Peregrine Falcon eggs….waiting for eggs to hatch!

April 28, 2014 in In the Nest Box

The peregrine falcon couple living in an 8th floor falcon condo in the Ayer Mill Clock Tower will soon welcome their 2014 chicks, or eyases, to the city of Lawrence.  The female has laid 4 eggs this year, and we are now at the back end of the normal incubation period of 29-33 days.

Falcons will eventually get rid of eggs if they do not hatch. Two years ago, the couple laid 4 eggs but only 2 eggs hatched.  They waited a few weeks before discarding the 2 unhatched eggs.

The first egg was laid March 21 this year!  Incubation of the 4 eggs started after the last egg was laid on March 26th.  Stay tuned!

Bald Eagles, juvenile pair

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.


American Kestrels return!

April 28, 2014 in American Kestrel

The Kestrels have returned again to Lawrence for another breeding season!  Today was the first sighting of a male kestrel near the Duck Bridge along the Merrimack River.

According to Mass Audubon, the adult male, which has blue wings, two sharp, vertical, black stripes contrasting against a light face, and a bright rufous tail, is certainly the most colorful of North American hawks. The somewhat larger female is not as brilliant as the male and has its upperparts entirely rufous, and barred with black. Kestrels tend to perch high and conspicuously in the open, making them easily visible. They can be tamed readily and will reproduce in confinement. Many falconers have noted that the small males are more docile and tractable than the females.

Spring migration occurs mainly during March and April, and by the latter month local breeders are on their territories at woodland borders, fields, pastures, and the edges of highways. As the breeding season approaches, kestrels abandon their solitary winter habits. Members of a pair often perch side by side, and courtship consists of aerial displays by the male above a perched or flying female. The male ascends on rapidly fluttering wings and then plunges steeply, giving the familiar, repetitive killy-killy or kee-kee call, which is used not only in courtship but also at other times of excitement. Copulation during this period is frequent and precedes egg laying by several weeks.

Peregrine Falcon eggs – still waiting!

April 26, 2014 in In the Nest Box

As of 6:15 pm Saturday night, we continue the vigil awaiting the hatching of the first falcon egg!  In the worth noting department: from time to time, the birds stand up and rotate the eggs. This is an important chore, as it ensures that the eggs are uniformly warmed and prevents the embryos from sticking to their shell, which could be a problem during hatching.

An egg is an amazing creation. It is fragile enough for a tiny chick to peck its way out, yet strong enough to withstand the weight of an incubating adult. That wasn’t always true. According to the staff at the Peregrine Fund in Idaho, in the 1960s, scientists discovered that the pesticide DDT caused physiological problems in female Peregrine Falcons, resulting in thin-shelled eggs that broke during incubation.

DDT was banned in 1972 and The Peregrine Fund helped recover this once-endangered species with captive breeding and releases to the wild. It was one of the most successful conservation efforts in history!

Bald Eagles – 2 chicks!!!!

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!!

Peregrine Falcons 4 eggs close to hatching!

April 26, 2014 in Near the Clock Tower

The Peregrines have been incubating the 4 eggs hatched during the 3rd and 4th week of March.  The estimated incubation period runs normally between 29-33 days.  As of Friday afternoon, at the 30 day mark, all 4 eggs were seen and documented with this photograph.  These eggs are ready to hatch and hatching should take place today or next few days!  Stay tuned!

Great Horned Owlet – Methuen Rookery

April 25, 2014 in Great Horned Owl

The Great Horned Owlet continues to grow in size and darken slightly in plumage.  Best guess is that the owlet is about 6 weeks old.  It is likely days away from breaking out of the nest and starting the process of climbing around on nearby branches prior to fledging, or making its first flight!  Stay tuned!!

Peregrine Falcon, adult male

April 22, 2014 in On the Clock Tower

The incubation period is ready to draw to a close fairly soon with four eggs having been under constant incubation from March 24th.  Hatching should take place in the next few days.  the male has been keeping a proximate vigil nearby the nest.  He is always nearby and has been sharing part of the incubation duties!  In this photo, he is perched on the NE corner of the Clock Tower.

Great Horned Owlet – Methuen Rookery

April 22, 2014 in Great Horned Owl

The Great Horned Owlet in Methuen continues to grow in size and change in plumage with darker colors. Nice observation time this morning while owlet in nest with adult no where to be seen. At first, owlet low in nest and then it just seemed to straighten right up providing much better looks. Estimated age is around 5-6 weeks old and ready to start “branching” very soon!

For those with interest, 7 photos posted:

Click “next” in upper right corner to advance frames!

Killdeer – Nevins Farm, Methuen

April 16, 2014 in Nearby Landbirds

This species is among the earliest spring migrants to arrive in our area. In normal years, Killdeer appear by the middle of March.  Early arrivals are found in agricultural fields, congregating around snowless areas where manure has been spread for fertilizer. By mid-April, Killdeer are present in a variety of open areas, where they will establish territories for nesting. These include fields, pastures, airports, golf courses, playgrounds, gravel pits, beach dunes, unpaved driveways, and lawns. In recent years, they have taken to nesting on the flat rooftops of one- or two-story buildings. Despite the questionable suitability of the latter nesting sites, there is evidence that some young are raised to maturity.