Helpers and egg investment in the cooperatively breeding acorn woodpecker: testing the concealed helper effects hypothesis [0.03%]
合作繁殖的橡树啄木鸟中的辅助者和卵投资：检验隐藏的助手效应假说
Walter D Koenig,Eric L Walters,Joseph Haydock
Walter D Koenig
In cooperatively breeding acorn woodpeckers (Melanerpes formicivorus), helper males have a large positive effect on fledging success in good acorn crop years but only a small positive effect in poor acorn crop years, while helper females ex...
The effect of rearing environment on blue structural coloration of eastern bluebirds (Sialia sialis) [0.03%]
饲养环境对东方蓝鸟(Sialia sialis)蓝色结构色的影响
Lynn Siefferman,Geoffrey E Hill
Lynn Siefferman
We used a brood-size manipulation to test the effect of rearing environment on structural coloration of feathers grown by eastern bluebird (Sialia sialis) nestlings. Ultraviolet (UV)-blue structural coloration has been shown to be sexually ...
Body size preferences in the pot-bellied seahorse Hippocampus abdominalis: choosy males and indiscriminate females [0.03%]
腹部拟腹海马Hippocampus abdominalis体形偏好：挑剔的雄性与无所谓的雌性
Beat Mattle,Anthony B Wilson
Beat Mattle
Male seahorses (genus Hippocampus) provide all post-fertilization parental care, yet despite high levels of paternal investment, these species have long been thought to have conventional sex roles, with female mate choice and male-male comp...
Food site residence time and female competitive relationships in wild gray-cheeked mangabeys (Lophocebus albigena) [0.03%]
食物场地停留时间和野生白颊燕尾猴(Lophocebus albigena)的雌性竞争关系
Rebecca L Chancellor,Lynne A Isbell
Rebecca L Chancellor
Authors of socioecological models propose that food distribution affects female social relationships in that clumped food resources, such as fruit, result in strong dominance hierarchies and favor coalition formation with female relatives. ...
Female-biased sex allocation of offspring by an Apodemus mouse in an unstable environment [0.03%]
不稳定的环境中通过小鼠Apodemus雌性偏态分配后代性别比例
Fumihito Shibata,Takeo Kawamichi
Fumihito Shibata
We investigated the effects of population fluctuation on the offspring's sex allocation by a weakly polygynous mouse, Apodemus argenteus, for 3 years. In acorn-poor seasons, heavier mothers invested more in sons, and lighter mothers investe...
Developmental stress affects song learning but not song complexity and vocal amplitude in zebra finches [0.03%]
发育压力影响斑马雀歌曲学习但不影响歌曲复杂性和鸣叫幅度
Henrik Brumm,Sue Anne Zollinger,Peter J B Slater
Henrik Brumm
Several recent studies have tested the hypothesis that song quality in adult birds may reflect early developmental conditions, specifically nutritional stress during the nestling period. Whilst all of these earlier studies found apparent li...
Aging and demographic plasticity in response to experimental age structures in honeybees (Apis mellifera L) [0.03%]
Olav Rueppell,Robyn Linford,Preston Gardner et al.
Olav Rueppell et al.
Honeybee colonies are highly integrated functional units characterized by a pronounced division of labor. Division of labor among workers is mainly age-based, with younger individuals focusing on in-hive tasks and older workers performing t...
Mark E Laidre,Sandra L Vehrencamp
Mark E Laidre
In this commentary, we discuss recent experiments on the reliability of bird song as a signal of aggressive intent during territorial conflicts. We outline relevant theoretical views on honest signaling, highlighting the vulnerability handi...
Sex-biased lactational duration in a human population and its reproductive costs [0.03%]
人口中哺乳时间的性别偏向及其生殖成本
S W Margulis,J Altmann,C Ober
S W Margulis
The authors tested the proposition that among humans (1) differences in lactational duration result in differences in costs of reproduction even under rich nutritional conditions; and (2) elimination of factors postulated to favor male-bias...