Publication
Title
Variation in plasma oxidative status and testosterone level in relation to egg-eviction effort and age of brood-parasitic common cuckoo nestlings
Author
Abstract
To avoid competition for parental care, brood-parasitic Common Cuckoo (Cuculus canorus) nestlings evict all of the host's eggs and nestlings within a few days after hatching. Little is known about the physiological effects of eviction behavior on the cuckoo nestling's oxidative balance or about age-related variation in plasma oxidative status and testosterone level of developing birds. We examined whether the cuckoo nestling's plasma oxidative status was related to prior effort in eviction and quantified variation in the level of reactive oxygen metabolites, of nonenzymatic antioxidant capacity, and of testosterone concentration in plasma at various phases of the cuckoo's development. Levels of both reactive oxygen metabolites and antioxidant capacity were greater in older than in younger nestlings, suggesting that younger nestlings effectively counterbalance their increased production of free radicals, whereas, near fledging, levels of reactive oxygen metabolites increase despite improved antioxidant capacity. Possibly, overall energy expenditure increases with age and elevates the production of reactive oxygen species to a rate higher than what the antioxidant system could eliminate. Plasma testosterone level was the highest at nestlings' intermediate phase of growth. High levels of testosterone may be required during the period of fastest growth, and when the growth rate levels off near fledging, testosterone levels may also decline. Cuckoo chicks that evicted more host eggs from steeper nests had higher plasma levels of reactive oxygen metabolites shortly after the eviction period, suggesting that eviction is costly in terms of an increased level of oxidative stress.
Language
English
Source (journal)
Condor: journal of the Cooper Ornithological Society. - Berkeley, Calif.
Publication
Berkeley, Calif. : 2012
ISSN
0010-5422
Volume/pages
114:4(2012), p. 782-791
ISI
000311882700012
Full text (Publishers DOI)
Full text (publishers version - intranet only)
UAntwerpen
Faculty/Department
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 06.10.2015
Last edited 10.05.2017