵期集中在4月中旬至5月下旬,喜筑巢于灌木和人工种植的苹婆(Sterculia nobilis)树。平均窝卵数为(3.4±0.5)枚(3~4枚),卵重(2.59±0.29)g,卵大小(21.10±1.73)mm×(15.35±1.50)mm(n=31)。总的繁殖成功率为36.16%,繁殖失败的主要原因是天敌捕食、弃巢和人为干扰。一年繁殖一次和较低的繁殖成功率是研究地的红耳鹎有较大窝卵数的主要原因。红耳鹎在巢址选择时主要考虑避雨因子、避敌因子和灌木因子。     

Characterization of plasma cholinesterase activity in the Eurasian Griffon Vulture Gyps fulvus and its in vitro inhibition by carbamate pesticides

The legal and illegal use of organophosphorus and carbamate pesticides represents one of many threats to birds. The activity of the cholinesterase enzyme in plasma is used as a non‐destructive biomarker to diagnose the exposure of birds to these pesticides. Scavengers are one of the most important bird groups threatened by the use of baits poisoned with anticholinesterase pesticides. Knowledge of the characteristics of this enzyme in each bird species is crucial, as several studies indicate that more than one cholinesterase form may be present in the plasma of birds. In this study, cholinesterase activity was characterized in the plasma of the Eurasian Griffon Vulture Gyps fulvus by using several substrates and inhibitors of the enzyme, and its normal activity value was also determined. The in vitro sensitivity of Gyps fulvus plasma cholinesterase to carbamate insecticides (aldicarb, carbaryl and methomyl) was also investigated. The results indicated that propionylthiocholine iodide was the preferred substrate to determine plasma cholinesterase activity, followed by acetylcholine iodide and S‐butyrylcholine iodide, and acetylcholinesterase was the predominant enzymatic activity in Gyps fulvus plasma. Aldicarb was the most potent in vitro inhibitor of plasma cholinesterase activity in this species. However, cholinesterase enzymatic activity was significantly inhibited by all tested carbamates, providing further evidence that this biomarker is a suitable tool to monitor the exposure to these poisons in the field, highlighting its utility in conservation programmes.     

兀鹫在中国的分布

兀鹫(Gyps fulvus)隶属于隼形目(Falconiformes)鹰科(Accipitridae),被列入CITES附录Ⅱ,在国内几乎没有相应的研究。作者于2013年6月5日在西藏阿里地区改则县(33°6′52.2″N,85°39′9.18″E,海拔5 021 m)发现1只兀鹫。结合国内其他研究者的记录,此次发现增加了我们对兀鹫分布区的认识,表明了兀鹫在西藏的分布区可能被低估。根据以前研究者对兀鹫种群数量的估计值(100~300只)和平均群体大小(3只或4只或单只),以及本次的发现,我们认为兀鹫在新疆、西藏仍有未被发现的分布区,且在新疆、西藏的邻近省份可能存在其潜在分布区;此前兀鹫在西藏地区未有确切的观察记录或照片,本次记录可为西藏珍稀物种的保护提供依据。     

Density-dependent effects on productivity in the Griffon Vulture Gyps fulvus: the role of interference and habitat heterogeneity

Griffon Vultures Gyps fulvus in northern Spain were studied between 1969 and 1994. The number of breeding pairs increased from 221 in 1969–1975 to 1395 in 1994. The annual population growth rate decreased in the last 5 years, and this may reflect population regulation through density-dependent phenomena. Breeding success was monitored in 1994 and examined in relation to colony size, density of breeding pairs within a radius of 25 km (regional density), climate, human disturbance and food availability. We also recorded whether the year of first occupation of each nest site was before 1989 or after 1989 and whether or not the nest had a rocky shelter. The probability of successfully raising young declined as the regional density increased, which suggests that resource limitation would take place at foraging sites because the Griffon Vulture scavenges socially and no permanent feeding hierarchies are established. The other significant variable was the year of occupation of the nest; nests occupied after 1989 had a lower probability of raising a chick. The increase in the regional density of Griffon Vultures produced a decrease in the productivity at both optimal and suboptimal nest sites. This suggests that density-dependent regulation of breeding success operates through interference and that all the individuals in a colony are similarly affected. In birds of prey, prevalence of interference or habitat heterogeneity may be dependent on the social strategy of each species in space exploitation.     

On the evolution of clutch size and nest size in passerine birds

Summary I examined the hypothesis that the clutch size of some altricial birds may be limited by over-crowding of the nestlings in the nest, by comparing data on different species of European passerines. Large-sized birds build, relative to the body, larger nests than small-sized birds, both as regards the inner and the outer nest widths and as regards edge breadth; only inner nestcup depth did not change relatively to body size. Nest size also varied in relation to nesting place. Birds with open nests built off the ground had a rather narrow nestcup, whereas those with a domed nest, or which nest in a cavity, had a wide nestcup. When only open-nesters were compared, birds nesting on, or close to, the ground tended to have a wider nestcup than birds nesting above the ground. Inner nestcup width was correlated with the amount of mosses and lichens used in building the nest; the more of such materials the narrower the nestcup. The three variables: standardised body size, nesting place, and type of nesting material used accounted for 92% of the overall variation observed in inner nestcup width. When controlling for adult body size, clutch size was positively correlated with the size of the nestcup. A multiple regression analysis showed that relative nestcup depth, nest site, and type of nesting materials used, accounted for 64% of the overall variation in clutch size.     

Modelling the effect of environmental variables on the reproductive success of Griffon Vulture (Gyps fulvus) in Sardinia,Italy

Old World vultures are experiencing dramatic population declines and now are among the species most threatened with extinction. Understanding the environmental variables that can influence the reproductive indexes of vulture populations can facilitate both habitat and species management. The aim of this study was to identify which environmental variables primarily affect the breeding successes of the Griffon Vulture Gyps fulvus in northern Sardinia by applying a Bayesian hierarchical model. A unique dataset of reproductive records (197 nests monitored over 39 years for a total of 992 breeding records) was used. Eight environmental and topographical variables describing the habitat at the nesting sites were considered as potential predictors of breeding success. These included mean annual temperature, mean annual precipitation, isothermality, elevation, the normalized difference vegetation index, wind speed, and the aspect and slope of the land surface. In addition, we also considered the effect of human disturbance and the type of nest. According to our best model, the probability of successfully raising a chick in Griffon Vultures was higher in nests exposed to a high wind speed, not covered by natural shelters, where the vegetation was mostly represented by shrub and pastures, with low human disturbance and in years with low rainfall. This model will be useful for management of the breeding habitat and to identify the area most suitable for Griffon Vulture reproduction. This information is crucial for programming conservation measures aimed at enlarging the area of occupancy of the species.     

甘肃莲花山黑冠山雀繁殖生态的初步研究

2017和2018年每年的4至8月在甘肃莲花山国家级自然保护区,对人工巢箱中黑冠山雀（Periparus rubidiventris）的繁殖生态进行了研究。共悬挂100个巢箱,两年共计招引到15巢黑冠山雀。此外,还记录到4个自然巢,分别位于干枯的糙皮桦（Betula utilise）树洞（1巢）、土坡的缝隙（1巢）和路边水泥护坡的出水管中（2巢）。黑冠山雀雌雄亲鸟共同筑巢,巢内壁为兽毛夹杂少量绒羽,外壁为草茎须根和苔藓。5月中下旬为黑冠山雀的产卵高峰期,清晨产卵,日产1枚,产下最后1枚卵后开始孵卵。平均窝卵数为6枚（4 ~ 7 枚,n = 15）,平均卵重（1.12 ± 0.02）g,卵长径（15.30 ± 0.10）mm,卵短径（12.09 ± 0.11）mm（n = 86）。孵卵由雌鸟承担,孵卵期为15 d（14 ~ 16 d,n = 5）。产卵期,雌鸟离巢时有用巢材盖卵的行为,开始孵卵后则不再盖卵。双亲共同育雏,育雏期为16 d和17 d（n = 2）。所记录的18巢黑冠山雀的繁殖成功率为83.3%,人工巢箱（15巢）中繁殖成功率为86.7%,巢捕食者主要为鼠类。     

营巢类型、巢捕食和窝卵数对高寒草甸雀形目雏鸟生长期的影响

根据1998—2001年高寒草甸10种雀形目鸟类的窝卵数、雏期和巢捕食数据,以Logistic方程拟合雏鸟生长过程,并计算出有关生长率参数;根据营巢类型将10种雀形目鸟划分为开放或半开放类群(GOB)和全封闭穴居类群(HCB)两类,将把雏鸟的生长过程划分为3个生长期(缓增期、快增期和渐增期)。3个生长期占雏期的比例因营巢类型而异,GOB类群快增期>渐增期>缓增期;HCB类群渐增期>快增期>缓增期。分析营巢类型、巢捕食和窝卵数与各生长期之间的关系,结果表明3个生长期的体重积累占离巢时体重的比例因巢型不同而有显著差异;营巢类型和巢捕食显著影响各生长期占雏期的比例和体重积累占离巢时体重的比例;窝卵数影响快增期和渐增期长度,而不影响缓增期长度。快增期体重积累与渐增期的生长率不相关,但与渐增期长度显著相关。因此,前期的能量积累不影响后期生长率,而影响后期生长的长度。该结果进一步印证在晚成鸟中不存在补偿性生长。     

天山南麓山前平原柽柳灌丛地上生物量

基于天山南麓山前平原柽柳灌丛样地调查和实验,研究了柽柳的地上生物量及其分布规律.结果表明,不同地貌带柽柳的地上生物量差异较大.在溢出带,柽柳的地上生物量最大,达1428.53 kg·hm^-2,其次是三角洲带和洪水剥蚀带,柽柳的平均地上生物量分别为745.97和544.37 kg·hm^-2,而两河交汇区柽柳的地上生物量最小,仅为111.18 kg·hm^-2.造成这种差异的主要原因是不同地貌带柽柳的密度不同.在轮台天山南麓山前平原4个地貌样带中,柽柳的地上生物量与表层土壤盐分含量均随地下水埋深的增加而下降,呈良好的相关性,但土壤盐分并不是影响柽柳地上生物量的主要因素,影响柽柳生长的主要生态因子是地下水埋深.