Local Eagle Nest


Protecting a Neighborhood Bald Eagle Nest


With good reason, Alaska usually comes to mind at any mention of Bald Eagles. Yet, it surprises some people to learn that, in the lower 48 states, breeding Bald Eagles are most numerous in Florida and Minnesota. In 1990 there were 535 breeding pairs in Florida, and 437 in Minnesota. The number of Florida breeding pairs rebounded rapidly to 1,102 pairs in 2001, then plateaued at 1,133 in 2005. In the meantime, Minnesota's population climbed slowly at first, to 681 pairs in 2001, then shot up to 1,312 pairs in 2005, surpassing the Florida population.

This US Fish and Wildlife Service graph illustrates the recovery of breeding Bald Eagles in the lower 48 states since DDT was banned in the early 1970s:



In an earlier post, I described why the numbers of Bald Eagles in the more northern of the lower 48 states increase during summer and early autumn, due not only to newly fledged eaglets, but to the influx of more southern eagles. The Florida birds perform an interesting "reverse" northward migration after the breeding season. It is hypothesized that this contrary behavior is caused by another sort of "migration," namely the vertical movement of the eagles' main food source.

As Florida's lakes heat up, the fish seek cooler temperatures in deeper water. Radio tagging of Florida eagles has shown that many follow the cooler water into the northeastern coastal states. Chesapeake Bay is a popular summer and fall gathering place for the Florida population. Immature birds tend to wander more widely than adults, with some even ending up in Canada. Conversely, North America's northernmost Bald Eagles move south with the approach of winter, seeking open water as the larger lakes and rivers freeze up.

Alaskan eagles are, on average, heavier than those in Florida and have longer wings. I photographed this one in Soldotna, Alaska, along the Kenai River:

 Bald Eagle 3-20110621

We have a particular interest in Bald Eagles, as we have been involved in protecting a recently discovered nest in our south Florida neighborhood. I served on the Pembroke Pines Mayor's Bald Eagle Sanctuary Steering Committee. During the first week of October, 2011, Mary Lou and I were pleased to see that both members of the pair had returned to the nest:

Two adult Bald Eagles at nest 3-20111005

They were already rearranging the nest materials:

Two adult Bald Eagles at nest 2-20111005

On October 12, 2011, I photographed one of the pair at sunrise, flying from the nest area in the general direction of the largest lake in our subdivision:

Bald Eagle at sunrise 20111012

On October 16, 2011, the female was sitting high on the nest...

Bald Eagle on nest 2-20111016

...while her mate (judging by its slimmer build and slightly smaller size) roosted in a nearby Australian Pine:

Bald Eagle roosting 2-20111016

We first became aware of the local pair of eagles on December 4, 2007, when I photographed them mating on the rooftop of a house just across the lake from our home:

2007_12_4_DoubleEagle 016CROP

As there had not been a record of an active Bald Eagle nest in Broward County since several years before DDT was abolished in the early 1970s, I reported the sighting on the Tropical Audubon Society's Web page, and birders in neighboring Pembroke Pines had a general idea of where they might be breeding. In March, 2008, Kelly Smith, a local middle school teacher found the nest, located only about 150 feet from a busy boulevard. It contained one nearly full-grown eaglet.

This photo of "P. Piney One" was taken by Kelly Smith on March 15, 2008 and is reproduced here with her permission: 





This pair of eagles has returned to the same nest each year, successfully raising and fledging two chicks in 2009, three in 2010, two more in 2011, a single chick in 2012, two in 2013 (one of these eaglets disappeared at about 15 days of age), two more the next year (both survived), but they did not breed in 2014. The story of their nesting failure and the interesting events of the 2015-2016 season are detailed towards the end of this post. 

The nest is about 50 feet high in an exotic Australian Pine tree with smaller trees blocking most of the view, so we only get distant looks. 

On December 11, 2008, the beginning of their first full breeding season under our observation, both adults are shown sitting on the nest, only two days before the first of two eggs was laid:: 

Eagle Pair at Nest 20081211

Local middle school students conducted a nationwide poll that chose names for the two eaglets, “Hope” and "Justice:” They hatched on January 15,2009. Here they are, 

squabbling with each other at exactly one month of age. Hope, the older and larger, is on the left:

Eagle Nest Mates 20090215

The eagle nest attracted a great deal of attention, and crowds of up to 100 people came to see the antics of the eaglets, causing traffic hazards as they stopped on the roadway and parked illegally.

Eagle Watchers 2-20090409

The Mayor took an interest in the nest, which is located on City of Pembroke Pines property, and he announced his intention to declare the site a City Bald Eagle Sanctuary, and took measures to protect both the eagles and observers.The City amended its planning documents which paved the way for an ordinance that provides extra safeguards against disturbance of any eagle nest in the city. During the summer of 2011, major resurfacing of the roadway and construction of a sidewalk were suspended in the area of the nest during the eagles' breeding season (May 15 - October 1).

I photographed these three eaglets on March 2, 2010. The Middle School students' poll resulted in them being named Chance, Lucky and Courage. All three fledged successfully:

Three Eaglets 20100302

The eagles returned in October, 2010 to refurbish the nest, and eggs were laid around December 11. ( * See end note about how we estimate the time of egg laying and hatching). On January 23, 2011 at the age of about 9 days, this chick was first seen, peering over the nest rim:

Eaglet and eagle 3-20110123

Here, it waits as its parent tears off a bit of food. A younger sibling was not yet visible from the ground:

Eaglet 20110123

The Parent eagle feeds the chick :

Eaglet feeding 20110123

This was about as good a view we could get from 150 feet. Vegetation now makes viewing much more difficult. Plans for a nest camera have not materialized:

Eaglet feeding 2-20110123

Here is the older of the two eaglets, on February 3, 2011. Much of her natal down has already disappeared:

Older of 2 eaglets 20110203

At one month old, on February 15, 2011, the down had been reduced to a fuzzy cap:

Older eagle chick 20110215

Less than two weeks later, on February 27, 2011, the eaglets looked almost as large as adults. We called them "P. Piney Seven & Eight."  Bald Eagles exhibit sexual dimorphism that starts when they are nestlings, with the females usually considerably larger than males. 


P Piney 7 is the larger and was presumed to be a female:

Eaglets 43 days old 20110227

At two and a half months of age on March 23, 2011 they were exercising their wings, preparing for their first flight, which usually occurs when they are between 10 and 12 weeks old. 


PP7, on the right, has more white underneath than her younger brother:

Eaglets 2-20110323

On March 30, 2011, we found PP8 alone in the nest; PP7 had flown off, but returned within three days to be fed:

Eaglet PP8 settled down 20110330

On March 30, PP8 was "helicoptering," hovering in place up to a foot off the ground:

Eaglet PP8 helicoptering 20110330

Here, on April 3, 2011, my last shot of PP7 shows her roosting in a tree next to the nest. PP8 was flying back and forth on branches in the nest tree:


P Piney 7 2-20110403

That year, both P Piney 7 and 8 fledged successfully. In the next (2011-2012) only one eaglet was known to have hatched, although there was a possible sighting of a very small second sibling. Unfortunately, P Piney 9 suddenly disappeared at about 9-10 weeks old, when nearly old enough to fly independently. It may have fledged prematurely but was never seen again.


Pride feeding P Piney 9 on FEB 17, 2012:

Bald Eagle male feeding eaglet 5-20120217

The next breeding season (2012-2013) produced two eaglets. Both fledged but the second (P Piney 11) disappeared from the nest 4 days later and presumably was killed during or just after its first flight. Ground search for this eaglet or its remains was not successful. The first flight is known to be associated with a high mortality rate.

Here is P Piney 10 in March, 2013:

Bald Eaglet 2-20130310

Breeding season 2013-2014 was a great success. Two eaglets (named Honor and Glory) both fledged in early April, 2014. 

Honor and Glory beg to be fed by their mother (Joy) on March 30, 2014:

Bald Eaglets begging from male adult Pride  20140330

However, in October 2014,  the original female parent (Joy) suddenly disappeared. Her mate (Pride) found a new mate (Jewel) in December. The pair bonded and mated but failed to breed in the 2014-2015 season, possibly because Jewel was only 4 years old and inexperienced.

Pride "introduced" us to his new bride, Jewel on December 7, 2014. She shows rather extensive dark feathers in her tail, having not yet molted into full adult plumage, which is usually completed after 4 years of age:

Bald Eagle new female 08-20141207

This photo, taken on March 12, 2015, provides a comparison between the heads of Jewel in nearly full adult plumage, (foreground) and Pride. Jewel is overall larger and her head appears more massive and rounded, while Pride's forehed slopes almost in line with the top of his beak. The angle (gape) of the female's beak usually extends at least to a point below the center of her eye, while that of the male is more aligned with the front edge of his eye:

Bald Eagle face comparison 20150312

Here is Jewel, probably 4 1/2 years old, on October 24, 2015 in fully adult plumage except for a few dark feathers in her head and tail. She was bringing in new sticks:

Bald Eagle female Jewel 03-20151024

Pride and Jewel (in nest) adding and rearranging sticks on October 24, 2015:

Bald Eagles L-R Male and Female 20151024

Disaster struck the next season (2015-16). Joy hatched at least one eaglet (P Piney 14) in mid-January 2016, but a severe storm damaged the nest and the little chick was never seen again. At first we thought that the parents had abandoned the nest, but they returned to produce a second brood. This is a very unusual event, but because of the widespread stormy weather several other south Florida eagle pairs also suffered similar losses and laid eggs a second time.

Two eaglets hatched in mid-March, 2016. This was my first photo of the younger and smaller one, P Piney 16 on April 2, 2016:

Bald Eagle eaglet 20160402

The older nestling (Spirit) grew very rapidly as is commonly seen in female eaglets. She towered over P Piney 16, out-competed for food and attacked him repeatedly. He disappeared or was killed by Spirit on April 11, 2016. 

Spirit is on  the left in this photo taken on April 4, 2016, a week before P Piney 16 suffered a particularly vicious assault by his sibling:

Bald Eagle 2 eaglets 20160407

Almost ready to fly, Spirit is larger than the adult male parent (Pride) on May 27, 2016:

Bald Eagles male and eaglet 02-20160527

Spirit fledged in mid-June and was observed foraging on her own into mid-August, 2016. Here is Spirit on JULY 17, 2016:

Bald Eaglet HDR 02-20160717

As of this writing, in August, 2016, the occupants of this nest of eagles is known to have hatched out at least 16 chicks, of which 12 were confirmed to have fledged successfully. Although we hope all 12 are still alive, the sad fact is that as few as 50% of the Bald Eagles which leave the nest survive into adulthood. (Research shows great variation in survival rates. The proliferation of Florida's eagle population suggests that conditions may be more favorable. However, when the eagles move into urban areas they are subject to new hazards, particularly motor vehicle collisions and injury from power lines. Aggression between eagles over territories and mates also may become more common where they compete for limited resources). Most mortality occurs within the first few months before the eaglets gain survival skills. 

A spreadsheet (PDF) which details observations of this nest since 2008 may be accessed AT THIS LINK

*In estimating the timing of the laying of eggs and hatching of the eaglets, we must depend upon clues from changes in the behavior of the adults. The onset of incubation coincides with the laying of the first egg, which is when we suddenly see one of the pair down deep and immobile in the nest. Hatching is a time of excitement, as the parents shift position frequently, peer down into the nest, and they start bringing in prey and tearing off bits to feed the tiny chick. The adults also sit a bit higher in the nest after the first egg hatches, supporting themselves on their wings to form a "tent" to shelter the chick and yet provide warmth to any eggs that have not yet hatched. Volunteer nest observers share their sightings and photos, and respond to queries in the Pembroke Pines Eagle Nest Watch FORUM here, which includes a link to spreadsheets that document observations over the past three breeding seasons .

1 comment:

  1. The nest was destroyed when branch fell on it. Haven't seen any information this season.

    ReplyDelete

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