May 10, 2017 in In the Nest Box
After 30 plus days of careful and shared incubation duties of the 4 eggs by both male and female, the time has come for the chicks to hatch. We are likely a day away at most from the first hatch! Here is a late afternoon view of the 4 eggs while the female is taking a regular break in the non-stop process of incubating the eggs.
April 19, 2017 in In the Nest Box
As the incubation process continues, many have asked for more specifics about how it all works?
Heat makes the eggs start developing. When the eggs reach about 98.6°F, or 37°C the egg begins changing into an eyas. Conveniently enough, a Peregrine’s natural body temperature is about 103°F, or 39.5°C, so to heat up the eggs all they need to do is to get some of that body heat onto the eggs. Now, a Peregrine’s feathers make very good insulation. That’s how they can stand to stay out in cold temperatures without freezing to death. But while those feathers keep the cold air away from the falcon’s skin, they also keep their body heat from getting out. So to incubate the eggs, the Peregrine carefully settles down, shifting from side to side to get the eggs beneath their feathers. Falcons have brood patches, areas on their breasts with a lot of blood vessels close to the surface of their skin. The blood vessels concentrate their body heat, making it easier to transfer the heat to the eggs. Both adults have brood patches, though his are smaller than hers, which makes sense since he’s a smaller bird.
Peregrines incubate their eggs for 29 to 33 days. In the early days of brooding it’s important to keep the eggs as close to their ideal incubating temperature as possible. Too hot or too cool and the eggs won’t develop properly. Later in the incubation process, proper temperature isn’t quite as important. In fact, after a couple of weeks the falcons will be able to leave the eggs uncovered for longer periods of time. Sometimes leaving the eggs uncovered frequently, or for long periods can mean that the eggs hatch a few days later than normal. For the Lawrence Peregrines, their nest box is in a place where it’s not likely to be disturbed, so they most often incubate steadily until the eggs hatch.
April 10, 2017 in On the Clock Tower
Made a later afternoon visit to the west side of the Clock Tower and found the female in flight and landing mode a number of times around the NW corner of the below the clock face. The skies were clear with bright late day sun, light winds front he SW, and temps just below 50F. No doubt the female is stretching her wings after hours incubating 4 eggs!
April 10, 2017 in In the Nest Box
The female Peregrine in Lawrence has finally laid all four eggs, a bit later than usual for this location. Here’s how the process works. Once fertilization occurs the egg begins moving down her oviduct. It’s sort of on an assembly line where the egg gets built, layer by layer. First comes several coatings of yolk. The egg moves a little farther down the ovidicut where it gets covered with albumen (the clear fluid that we’d call egg white) and various membranes. Then it continues on its way until shortly before she’s ready to lay the egg, it gets its final layer, the shell. The whole process takes a little more than a day.
The actual act of laying the eggs can take as little as a few minutes or as long as an hour or more. When she’s ready to lay her egg, the female will sit in the scrape. She may look like she’s sleeping, or at least taking a nap, but if you watch carefully, you’ll notice that she starts to move around as the egg is laid. She typically keeps the egg covered after it’s laid for 10 to 20 minutes before moving off the nest and letting us have a good look.
Peregrine eggs are speckled, and vary in color from light pink to darker brown or purple. Older falcons may produce lighter colored eggs. Each one is about the size of a small chicken egg.
One bit of behavior that many people find unusual is that she won’t begin incubating the eggs, or brooding, right away. Believe it or not, that’s perfectly normal for Peregrines. She’ll begin brooding when the next to last egg is laid, so when she starts, we can be pretty sure we know how many eggs she’ll lay– just add one to the current number. Before then, she’ll mostly leave the eggs uncovered. Don’t worry though– Peregrine eggs can survive just fine unless the temperature drops below freezing. If that happens, she’ll sit on the eggs just to keep them warm enough to stay viable. We’ll talk more about brooding and incubation soon. In the meantime, keep watching!
In this photo on Monday morning after the last eggs were laid over the weekend, the female is taking a break and resting on the outer edge of the nest box!
April 5, 2017 in Near the Clock Tower
Mating starts as many as four weeks, or more, before egg laying and continues through the process, up to several times an hour. The male will mount the female, typically no longer then ten seconds, then he will disengage and fly off. Fertilization of an egg happens every 48 hours. After being fertilized, it takes an egg 24 hours to develop and be laid… resulting in a new egg being laid every 48 hours! We are likely a day or two away from the first egg being laid, if it hasn’t happened all ready!
April 3, 2017 in On the Clock Tower
Both male and female seen this morning in and near the nest box! Clear skies, bright sun, light winds from SW and temp around 40F. The female was hunkered down at the outer edge of the nest box and the male, with leg band barely visible, was perched on a nearby roof edge, keeping watch on all around.
March 30, 2017 in In the Nest Box
The adult female and male continue to be seen and very active around the nest box but no signs of eggs laid just yet. This is just a bit later than past seasons for the onset of eggs being laid, but other peregrine nests are also a bit late! We’re getting much closer to the time!!
March 29, 2017 in Near the Clock Tower
Lots of pair bonding continues with the male and female. they are frequently seen in very close proximity to each other with the breeding cycle in full swing. This morning the female was seen eating prey on one of the triangle pediment ledges above the entry to one of the New Balance buildings located at 200 Merrimack Street under dark overcast sky conditions. The male was just to the east on one of the short steel beams just below the roof line.
March 23, 2017 in Near the Clock Tower
A late afternoon visit by the Clock Tower with both peregrines in sight. The male was seen on a window ledge along the very west wing of the New Balance Building. These ledges are more regularly used by fledglings after first flights. From time to time the adults will be perched on these granite ledges to be near the nest or just to be out of the wind and to soak up the warmth of the late day sun!
March 21, 2017 in Near the Clock Tower, On the Clock Tower
The Lawrence Peregrines continue to be very active around the Clock Tower! They perch in and near the nest box, make all kinds of aerial flight patterns, and continue with copulation activities. Late this afternoon, discovered the female perched on a NW ledge just below the clock face, the male circling in flight, and then finally, the male landed on the outer edge of the next box. He was good enough to provide a look at his alphanumeric leg bands for positive ID!
