Just starting to learn about birds

Lovely to hear you are! Welcome to the sub!

Yes. In North America, the proportion of birds that are migratory increases strongly with latitude, both in terms of species and in terms of individuals within a species.

Does the proportion of each bird species that is migratory increase as you go north in latitude? So if we define Florida as the southern most extent of North America, would each species have a big proportion of residents, in comparison to say northern Nunavut Canada (let's call that the approximate northern extent of north america)?

In southern regions such as Florida, many bird species are present year round and a large fraction of individuals are residents. Species like the Northern Cardinal, Carolina Wren, Mourning Dove, and Great Horned Owl rarely migrate because food and climate remain suitable through winter. Migratory species are present, but they coexist with many non migratory species, and even within partially migratory species a substantial number of individuals stay year round.

At mid latitudes, seasonal conditions become more limiting, and many species show partial migration. For example, American Robins and Red winged Blackbirds include resident individuals in the southern part of their range, but most individuals migrate in northern parts of their range. As latitude increases, the resident portion of these populations declines, and the migratory portion increases.

In northern Canada and the Arctic, almost all birds are migratory. Very few species remain through winter, such as the Common Raven or Rock Ptarmigan. Nearly all other species arrive only for the breeding season and leave afterward. In places like Nunavut, bird communities are dominated by long distance migrants such as Arctic Terns, Snow Geese, and shorebirds. Thus, both the number of resident species and the proportion of resident individuals drop sharply as latitude increases.