JBS American Bald Eagles 2018-2019 Breeding Season While American bald eagles have been observed in the wetland since 2008, nesting began in 2012. Since then, our eagles have successfully hatched, raised and fledged 12 eaglets. Thanks to Wetland Steward Tom Fleming for his photos and observations of the eagles’ 2018-2019 breeding season. They provide this retrospective. Previous page: The adult male guards his territory against a 4th-year sub-adult and 3rd-year juvenile. Oct. 23 23 The eagles are back [the first eagle returned Oct. 3, the second Oct. 6]. This morning, one was on station at the nest tower. We may call this “surveying their realm,” which they do constantly. Or, we could call it energy conservation mode. Like lions, eagles spend a good part of their day resting and digesting the abundant energy obtained from their prey. Nov. 1 (below, via webcam) Just caught both eagles hanging out in the nest. Nov. 21 Surprise Visit: While walking the Pond Trail east of the Center, I noticed some hawks just north of the woods. There were several red-tails, and I heard one call to my left. There I saw a large “hawk” perched in a dead tree. Turned out to be a young bald eagle. It has survived that first difficult year and is well into its second. This eagle left its perch and flew over to inspect me. The young are naturally curious. Dec. 12 Dec. 14 Male and female eagles appear identical to the casual The eagles will now be mating with increasing frequency. observer. But curiosity drives us to ask, “Who's on the These matings stimulate hormone production in the female, nest?” It's easy to decide when the eagles are side-by-side. and eventually the female ovulates. and we get a fertilized The female is considerably larger (about 25%). The other embryo. Three days later, the egg is laid. The top of the way is to spend a lot of time observing them. Their tower is a favored location for mating. When you visit the mannerisms and fine physical details will begin to reveal wetlands, how can you tell if they will be mating while you themselves to you. This image shows the easily discerned are there? There are some preliminary behaviors that can size difference. give you some idea. The tower structure affords the opportunity for the male to perch on a strut at a 90° angle to her perch. They can remain like this for 20 minutes or more. They may vocalize. If mating is about to take place, the male will hop over to her strut. Then he sidles closer. They make “greeting” calls, and then he begins to mount her. That part lasts 15-20 seconds, and then it’s all over. Dec. 16 Dec. 20 WE HAVE AN EGG! Mom was exhibiting a lot of attention to TWO EGGS!! The second egg was laid before 5 p.m., Dec. 19. the egg cup this morning. And then she shifted and revealed This picture from the webcam the morning of Dec. 20 shows an egg at 8:40 a.m. by the screen clock on the webcam. Dad both eggs while the parents trade places. This egg will likely hatch on Jan. 23. arrived to take over incubation, and the shift revealed the egg for us to see [pictured below on Dec. 17 from webcam]. This egg will likely hatch on Jan. 20. Dec. 25 In the spirit of holiday sweets, I offer this bit of “eye candy.” The same tree that hosted recent images of a young eagle and a red- tailed hawk has delivered one of our bald eagle pair for this photograph. This particular image shows the bird leaving the “raptor tree” and exposes the talons to good advantage. The talons can deliver 400 psi of pressure when clamping onto prey. Inset photo: Red-tailed hawk on Dec. 3 in the raptor tree. This dead tree is 100 feet to the west of the intersection of the gravel road and Bunker Pond Trail. Jan. 28 CONFIRMATION: I observed Mom upright above the crib rails. For a period of about 10 minutes, her behavior/body language was consistent with an adult feeding young. The adult female spends about 80% of the time on the nest, and the male has the remainder of nest duty. So referring to the adult on the nest as “mom” is convenient when observing from a long distance. It will probably be 2-3 weeks before the newly hatched become big enough and active enough to be seen. Feb. 2 (right) With one eagle on the nest almost constantly, the other is usually nearby. There’s the perch at the top of the tower and another perch in the tree line that faces the wetland ponds. As you make the walk from the Center to the tower, scan to the right. About 800 feet to the right, there is a tall pair of trees that are a favored perch. Feb. 4 (far right) BALMY: The weather was warm and pleasant. Mom used this opportunity to give the eaglets some fresh air and sunshine. At this age, the young birds are getting lots of nap time interspersed with meals. They're still not quite big enough to be seen above the crib rails, but they grow fast and that time is coming soon. Feb. 14 NEST MAINTENANCE: Newborn eagles will begin to direct their waste over the side of the nest after reaching the age of a week or so. Old prey lying around the nest is currently the main hygiene issue. Also, the soft bedding is now getting trampled steadily by the young birds. So nest maintenance is one additional duty that falls to the adults. In this image, one of the adults is bringing in some fresh bedding material. Feb. 18 THE SHERIFF: The job of any good sheriff is to patrol the borders of his jurisdiction. While federal law requires a separation of 200m for an active nest (our viewing area is 250m away), our intrepid enforcer will come out to let you know he is watching you - or just to say “hi,” depending on how you look at it. Feb. 19 The eagles mounted an unusual number of aggressive attacks on birds passing near the nest. First, a flight of pelicans drifted too close and had to be steered away. Next, four crows came in yelling, and the eagles responded to this brazenness with a fierce attack. Most of this conflict was low level. Then a hapless vulture cruised by unawares, but now the eagles were in no mood to tolerate any kind of invasion. An aerial dogfight ensued, with the vulture beating a hasty retreat. The fourth and final attack (shown here) involved two red-tailed hawks. This mated pair are seen frequently near the nest as their territory overlaps the eagles’. But again, no intruder was tolerated on this day. As the attack began, each eagle paired up with a red- tail. The action was frenetic, and the aerobatic maneuvering was awe-inspiring. All four attacks lasted only a minute each, but huge amounts of energy were expended covering an impressive volume of sky. Feb. 22 Female eagles spend about 80% of the time on the nest. It may be an old human stereotype that Mom stays home and Dad brings home the bacon, but the type holds up for the male eagles as well. They bring in most (but not all) of the food for the eaglets. On this day, however, Mom did her gender proud, bringing home an impressively large fish. March 1 March 3 FINALLY! Confirmation of both young eagles on the nest. The Today’s session started with Dad on duty. Mom returned, and overcast makes for difficult lighting on the beautiful subjects of they remained together for about 10 minutes. Then Dad this picture. The head of the 2nd eagle (lower) is turned away headed north to the tree perch about 800 feet away. About 10 in this image. minutes later, a black vulture sailed above the tower. Dad was a bit late but came in hot pursuit. Mom joined in, but the vulture was well past the nest by now, and the chase was more of an escort out of their territory. The aggressive defense theme for this year continues. This shot shows Dad on a return swing by the tower with the head of one of the eaglets showing above the nest. March 11 CATCH-OF-THE-DAY: Our adult eagles bring mainly fish for the young. But birds are on the menu as well along with the occasional small mammal. The birds that are brought in are mostly coots and cattle egrets. March 14 (below) Today was beautiful but breezy with some blue skies and sun to show off the eagles’ plumage. Our eagle is seen here with gear down and full flaps as he lands into a 20 mph headwind. March 15 TWO HEADS ARE BETTER THAN ONE: Shy, lazy or bad timing. Whatever the reason, these young eagles have been uncooperative in helping me capture an image of the two simultaneously. They are now roughly two months of age and about 90% of their size and weight when they fledge. March 28 FAMILY PORTRAIT: Dad is on the far left just returning from removing another vulture from the area. Mom is attending the nest having just brought in a fish. The attention-getting eaglet is wingercising, and the shy eaglet is hiding behind the tower strut.