Notes from a California naturalist

For some reason, the barn swallows at the marine lab like building their nests above doors. It seems that little 1/2-inch ledge of the door frame provides support for the mud nest. And the birds don't always choose little-used doors, either. This year a pair constructed their nest above one side of a double-door that people walk through all day. The mother laid and incubated her eggs, but would occasionally get flushed off the nest if someone came through the door. I always tried not to disturb her any more than necessary. The animal is always right, so I figured she knew what she was doing.

The eggs hatched about a week ago, I think. The mom would sometimes leave the nest when people approached, and even though I couldn't see anything in the nest I'd hear little cheeps. Earlier this week I thought I could see little heads poking above the edge of the nest.

It seems there are three baby birds in this nest!

I haven't spent much time watching the nest closely, because I don't want to scare the mother off and keep her away. Today I was lucky and stuck around just long enough, and with the big camera at hand, to capture both parents returning to feed the babies. The first parent arrived with an insect and landed on the nest. The other parent alit on the door frame.

After depositing the insect into one of the gaping yellow mouths, the first parent flies off. The second parent doesn't seem to have anything to offer the babies, though.

Ooh, maybe this parent has food!

The second parent lands on the nest. . .

. . . and promptly takes off again. . .

. . . leaving the babies alone in the nest again.

These babies still need to grow feathers, although they are clearly big enough to thermoregulate without a parent sitting on them. Growing feathers takes a lot of metabolic energy, and aside from when the parents arrive with food the nestlings will sleep. But it's funny. They seem able to keep an eye (or maybe an ear) out for the parents flying around, and whenever one flies past the doorway they all perk up and start cheeping. There are lots of swallows at the marine lab right now, and I wonder if these babies can identify their parents from among all the other adults in flight.

They'll grow fast, being fed frequently by their parents. They'll have to get big and strong, to prepare for their migratory trip south in the fall I've never noticed exactly when they leave, I think because by the time they head south they've dispersed from the nest site. I always look forward to their return in the spring, though.

Every year we are fortunate to watch a pair of red-tailed hawks (Buteo jamaicensis) raise young in a tree across the canyon. We're not always sure if the parents are the same birds every year, and I think this year's female is a different bird from last year. Her mate may be the male who has used this nest site for a couple of years now, but again, we don't know.

This year the parents raised three youngsters, who have just begun leaving the nest. They prepare for their first flights by making their way to the edge of the nest and flapping their wings to exercise the flight muscles. This is usually fun to watch, as they don't seem to care whether or not a sibling is in the vicinity. This flapping activity begins before the bird is fully feathered, and they look like awkward punk-rocker teenagers, trying to be cool and not even close to pulling it off.

The hawk nest is in a eucalyptus tree. As the time to fledge approaches, one or both of the parents often perches at the top of a nearby cypress tree. Usually the youngsters' first flights are to the cypress tree. Cypress trees may be the ideal location for fledging, because they have lots of soft-ish branches to fall on when the birds biff the landing. The first flights don't go far from the nest, and the birds end up hopping along branches as they flap their wings. So they are called branchers.

With raptors, the females are bigger. Males tend to leave the nest before their sisters, who have more growing to do, so we always assume that the first one to depart is a boy. This year the females lagged by only a day or so behind their brother. And all three of them seem to be progressing pretty quickly, compared to cohorts we've watched in previous years. Good little branchers!

We watched these two for a while in the early evening. I don't know where the third one was. The branchers watch their parents soar around effortlessly. Here they are at the very top of the cypress tree:

Okay, my digiscoping skills need work. I did, however, get lucky enough with the spotting scope and my phone to catch a few video clips.

You can see them trying to maintain their footing as the wind blows the tree around. They're able to use their wings for balance, but then they catch a little lift and get knocked about. In the second clip one of the birds is hanging out when its sibling crashes into it. If they were human teenagers, you'd hear one yelling "Look out below!" while the other hollers "Get off me!" Yeah, landing is toughest part of flight!

Over the next few weeks the branchers will get better and better at landing, and their flights will get longer. They will learn how to find thermals and soar. Their parents will continue to provide food for them, but at some point the kids will learn how to hunt on their own. Rodents of the neighborhood, look out! Eventually the branchers will be as badass as their parents. Then they'll disperse to find territories of their own.