SEASONAL AND INTERANNUAL VARIABILITY IN LAYING DATE, CLUTCH SIZE, EGG VOLUME AND HATCHING ASYNCHRONY OF FOUR LARK SPECIES IN MEDITERRANEAN SPAIN
SUMMARY.—Seasonal and interannual variability in laying date, clutch size, egg volume and hatching asynchrony of four lark species in Mediterranean Spain Aims: To describe the variation in laying date, clutch size, egg volume and hatching asynchrony of four lark species (Skylark Alauda arvensis, Sho...
Main Authors: | , , , , , |
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Format: | Text |
Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.384.1990 http://www.escet.urjc.es/biodiversos/publica/ardeola 2-2005 alondras.pdf |
Summary: | SUMMARY.—Seasonal and interannual variability in laying date, clutch size, egg volume and hatching asynchrony of four lark species in Mediterranean Spain Aims: To describe the variation in laying date, clutch size, egg volume and hatching asynchrony of four lark species (Skylark Alauda arvensis, Short-toed Lark Calandrella brachydactyla, Thekla Lark Galerida theklae and Lesser Short-toed Lark Calandrella rufescens) and at two different time scales: between years (large-scale variation), and within seasons (short-scale variation). Location: Two climatically contrasting Mediterranean areas: Layna, located in the centre of the Iberian Peninsula and with a continental Mediterranean climate, and Cabo de Gata, located in the south-western Iberian Peninsula and with a semi-arid climate. Breeding Skylarks and Short-toed Larks occur in Layna, whereas breeding Thekla Larks and Lesser Short-toed Larks occur in Cabo de Gata. Methods: During the study period between 1991-95 in Layna and between 1991-94 and 1996-97 in Cabo de Gata, searches were carried out for nests of the four species and laying date, measured egg-length and width, and hatching asynchrony recorded. Overall, 118 nests of Skylarks, 165 of Short-toed Larks, 334 of Thekla Larks and 259 of Lesser Short-toed Larks were studied. Between-year variations in breeding parameters were analysed with General Linear Models (GLM’s). To investigate the presence or absence of |
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