Year of the Osprey
Come by our museum and see our Year of the Osprey exhibit!
Osprey Facts
Osprey are Raptors, also know as bird of prey, who predominantly eat meat (specifically fish).
They are known as the river hawk because of their skilled fishing ability.
The species is at least 11 million years old.
Their wingspan can grow up to 4.5 - 5.5 feet.
They live for 15 to 20 years, the oldest osprey known was 25 years old.
They use 8 different vocalizations to communicate.
They are an endangered or threatened species in the US.
They are aggressive towards intruders near their nests.
Ospreys tend to sleep away from their nests. One parent will stay with eggs or chicks but generally they will not sleep there. They will roost somewhere nearby in a tree or something similar.
They must live within 12 miles of water, but many choose to live much closer than that.
Telling Males and Females apart: Female ospreys have a brown necklace marking while males have a lighter or no necklace.
Migration Pattern
During their lifetime they will fly roughly 160,000 miles.
Migration normally travel from Canada and Northern US to Central and South America.
Osprey that migrate between Sweden and Africa will travel 4,200 miles a day for a 45 day period.
Osprey migrating between Massachusetts and South America travel 2,700 miles a day for 27 days.
After migration, they return to the same area and typically the same nest as the previous year. They will repair the nest for the next mating season and eggs.
Diet
Following its classification as a Raptor, the osprey’s diet is almost exclusively made up of fish. The fish they catch tend to be 4-12 inches long and can swim as low as 3 feet below the surface level. The osprey has many adaptive advantages that allow them to be successful hunters. First, the osprey can submerge themselves underwater to catch their prey before flying away, opposed to many other fish eating birds because many can only claim the fish swimming at the surface level.
Along with that, the osprey have specially adapted feet that allow them to catch fish easier. Their toes can rotate backward to provide more security when holding fish. They also have tiny points on their feet that creates more tractions and a securer hold. On top of that, the osprey have a nictitating membrane, which acts as a third eyelid, protecting their eyes underwater so that they can see their prey.
Among these physical characteristics of the osprey, they also have natural habits that benefit them while hunting as well. The birds will capture fish with its feet in such a way that the head of the fish will be facing forward. They do this because it reduces wind resistance while flying. Also, due to their consumption of fish, the bird rarely drink water. The fish that they eat makes up 99% of their diet and the intake of water from the fish allows them to stay hydrated. They will catch 1 out of every 4 dives and it takes approximately 12 minutes to catch food.
Mating & Nesting
The osprey tend to nest in tall tree or poles. They like to be in clear open spaces that allow for them to easily defend their nest. Osprey predominantly use sticks and twigs to build their nest. Due to the large size of the nests (3-6 feet in diameter, 10-13 feet deep, and 2 feet thick), other birds such as starlings or sparrows will nest in the lower parts of the nest. The nests weight around 300 lbs.
Osprey are know to be monogamous birds, meaning that they will stay will one mate for their life time. However, in the instance that one of a pair dies, the other will find another mate. Their monogamy tends to be more based out of needing to defend territory rather than love.
During courting, the male will bring sticks and twigs to help prepare the nest. He will also bring food which inspires the mating. The more food brought, the more likely the female will mate with the male. The males will also perform a “sky dance” to attract a mate. Once eggs have been laid, the male will decide if they will claim them or not. If they do not accept the egg, they will toss it out of the nest. The females mostly incubate the eggs. Once the first egg hatches, there can be up to a 5 day period between the first and last egg.
Once the eggs have hatched, within 3-4 weeks the hatchlings will be 70-80% of their adult size. Due to the locations that they choose for their nests (open area), there isn’t much shade, so the female will use their wings to shade the chicks until they can regulate their own body temperatures. Then around 7-8 weeks the chicks will fly for the first time or fledge. Two weeks after fledging, they will begin to hunt with their father and two weeks after that they will begin to hunt on their own. The females will leave the nest first and the males will follow.
for more information check out these websites:
https://www.daysatdunrovin.com/ospreys-101-nesting-mating-chicks/
https://avianreport.com/osprey-calls-types-and-meaning/
https://www.allaboutbirds.org/guide/Osprey/maps-range
https://www.nwf.org/Educational-Resources/Wildlife-Guide/Birds/Osprey
https://peregrinefund.org/explore-raptors-species/osprey/osprey