四川南充市城市白头鹎的巢址选择和巢材研究

2005年3~9月,在四川南充市对白头鹎巢址进行了研究。主成分分析表明:影响白头鹎巢址选择的主要因素有7种,依次为巢位高度需求因素、栖位因素、巢上隐蔽因素、食物因素、种竞争因素、种内竞争因素、水源因素;其巢材较为广泛。     

DOES PREY BIOMASS OR MERCURY EXPOSURE AFFECT LOON CHICK SURVIVAL IN WISCONSIN?

Abstract: Past studies suggest that the productivity of common loons (Gavia immer) is lower on acidic lakes in northern Wisconsin, USA, than on neutral lakes. Two hypotheses have been proposed to explain low chick survival: (1) reduced food consumption related to changes in prey communities on lower pH lakes and (2) high mercury (Hg) exposure on lower pH lakes. To address these hypotheses, we quantified prey and Hg consumption by loon chicks on 51 lakes and survival on 55 lakes ranging in pH from 4.9 to 9.5 in northern Wisconsin in 1995 and 1996. The time adults spent providing prey to chicks was unrelated to lake pH but increased with number of chicks and chick age. The number of prey caught per provisioning time declined as lake pH declined because adults made fewer dives, not because success of prey capture declined. Chicks consumed more insect larvae on acidic lakes and more crayfish (Family Astacidae) on neutral lakes. Biomass consumed ranged from an average 1.99 ± 1.05 (SE) g/hr/chick during the first week of a chick's life to a peak of 7.93 ± 1.93 g/hr/chick during the eighth week. Biomass intake per chick body weight (g/W_g/hr) declined with lake acidity but was not related to chick survival (P = 0.25). Although the Hg concentration in the 3 major prey species was positively related to lake acidity and blood Hg level of chicks at a lake, total Hg consumption (μg/W_g/hr) was highest on moderately acidic lakes rather than on the most acidic lakes. We suggest that loon chick survival in northern Wisconsin lakes is more likely related to prey availability than to Hg exposure. When we removed from our analysis 1 lake where 2 11-day-old chicks were killed by predators, chick survival was negatively related to lake acidity but not to biomass or Hg consumption. We discuss mechanisms of Hg excretion that may allow young chicks to survive on acidic lakes in northern Wisconsin despite high Hg intake.     

新疆巴音布鲁克繁殖期大天鹅的生境选择

2011年和2012年的6-8月,考察了分布于巴音布鲁克自然保护区的大天鹅(Cygnus cygnus)种群,分析了大天鹅巢址选择特征和育雏期生境选择特征。在野外共记录到了26个大天鹅巢址。与对照样方比较发现,植被高度、水深、所在水域面积、距干扰源距离和安全等级存在显著差异。进一步逻辑斯蒂回归分析表明,植被高度、水深和安全等级是影响大天鹅巢址选择的最主要的3种生境因子。采用样线法对育雏期大天鹅的生境选择进行了调查,发现大天鹅对沼泽湿地表现出正选择性,对草地表现出负选择性。样方法调查中,利用样方与对照样方比较发现,9种生境因子均存在显著差异,逻辑斯蒂回归分析表明,距干扰源距离和安全等级是影响大天鹅育雏期生境选择的最重要的两种因子。这样的选择机制有利于大天鹅更好的躲避敌害,顺利完成孵化和育雏工作。     

Do movement behaviors identify reproductive habitat sampling for wild turkeys?

Selection of habitats has regularly been suggested to influence species demography at both local and broad scales. The expectation is that selection behaviors have positive benefits via greater fitness or increased survival. The current paradigm of habitat selection theory suggests a hierarchical process, where an individual first selects where they choose to live (e.g., range) and then searches and selects locations within this range meeting life history needs. Using high‐frequency GPS data collected from reproductively active Rio Grande (n = 21) and Eastern (n = 23) wild turkeys, we evaluated a long‐standing theory for ground‐nesting galliformes, in that movements during the prenesting period are behaviorally focused on sampling available habitats to optimize the selection of nesting sites. Contrary to expectations, we found no evidence that reproductively active females engage in habitat sampling activities. Although most nest sites (>80% for both subspecies) fell within the prenesting range, the average minimum daily distance from nest sites for Rio Grande and Eastern wild turkey females was large [1636.04 m (SE = 1523.96) and 1937.42 m (SE = 1267.84), respectively] whereas the average absolute minimum distance from the nest site for both Rio Grande and Eastern wild turkey females was 166.46 m (SE = 299.34) and 235.01 m (SE = 337.90), respectively, and showed no clear temporal reduction as laying approached. Overall, predicted probability that any female movements before laying were initiated intersected with her nesting range (area used during incubation) was <0.25, indicating little evidence of habitat sampling. Our results suggest that the long‐standing assumption of hierarchical habitat selection by wild turkeys to identify nest sites may be incorrect. As such, habitat selection may not be the proximate driver of nest success and hence population‐level fitness. Rather, based on our results, we suggest that wild turkeys and other ground‐nesting species may be fairly plastic with regard to the selection of reproductive habitats, which is appropriate given the stochasticity of the environments they inhabit.     

黑颈长尾雉的巢址选择

2004年至2005年,在广西百色岑王老山自然保护区对黑颈长尾雉(Syrmaticus humiae)的巢址选择进行了研究。野外工作中共发现5巢,其中3巢在针叶林中,2巢在灌草丛中。结果表明,黑颈长尾雉的巢都是选择在向阳的东南坡且位于坡的下位,靠近林缘、水源和林间小道。对巢址10 m×10 m和1 m×1 m植被样方不同层次盖度作统计发现,黑颈长尾雉巢址选择更多的依赖于灌木层和草本层的盖度。     

影响灰脸鵟鹰巢址选择的主要生态因素

1996～1997年,在吉林省左家自然保护区及土门岭地带对灰脸鵟鹰(Butastur indicus)的巢树和巢址特点进行了系统研究。运用逐步判别分析的方法,通过对因子进入判别方程的先后顺序检测因子的重要性,通过对Wilk’sλ值的检测确定各因子对判别模型的贡献率,根据生态因子的重要性和贡献率大小确定影响灰脸鵟鹰巢址选择的主要生态因素。两年共观测灰脸鵟鹰的巢址12处,其中83．3％(n=10)位于山坡的上部位置,66．7％(n=8)位于山北坡;在灰脸鵟鹰所利用的巢树中,松科(Pinaceae)植物占的比例最大,为75％(n=9)。逐步判别分析结果表明,胸径大于30cm乔木的基面积、针叶林的基面积和灌木数量等生态因子是影响灰脸鵟鹰巢址选择的主要生态因素。     

鸡形目鸟类巢址选择研究进展

鸟巢是鸟类繁育后代的场所, 巢址选择对鸟类的生存和繁衍意义重大。许多鸡形目Galliformes鸟类被列入IUCN濒危物种红色名录, 了解其巢址选择的特征及影响因素有助于采取针对性保护措施。本文从影响鸡形目鸟类巢址选择的植被、地理和温度3个因素综述了其巢址选择特点, 指出未来的研究方向应包括探明巢址选择的机制、从不同时空尺度进行研究, 以及探索未知的筑巢策略。     

浙江五峙山列岛黄嘴白鹭的巢位选择研究

黄嘴白鹭(Egretta eulophotes)是全球性受威胁鸟类。2005年7月, 我们在浙江五峙山列岛对黄嘴白鹭的巢位选择进行了研究, 共测量了74个巢。研究发现, 在0.99 hm2的馒头山小岛上, 黄嘴白鹭的巢呈聚集性分布, 平均巢间距为119.6 cm, 最小巢间距为15 cm。黄嘴白鹭对巢位具有明显的选择性, 优先选择在灌丛, 尤其是那些相对较高的灌丛(高于50 cm)下营巢, 其次是较低的灌木(低于64 cm)内部和草丛上。多数巢存在遮蔽物。避风和遮荫是黄嘴白鹭巢位选择的主要要求。台风是决定五峙山列岛黄嘴白鹭巢位选择的最主要因素, 而高灌木的数量直接影响五峙山列岛黄嘴白鹭的繁殖成功和今后的资源状况。