Factors affecting breeding season survival of Red-Headed Woodpeckers in South Carolina.

Journal Article · Fri Nov 18 04:00:00 EST 2011 · Journal of Wildlife Management

DOI:https://doi.org/10.1002/jwmg.282· OSTI ID:1033556

Vukovich, Mark

Red-headed woodpecker (Melanerpes erythrocephalus) populations have declined in the United States and Canada over the past 40 years. However, few demographic studies have been published on the species and none have addressed adult survival. During 2006-2007, we estimated survival probabilities of 80 radio-tagged red-headed woodpeckers during the breeding season in mature loblolly pine (Pinus taeda) forests in South Carolina. We used known-fate models in Program MARK to estimate survival within and between years and to evaluate the effects of foliar cover (number of available cover patches), snag density treatment (high density vs. low density), and sex and age of woodpeckers. Weekly survival probabilities followed a quadratic time trend, being lowest during mid-summer, which coincided with the late nestling and fledgling period. Avian predation, particularly by Cooper's (Accipiter cooperii) and sharp-shinned hawks (A. striatus), accounted for 85% of all mortalities. Our best-supported model estimated an 18-week breeding season survival probability of 0.72 (95% CI = 0.54-0.85) and indicated that the number of cover patches interacted with sex of woodpeckers to affect survival; females with few available cover patches had a lower probability of survival than either males or females with more cover patches. At the median number of cover patches available (n = 6), breeding season survival of females was 0.82 (95% CI = 0.54-0.94) and of males was 0.60 (95% CI = 0.42-0.76). The number of cover patches available to woodpeckers appeared in all 3 of our top models predicting weekly survival, providing further evidence that woodpecker survival was positively associated with availability of cover. Woodpecker survival was not associated with snag density. Our results suggest that protection of {ge}0.7 cover patches per ha during vegetation control activities in mature pine forests will benefit survival of this Partners In Flight Watch List species.

• Research Organization: USDA Forest Service-Savannah River, New Ellenton, SC
• Sponsoring Organization: USDOE; USDOE EM Office of Program and Site Support (EM-50)
• DOE Contract Number: AI09-00SR22188
• OSTI ID: 1033556
• Report Number(s): 11-18-P
• Journal Information: Journal of Wildlife Management, Journal Name: Journal of Wildlife Management Journal Issue: 2 Vol. 76; ISSN JWMAA9; ISSN 0022-541X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ADULTS
AVAILABILITY
Accipiter
BIRDS
BREEDING
FEMALES
FORESTS
MALES
Melanerpes erythrocephalus
PINES
PLANTS
PROBABILITY
SEASONS
SOUTH CAROLINA
cover
known-fate models
mortality
radio telemetry
red-headed Woodpecker
snag density
survival