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Demography of Reintroduced Eastern Bluebirds and Brown‐Headed Nuthatches
Author(s) -
LLOYD JOHN D.,
SLATER GARY L.,
SNOW SKIP
Publication year - 2009
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.2193/2008-009
Subject(s) - biology , national park , ecology , extinction (optical mineralogy) , population , demography , geography , zoology , paleontology , sociology
ABSTRACT Species reintroductions are used commonly as a tool for conservation, but rigorous, quantitative assessments of their outcome rarely occur. Such assessments are critical for determining success of the reintroduction and for identifying management actions needed to ensure persistence of reintroduced populations. We collected 9 years of demographic data on populations of brown‐headed nuthatches (Sitta pusilla) and Eastern bluebirds ( Sialia sialis ) reintroduced via translocation into Long Pine Key, Everglades National Park, Florida, USA. Realized population growth of brown‐headed nuthatches was positive in the first 3 years after cessation of translocations (λ 2002 = 1.15, SE = 0.13; λ 2003 = 1.28, SE = 0.12; λ 2005 = 1.32, SE = 0.20) but became negative thereafter (λ 2006 = 0.67, SE = 0.10; λ 2007 = 0.77, SE = 0.13). Realized growth rate for the Eastern bluebird population did not vary among years and indicated either a stable or a slowly declining population (λ = 0.92, SE = 0.04). Reintroductions were a qualified success; they resulted in the re‐establishment of populations of both species, but neither population grew to the extent expected and both remained at risk of extinction.