Territory and nest site selection patterns by Grasshopper Sparrows in southeastern Arizona
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- More information: Publisher Index Page (via DOI)
- Data Release: USGS data release - Habitat Data for Arizona Grasshopper Sparrow Territories, Nest Plots, and Random Transects, 2009 to 2013
- Open Access Version: Publisher Index Page
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Abstract
Grassland bird populations are showing some of the greatest rates of decline of any North American birds, prompting measures to protect and improve important habitat. We assessed how vegetation structure and composition, habitat features often targeted for management, affected territory and nest site selection by Grasshopper Sparrows (Ammodramus savannarum ammolegus) in southeastern Arizona. To identify features important to males establishing territories, we compared vegetation characteristics of known territories and random samples on 2 sites over 5 years. We examined habitat selection patterns of females by comparing characteristics of nest sites with territories over 3 years. Males selected territories in areas of sparser vegetation structure and more tall shrubs (>2 m) than random plots on the site with low shrub densities. Males did not select territories based on the proportion of exotic grasses. Females generally located nest sites in areas with lower small shrub (1–2 m tall) densities than territories overall when possible and preferentially selected native grasses for nest construction. Whether habitat selection was apparent depended upon the range of vegetation structure that was available. We identified an upper threshold above which grass structure seemed to be too high and dense for Grasshopper Sparrows. Our results suggest that some management that reduces vegetative structure may benefit this species in desert grasslands at the nest and territory scale. However, we did not assess initial male habitat selection at a broader landscape scale where their selection patterns may be different and could be influenced by vegetation density and structure outside the range of values sampled in this study.
Study Area
Publication type | Article |
---|---|
Publication Subtype | Journal Article |
Title | Territory and nest site selection patterns by Grasshopper Sparrows in southeastern Arizona |
Series title | The Condor |
DOI | 10.1650/CONDOR-16-210.1 |
Volume | 119 |
Issue | 3 |
Year Published | 2017 |
Language | English |
Publisher | American Ornithological Society |
Contributing office(s) | Fort Collins Science Center |
Description | 15 p. |
First page | 469 |
Last page | 483 |
Country | United States |
State | Arizona |
County | Santa Cruz County |
Other Geospatial | Audobon Appleton-Whittell Research Ranch, Davis Pasture |