Hello fellow Kestrel fans, I'm new to the forums although I have some photography featured on this site. My focus is on urban raptors: http://kestrel.peregrinefund.org/index.php?action=pro-photo&photog=green...
A local pair of Kestrels have been feeding their 3 fledglings for over 3 weeks... Now, here's the strange part... After the mom feeds the fledglings, she returns to the nest and waits in there for 30 min to an hour before exiting again. She does not enter or exit with food. I discussed this odd behavior with some experts... "Why would she be spending hours in the box when her fledgings have already been out for 3 weeks?" I suspected she laid more eggs... they said I had to see what was inside the box...
So today I borrowed a ladder, waited for the mom to exit, and was able to fit my iPhone into the box for a few pictures. I was expecting to see some eggs, but was surprised by 5 newborn nestlings!
These amazing Kestrel parents are simultaneously feeding 3 fledgings and 5 nestlings. I know Ketsrels can lay a second clutch if the first is destroyed or unsuccessful, but that is not the case here. I've witnessed the mom feed 3 fledglings then immediately fly back into the box. It's the same adult female and her first clutch was definitely successful. I've also seen the adult male return to the box and look inside, but not enter completely. I'll compile a complete photos series after these nestlings have fledged too.
Has this double-clutching behavior been documented before?
Thanks in advance for any replies.
Comments:
Hey Peter!
Hey Peter!
Thanks for sharing this with the rest of the kestrel community! I enjoyed our phone chat the other day and I'm so glad you were able to get access to the inside of the building to see what was going on! You were right! The female was certainly on eggs all those times that you saw her go in the vent for an hour or more per visit!
Based on your observations, you've seen parents feed fledglings and watched the exact same female then go into the vent (i.e., without a break in observation)? If that is the case, this is indeed very cool, indicating that she laid eggs very soon after her previous clutch fledged. Do you know the date that the previous chicks fledged? I'll be interested to get feedback on this discussion board from others in the kestrel monitoring community to hear if anyone else has observed the same thing.
Did you take detailed notes during your observations? If not, we recommend that you do so in the future to get info such as time of entering vent, time of exit, if she is bringing food into vent, food item type, time of feeding fledglings, etc.! It would be great if you could connect with a local bird bander so that you have the chance of distinguishing individuals in your area in the future. We encourage you to plan for similar observations next year!
The final kicker that could help in retroactively determining if this female is the parent of both the fledged chicks and the new chicks would be to assess parentage using genetics (there is my genetics background speaking up!).
Many thanks for your contribution to the American Kestrel Partnership, both in sharing this interesting finding and for your AMAZING images of the "Urban Kestrel."
Wishing you the best,
Sarah, Asst. Director AKP
Thanks Sarah, it certainly is
Thanks Sarah, it certainly is exciting! I'm taking notes and pictures which show the exact time they were taken. Yep, the telephone pole in the photo above is across from the vent... I saw the mom feed the fledglings then go directly into the vent with no food. Now that the second clutch has hatched, I've seen the mom bring a rodent into the vent to feed them. I've only seen one fledgling this week and the mom didn't feed her despite being followed around. Eventually the fledgling left.
My first sighting of fledglings this year was on June 19. I did not discover the vent until June 26 when I saw mom fly into it.
I can confirm it's the same father too – he has a large tumor on his foot so that's just as identifiable as band numbers. He fed the fledglings last month and this week I've seen him enter the vent to check on the nestlings. He also delivered a Tomato Hornworm to mom.
Now I'm guessing the parents did not feed both sets at the same time... perhaps they fed the fledglings while incubating the second clutch, but once the eggs hatched, they stopped feeding the fledglings to devote all their efforts on the new nestlings.
I do know a bird bander who would probably band them, but I fear alerting the building owner would not be a good idea. They may not appreciate the kestrels using their vent and I fear they would kick them out – so I'm keeping the nest a secret.
I don't see how to attach photos to this reply, so I will add more to my first post.
All the best, Peter
Today I spoke to an expert
Today I spoke to an expert who pointed me to a few documented cases of double-brooding by American Kestrels:
Double Brooding By American Kestrels In Idaho
Double Brooding by American Kestrels in Central Missouri
He also clarified for me: a double-clutch would suggest the eggs were laid but not that they necessarily hatched, double-brood means they have hatched
Hi Peter,
Hi Peter,
Looking at the Steenhof and Peterson 1997 paper you've linked to above, the authors note that there had been no previous reports of double brooding by kestrels north of 40° latitude, but they reported in that paper that through their long-term study they detected that a pair of kestrels successfully raised two broods in a season at their location in SW Idaho (43°N). In a later paper (Steenhof and Peterson 2009) that incorporated several more years of the study, they reported that "pairs attempted to raise second broods during the same season 12 times (2% of the 577 successful first nesting attempts) during the study."
In Providence, Rhode Island you are at 41.8° N latitude. You've nonetheless found an interesting behavior for your neck of the woods, one that has been shown to occur, but not so commonly. We thank you for sharing your finding with the kestrel community and for capturing stunning photographs as you make these important observations.
Cheers,
Sarah