Day 79: Cassin's in a box

Cassin's auklets are one of the few species that are still in the midst of breeding right now. We had a very high rate of double brooding this year. After pairs raised one chick they decided it was so much fun they wanted to do it again so they started over. Many of these second broods are now hatching, and young chicks need to be fed. This photo was taken around 10:30pm and this Cassin's probably just came in to feed its chick in the nest box and is now hanging out near the entrance tube. Cassin's are very vocal at night and socialize quite a bit outside their burrow and boxes. Their calls have been described as sounding like crickets on steroids.

Day 67: They grow up so fast

This is cheating a bit since it's really 6 pictures but they are all showing the same chick. This is a chick from one of our nest boxes. I took a picture of it every time it got weighed (every 5 days) until it fledged just a couple days ago so we could see the progression of its development. First picture is probably 5-7 days old so this chick fledged between 30-35 days old. As you can see, it was looking good, nice fresh feathers and a fantastic cowlick. Most chicks from the first attempts by Cassin's have fledged and a substantial number of those adults are now incubating eggs again, going for a second chick. This double brooding is rare among seabirds and Cassin's can only do it in the southern parts of their range.

Photo a day (and me) will be taking a two week break starting tomorrow. But never fear, I will return!

Day 54: Band it

The little blue foot there is the foot of a mostly feathered Cassin's Auklet chick and it's about to get some jewelry. Once the chicks are nearly fully grown, they get an individually numbered leg band. This band will last their entire lifetime and it allows us to track this individual across years. If it returns to breed as an adult, the band number tells us how old the bird is.  These known-age birds are especially valuable since they allow us to answer questions about how survival and reproduction change with age and how many young and old birds there are in the current population.

Day 18: Too cute

I know I just had a Cassin's chick photo but I couldn't resist this one. We had a big Cassin's auklet breed check today. We were checking empty nest boxes for new breeding attempts as well as checking occupied boxes for hatching and weighing chicks that were on their own. We had quite a few new breeding attempts today and lots of hatching chicks. Good signs. This chick in a nest box is still being brooded its parent and is just poking its head out from under the right wing. Definitely one of my favorite things to see, it's almost too cute to handle.

Day 13: Cute chicks

First Cassin's auklet chick weighed today! Once chicks are left alone by their parents, usually after about 10 days, some of them are weighed every five days so we can document how quickly they are developing. This tells us about their health and also about how much food is available for their parents to bring back to the colony. In years when food is scarce, chicks are underweight and slow growing. Jen was pretty happy to be able to hold her first Cassin's chick here. This guy weighed in at a healthy 58 grams.

Day 6: Think inside the box

Cassin's auklet check today. This involves checking some of the 400+ nest boxes like this one (there is a box in there under all that Farallon weed).  Cassin's started breeding extremely early this year, one of the earliest starts on record, but they seem to be struggling lately. Occupancy is good but many of the boxes that should be hatching chicks at this time appear to be abandoned. It's early yet so there is still lots of time for birds to relay but it is a bit worrying.