Category Archives: Ospreys

The Eagle Has been watching.    “There’s something going on here, but I don’t know what it is.”

Ospreys transfer their heat via a temporarily bare area of abdominal skin called the brood patch. Large birds of prey such as ospreys and eagles have small brood patches which corresponds to a longer incubation time. Ospreys can sense their embryo’s … Continue reading →

The act of sitting on eggs to incubate them is called brooding. For an osprey egg to develop normally, it must be exposed for a considerable length of time to temperatures a few degrees below the normal avian body temperature of … Continue reading →

Male provides female with all food during incubation. When the male brings in a fish, there is usually a” switch off”. Female takes fish to nearby perch and feeds there; male incubates while female feeds, but sometimes will initiate incubation … Continue reading →

Both sexes incubate. Females 80%, Males 20% –  during daylight hours. Females nearly always incubates at night.   “Switching off”  

 Incubation begins with the first egg, so the eggs hatch in sequence in 37-38 days.  (Due date May 17 – 18)

 A three-egg clutch takes about 6-7 days to complete; a 4-egg clutch probably 8-10.  Looks like a two-egg clutch this year. But that is wonderful. Two is company

Oh Wow! Two! April 16, 2020

Osprey “clutch size” ranges from 2 to 4 eggs. Roughly 80% of North River females lay three. It is known from banding studies that a 2-egg clutch reflects a young female, a first-time breeder.  4-egg clutches are associated with food-rich … Continue reading →