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