This video of a bird dive bombing unwary passers-by near Stow Lake in Golden Gate Park has been making the rounds on social media lately. While this may seem like a uniquely disgruntled critter, this behavior is actually quite common around the country in spring and early summer. The offending bird is a male Brewer’s Blackbird. Some commenters have speculated that the bird is collecting hair for a nest, but as the video explains, it’s simply defending its nest against perceived trespassers. I like to think it’s some kind of evolutionary holdover from when they were all dinosaurs.

Brewer’s Blackbirds will build nests just about anywhere including sidewalk flower pots, landscaping hedges, even streetlights. Sometimes business will post signs warning people of impending attack but most people don’t believe it until they see it. Some cities will even close sidewalks during mating season. I’ve seen this in a few places around the states and of all the dozens of bird bombings I’ve witnessed, not a single one was directed at a person’s face.

As embarrassing as it may be to get bird-checked in the back of the head, it’s extremely unlikely that this yearly phenomenon will ever pose any real threat to pedestrians. And in case you’re wondering what that white thing is that comes out of one of the babies at the end of the video, it’s a fecal sac. It basically makes cleanup easier for Ma and Pa Blackbird.

H/t: Richmond SF Blog; photo by Wolfgang Wander via Wikimedia.