Thursday, April 22, 2010

No nesting this year?

Hi All,

Despite frequent visits hopes for nesting are diminishing as the season progresses.

Regarding a few questions that we have received:

(1) It is not possible to determine whether these birds are the same as last year or in years past. Some webcam watchers are confident in their ability to identify individual eagles based on certain feather pattern characteristics. These methods should be used with the most caution.

Notably on the BRI eaglecam2 the female of the pair is in fact banded and is likely the same bird that nested at this site last year.

(2) Based on sounds I do suspect that there has been some activity or a repair of some type near the microphone at this site. I've not been able to make a visit personally but do know of nearby buildings. It is important to note that the microphone is located some distance from the nest. Based on the behavior of birds at this site in the past it seems unlikely that limited sound and ground traffic would deter birds from using this site. However, it is not possible to completely rule this out.

Thanks for the posts and keep your fingers crossed for a late season nesting attempt.

Until Next Time,

Patrick Keenan
BioDiversity Research Institute

Thursday, April 08, 2010

Eagle visits but still no nesting!

Well, the subject line of this post pretty much sums it up. Although we have seen the eagles on a regular basis the birds at this site are not showing the signs of nesting this year. Many have put forth suggestions as to why they might not be nesting and unfortunately it is very difficult, if not impossible, to know for certain why these birds are again not nesting.

Last year, their nesting efforts waned directly after the arrival of a 'third' eagle which interrupted the nesting pair fairly early in the season. We've not seen any antagonistic interactions yet this year but other eagles have appeared at this nest on occasion over the past few months.

One possibility is that the birds are using this nest as a 'dummy' nest and nesting elsewhere. I have no knowledge of an additional nest but again this is difficult to rule out without a thorough survey of the area surrounding this nest or possibly aerial surveys.

Additionally, it is well documented that individual eagles do not necessarily nest every year. Perhaps these birds are simply taking an 'extended break' from nesting due to any number of reasons such as food supply, territorial disputes, body condition, or the condition of the nest or nest tree.

We will have to keep watch as the birds may still nest late but a general rule in coastal Maine is that if the birds do not lay eggs by early May it is unlikely that they will nest.

Until next time,
Patrick Keenan
BioDiversity Research Institute