Effects of radiotransmitters on northern goshawks: Do tailmounts lower survival of breeding males?

Richard T. Reynolds, Gary C. White, Suzanne M. Joy, Robert W Mannan

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

We used the Cormack-Jolly-Seber model to estimate the effects of radiotransmitters on survival of breeding northern goshawks (Accipiter gentilis). We separately compared apparent annual survival of leg-banded goshawks with (1) tailmount- and (2) backpack-style radiotransmitters (hereafter tailmounts and backpacks) to apparent annual survival of breeding adults with legbands only. The best model without radiotransmitter effects, evaluated with Akaike's Information Criterion (AlCc), suggested no gender- or year-specific effects on survival. We then added radiotransmitter attachment type (tailmount or backpack) and mass of radiotransmitter as covariates to the base model to estimate the effect of radiotransmitters. Tailmounts on males significantly reduced apparent annual survival from 0.75 (SE = 0.02, 95% Cl: 0.71 to 0.78) without radiotransmitters to 0.29 (SE = 0.15, 95% Cl: 0.09 to 0.63) with radiotransmitters. Backpacks had no significant effect on survival of adults (0.79, SE = 0.17, 95% Cl: 0.33 to 0.97). The strikingly lower survival of goshawks with tailmounts was surprising because tailmounts weighed less (10 g, 1.5% body mass) than backpacks (16-23 g, max = 3.4% body mass) and likely were carried for shorter periods. Due to the small number of goshawks with tailmounts (n = 14) in this study, our results possibly were due to chance. We therefore recommend additional study of the effects of tailmounts on survival of breeding male northern goshawks.

Original languageEnglish (US)
Pages (from-to)25-32
Number of pages8
JournalJournal of Wildlife Management
Volume68
Issue number1
DOIs
StatePublished - Jan 2004

Fingerprint

Accipiter gentilis
breeding
legs
body mass
gender
Akaike information criterion
effect

Keywords

  • Accipiter gentilis
  • Backpack
  • Kaibab Plateau
  • Northern goshawk
  • Radiotelemetry
  • Radiotransmitter
  • Survival
  • Tailmount

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Ecology

Cite this

Effects of radiotransmitters on northern goshawks : Do tailmounts lower survival of breeding males? / Reynolds, Richard T.; White, Gary C.; Joy, Suzanne M.; Mannan, Robert W.

In: Journal of Wildlife Management, Vol. 68, No. 1, 01.2004, p. 25-32.

Research output: Contribution to journalArticle

Reynolds, Richard T. ; White, Gary C. ; Joy, Suzanne M. ; Mannan, Robert W. / Effects of radiotransmitters on northern goshawks : Do tailmounts lower survival of breeding males?. In: Journal of Wildlife Management. 2004 ; Vol. 68, No. 1. pp. 25-32.
@article{09a19786accd4858bd5c5e04281a8d19,
title = "Effects of radiotransmitters on northern goshawks: Do tailmounts lower survival of breeding males?",
abstract = "We used the Cormack-Jolly-Seber model to estimate the effects of radiotransmitters on survival of breeding northern goshawks (Accipiter gentilis). We separately compared apparent annual survival of leg-banded goshawks with (1) tailmount- and (2) backpack-style radiotransmitters (hereafter tailmounts and backpacks) to apparent annual survival of breeding adults with legbands only. The best model without radiotransmitter effects, evaluated with Akaike's Information Criterion (AlCc), suggested no gender- or year-specific effects on survival. We then added radiotransmitter attachment type (tailmount or backpack) and mass of radiotransmitter as covariates to the base model to estimate the effect of radiotransmitters. Tailmounts on males significantly reduced apparent annual survival from 0.75 (SE = 0.02, 95{\%} Cl: 0.71 to 0.78) without radiotransmitters to 0.29 (SE = 0.15, 95{\%} Cl: 0.09 to 0.63) with radiotransmitters. Backpacks had no significant effect on survival of adults (0.79, SE = 0.17, 95{\%} Cl: 0.33 to 0.97). The strikingly lower survival of goshawks with tailmounts was surprising because tailmounts weighed less (10 g, 1.5{\%} body mass) than backpacks (16-23 g, max = 3.4{\%} body mass) and likely were carried for shorter periods. Due to the small number of goshawks with tailmounts (n = 14) in this study, our results possibly were due to chance. We therefore recommend additional study of the effects of tailmounts on survival of breeding male northern goshawks.",
keywords = "Accipiter gentilis, Backpack, Kaibab Plateau, Northern goshawk, Radiotelemetry, Radiotransmitter, Survival, Tailmount",
author = "Reynolds, {Richard T.} and White, {Gary C.} and Joy, {Suzanne M.} and Mannan, {Robert W}",
year = "2004",
month = "1",
doi = "10.2193/0022-541X(2004)068[0025:EORONG]2.0.CO;2",
language = "English (US)",
volume = "68",
pages = "25--32",
journal = "Journal of Wildlife Management",
issn = "0022-541X",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Effects of radiotransmitters on northern goshawks

T2 - Do tailmounts lower survival of breeding males?

AU - Reynolds, Richard T.

AU - White, Gary C.

AU - Joy, Suzanne M.

AU - Mannan, Robert W

PY - 2004/1

Y1 - 2004/1

N2 - We used the Cormack-Jolly-Seber model to estimate the effects of radiotransmitters on survival of breeding northern goshawks (Accipiter gentilis). We separately compared apparent annual survival of leg-banded goshawks with (1) tailmount- and (2) backpack-style radiotransmitters (hereafter tailmounts and backpacks) to apparent annual survival of breeding adults with legbands only. The best model without radiotransmitter effects, evaluated with Akaike's Information Criterion (AlCc), suggested no gender- or year-specific effects on survival. We then added radiotransmitter attachment type (tailmount or backpack) and mass of radiotransmitter as covariates to the base model to estimate the effect of radiotransmitters. Tailmounts on males significantly reduced apparent annual survival from 0.75 (SE = 0.02, 95% Cl: 0.71 to 0.78) without radiotransmitters to 0.29 (SE = 0.15, 95% Cl: 0.09 to 0.63) with radiotransmitters. Backpacks had no significant effect on survival of adults (0.79, SE = 0.17, 95% Cl: 0.33 to 0.97). The strikingly lower survival of goshawks with tailmounts was surprising because tailmounts weighed less (10 g, 1.5% body mass) than backpacks (16-23 g, max = 3.4% body mass) and likely were carried for shorter periods. Due to the small number of goshawks with tailmounts (n = 14) in this study, our results possibly were due to chance. We therefore recommend additional study of the effects of tailmounts on survival of breeding male northern goshawks.

AB - We used the Cormack-Jolly-Seber model to estimate the effects of radiotransmitters on survival of breeding northern goshawks (Accipiter gentilis). We separately compared apparent annual survival of leg-banded goshawks with (1) tailmount- and (2) backpack-style radiotransmitters (hereafter tailmounts and backpacks) to apparent annual survival of breeding adults with legbands only. The best model without radiotransmitter effects, evaluated with Akaike's Information Criterion (AlCc), suggested no gender- or year-specific effects on survival. We then added radiotransmitter attachment type (tailmount or backpack) and mass of radiotransmitter as covariates to the base model to estimate the effect of radiotransmitters. Tailmounts on males significantly reduced apparent annual survival from 0.75 (SE = 0.02, 95% Cl: 0.71 to 0.78) without radiotransmitters to 0.29 (SE = 0.15, 95% Cl: 0.09 to 0.63) with radiotransmitters. Backpacks had no significant effect on survival of adults (0.79, SE = 0.17, 95% Cl: 0.33 to 0.97). The strikingly lower survival of goshawks with tailmounts was surprising because tailmounts weighed less (10 g, 1.5% body mass) than backpacks (16-23 g, max = 3.4% body mass) and likely were carried for shorter periods. Due to the small number of goshawks with tailmounts (n = 14) in this study, our results possibly were due to chance. We therefore recommend additional study of the effects of tailmounts on survival of breeding male northern goshawks.

KW - Accipiter gentilis

KW - Backpack

KW - Kaibab Plateau

KW - Northern goshawk

KW - Radiotelemetry

KW - Radiotransmitter

KW - Survival

KW - Tailmount

UR - http://www.scopus.com/inward/record.url?scp=1642476749&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=1642476749&partnerID=8YFLogxK

U2 - 10.2193/0022-541X(2004)068[0025:EORONG]2.0.CO;2

DO - 10.2193/0022-541X(2004)068[0025:EORONG]2.0.CO;2

M3 - Article

AN - SCOPUS:1642476749

VL - 68

SP - 25

EP - 32

JO - Journal of Wildlife Management

JF - Journal of Wildlife Management

SN - 0022-541X

IS - 1

ER -