Bird Island Standley Lake

Broomfield, Colorado, United States

0 266,237

Bald Eagle History:

Since January of 1993, a mated pair of Bald Eagles has been nesting on the northwest side of Standley Lake. When the eagles were first observed building a nest, Standley Lake officials closed off access to the area so the eagles would be undisturbed in their attempt to nest. Bald eagles usually mate for life and reuse nest sites. Because they are sensitive to human disturbance, it is imperative that the area remains closed to protect the nesting habitat.

In 1996, the eagles successfully produced their first pair of offspring. They have continued in that success for the last 21 consecutive years, producing two eaglets each of those years, except in 2015 and 2017 when they were successful in raising three eaglets! The eagles have been using that same nest for 24 years, until this past year when they decided to build a new nest just to the east of their old nest site.

They usually lay their eggs in the first weeks of February. Incubation lasts for a period of approximately 35 days, at which time one to two nestlings will hatch. These nestlings will first leave the nest in late May to early June, approximately 72 days after hatching. Both parents take care of the young eagles even after they leave the nest. The young will leave the area sometime before October or November, either on their own or when the parents force them out.

2021 Season

Season Summary:

September 8, 2020 - Early snowfall on the nest, one eagle seen roosting in the nest
September 22, 2020 - Both Dad and F420 are seen in the nest
October 22, 2020 - Both Dad and F420 are seen moving sticks around in the nest, leaving and returning with sticks several times
December 23, 2020 - High winds snapped the branch holding the adult eagles active nest, the eagles were seen relocateing to the older nest on the other side of the tree.
December 26, 2021 - Both Dad and F420 spend the past few nights in the old nest, during the day the eagles rebuild the old nest bringing in sticks and other nesting materials.
January 5, 2021 - A raccoon visits the nest several times and was shiftly chased out by F420.
January 9, 2021 - Both adult eagles are busy rebuilding the nest.
February 27, 2021 - First Egg laid
March 2, 2021 - Second Egg laid
April 7, 2021 - First Hatch, referred to as SL1
April 10, 2021 - After close observation, it is determined that there is no sign of a second eaglet in the nest.
April 15, 2021 - The eagles experience their first winter storm with the eaglet
April 20, 2021 - F420 shields her nestling SL1 under here as a snow storm piles a few inches of snow in the area
April 28, 2021 - SL1 gets bigger and bigger with every feeding
May 6, 2021 - The adult eagles spend more time out of the nest but close by, the eaglet starts to gain independence in the nest, learning to pick up sticks and moving around while its parents watch at a distance on an adjacent branch or tree
May 12, 2021 - SL1 develops more flight feathers and is seen testing out the new wings by flapping and mimicking the act of flight
May 13, 2021 11:45am - Tragedy strikes again at this nest site. At 11:45am the cottonwood tree supporting the nest splits down the middle, causing the nest to fall and collapse to the ground. There were no high winds at the time, but the tree was old and mostly dead which may have led to the split. The 5 week old eaglet, SL1 did not survive. SL1 was brought to National Eagle Repository and will be cremated and buried with a sacred ceremony in a blessed burial site located in Rocky Mountain Arsenal and National Wildlife Refuge. The site was created specifically for eagle burial by Tribal representatives from Cheyenne and Arapaho tribes of Oklahoma, Oglala Lakota and Southern Ute.

2020 Season

Season Summary: This was an eventful season, 3 eggs were laid. Late in the incubation period the female eagle was attacked by another female eagle. After this incident the egg laying female did not return to the nest and "Dad" took over the incubation responsibilities. One egg hatched and "Dad" tried his best to care for this egglet, trying to get the eaglet food on his own while trying to survive himself. Unfortunately, the eaglet did not make it. The unknown female eagle was seen frequenting near the nest area at that time and even joined "Dad" in the nest a few times moving around the eggs, but not consuming them. The remaining eggs did not hatch. However, the female eagle and "Dad" began to bond and tolerate one another. At the end of the season a few mating attempts were made.

March 1, 2020 - First Egg Laid
March 4, 2020 - Second Egg Laid
March 7, 2020 - Third Egg Laid
April 6, 2020 - Intruding Eagle attacks nest, Mom leaves the nest
April 7, 2020 - Male eagle returns to nest with an unfamilar female eagle
April 10-11, 2020 - Mom has not returned to the nest, Male eagle incubates the eggs
April 12, 2020 - One Eaglett hatches in the nest
April 14, 2020 - It is believed the Eaglett passed away
April 17th, 2020 - The unknown female eagle has been seen around the nest, the male has begun to tolerate her presence near the nest
April 20th, 2020 The female eagle is known as F420, F for female, 4/20 for the date she enters the nest, she has begun to move sticks around in the nest
April 21, 2020 Dad and F420 are seen together in the nest and breifly for a mating attempt
April 22, 2020 Dad and F420 are seen copulating and the female brings a new stick to the nest
April 24, 2020 Dad and F420 are joined at the nest, Dad brings F420 food to the nest to eat, the two eagles work intently on building the nest leaving and returning with new sticks
May 8, 2020 Dad and F420 are seen regularly working on the nest and copulating, they make a few visits to the nest but for the remainder of the summer with no young eggletts to tend to, the pair are seen perched on many spots in the park near the nest

Photo Credit: City of Westminster