Forest Restoration Treatment Effects on the Nesting Success of Western Bluebirds (Sialia mexicana)

Abstract

We examined the effects of presettlement forest restoration treatments on the nesting success of Western Bluebirds in ponderosa pine forests of northwestern Arizona, U.S.A. From 1998 to 2001 we monitored 97 active Western Bluebird nests, 41 in current‐condition untreated forest and 56 in restoration‐treated forest. We found no effect of restoration treatments on clutch size and little effect on the number of nestlings per nest. However, in treated forest stands number of fledglings per nest averaged 1.6 times greater, and probability of a nest surviving to successfully fledge at least one young was up to 4.2 times greater than in untreated forest. Probability of a nest succeeding averaged 0.39 ± 0.11 (SE) and 0.75 ± 0.06 from 1999 to 2001 in untreated and treated forests, respectively. In addition, in treated forest, average number of nests infested with the blowfly parasite Protocalliphora sialia was up to 4.3 times greater, and number of parasites per fledgling was up to 10.7 times greater than in untreated forest. Overall, the data suggest that in treated forest Western Bluebirds have a higher probability of successfully fledging young, but they are at greater risk of parasitic infestations, of which the ultimate effects on post‐fledging survival are unknown.

Wildlife responses to thinning and burning treatments in southwestern conifer forests: A meta-analysis

“…Battin (2003) found an increase in fledging success for plumbeous vireos (Vireo plumbeus) and western tanagers (Piranga ludoviciana) within 4 years of treatment in thin/burn versus untreated areas. Germaine and Germaine (2002) found thinning and burning treatments had little effect on the number of eggs or nestlings per nest of western bluebirds within 5 years of treatment, but were associated with a higher number of fledglings per nest and greater probability of fledging at least one young compared to controls. They also found a higher incidence of parasitic infestations by blowflies in nests in thin/burn treatments compared to controls (Germaine and Germaine, 2002).…”

“…Germaine and Germaine (2002) found thinning and burning treatments had little effect on the number of eggs or nestlings per nest of western bluebirds within 5 years of treatment, but were associated with a higher number of fledglings per nest and greater probability of fledging at least one young compared to controls. They also found a higher incidence of parasitic infestations by blowflies in nests in thin/burn treatments compared to controls (Germaine and Germaine, 2002). Wightman and Germaine (2006) found that successful western bluebird nests, determined by number of young in the nest on the last day prior to fledge, were associated with increased understory and bare ground and lower conifer tree densities found in thinned and burned treatments 7 years post-treatment.…”

Local habitat management and landscape‐scale restoration influence small‐mammal communities in grasslands

“…Despite these calls, the number of 71 studies of restoration effects on vertebrates is still low and most of them focus on birds in forests 72 and shrubs (e.g. Brawn, 1998;Germaine and Germaine, 2002;Hoover, 2008;Machmer, 2002). 2001) and pollination (Vieira et al, 2009).…”

Short-term effects of fire and fire surrogate treatments on foraging tree selection by cavity-nesting birds in dry forests of central Washington

“…Previous studies have shown short-term (1-3 years) neutral to positive responses of avian communities and many species to fire and fire surrogate treatments in dry forest (Germaine and Germaine, 2002;Zebehazy et al, 2004;Wightman and Germaine, 2006;Gaines et al, 2007). Our study contributes to this knowledge base by providing managers with information on the foraging response of bark gleaners to these treatments.…”