Observation 2: Aggressive Birds

During our time in the Lincoln Park Zoo last week, I spent my time in the birdhouse. There I noticed that no exhibit or enclosure had less than 2 species of birds kept together. Most of these were enclosures meant to simulate or represent their native habitats, so birds grouped together were species that might naturally live in close proximity to each other. There was one enclosure, much bigger than any of the others, the Free Flight Area, that housed dozens of species of birds, all living in close proximity to each other, that, as we had just learned, were from different ecosystems. While I was there I started to wonder how these different species could coexist with each other, and how this living situation was handled. As I've been harassed by my fair share of birds in Florida, and the Golden Breasted Starling darted pretty close to my face a couple times, I don't view these winged creatures, though beautiful, to be peace-lovers. (I don't care if its a Chocolate Breasted Starling, don't fly near my face.)

I did some preliminary research on bird aggression, to see what might draw out their more aggressive behavior, and what, if anything, would draw it out against other birds. My most obvious suspicions of territory were confirmed here, as "Nearly all birds will display aggressive behavior when they perceive a threat to their nest or young." I did gather one new bit of information on my Florida assailant, the blue jay, "Birds that nest in close proximity to people; the Northern Mockingbird, American Robin, Gray Catbird, and Blue Jay, are the most frequent assailants." Now I will stay up at night knowing I'm not their first target, will not be their last, and no one is safe. "...the mockingbird is without a doubt the most zealous, harassing, people, domestic animals, and other birds." Though, there's always someone worse off. Those someones are people who live next to mockingbirds. 

Anyway, while none of these birds were in the McCormick Bird House, "Birds are most aggressive towards humans during the nestling period (the interval between hatching and the young bird's departure from the nest), a span of about two weeks in common backyard nesters. Some birds (e.g., robins, mockingbirds, cardinals) can produce two or three broods a season; as a result, their defensive behavior may occur in the spring and again in mid- to late summer." Well, if it isn't mid- to late summer. The McCormick Bird House did inform us through signs that it was their nesting period, so their pools of water were drained much lower so no chicks would fall in and drown, they left out the part about them not wanting us around.

While this explains the admittedly minimal aggression shown to me, I was still surprised that the various bird species were not fighting with each other, nesting season or not. A little info from Bob and Liz Johnson, directors and caretakers of the Shyne Foundation, a Free Flight Natural Habitat Sanctuary in South Florida, which comprises more than 200 birds of 20 species, gave me some insight. “There are no absolutes, especially with birds,” said the Johnsons. “There are probably as many differences within the same species as there are between species. Whether they get along or not depends on the individuals. We have birds of the same species that cannot cohabit peacefully and many various species that do fine together.” 

While this is not the black-and-white specific answer I was hoping to find, it does make sense. I suppose that of the various birds of all these species the zoo has, they've tested and chosen which birds can live peacefully together or have removed any trouble-makers from this Free Flight Area. 

-guillermo