NORTHEASTERN NATURALIST 2012 19(1):123–129 Site Fidelity and Natal Philopatry in Dickcissels Daniel M. Small 1,* , Maren E. Gimpel 1 , and Douglas E. Gill 2 Abstract - Spiza americana (Dickcissel) colonized a restored Conservation Reserve Program grassland in Maryland during the second year of restoration and has continued to return in subsequent years. In 2000–2010, we banded 125 adult and hatch-year birds; during this period the population ranged annually from one to 16 individuals. Twenty-one percent of adult male Dickcissels (n = 38) returned in a subsequent nesting season, 30% of adult females (n = 20) returned, and 1.7% (n = 67) of the banded hatch-year individu- als returned. A female Dickcissel returned to these grasslands after being banded as a nestling the previous year; this bird is the first nestling Dickcissel ever to be re-sighted in a subsequent year across this species range. This same female Dickcissel nested an aver- age of 196.5 m (range = 84–297 m) from her natal site over four breeding seasons, and now holds the longevity record (4 yrs, 11 months) for the species; she also became the first known female Dickcissel to return to a breeding site in Maryland. At our study site, whether adult Dickcissels returned the following summer was not related to their nesting experience (success or failure) the previous year. However, males that were unsuccess- ful in procuring mates often did not return the following year, and females returned at a greater rate than males. Introduction Interspecific and intraspecific variation in site fidelity and dispersal among grassland passerines is highly variable among species, and even among popula- tions within a species complex. Some variation stems from the availability and quality of breeding sites from one year to the next, success of nesting attempts in previous years (Zimmerman and Finck 1989), and perhaps location of suitable breeding areas within the range of the species. Jones et al. (2007) report 5.4% (n = 37) return rates for adult male Passerculus sandwichensis (Gmelin) (Savan- nah Sparrow) in Montana, whereas Bedard and LaPointe (1984) report 38.7% (n = 86) and 31.2 % (n = 38) return rates for male and female Savannah Sparrows, respectively, in Québec, Canada. Jones et al. (2007) report 8.9% (n = 45) of the adult male Ammodramus savannarum (Gmelin) (Grasshopper Sparrow) returned in Montana compared with an average of 58% (n = 568) returning adult males over a nine-year period in Maryland (Small et al. 2009). Site fidelity in Spiza americana Gmelin (Dickcissel) is highly variable, includ- ing differences within or between male and females, interannual differences, and variation across geographical regions (Temple 2002). Reasons for Dickcissel site fidelity are numerous and can include but are not limited to previous year’s nesting success (Hoover 2003, Sedgwick 2004, Zimmerman and Finck 1989), age of indi- viduals, habitat changes, and possibly adverse weather conditions (i.e., drought; 1 Chester River Field Research Center, The Custom House, 101 South Water Street, Ches- tertown, MD 21620. 2 Department of Biology, University of Maryland, College Park, MD 20742. * Corresponding author - DSmall2@washcoll.edu.