SEASONAL AND INTERANNUAL VARIABILITY IN LAYING DATE, CLUTCH SIZE, EGG VOLUME AND HATCHING ASYNCHRONY OF FOUR LARK SPECIES IN MEDITERRANEAN SPAIN

• Main Authors: Francisco Suárez, Jesús Herranz, Miguel Yanes, Ana M. Sánchez, Jesús T. García, Juan Manrique
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Gata; Alauda arvensis
• 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.—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