Egg investment strategies adopted by a desertic passerine, the Saxaul Sparrow(Passer ammodendri)

Background:As one of the reproductive strategies adopted by bird species,variation in investment in egg production and its influencing factors are important and well-studied subjects.Intraclutch changes in egg size associated with laying order may reflect a strategy of"brood survival"or"brood reduction"adopted by female birds in different situations.Methods:We conducted field studies on the breeding parameters of the Saxaul Sparrow(Passer ammodendri)in Gansu Province,China from 2010 to 2017,to clarify the factors affecting the egg investment and reproductive performance of this passerine species.Results:Our results revealed significant differences in clutch size,egg size and the fledging rate between the first and second brood of Saxaul Sparrows and suggested that this typical desert species allocates more breeding resources to the more favourable second brood period,leading to greater reproductive output.Female body size presented a positive relationship with egg size,and male body size presented positive relationships with clutch size and hatchability.The females that started their clutches later laid more eggs,and hatchability and the fledging rate also increased with a later laying date in the first brood period.With successive eggs laid within the 5-egg clutches(the most frequent clutch size),egg size increased for the first three eggs and then significantly decreased.Conclusions:Our results indicate that female Saxaul Sparrows increased egg investment because of good quality of paired males and good environmental conditions.The intraclutch variation of egg size suggests that this species inhabiting an arid environment adopts a"brood reduction"strategy.

黑顶麻雀的巢址选择

2009年在安西极旱荒漠国家级自然保护区对黑顶麻雀Passer ammodendri的巢址选择进行了研究。所发现的92个黑顶麻雀只营巢于沙枣Elaeagnus angusifolia上,巢位于营巢树树高的1/3处。分析表明,黑顶麻雀偏好在胸径较大且较高的树上营巢,以减少环境的影响,同时选择枝条数最多的位置,增加巢的稳定性和隐蔽性,减少被天敌捕食的机率。黑顶麻雀对巢址特征的选择是其对大风天气环境的适应和减小捕食压力的结果。

巴音温都尔沙漠春季鸟类多样性调查

对巴音温都尔沙漠的国家级自然保护区——乌拉特梭梭林-蒙古野驴自然保护区进行了考察。2019年5月,调查组较为系统地对巴音温都尔沙漠地区的春季鸟类的种类、分布和生境等进行了调查,共观察到鸟类10目24科51种,其中国家重点保护鸟类8种。调查结果显示:春季鸟类中,共有留鸟17种、夏候鸟30种、旅鸟6种、居留型不确定鸟类1种;繁殖鸟(包括夏候鸟和留鸟)47种,占总数的92.2%;鸟类区系以古北界鸟类为主,占繁殖鸟种数的85.1%。本次调查为未来研究巴音温都尔沙漠地区鸟类多样性提供基础性资料,也为未来监测治理巴音温都尔沙漠的成效提供生物指标。

Male parent birds exert more effort to reproduce in two desert passerines

Background:Parental investment by birds is limited by the habitat environment,and a male parent increases its effort to reproduce in birds that live in high-altitude areas.Methods:A study of the reproductive behaviour of the Saxaul Sparrow(Passer ammodendri)and the Isabelline Shrike(Lanius isabellinus)was carried out at the Gansu An’xi Extremely Arid Desert National Nature Reserve in northwest China to determine the reproductive input of passerine species in desert habitats.Results:In Saxaul Sparrows,compared to the female parent,the male parent exhibited a significantly higher fre-quency of nest-defense behaviour(chirping and warning)during nesting,hatching and feeding periods.In addition,in comparison to the female parent,the male parent exhibited almost equal frequencies of nesting and incubation but fed nestlings significantly more times.Similar to the male sparrows,the feeding rates of the male Isabelline Shrikes were significantly higher than those of the females.The hatching rate and fledging rate of the Saxaul Sparrow on aver-age in this study were 81.99 and 91.92%,respectively,while those of the shrike were 69.00 and 96.53%,respectively.Conclusions:These two different passerine species living in the same desert environment exhibited the same trend in their reproductive investments.Adapting to desert environments is a strategy that may have evolved in passerines where male parent birds put more effort than females into reproduction to ensure high reproductive output.

民勤县民昌路荒漠区林业鼠害调查及综合防治技术

通过调查武威市石羊河民昌南路干旱荒漠区荒漠植被主要林业有害生物发生情况,发现鼠害是毁坏林业资源的主要原因。通过进一步了解民昌路管护区梭梭生长主要鼠害及其发生危害情况,分析其发生特点和原因,并结合有效防治经验,对照比较分析,归纳并总结出鼠害相关综合防治技术,不但有助于保护荒漠区林木植被,而且在维护林业生态植被方面也有着重要的意义。