In the fields around the HBP leash free area you can see Bobolinks.

From https://www.allaboutbirds.org/guide/Bobolink/id

"Bobolinks are small songbirds with large, somewhat flat heads, short necks, and short tails. They are related to blackbirds and orioles, and they have a similar shaped, sharply pointed bill.

Breeding male Bobolinks are mostly black with a white back and rump, and a rich buffy nape. Females and nonbreeding males are warm buffy brown, streaked with dark brown on the back and flanks. They have bold brown stripes on the crown but are unstreaked on the nape of the neck. The bill is pinkish.

In spring, male Bobolinks give conspicuous display flights low over grasslands, fluttering their wings while singing. At other times, Bobolinks stay hidden in tall grasses or brush, clinging to seed heads or foraging on the ground amid the stems. They often migrate in large flocks.

Bobolinks are birds of tall grasslands, uncut pastures, overgrown fields and meadows, and the continent’s remaining prairies. While molting and on migration, look for them in marshes and in agricultural fields, particularly rice fields.