In winter, this species migrates to the southern and eastern United States. They are differential migrants with females migrating farther, increasing the proportion of females at lower latitudes in the Atlantic flyway. Females are smaller so they would not perform as optimally at colder, higher latitudes, and females avoid competition with the dominant males of the winter hierarchies by migrating farther.
Beautiful photos, H.J.! I love the variation in coloration of each sparrow, so distinct. When I first became familiar with White-Throated Sparrows they were all the White-striped variety but now it seems the Brown-striped are becoming dominant. Either way, some of my favorite birds, and great singers. Thank you for these photographs.
H.J. Ruiz - Avian101 
Reblogged this on Wolf's Birding and Bonsai Blog.
I like the little notes you include with your photographs.
Thank you, Susan. I’m glad. 🙂
Your first shot direct-on beautifully shows off all the colors and patterns of this pretty bird. Nice, HJ!
Thank you very much, Donna. 🙂
Their migration strategy is most fascinating, H.J!
Yes, It is! Thank you, my friend. 🙂
Beautiful photos, H.J.! I love the variation in coloration of each sparrow, so distinct. When I first became familiar with White-Throated Sparrows they were all the White-striped variety but now it seems the Brown-striped are becoming dominant. Either way, some of my favorite birds, and great singers. Thank you for these photographs.
Birds of the same species can show slight differences from one to another. Thank you for sharing, Lisa. 🙂