Common Cape May Birds

I digiscoped so many images this weekend, I'm having trouble organizing them into blog entries. I found a most cooperative northern mockingbird at Higbee Beach. I know for some of you southern readers that a mocking bird is not the most exciting bird on the planet, but for a Minnesota girl, getting a chance to see that yellow eye gleam in the sun.

The hawk migration is still going strong in Cape May and Cooper's hawks like this juvenile above were all over the place. A DC Birding Blog (who is banding hawks at Cape May this year) mentioned that they are seeing more Cooper's hawks passing through than sharp-shinned hawks. We usually see the opposite at Frank's banding station in Duluth. A quick scan over at Birds of North America Online says that the ability of Cooper's hawks to adapt to humans has been great, their population has increased very well, however it's uncertain if their increase in population could have a negative effect on other raptor (or even prey for that matter). There is some evidence that Cooper’s Hawks regularly take American Kestrels, and that they may be playing a role in the current declines in this species in the eastern part of their range.

I was trying to take a photo of a couple of black vultures and I even got a blur of a Coop's passing behind it.

I did get a shot of the full black vulture. This was was another common to Cape May but exciting to a Minnesota girl type species. All we get in MN are turkey vultures, so the smaller guys with the all dark head were a treat.

Here is a pair. The one higher up is an adult, the lower, shaggier looking one with a black bill is a juvenile. They had a beautiful blue sky behind them and were on a blue water tower. Looking at the photos, the two blues look kinda weird.

I wonder what we're missing in Minnesota so that we do not get black vultures? We have turkey vultures for part of the year. I'm sure we'd have places for black vultures to nest. It's interesting to note that turkey vultures find their food using their sense of smell, but not black vultures That ability is not nearly as highly developed in black vultures, so they follow turkey vultures to find carrion.

Doing some reading on BNA found an interesting theory: according to some studies, the large communal roosts that black vultures form at night might serve as a means for communicating food locations. They had several studies to back it up. Birds that were marked returned to same carcasses on successive days, could they be leading birds at the roost to food? When the black vultures leave the roost in the morning, smaller groups fly off at different intervals...are the groups following a specified forager vulture (kind of like a forager honey bee)? In one study, black vultures deprived of information about local distribution of carcasses and were released in evening at communal roosts and joined the ends of groups departing from roosts to feeding sites the next morning and tagged vultures that were not privy to a carcass and released to a roost, still arrived at food sites in early morning as members of groups that have come directly from roosts.

Fascinating stuff!