Harpy eagles are known to form monogamous pairs and mate for life. They are solitary hunters that use their keen sense of sight to locate arboreal prey in thick rainforests. Harpy eagles require large territories of about 30 square km for adequate hunting and are very territorial, driving out any competing individuals.
Mating and Nesting Behavior of Harpy Eagles
During the nest building phase, the pair will rarely radiate more than 180 m from the nest. The mating pair of harpy eagles does not have a courtship display before mating, and will mate multiple times over a period of a few days. The breeding season for harpy eagles coincides with the start of the rainy season, which usually begins in April or May.
Harpy eagles construct large nests that measure 1.2 m thick and 1.5 m across. The nests are built 27 to 43 m above ground and consist of woven sticks lined with soft vegetation and animal fur. These impressive nests are reused by breeding pairs every year.
Reproduction and Parental Care
Image source: Harpy Eagle by Bjørn Christian Tørrissen
The female lays two eggs, but will raise only one chick. Eggs are incubated for an average of 56 days. Both parents tend the chick for 10 months, well after the chick fledges between 6 and 7 months of age. Juveniles often stay near their parents for some time and will occasionally beg for food. Juveniles do not reach maturity until 5 or 6 years old, at which time they often return to their original nesting area to breed.
Incubation and Chick Rearing
Harpy eagles invest a lot of time and energy into their offspring. Both parents incubate the egg for the 56-day incubation period. The female will perform most of the incubation while the male is in search of food. Chicks are hatched altricial, and thus are helpless with downy feathers and eyes open. The parents will only tend a single chick, so if two eggs are laid, the first-born will be fed and the second will perish from starvation.
The parents actively tend the young for 10 months, which is several months after the chick fledges at 6 or 7 months old. The parents feed the juvenile once every few days, and during this time, the juvenile is mostly inactive while occasionally begging for food. Juvenile harpy eagles often remain in the parents’ territory for at least 1 year.
Lifespan and Survival
Harpy eagles are estimated to live 25 to 35 years if they remain healthy. Disease and injury dramatically affect their chances of survival by inhibiting their ability to find and capture prey.
In conclusion, harpy eagles are indeed known to mate for life and form monogamous pairs. They invest a significant amount of time and energy into their offspring, with both parents actively participating in incubation and chick rearing. The long-term parental care and the juveniles’ extended stay in the parents’ territory are key characteristics of the harpy eagle’s mating and breeding behavior.
