This Week's Crops & Clips: Bald Eagles renovating nest

This is the seventh breeding season during which we have monitored a Bald Eagle nest near our south Florida home, the first recorded active Bald Eagle nest in Broward County in more than fifty years since before the use of DDT was prohibited.  

Several  attempts to install a nest camera have been unsuccessful, so all our observations are from the ground. Local eagle-watchers report their findings and post photos to my Bald Eagles of Broward County FORUM. You are invited to subscribe if you wish receive copies of observations as they are posted or in digest form.

Located in an exotic Australian Pine, the nest is massive.  Each year the eagles return to  enlarge and renovate it.



The eagles have produced at least eleven chicks, ten of which successfully fledged. Last season they hatched out two eaglets, but one disappeared when only two weeks old, and the second may have fledged at 86 days of age, before it was prepared for free flight, and was lost.

If you visit the above link to the FORUM you may see the data we compiled about the life events in this pair, whose nest is clearly visible from a main thoroughfare in Pembroke Pines, a little more than a mile away from our home. The nest site is located on City land. The eagle-watchers rallied successfully in support of its official designation as a Bald Eagle Sanctuary. 

This season, the eagles were first seen at their nest site on September 18, which is about average, and they started rebuilding the nest on October 15. Over the years they have laid their first egg between November 24 and as late as December 11.

Yesterday morning (October 30) Mary Lou and I arrived at the nest site at 9:05 AM  and found the male on the nest.



He flew off almost immediately but both male and female returned at 9:13 AM. We think it was the the male who brought in a large stick. The female watched as the male worked with the nest material for a short time.



Then the female flew down and joined him at 9:15 AM.





While both sexes have similar plumage, the female is larger and can also be distinguished by the profile of her head and beak. She has a higher forehead as compared to the male, whose bill and forehead are almost in line. The female's bill is also deeper at the base. When roosting her lower belly appears proportionately wider than that of the male. When not seen side by side, these subtle differences may not be easy to detect. 

Here, the female supervises as the male moves the stick. Is that a look of disapproval?



The pair worked together on nest construction until the female flew off at about 9:18 AM.



The female returned with a stick at 9:32 AM and the pair touched bills and postured in a recognition ritual that lasted less than a minute (the female is on the right).







The female then rearranged some sticks that the male had already placed.



However, they did work cooperatively.



Then at 9:35 the male pulled at a string that looks like monofilament fishing line, which could pose a hazard. This is worrisome, as an adult or eaglet could become hopelessly entangled.

My FLICKR photo collection from the eagle nest site includes other wildlife seen while standing watch.