Unhatched “addled” egg remains?

May 12, 2019 in In the Nest Box, lawrence peregrines

Today started off under light winds, overcast skies and temp at 47F. How nice to see the little ones starting to move around a bit more.  They were first seen tightly huddled around each other and the remaining unhatched egg.  It almost looked like they were trying to incubate the egg themselves!

2019.0512.2The female was observed around 9:20 AM this morning taking a break, moving to front edge of nestbox, and calling for food!  The fourth egg has not hatched, and at this point, it is unlikely to hatch.  In prior years, the falcons have had unhatched eggs.  An unhatched egg, may also be referred at as an addled egg.  This is an egg in which the developing embryo has died. Not to be confused with a clear or infertile egg, though in common usage the term is often applied to any egg gone bad.

2019.0512.3Around 9:25AM, after a lot of vocalizing, the female was provided with another meal, by the male for the chicks.  The photo shows the female returning to the huddled chicks, with prey in her bill.  The bird in her bill has been stripped of feathers and is ready for her to rip apart for feeding purposes.  Also visible is the remaining unhatched egg. Addled eggs are usually left, and may survive after the young have gone as dried and bleached relics, kicked to the side of the nest box, but they are often broken and trampled to pieces!

Literature cited:

Ratcliffe, D. 1993. The Peregrine Falcon. 2nd ed. Carlton, England: T. and A. D. Poyser.

Lawrence Peregrines: feeding time for 3 chicks!

May 9, 2019 in In the Nest Box, lawrence peregrines, Peregrine Falcons Eastern Massachusetts, Peregrine Falcons Massachusetts

LP.2019.0509.1The morning started off under clear skies, calm wind conditions, and cool at 37F just after 6AM. The female lifted up and off the 3 chicks just before 6:15AM for brief flight and returned with breakfast for the three chicks.  The fourth egg remains unhatched.  This has happened in years gone by.

Peregrine Falcon chicks are helpless. One parent (often the female but sometimes the male) stays with the chicks while the other finds food for the brood. Eyases eat an incredible amount of food – but then, they double their weight in only six days and at three weeks will be ten times birth size.

LP.2019.0509.2Newly hatched chicks are wet and covered with white down. But by three weeks of age, brownish juvenile feathers can be seen poking through the white fuzz. By five or six weeks of age, the white fuzz has been completely replaced by brown feathers. The eyases can be observed jumping around and testing their wings, getting ready to fly.

Peregrine chick: Woburn!

June 3, 2016 in Peregrine Falcon Woburn

CF2C2674-001After months of watching the Peregrine Falcons in Woburn, and wondering whether a young female, not yet a year old, would form a mating pair bond with the resident, older, unbanded male…..they finally came together!

The mating process started much later, and lasted much longer than any of the regular observers thought possible. Then in the middle/later weeks of April, the female began to demonstrate nesting behavior consistent with the egg incubation process.

Since then, the female has been sitting low and practically out of sight, consistent with sitting on, and incubating
eggs. No way of knowing how many eggs were hatched this year. The peregrine falcon female usually lays
3 to 4 eggs. Stay tuned….

This afternoon, stopped by and observed the female in visible feeding mode….confirming chicklets! The chicks are probably around 10 – 12 days old. From quite a distance away, and under challenging light conditions, was able to capture a few documenting photos.

For those with an interest, 3 feeding photos posted:


Click “next” upper right to advance frames!