Virginia.gov

VDGIF/Norfolk Botanical Garden Eagle Cam: 02/01/2008 - 03/01/2008

The Virginia Department of Game and Inland Fisheries, in partnership with the Norfolk Botanical Garden and WVEC, is providing a rare glimpse into the life of two bald eagles and their offspring!

Friday, February 29, 2008

“Settling Back In”

The original pair continue to roost and perch together and have been seen mating again. If the first mating attempt seen on the 23rd was fruitful we will expect to see an egg laid over the next few days. At least one other breeding attempt has been recorded (2/27). Both adults have been bringing sticks to the nest and are actively preparing the nest bowl.

*Photo courtesy of Joe Foreman ©

Saturday, February 23, 2008

“Original Female Returns”

The potential for a replacement clutch seems to be improving. On Fri. Feb 22nd we were able to confirm that the original female had returned to the nest. Both she and the male returned to the nest repeatedly through the day adding sticks and pine needles to the nest. The sub-adult female has not been seen over the last few days. We will hope to see some mating behavior soon. Given this pair's familiarity with each other we are hopeful that things will proceed apace.

In other news the two eggs recovered from the nest are at VIMS (Virginia Institute of Marine Sciences) where they will be analyzed. The eggs will provide information regarding the presence of any environmental contaminants in the eagle's diets. The development of the embryos will also be measured. Given the fairly precise data we have regarding mating episodes and egg laying this information will be especially informative.

The eggs have been measured and weighed. They are pictured next to a regulation baseball to give an idea as to their relative size.

Egg 1 735cm X 565cm 126.1 grams (4.5oz)
Egg 2 740cm X 565cm 122.4 grams (4.3oz)


When climbers were retrieving this eggs two squirrels abandoned their den in the underside of the eagle nest. They were noted on Friday collecting eagle down to line their own nest. If the eagles continue to utilize the nest regularly we expect squirrel activity to decrease.

Tuesday, February 19, 2008

“Only Two”

The eggs were removed from the nest today. Much to our surprise we learned that our assumptions regarding a third egg were erroneous. We had based our assumptions of a third egg on the behavior of the female at the nest - turns out we were fooled. The nest only contained two eggs this year. The pine straw of the nest bowl was thoroughly searched no shell fragments or egg remnants were found. Had a predator of some sort gotten to the eggs, we would expect plenty of evidence left behind. The shrubs below the nest were thoroughly searched as well.

In previous posts I've pointed out that competitive interactions like what we've witnessed at this nest are a sign of a recovered Eagle population. Another side of this same coin is cautionary however. The recovery of Bald Eagles will remain dependent on available breeding habitat. Continued development may encroach on Eagle habitat, reversing the population gains of the previous decades. Careful planning and habitat preservation will ensure that Virginia continues to enjoy a thriving Bald Eagle population.

“Update”

The original female has not been seen for almost three days now and the eggs have been unattended. The eggs are no longer viable at this point, but can still provide data to scientists. Researchers from the Center for Conservation Biology at William & Mary will remove the eggs this afternoon. The eggs will provide valuable information in regards to many aspects of Bald Eagle's reproduction. While all involved with the project are disappointed with the outcome for this clutch, there will be a positive aspect - adding to our knowledge of these birds to ensure a long term recovery of the species.

Collection and/or possession of eggs, feathers or nests of birds is regulated by both the Federal Fish & Wildlife Service and the Virginia Dept. of Game & Inland Fisheries and requires very specific permits.

The new female and resident male continue to be seen perching together at the Garden. We are still early enough in the breeding season tht a replacement clutch is entirely possible...we'll all keep our fingers crossed.

Saturday, February 16, 2008

“Changes in Norfolk”

We are starting to get a picture of what has happened at the Norfolk Botanical Garden nest over the past week.

The intruding eagle has been identified as a 4th year female. While this bird has attained its adult plumage it still retains some darker feathers on both the tail and head giving it a somewhat "smudged" or mottled appearance. At times this intruding female has been seen with both resident eagles, with some mating behavior noted with the resident male. The resident female can be identified by the scalloped shape of her white "bib", while the male's bib has a relatively straight edge.

Oddly, at times the resident female & the intruder have been seen either flying with each other or perched quite close with no apparent conflict, at other times the tension between the birds is shown in threat displays and chasing behaviors.

The eggs have been left unattended for long periods of time and their continued viability is very much in doubt. The good news is that there is still time for this dispute to be settled and a new clutch laid.

In addition to the three eagles at the center of this territorial dispute there have been several other Eagles sighted in and around the Garden of late. Two 2nd year birds were noted soaring (and diving on the adults) on Thurs. 2/14 and another sub-adult was seen on Fri. 2/15.

Thursday, February 14, 2008

“Upheaval at the Garden”

Events at the Norfolk Botanical Garden have become increasingly complicated over the last few days. What began as harrassment by an outside Eagle appears to have resulted in one of our resident pair being evicted by the interloper.

We are reviewing video footage and images to determine exactly who's who and what all has transpired. It is tempting to leap to conclusions but it's important to realize that no one view of the situation provides a complete picture. While the camera provides an excellent "eyewitness" of events it is a small window into a much larger territory. Norfolk Botanical Garden staff and biologists from DGIF and William & Mary Center for Conservation Biology were on hand at the Garden for a significant portion of the afternoon - assessing the situation and examining the birds from a distance. We will compare images from today with past images to try to detect differences in plumage, hopefully helping us I.D. the birds at the nest.

The eggs were left unattended for significant periods of time today - given the temperatures we are seriously concerned about the continued viability of these eggs. At the writing of this update (6:35pm Thurs.)an adult appears to be incubating the eggs. We will continue to monitor and assess. Once we are confident that we have reconstructed the chain of events accurately we will report our findings here.

Tuesday, February 12, 2008

“Uninvited Guests”



One of the consequences of the successful recovery of the Bald Eagle is that there are now more...Bald Eagles! This has been evident over the last few weeks as the resident pair has had several interactions with other Bald Eagles. On Feb. 2nd a visitor to the garden caught this following photo as an unattached adult eagle was chased fom the area by the male as the female watched from the nest.



On Feb. 7th a pair of eagles were noted by observers at the garden. These birds were escorted off by both the resident birds.



All of this culminated today with three incursions at the nest itself by an adult male. Mature unmated eagles will try to take over the nests of established pairs, requiring extra vigilance. In each case the trespassing eagle was driven off.



video

*Photo courtesy of Andy Mueller©

Monday, February 11, 2008

“Egg Number Three!”

For the third consecutive year the eagles at the Norfiolk Botanical garden have laid a third egg. This is a testament to the richness of the habitat. With the freshwater of Lake Whitehurst adjacent to the Garden and the Chesapeake Bay nearby (not to mention ALL those tasty gulls), this pair have found the resources to support their remarkable production. The third egg was laid Friday Feb. 8th at 11:41 pm. A full week seperated the laying of the 1st and 3rd egg (just as last year). The parents will be busy once these eggs hatch, trying to provide enough food for three hungry mouths.

Wednesday, February 06, 2008

“Owl Visit”

We've posted a video of the Great Horned Owl's visit to the nest on Feb. 1st - Enjoy!

Note how quickly the Owl decides to retreat.

video

Tuesday, February 05, 2008

“Egg #2”

The Eagles at the Norfolk Botanical Garden have a second egg. The second egg was laid close to dusk on Monday February 4th, two days after the first egg was laid. While we we not able to actually get a glimpse of this egg (the nest bowl is fairly deep) the female's posture and behavior were consistent with egg laying. Two eggs is common for Bald Eagles while three (as laid by this pair in 2006 & 2007) is very unusual. There is often a significant delay between the date of the first egg and any subsequent eggs (last year there was a full week between egg#1 and egg#3). We'll continue to monitor to see if any more eggs are forthcoming.

The youngest sibling in a nest is often at a disadvantage. The first to hatch have the benefit of their parents undivided attention, getting all the food. They grow rapidly and get a head start on later hatchlings. This larger eaglet dominates at the nest, often receiving the lions share of food deliverd by the parents. Food must be plentiful and the parents good hunters to successfully raise a brood of three eagles.

Monday, February 04, 2008

“First Egg....& Another Visit”


The first egg was laid just before 6:30pm on Friday evening. After a windy day that tossed the nest to and fro - the weather calmed and the female laid her 1st egg.

Either during or immediately after the egg was laid the Great Horned owl put in an appearance, landing on the rim of the nest. The female eagle wasted no time chasing the intruder away and then settled into the nest. The Great Horned Owl visited the nest three times during the night but never threatened the Eagles.

Bald Eagles typically incubate their eggs for 35 days, although this pair seems to take a bit longer with the first egg hatching after about 38 days for the last few years. Bald Eagle eggs are white and rough textured - measuring up to 2.75-3 inches long and and 2-2.25 inches across. Two eggs is typical although this pair has laid three for the last two years- and successfully fledged all 3 each year! This success is a testament to the skill and experience of these parents as well as the richness of the habitat. The female will do most of the incubating although the male will occasionally take a shift.

We'll continue to watch for more eggs, its not at all unusual for eggs to be laid a few days apart. These eggs will hatch asynchronously (in the order they were laid) so the first to hatch will have a size advantage over its siblings.