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

The Buller's Albatross

Named after the lawyer and ornithologist Walter Buller, Buller’s Albatross, Thalassarche bulleri or Diomedea bulleri, is a relatively small mollymawk, normally to be found around New Zealand and the Southern Pacific.

In terms of breeding populations though the Buller’s Albatross is confined to the islands of New Zealand, where all 32,000 breeding pairs make their nests. This low number of birds is of concern, although no albatross is especially populous, and currently the Buller’s Albatross is classed as being Near Threatened in terms of endangerment. This though is an improvement on only a few years ago when the bird was classed as Vulnerable. Numbers have remained stable for a number of years, despite the continued threat of longline fishing.

Buller's Albatross or Buller's Mollymawk - Sabine's Sunbird - CC-BY-SA-3.0

Despite its relatively small range, some sources do name two subspecies, Diomedea bulleri bulleri, or the Southern Buller’s Albatross, and Diomedea bulleri plateir, the Northern Buller’s Albatross. In terms of appearance though there is not a great deal of difference.

The adult Buller’s Albatross is normally about 80cm long, with a wingspan of about 205cm. These birds tend to have silvery-grey foreheads; with the rest of the head and throat being grey. They also have white rumps and under areas, with a dark grey back, tail and upper wing areas. The Northern Buller’s Albatross is normally slightly darker grey. The bills of these albatrosses are large and black, with splashes of yellow.

The Buller’s Albatross feeds mainly on fish and squid, although shrimps, lobsters and octopuses often supplement their diet. Food is foraged for often by individual birds, although groups do gather around abundant sources. Buller’s Albatrosses have the ability to make shallow dives as well as surface plunges. The aid in the excretion of excessive salt levels, the Buller’s Albatross has a nasal salt gland. The Buller’s Albatross may fly for many miles, and like many of their family, they are able to produce energy rich stomach oil. This oil is also useful in feeding young during the breeding season.

Buller's Albatross - Duncan Wright - CC-BY-SA-3.0

The breeding season of the Buller’s Albatross is a colonial affair, and largish groups of mating birds form on Snares Island, Solander Islanders, Forty-fours Island, Big Sister and Little Sister Islands. Nests are constructed on cliffs, in meadows and under trees, with the nests being a mound constructed from soil and vegetation.

Buller’s Albatrosses start to breed when they are ten years old; these birds are long lived, often reaching thirty years of age. Breeding subsequently is an annual occurrence. A single egg is laid into the nest, and is then incubated for two months. Each parent undertakes alternate ten day shifts in sitting on the egg. Once hatched fledging of the chick takes up to six months.

Currently the future of the Buller’s Albatross is looking relative good, with some evidence in increasing breeding numbers. Low population levels and a relatively limited range in terms of breeding areas though means that nothing is certain though.

Copyright - First Published 10th November 2011

Keywords -  Buller’s Albatross, Thalassarche bulleri, Buller's mollyhawk, Diomedea bulleri,

The California Condor

The California Condor, Gymnogyps californianus, has proved, at least in the short term, to be a story of conservation success. Briefly extinct in the wild, a reintroduction programme has once again ensured that the large bird can be seen in its American environment.

In the time that written records have existed, it would seem that the California Condor was never the most prolific of birds, with figures for between the World Wars numbering about seventy. With all birds counted existing within the borders of California. This figure then dropped to twenty two birds by 1981.

In 1987, as a last gasp measure, the remaining six wild California Condors were caught and placed into a captive breeding programme. The breeding programmes were a relative success and by the start of the twenty first century captive birds were reintroduced into the wild at specifically chosen release sites. The success has continued with new California Condors being born in the wild.

Statistics taken from 2009 and 2010 now suggest that there are now 170 California Condors in the wild and a further 150 in captivity.

Despite the success of the conservation programme, the California Condor remains classified as Critically Endangered. The biggest risk today is lead poisoning and whilst the condor is not hunted, lead shot used on other animals is being ingested.

California Condor in Flight - Brian Sims - CC-BY-2.0

To catch a glimpse of the California Condor then a trip to the open scrubland areas of California and Arizona will be necessary, only a small fragment of a range that once spread from Canada to Mexico. The open savannah areas offer cliffs and large trees as nesting sites, as well as offering up carcasses of mammals which make up the bird’s diet.

If the bird is observed then the California Condor is unmistakable. The scavengers are predominantly black in colour, with bald heads and necks. The colour of the neck region can vary from red to yellow and even light blue, with the birds having the ability to change colour depending upon their mood.

It is of course the size of the California Condor that of course distinguishes, it is after all one of the largest flying birds alive today. On average the bird will stand to a height of four foot, and will have a body length of up to four and half foot. The wingspan though can reach in excess of nine foot.

The large wingspan allows the California Condor to soar on up currents, and can reach heights of up to 15000ft. It is whilst soaring that the birds will catch sight of their next meal, the eyesight of the condor being exceptional.

The social nature of the bird also means that where one California Condor is spotted, several more are likely to be found in the same area.

California Condor Standing - Mark Lellouch - PD-US-NPS

The California Condors are long lived birds, and in ideal conditions, an average lifespan of sixty years can be achieved. This is one reason why the condors have fewer offspring than many other birds. The female California Condor will on average lay a single egg every couple of years.

The egg is normally laid in a nest situated in a cleft in rocks or within a cave, and during the eight weeks of incubation, both the male and female condor will take turns sitting on the egg. Once hatched, the young condor will stay with its parents for up to a year.

The California Condor is one of the most imposing of all birds. The size is impressive, as its ability to soar on air currents. Despite its low numbers, current conservation undertakings will hopefully ensure that the bird remains a fixture of the American skies.

Copyright - First Published 27th June 2011

The Madagascar Fish-eagle

With only 222 birds now thought to be alive, the Madagascar Fish-eagle, Haliaeetus vociferoides, is one of the rarest of all raptors.

Endemic to the island of Madagascar, the Madagascar Fish-Eagle is primarily only found upon the northwest coastline of the island, although a secondary population can be found along the west coast. This is one reason as to why the eagle is classed as Critically Endangered. The coastline provides the Madagascar Fish-Eagle with the wooded areas, mangroves and estuary areas upon which the birds make the home. The tall trees normally found in such locations provide the birds with areas to roost, and also perches from which they can spot potential prey.

Madagascar fish-eagle - Charlesjsharp - CC-BY-SA-3.0

The Madagascar Fish-Eagle will primarily feed upon fish, and in particular tilapia. Fishing though is done by catching birds near to the surface of the water rather than having to dive in.

There has been a notable decrease in the population size of the Madagascar Fish-Eagle in the last fifty years, although it is also though that the eagle has never been particularly well represented number wise on the island.

Deforestation has proven to be the biggest recent threat to the survival of the bird, although an increase in fishing by locals has also reduced the food available to the eagle.

The Madagascar Fish-Eagle is not amongst the largest of raptors, and normally only measures 70cm to 80cm in length, with a corresponding wingspan of 200cm, making it a medium sized Fish Eagle. The female are slightly larger in length and weight, although the difference is not as pronounced as with other raptors. The eagle has a body and wings that is primarily a dark brown, with a hint of red. The tail and cheeks of the bird are white, although the rest of the head is a pale brown. Legs are grey and the bill of the bird is normally black.

Haliaeetus vociferoides -
John Gerrard Keulemans (1842–1912) - PD-art-100

The breeding season for the Madagascar Fish-Eagle will run from May through to October, at which time a pair of birds will find a cliff or large tree in which to build their nest. The normal clutch size is only two eggs, but as with many eagles the parents are only looking to raise one offspring and will ignore the second egg if the first successfully hatches. As with many of the rare Madagascan birds, the fledging rate for Madagascar Fish-Eagles is relatively low though, something which threatens future population levels.

Copyright - First Published 18th March 2010

Keywords - Madagascar Fish-eagle, Haliaeetus vociferoides