Parental body mass changes during the nestingstage in two Lark species in a semi-arid habitat

Parental body mass changes during the nesting period were analysed for Thekla Larks,Galerida theklae, and Lesser Short-toed Larks, Calandrella rufescens. Body mass of femaleThekla Larks declines from the start of incubation until the chicks fledge; laying date,interpreted as the number of renesting attempts, also has a negative effect. Body mass offemale Lesser Short-toed Larks was not related to any of these variables, except laying dateduring the incubation stage. Male Thekla Larks lost body mass during the nestling phase. Allfemale Thekla Larks which were recaptured lost body mass during incubation and femaleLesser Short-toed Larks lost body mass during the post-hatching period. Body mass lossesthroughout the whole nesting period were 14% and 16% for adult female Thekla Larks andLesser Short-toed Larks, respectively, and 2.5% and 2.6%, respectively, for the males of thesetwo species during the nestling phase. Body mass declines in the two species seem to be relatedto the number of clutches laid and not to clutch size, but the two show different patterns ofbody mass variation, which are also different from the only other lark of desert environmentsin which body mass when nesting has been studied to date.

F. Suarez, A.M. Sanchez, J. Herranz, J. Traba, M. Yanes, Journal of Arid Environments 62 (2005) 45-54