Courtesy Preview
You are currently viewing one of the free sample accounts available in our complementary tour of BNA. In this courtesy preview, you can access all of this species account material as you would were you a subscriber. This includes all the life history articles and the multimedia galleries. More sample accounts are available on our homepage.
If you are a current subscriber, you can sign in with your login information to access BNA normally.
Measurements
Linear
See Table 4 . In all linear measurements males are significantly larger than females (MC). Wing length appears to increase with age. Captured breeding birds could not be aged, but in 102 males captured over at least 2 consecutive years, wing length increased by at least 1 mm (max. 4 mm) after the initial year in 80 (80%). In 85 such females, at least 1 mm increases were observed in 54 (64%). No decreases observed (MC).
Mass
No significant difference between sexes in Pennsylvania during the breeding season (MC). Males: n = 15, range 11.5–14.3 g, mean = 13.1 ± 0.67 SD g. In s. New York, breeding males: n = 23, range 12.0–15.0 g, mean = 13.2 ± 0.85 SD g (DAN); females: n = 17, range 11.4–14.0 g, mean = 13.0 ± 0.72 SD g.
Mass increases to a maximum in midwinter, minimum in breeding season (Olson and Kendeigh 1980). In w. Pennsylvania, mean masses of adult birds (Jun–Aug) ranged from 11.7–13.8 g; mean masses (Dec–Feb) ranged from 13.2–15.7 g (Clench and Leberman 1978).
Carey, Michael, M. Carey, D. E. Burhans and D. A. Nelson. 2008. Field Sparrow (Spizella pusilla), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/103
