[Use of biometrical data for studies Corncrake Crex crex population in Latvia]
Keiss, O.(University of Latvia, Riga (Latvia). Faculty of Biology. Dept. of Zoology and Animal Ecology)E-mail:grieze@lanet.lv | Granats, J.(University of Latvia, Riga (Latvia). Faculty of Biology. Dept. of Zoology and Animal Ecology) | Mednis, A.(University of Latvia, Salaspils (Latvia). Inst. of Biology. Dept. of Ornithology)
The Corncrake Crex crex population in Latvia was monitored by capturing 509 individuals in the time period between 1995 and 2003. During the breeding season Corncrakes attracted by playback of the territorial call of the male were captured at night, and during the migration birds were captured by cage traps. Only birds, which were identified as males (n=498) and captured during the breeding season (May - July) were analyzed, except for variation in size by age, when all birds (including those captured on migration) with known age were used. Wing length of Corncrake males in Latvia varied between 130 mm and 152 mm (mean = 142.1; SD = 4.22; n = 455), tarsometatarsus length between 35.6 mm and 50.0 mm (mean = 40.5; SD = 2.94; n = 181), and weight between 134 g and 182 g (mean = 162.8; SD = 11.1; n = 120). Significant differences (p less than 0.01) in wing length were observed in males from Latvia and other European countries, and comparing other countries with each other, but the expected tendency for northern animals of the species being larger than their con-specifics in the south was not clearly observed.
显示更多 [+] 显示较少 [-]