Yesterday, we had a bit of a kerfluffle, and I can't actually find any information about it on the 'nets, which is interesting. Mid afternoon, I saw a black vulture walking around on the ground by the bird feeders (near-ish to the coop), and thought it was one of ours, so went out to say hi. It didn't fly away, but kept walking around, then suddenly spread its wings and stood with its back to me... which is when I heard growling from the roof, and realized this was not one of ours. The parent on the roof growled really loudly (it's the oddest noise - black vultures don't have vocal cords, so they communicate entirely with hisses, grunts, and body language - I've never heard one of them make this noise before), and flew down and attacked the strange vulture.
I can't find anything about vultures defending their nests - in fact, most of the writings I've found say that black vultures don't defend their nesting territory, and often nest in groups. I can only guess that the coop is such a cherry spot that our vultures have become extremely possessive of it, and will drive off any alien vultures that come to check it out. After all, it's entirely protected from rain, it is in a shady spot under the trees, and the trees around it are black walnuts, which have large open branches that are ideal for vultures to sit on.
I've seen them do this before - earlier in the spring, they drove off another pair of vultures - but apparently, they're rather unusual in their defense. This time, I think they were being ultra-protective of their chicks, since they can't fly yet, and are vulnerable while they're on the ground. Certainly, the juveniles were very nervous, and hid in the coop for the rest of the day.
Once the interloper was successfully driven off, our vulture went back to the peak of the roof, obviously keeping watch. She/he (can't tell without dissecting them) finally flew off when Bob started shooting practice in the back yard. She (we'll go with she) was so intent on driving off the outsider that she came within four feet of me, as I was watching the action. At no point, though, was she aggressive towards me, only the alien vulture. I've been working on making them more comfortable around me (so they keep nesting now that we're here all the time), but I've never had one be that close without flying off. It was exciting, but weird.
But, the babies are back to flying practice this morning - one of the parents is sitting in the closest tree, trying to encourage them to come out. They're remarkably cute, in an ugly way, with their ruff of fluff around their heads. They are really affectionate towards each other, too - the juveniles and one of the parents will often all sit together in the window, and groom each other gently. Soon, if all goes like it did last year, the kids will start flying, and will start to learn to look for food, under the constant supervision of one or other parent. They're very curious, checking out everything, not just looking for food; last year, I watched them poking at metal things, turning stuff over, and generally exploring, while the parent stood nearby, looking hilarously bored, like a human parent waiting for their child to get bored with whatever it is that has caught their attention.
I like my vultures.