Influence of Radiotransmitters on Fecal Glucocorticoid Levels of Free-Ranging Male American Kestrels

Author(s)

Garcia Pereira, Ricardo Jose ^[1] ; Monteiro Granzinolli, Marco Antonio ^[2] ; De Barros, Fabio Monteiro ^[2] ; Barbanti Duarte, Jose Mauricio ^[3]

Affiliation

^[1] UNESP, Fac Ciencias Agr & Vet, Postgrad Dept Reprod Anim, BR-14884900 Jaboticabal, SP - Brazil

^[2] Univ Sao Paulo, Dept Ecol, Inst Biociencias, Lab Ecol Aves, BR-05508900 Sao Paulo - Brazil

^[3] UNESP, Fac Ciencias Agr & Vet, Nucleo Pesquisa & Conservacao Cervideos, BR-14884900 Jaboticabal, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF WILDLIFE MANAGEMENT; v. 73, n. 5, p. 772-778, JUL 2009.
• Web of Science Citations: 7

Abstract

Although radiotelemetry is considered a valuable technique for ornithological field studies, several assumptions have been made about the impact that transmitters may have on the estimation of behavioral, ecological, and reproductive parameters. To assess the potential effects of backpack radiotransmitters, we captured and assigned 8 male American kestrels (Falco sparverius) into 2 groups: radiotagged (n = 6) and control individuals (leg-banded, n = 2). Thereafter, we collected feces approximately 2 hours after capture (day -1), and subsequently during days 0 (releasing day), 4, 7, 15, 30, 40, and 55. Prior to fecal analysis, we validated the corticosterone enzyme immunoassay using standard procedures (e. g., parallelism, dose-response curve), and we confirmed physiological significance of fecal glucocorticoid metabolites through adrenocorticotropin challenge, which induced an increase of 4-fold (446.10 +/- 60.73 ng/g) above baseline (114.27 +/- 15.23 ng/g) within 4 hours (P < 0.001). Both groups exhibited a significant increase in fecal glucocorticoids during day 0 (P < 0.001), but concentrations returned to preattachment values within 4 days. Fecal glucocorticoid concentrations did not differ between samples of radiotagged and leg-banded kestrels (P > 0.05). In spite of the small number of monitored subjects, these findings suggested that radiotransmitters did not affect adrenocortical activity in these male American kestrels. (JOURNAL OF WILDLIFE MANAGEMENT 73(5): 772-778; 2009) (AU)

• FAPESP's process: 05/01927-4 - Behavioral and endocrinological monitoring of the annual reproductive activity of free-ranging American kestrel males (Falco sparverius)
• Grantee: Ricardo Jose Garcia Pereira
• Support Opportunities: Scholarships in Brazil - Doctorate