Taken at Wid Wings Birds of Prey Centre. Leigh Road, Worsley. M28 2LJ.
The Harris Hawk is native to the central part of the Americas, the Southern North American territoy and much of South America. There is some evidence that they are spreading their range further into North America. Like many other raptors, the population of Harris Hawks is currently on the decline. There are two sub-species of Harris Hawk, Parabuteo Unicinctus Harrisi is found mainly in North America down to Northern South America, generally referred to as Harris Hawk. Parabuteo Unicinctus Unicinctus is found mainly in South America and are generally referred to as Bay-Winged Hawks.
The Latin name Parabuteo Unicinctus is similar to a Buzzard(Parabuteo) with a single stripe(Unicinctus - referring to tail). The Ornithologist, Audobon, gave the bird the name Harris Hawk, after his friend Colonel Harris. In the wild, Harris Hawks prey on small rodents, such as Rats, Mice, Lizards, small birds (often taken in flight) and small mammals, such as young Rabbits. If prey is scarce, they have been known to feed on Carrion. In the wild Harris Hawks will live up to 12 years, in captivity they can live for twice that long.
Very often, a female Harris Hawk will mate with two males, the nest may be made in co-operation of several other birds. Nests are made in the tops of trees or on the top of a tall Yucca or Cactus. Up to 5 eggs are laid and incubation is performed by the female(33-36 days). Feeding of the young is by the female or both of the males she mated with. The young are fully fledged within 7-8 weeks from hatching, though the young may stay with the parents for up to 1 year. Sometimes two clutches of eggs are laid in a season, between early March to late June.
At least one study has shown that the polyandry (mating with more than one male) exhibited by the female Harris Hawks is not due to an imbalance in the ratio of males to females, the ratio is roughly 50:50. Whilst it is not certain why the polyandy exists, one theory suggests that the amount of available food available may be an issue. Some studies have shown that in areas of large amounts of food, the males (who usually provide most of the food during the early part of the breeding season) are more likely to mate with more than one female (polygamy) as they are able to provide food for both. In areas of low amounts of food, polyandry is more likely, as the chances of survival for the young is improved with two or more males providing the food. As Harris Hawks naturally hunt co-operatively, they are usually more successful hunters, this has been suggested as a major reason for the female Harris Hawks taking two mates.
Harris Hawks are one of the few broad-winged Hawks that will readily hunt in a team (sometimes called a cast), when they socialise with each other. When hunting as a team, they will take turns in flushing the quarry while the others wait to attack . This enables the hunting to carry on for longer than usual, often with the prey tiring before the birds. If the prey hides in bushes then some of the group will attempt to go in after the prey, while the rest wait on the other side for the prey to rush out. In the wild, this co-operative hunting is most often during the winter months when prey is scarce. The prey will be equally shared at the end of the hunt, often with the juveniles being given the first share, while the adults wait.
Since being introduced into Falconry in this country around 35 years ago, Harris Hawks have become one of the most popular Falconry birds in the UK. Due to its size, intelligence and temperament the Harris Hawk is regarded as an ideal beginner's bird (some believe they are not suitable as a beginners birds, because they are too easy to train, so often beginners actually learn very little). Although generally amiable, Harris Hawks can be temperamental, females being particularly prone to aggression in adulthood. Young birds can have very anti-social manners. Early imprinting on handlers, occasionally when kept singly, causes partial imprinting on the owner and associating people with food, this inevitably can produce birds that scream for food when the owner is in sight. Juveniles tend to grow out of this after the first moult, but it is not guaranteed.
In the wild, Harris Hawks have been seen to indulge in stacking - sitting on each others backs, often up to three high, either on the ground or on the top of a cactus. It is not certain why they do this, though it has been suggested as either due to lack of roosting space or as a method of still hunting, giving slightly more height so further distances can be observed, in desert areas which do not have the benefit of trees or poles to sit on.
