June 24, 2014 in Bald Eagle
The Bald Eagle nest in northeast Essex County along the Merrimack has 2 chicks this year. Stopped by on a warm late June afternoon and observed the eaglet panting in the warm heavy air. Like dogs, eagles don’t have sweat glands. They control heat by panting, radiation through their unfeathered legs and feet, and perching in the shade.
May 31, 2014 in Bald Eagle
The nest in NW Essex County has two healthy eagle chicks this year. They are getting larger and are starting the wing flapping process as they move around the nest and move more frequently onto the ridge of the nest providing better views!
As nestlings, eagles progress through three different sets of feathers including natal down, thermal down, and juvenile feathers. Chicks are hatched with a coat of natal down. This down is very light in color and does not have much insulating ability such that chicks must be brooded by an adult for warmth. Natal down is replaced by thermal down beginning around 10 days of age. Thermal down has very good insulating qualities and by 15 days chicks are typically able to thermoregulate on their own. The emergence of juvenile feathers including contour and flight feathers typically begins on or before 27 days. These dark feathers are arranged in tracts and emerge in sequence beginning with the capital (head) and dorsal (back) tracts. The ventral (belly) tract is the last feather group to emerge. Flight feathers including the wing and tail continue to grow throughout the development period reaching their maximum lengths around the time of fledging. The last phase of development as nestlings is neurological or the learning of coordinated movements. This includes walking, feeding, and flying. The final month of development is consumed by acquiring the coordination needed for movement and flight.
May 31, 2014 in Bald Eagle
The Bald Eagle nest in NE Essex county continues to look good for chicks. Reports have been coming in that the small brown headed chicks are starting to poke their heads up and are just starting to be seen. Stay tuned!
May 21, 2014 in Bald Eagle
Another Bald Eagle nest has been added to the local observation circuit! This nest is in the northeast area of Essex county and near the Merrimack River. It has been productive the last few years and chicks from this nest have been seen and photographed on the Merrimack in Lawrence, MA. The female is on nest with possibly 2 chicks ready to make an appearance very soon!
April 28, 2014 in Bald Eagle
Once the bald eagle has reached the stage where its secondary down is beginning to be replaced, it is called a juvenile. From the fourth to the eighth week, the juvenile bald eagle continues to grow at a rapid rate. It continues to molt, losing its secondary down and gaining the feathers or plumage of the juvenile eagle. The plumage of the juvenile eagle is far less striking than that of the adult eagle. It appears to be a dark grayish brown. The coloring of the juvenile bald eagle is very similar to the coloring of the adult golden eagle.
The physical changes that the juvenile eagle undergoes in its growth from youth to adulthood can be described as moving from muted, darker, all-one-color shades to the striking high-contrast colors of the adult.
For example, the juvenile’s eyes progress from a dark brown, to a lighter brown, to a cream to its adult coloring of yellowish white. The bald eagle’s beak and cere transfrom from a dark black or gray to a mixture of gray and black to a mixed yellow and gray to the adult vibrant yellow. Its head feathers are dark brown to black in the juvenile but get progressively lighter brown and gray until they turn a dirty gray just before achieving the brilliant white head feathers of the adult bald eagle. The lower breast of the juvenile is a dark brown which becomes molted and then returns to a very dark brown in the adult. The tail changes from black with gray near the vane to a mixed gray and black to a final pure white in the adult eagle.
The size of the juvenile bald eagle is remarkable in that it is actually larger than the size of the fully grown adult bald eagle. This is because the plumage of the juvenile bald eagle is actually longer and thicker than that of the adult bald eagle. The adult bald eagle is more streamlined with fewer and shorter feathers than the juvenile. This streamlining contributes to the more graceful flight of the adult bald eagle. The longer feathers tend to make the juvenile eagle a bit clumsy in flight.
April 26, 2014 in Bald Eagle
The recent posting on the Bald Eagle pair in Essex County included a series of copulation sequence photos. It was unclear if this was part of a post egg hatching ritual for this pair of Eagles. Although a posting was made on April 1 that made mention of a likely feeding process, no chick was observed during that observation period.
A late visit to the nest provided an opportunity to observe an adult perched on the rim of the nest under cloudy conditions. The adult then flew off to the northeast. Every effort was made to look for any sign of a chick. Nothing is sight…..and then to my delight and surprise, a wing and then the dark crown of a chick head appeared. Great news for the breeding effort this year.
A few minutes later, moved to another vantage point, looking for a better view of the chick. This effort afford another terrific surprise with the sighting of second chick int he nest! WOW! Low quality photos of 2 chicks, one with head raised and other just showing its shoulder. Stay tuned!!
April 9, 2014 in Bald Eagle
While checking on a pair of nesting Bald Eagles along the Merrimack River, observed the male launch into flight from a perch on back side of the nest tree. He made a large aerial loop and then seemed to go into a stall above a taller nearby pine tree. Then he began to descend with legs and talons outstretched while making loud calls. To my surprise, a female was atop the pine tree and bowing forward. Up until now, I’m under the impression that at least one chick has hatched and should be large enough to be seen fairly soon, based on prior feeding observations. The bald eagles engaged in a copulation sequence that lasted just a few seconds. Found some commentary on the web that perhaps explains the behavior:
1. Sometimes the male initiates the act, but the male must be careful approaching the larger female, and occasionally, the female injures or even kills the male (Wolfe and Bruning, 1997). In most cases, the female initiates mating. She bows her head, spreads her legs, and raises her tail. The male then approaches the female with his tail raised. The female emits a single-note call, and the male clenches his talons so he won’t hurt his mate and then climbs on her back. He lowers his tail and cloaca to meet the female’s as she raises her tail and cloaca. Copulations occur often during the breeding season but slow down once the eggs are laid and stop after the eggs hatch (Wolfe and Bruning, 1997) .
2. In the book “The Bald Eagle,” eagle biologist Mark Stalmaster says, “Copulation takes place in as little as five to fifteen seconds, but can last one to two minutes, and may occur several times a day. Most copulations occur from six days before to three days following the laying of the first egg. Sex is more common in the early morning hours. The sex act, however, has been observed after construction of the nest, and might even happen outside the breeding season.”
For those with an interest, more sequence photos posted: http://www.pbase.com/birdshots/image/155168871
Click “next” in upper right corner to advance frames!
April 1, 2014 in Bald Eagle
For first 2–3 wk of nestling period, female present at nest about 90% of time, male present about 50% of time; at least 1 adult at nest almost 100% of time. Both sexes hunt and feed young. Adult brings food to nest, tears off small pieces, and delivers them to young at early age. Male provides most of food in first 2 wk, while female tends young in nest . After 3–4 wk, female delivers as much prey as male. After 3–4 wk, young able to peck at food but not able to tear off food and feed self until 6 wk. Male was tearing apart food and feeding chick during my observation time late afternoon.
March 27, 2014 in Bald Eagle
The Bald Eagle pair near the Merrimack River in Essex County is back on nest again this year! In 2013, this pair raised one chick. the growth of the 2013 chick was monitored and documented on tis blog last year. The egg or eggs were laid around middle/late February and hatched mid/late March. The female is now sitting much higher in the nest and we await first sightings of this year’s brood! According to Birds of North America Online: “At hatching, covered with light-gray down, initially wet but dries quickly, eyes brown, gape and legs pink, and skin pink. Capable of limited locomotion. Second down begins to emerge at 9–11 d. Flight feathers emerge at 2–3 wk; body contour feathers begin emerging with the humeral tract at 3–4 wk. Great variability in emergence of contour feathers, such that same-aged individuals may look different. Feathers on head and back emerge at 4–5 wk; Maximum growth attained at about 3–4 wk of age. Male develops flight feathers and asymptotic size more rapidly than female, such that measurement of wing-chord, central rectrice, and eighth primary not sexually dimorphic during nestling period, although these characters show considerable sexual dimorphism in fully developed birds.”
4 Photos: http://www.pbase.com/birdshots/image/154998869
Enjoy,
Craig
March 12, 2014 in Bald Eagle
While watching gulls and crows peck away at a dead carp on the ice in front of the Bashara Boathouse on the Merrimack River in Lawrence this morning, noticed a likely Bald Eagle flying eastbound from Rt. 93 direction. Reached for camera and lost sight of the eagle. All of a sudden it was almost right overhead. It circled the carp feeding frenzy and then lumbered down river towards the dam in Lawrence. A few minutes later, headed to the dam and crossed over to north side for a look back at trees and ice. Sure enough, a subadult was on the ice just west of the dam and on the south side of the river. It was feeding on some unknown delight. A further scan showed a second subadult nearby. The played a bit in aerial flight near shore and then one of them flew west and the other remained near the dam. Nice treat on the way to work!
