Birds in mexico city don’t have much variety. The birds you’ll see will basically be just grackles, inca doves, and the occasional humming bird. it’s mainly outside of the city where you will find a good, yet not even great, variety of birds you might not see where you come from. The pyramids outside the city gives you an ok variety of wrens, occasional hawks and some flycatchers. chapultapec park itself being the biggest park in mexico and one of the biggest in the world even being considered a forest is unrewarding if you don’t spend plenty of time there unless you go to the pond and/or lake. The most rewarding place i went was about an hour drive from my hotel was on the south side was an ecological park called Xochimilco which was mainly a marsh full of multiple types of ducks, flycatchers, herons, egrets, coots, and gallinules.