Open AccessResource allocation between growth and endothermy allows rapid nestling development at low feeding rates in a species under high nest predation
Author(s) -
Węgrzyn Ewa
Publication year - 2013
Publication title -
journal of avian biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.022
H-Index - 76
eISSN - 1600-048X
pISSN - 0908-8857
DOI - 10.1111/j.1600-048x.2013.05846.x
Subject(s) - altricial , biology , ectotherm , predation , nest (protein structural motif) , ecology , homeothermy , thermoregulation , fledge , zoology , adaptation (eye) , passerine , biochemistry , neuroscience
Nestling development is among the most energy‐demanding periods of a bird’s lifetime and altricial species require extensive parental energy investment in the form of feeding and heating. In the present study I analyze the relation and trade‐offs between nestling growth, development of thermoregulation and feeding rate in blackcap Sylvia atricapilla , a species suffering from high nest predation. Nestlings were characterized by rapid growth but they achieved only 80% of adult mass prior to fledging. Body mass showed highest relative growth rate before nestlings achieved homeothermy. The onset of endothermy, indicated in day 7, coincided with 90% of nestling fledgling weight, indicating that the two processes are separated in time. A strong negative correlation between feeding rate and growth rate demonstrates that blackcap nestlings develop their bodies under relatively low feeding rates and more feeding is needed for maintenance of body temperature than for body growth. The study indicates high cost of endothermy for parents – endothermic nestlings received over 100% more feedings than ectothermic ones. The findings are discussed in the light of adaptation of the species to high predation risk.