Skip to content

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!

Pair of sibling red-tailed hawks (Buteo jamaicensis), or branchers
2020-06-12
© Allison J. Gong

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:

Pair of sibling red-tailed hawks (Buteo jamaicensis), or branchers
2020-06-12
© Allison J. Gong

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.

Every year, in June, my big whelk lays eggs. I have a mated pair of Kellettia kellettii living in a big tub at the marine lab. I inherited them from a lab mate many years ago now, and they've been nice pets. They've lived together forever, and make babies reliably. As June rolls around I start looking for eggs. This year I want to document the entire process, from egg-laying to larval development. Fortunately, I had the foresight to photograph the parents in May, as I didn't want to disturb the female once she began laying.

The female is significantly larger than the male. I know the big one is the female because that's the one that lays the eggs. I've never managed to catch the whelks copulating, but given the female's track record they either copulate regularly or she is able to store sperm for a long period of time.

In any case, she started laying eggs today. I went in to check on them and there she was!

Female whelk laying eggs
Female whelk (Kellettia kellettii) laying eggs
2020-06-12
© Allison J. Gong

I know from previous years that it can take over a week for the female to lay her entire clutch of eggs. Each of those pumpkin seed-shaped objects is an egg capsule, containing a few dozen embryos. The newly lain capsules are white, as you see above, and will gradually get darker as the embryos develop into larvae. The mother will lay the eggs and then depart. When the larvae are ready to leave the capsule, a small hole will wear through in the top of the capsule and the larvae will swim out. More on that later, hopefully.

I took some time-lapse video of the female, and was able to record her moving over the egg capsules and then leaving. I'd also put some food in the tub, and I think she got distracted.

I think it's really cool to see how well the snail can swivel around on her foot. Snails are attached to their shell at only a single point called the columella, the central axis around which the shell coils. Some snails can extend quite far outside the shell, and they can all pull inside for safety. The dark disc on the back of the foot is the operculum that closes up the shell when the snail withdraws into it.

Tomorrow when I check on things at the lab I'll see if she has resumed laying.

%d bloggers like this: