The Harpy Eagle

The Harpy Eagle, Harpia harpyja, is one of the most identifiable of birds of prey and not just because of its size. The Harpy Eagle is noted for having slate black feathers on the upper areas of the bird. The underside of the eagle is white, although there is a black band across its chest. The head has a double crest and is pale grey in colour.

The Harpy Eagle can be found from southern Mexico through to Southern Brazil, this range takes in Panama, where the eagle is the national symbol. The Harpy Eagle though is endangered and there is thought to be less than fifty thousand birds in the wild, and as the habitat is threatened so numbers are likely to decrease in forthcoming years.

Harpy Eagle - Michael Schamis - CC-BY-SA-2.0

The Harpy Eagle is generally considered to be the largest of the eagle family, although it does have a rival with the Steller’s Sea Eagle and Phillipine Eagle. The Harpy Eagle can grow up to 100cm in length, with the female being larger than the male, with the female weighing up to 9kg in weigh. The wingspan being up to 200 cm in length may seem long but is relatively short compared to its body length

The wings have adapted to allow for flight at speeds of up to 50mph, although the wings are more adapted to flight through the trees of dense forest. The Harpy Eagle will surprise its prey, swooping down on sloths, monkeys, opossums and small rodents. The size of the Harpy Eagle, and its 13cm talons, does mean that it can pick up prey up to 5kg in weight.

Harpy Eagles will breed in the wild, although many breeding schemes exist in zoos and other conservation organisations. Nests are made from branches and green twigs, and as befits the size of the eagle. The female Harpy Eagle will then lay either one or two eggs, although as with many other raptors the parents are only looking for one offspring, and if the first egg hatches the second will cease to be incubated. The first egg should hatch in eight weeks.

A harpy eagle and a white-headed sea eagle - CC-BY-4.0

Once hatched the parents will then raise it for six months, by which time it should be self-sufficient, and the offspring will stay around for a further six months.

One of the most impressive of birds of prey, the Harpy Eagle is currently under threat and in need of protection.

Copyright - First Published 17th March 2010

The Barn Owl

With an estimated population worldwide of 5million, the Barn Owl, Tyto alba, is one of the most common of all birds of prey. Rarely seen during the day, the night time hunter is more likely to observed and heard during dusk.

The Barn owl is probably one of the most recognisable of the owl family, although there are some slightly differing features depending upon which one of the 30 subspecies of the bird is being observed. Female Barn Owls are slightly larger than the male, as is the case with many raptors.

Barn Owl hunting at Dusk - Edd deane - CC-BY-SA-2.0

Female Barn Owls may be as much 40cm tall, with a wingspan of 100cm. The wings of the Barn Owl are impressive and the owl has evolved in such a way that it is more likely to be seen gliding than flying, and requires very little flapping of its wings to remain in the air.

In general Barn Owls are identified by a brown or buff body and wings, the wings often have lighter tan or grey tips. It is though the white face that makes it look like a ghoul, or an angel, depending upon your point of view. The white is normally in the shape of a heart which is offset by deep black but small eyes.

The Barn Owl does emit a long screech, rather than a normal owl hoot, and gives rise to one of the owl’s other names, the Screech Owl. The sound of a Barn Owl when walking through a dark countryside is enough to make most people jump out of their skins.

As previously mentioned there are some 30 subspecies of Barn Owl, located all around the world, with their own features. These subspecies are found on all continents other than Antarctica, and are primarily found in temperate and tropical regions of the world, although they avoid the hottest desert regions. There preferred habitat is light woodland areas with open areas nearby, particularly open farm land.

Barn Owls will find places to roost in tall trees, although they also have an eye for man made roosting places, like church steeples and barns, hence their name. Barn Owls were for countless generations considered the farmer’s friend, and farmers would entice Barn Owls to roost in their barns, well aware that the owls would help control rodent populations.

Barn Owl with Prey - Edd deane - CC-BY-SA-2.0

The Barn Owl will feed primarily upon rats and mice, although other small animals, such as rabbits and moles need to be aware during the night. It is quite possible to see a Barn Owl skimming over an open field at dusk in search of its prey, and in a normal night a Barn Owl will need to catch three or four rodents to be well fed. Hunting though is done primarily by sound rather than by sight. The evidence of a well fed Barn Owl though will come in the hours of daylight when shiny black pellets will be found. These pellets can be up to 5cm in length, and are the bones, fur and other indigestible bits of their meals.

Barn Owls are well known for being monogamous, but the mating ritual is something to behold. Male Barn Owls will put on a flying display for the potential mate, before acquiring a meal to seal the deal. Like most raptors, barn Owls do not go in for the building of intricate nests, and will make a simple twig one in a crevice, or make use of a pre-existing one.

The female Barn Owl will then lay an average of six eggs sequentially, with incubation starting immediately. The first eggs is normally laid at the end of March, although the breeding season may last through until October. The incubation period lasts for between four and five weeks, although as with other raptors the number of eggs actually hatched depends often on the availability of food. The earliest hatched eggs are the strongest and will get the majority of food that the male Barn Owl brings for his family. It takes only two weeks for the hatchling to be relatively self sufficient and will be mature enough to leave the nest after ten or twelve weeks.

The population of the Barn Owl has fluctuated over the years, although the overall decline of the past fifty years seems to have been reversed in more recent yeas. The main threat to the Barn Owl, as with most birds, comes from man, and in particular the changing face of farming. Farms have increasingly made use of chemicals to control pests, depriving the Barn Owl of its main source of food. Most farmers though do recognise the beneficial nature of the bird, and so many have started to give them a helping hand, reducing pesticide usage, and also cutting down on the removal of old building and other potential nesting sites.

Today the Barn Owl is classed as of being Low Concern, mainly due to the large numbers, and widespread nature of the bird. It is there probable that future generations will get to experience the Barn Owl in the wild, and be scared stiff when one screeches in your ear.

Copyright - First Published 19th March 2010

Britain's Rarest Bird

On the face of it the concept of rarest birds seems an easy one, and when talking about the world’s rarest bird, it is easy to quantify in terms of individual birds or breeding pairs, although there is also always the caveat of number of birds in the wild or in captivity. When it comes to narrowing the concept down to a single nation though, difficulties arise.

The question of which is Britain’s rarest bird, brings forth a number of different answers based on any number of criteria.

Most birds tend, to a greater or lesser degree, migrate, and Britain throughout the year attracts birds from continental Europe, the Arctic Circle and Africa. Occasionally though vagrants also appear, normally individual birds that shouldn’t be here, often getting lost in their own migrations. American wigeons and Baltimore orioles have been spotted within Britain, and could subsequently be called Britain’s rarest birds, although of course they are not British birds.

American Wigeon (Male) - Alan D. Wilson, www.naturespicsonline.com - CC-BY-SA-3.0

If a bird stays in Britain then this is another criterion that could be used to class a bird as Britain’s rarest, and indeed a single black-browed albatross made Scotland his home for many years. The albatross though, normally found around the Southern Oceans couldn’t reproduce so a population could never be established.

The need for an established population for a bird to be classed as rare is one of the reasons why birds are often counted as breeding pairs. In terms of breeding pairs, the Eurasian Eagle Owl could claim to be Britain’s rarest birds, as a pair have been breeding in recent years in Yorkshire. The Eagle Owl though is not a British native, and the pair of owls are probably a pair released, accidentally or on purpose, from captivity. Eagle owls should probably be classed as invasive, as they have the potential to disrupt the British ecology. Equally though, there are many other non-native birds to have escaped from captivity, some which have become established.

There are though some other birds which are often classed as Britain’s rarest. The Golden Oriole, Oriolus oriolus is a summer visitor to Britain, when the southeast of England becomes home to anywhere between five and seventeen breeding pairs. Likewise Common Cranes, Grus grus, have started breeding once again in Britain. Other rare summer breeders also include Montagu’s Harrier, Circus pygargus, and the Honey Buzzard, Pernis apivorus.

Oriolus oriolus - Paco Gomez - CC-BY-SA-2.0

A final category for rare British birds might well include those that are resident all year round, with the likes of the Redwing, Turdus iliacus, where only a handful of breeding pairs make their home in Scotland. The Redwing though is far from rare in the winter, when hundreds of thousands migrate to Britain. Far rarer though might well be the Cattle Egret, Bubulcus ibis, which may well become an established British bird in the future, although the current population is perhaps a hundred birds, but if sequential breeding seasons for the bird occur then it might well be Britain’s rarest bird.

Cattle Egret - Atamari - CC-BY-SA-2.0

Many birds can be called Britain’s rarest, and there are many discussions that could be had about the validity of any claims made. It is perhaps better to consider what can be done to help birds that are endangered, and hence rare, to ensure that future generations can view these birds in the wild.

Copyright - First Published 6th September 2011