City Life Turns Sparrows Mean, and Here's Why

Anyone who has lived in New York can tell you that city life doesn't exactly make you friendly. In fact, you can grow to be downright suspicious of strangers if you live in the wrong neighborhood. Now, a new study has found that the same is true for birds, with urban sparrows proving far more aggressive and unruly, compared to their rural relatives.

The study, recently published in the aptly-named journal Behavioral Ecology, details how urban song sparrows (Melospiza melodia) are much more territorial, when compared with rural sparrows. But while, it was initially suspected that, like humans, these sparrows were simply unhappy with less personal space in a heavily populated area, researchers quickly determined that it's actually all about food.

It is no secret that food is easy to come by in a large city, were restaurants, bars, and quick markets line every other block. This makes these areas a feeding haven for opportunistic wildlife, like specialized ants, pigeons, and yes, even sparrows, who have learned to live off humanity's substantial scraps. (Scroll to read on...)

With more food to go around, you'd think these sparrows would be more willing to share, but in-fact researchers found it was quite the opposite. When measuring how male sparrows respond to another male's song, it was found that they were far more aggressive when sitting on a treasure trove of food. This proved the most true for urban birds, but the phenomenon was also observed with rural birds when researchers boosted a territory's value with a supplemental food cache.

Still, the researchers remain unsure if this is an offensive or defensive strategy. In other words, they aren't sure if the sparrows out for blood are invaders looking to steal food-rich land, or if defenders are simply getting extra-aggressive when fighting for the dumpster of that Tex-Mex restaurant on Main st.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

 - follow Brian on Twitter @BS_ButNoBS