Territory Selection and Intra-seasonal Nesting Site Fidelity of Henslow's Sparrow (Ammodramus henslowii)
Advisor Information
L. LaReesa Wolfenbarger
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
4-3-2016 10:45 AM
End Date
4-3-2016 12:15 PM
Abstract
The Henslow’s Sparrow (Ammodramus henslowii) has been a species of high conservation concern by the U.S. Fish and Wildlife Service since 1987. Because the population size has decreased by over 90% since the 1960’s, habitat is actively managed for the species. Recent studies indicate that Henslow’s Sparrows can be double brooded, meaning that females may nest and produce offspring during two distinct nesting periods, one in May and one in June. Given the influence that double brooding could have on population growth and the importance of territories for nest success, I studied whether the characteristics of territories (specifically, size and location) change between the first and second nesting period. To map and measure male territories, I used the “flush” method, ArcPad and ArcGIS 10. I estimated the territory boundary using a 50% and 90% kernel density in program R. For the 50% density, mean territory size was 759.1 m2 with a standard error of ± 78.4 m2. The 90% density showed a mean territory size of 2451 m2 (±249.7 m2). There was no difference in territory size between May and June and no overlap in territory use between adjacent males. Our results show that territories do not change in area and that a uniform management scheme will work throughout the nesting cycle.
Territory Selection and Intra-seasonal Nesting Site Fidelity of Henslow's Sparrow (Ammodramus henslowii)
Dr. C.C. and Mabel L. Criss Library
The Henslow’s Sparrow (Ammodramus henslowii) has been a species of high conservation concern by the U.S. Fish and Wildlife Service since 1987. Because the population size has decreased by over 90% since the 1960’s, habitat is actively managed for the species. Recent studies indicate that Henslow’s Sparrows can be double brooded, meaning that females may nest and produce offspring during two distinct nesting periods, one in May and one in June. Given the influence that double brooding could have on population growth and the importance of territories for nest success, I studied whether the characteristics of territories (specifically, size and location) change between the first and second nesting period. To map and measure male territories, I used the “flush” method, ArcPad and ArcGIS 10. I estimated the territory boundary using a 50% and 90% kernel density in program R. For the 50% density, mean territory size was 759.1 m2 with a standard error of ± 78.4 m2. The 90% density showed a mean territory size of 2451 m2 (±249.7 m2). There was no difference in territory size between May and June and no overlap in territory use between adjacent males. Our results show that territories do not change in area and that a uniform management scheme will work throughout the nesting cycle.