title: Variation in russet sparrow (Passer cinnamomeus) breeding biology in relation to small-scale altitudinal differences in China.
abstract: Evolution of avian life histories is typically strongly influenced by both altitude and latitude. To date, most studies have investigated the effects of extreme differences in altitude and latitude on variation in reproductive traits. Studies based on small altitude and latitude spans are needed to better understand the resolution of selective pressures. We compared several aspects of russet sparrow (Passer cinnamomeus) breeding biology between a low-altitude (200 m) and a high-altitude (1,500 m) population in China, representing a relatively small altitudinal gradient (1,300 m). High-altitude birds initiated breeding significantly later compared to their low-altitude counterparts. Interestingly, breeding season was significantly longer in the high-altitude site (57 vs. 84 d). Lowland sparrows laid larger clutches (4.92 vs. 4.09 eggs) and showed greater fledging success (4.20 vs. 3.46 fledgings) than did upland birds. Variation in life history traits thus appears to occur even along a small scale altitudinal gradient. We suggest that the longer breeding season and smaller clutch size in the highland population may be an adaptation or acclimation to compensate for the reduced annual productivity resulting from unfavourable or sub-optimal habitats for these sparrows.
authors: College of Life Sciences, Hainan Normal University, Haikou, People's Republic of China.
authors: Canchao
authors: C
authors: Yang
authors: Wei
authors: W
authors: Liang
authors: Yan
authors: Y
authors: Cai
authors: Junqiu
authors: J
authors: Wu
authors: Suhua
authors: S
authors: Shi
authors: Anton
authors: A
authors: Antonov
mesh_terms: D000531:Altitude; D000818:Animals; D002681:China; D052284:Clutch Size; D017753:Ecosystem; D012098:Reproduction / Q000502:physiology*; D046370:Sparrows / Q000502:physiology*; D013997:Time Factors