Nonrandom dispersal of kin: why do European bee-eater (Merops apiaster) brothers nest close together?

Dispersal of close relatives within a breeding colony of Europeanbee-eaters, Merops aptaster, was investigated by comparing thespatial separation of breeding relatives with that between thesame individual and a control individual hatched nearby in thesame year. One-year-old males breed closer to their brothers,but not to their parents, than do controls. The main benefitof breeding in proximity to relatives appears to be enhancedhelping behavior: potential helpers are more likely to helpand to help more quickly after nest failure when their own nestis close to that of the potential recipient of help. Breedingin proximity to relatives also appears to carry a cost becausenest failure is spatially aggregated: this implies that individualsbreeding close to relatives are less likely to have a relativeavailable to help should their own breeding attempt fail. Therewas no evidence that the proximity of relatives enhanced nestestablishment, defense against predators, or information transfer.     

蓝喉蜂虎的捕食行为与食性

在我国有分布的7种蜂虎科鸟类中,蓝喉蜂虎(Merops viridis)分布范围最广,但相关野外研究还比较少。2011~2016年,我们以江西省吉安市郊区的一个蓝喉蜂虎种群为研究对象,在观察野外捕食行为的基础上,记录了其食物种类,研究了该鸟的食性。蓝喉蜂虎的食物主要是蜂类、蝶类和蜻蜓类昆虫,其被捕食频次的百分比分别为26.0%、26.3%和38.3%。其中,繁殖前期以蜂类居多,繁殖后期以蜻蜓类居多,数量比例存在显著的季节性差异。这种差异可能是昆虫生活史差异造成的。网络图片资料佐证了其食物种类主要为以上3类昆虫。在吞食食物前,蓝喉蜂虎会对不同类群的昆虫进行不同时长和不同方式的处理。此外,野外研究发现,产卵期蓝喉蜂虎巢室中散布着可能被吞食过带有食物残渣的小型贝类碎片。通过实验筛选营巢河滩地的沙土,发现这些贝壳碎片是外来。这表明,蓝喉蜂虎可能通过取食小型贝类贝壳,在产卵期获取短期额外的钙质补偿。蓝喉蜂虎在其分布区内属不常见鸟类,但其捕食的主要昆虫类群在我国南方比较常见,这说明食物不是限制该鸟分布的原因。蓝喉蜂虎是一个极具观赏价值的美丽小鸟,当前亟需深入研究,为该鸟的保护提供决策依据。     

Microsatellite loci for behavioural studies of rainbow bee‐eaters (Merops ornatus: Aves)

A set of polymorphic microsatellite loci was identified for population and behavioural studies of the rainbow bee‐eater (Merops ornatus). Eight loci were newly isolated from a rainbow bee‐eater genomic library enriched for GA‐containing repeats, and six loci from those previously reported for the European bee‐eater (Merops apiaster). From these two sources, the seven most variable loci that amplified reliably were unlinked and in Hardy–Weinberg equilibrium, had five to 13 alleles (mean 7.7) and an expected heterozygosity of 0.60–0.86 (mean 0.73).