16 December 2008

David vs. Goliath, Mice vs. Albatross

Tristan Albatross (Diomedea dabbenena), Critically Endangered

According to Scientists from The Royal Society for the Protection of Birds (RSPB), the Critically Endangered Tristan Albatross has suffered its worst ever breeding season. Out of 1764 chicks counted in January, only 246 survived to fledge.

Tristan Albatrosses, which breed only on British-owned Gough Island in the South Atlantic, are being decimate by mice. According to Richard Cuthbert, an RSPB scientist, mice have been known to prey on the birds for a long time. Previously, the birds were threatened by introduced and non-native rats, pigs, dogs, and cats. Once these predators were removed, the mice population expanded.

The mice, originally introduced in the 18th or 19th century by sealers, are now three times larger than their mainland brethren, and have adapted to be carnivorous--subsisting on young birds and eggs rather than seeds and insects. Even though the mice have become larger, they are still vastly outweighed by the albatross chicks. Why don't the albatrosses fight back? Although they do fight back against other types of prey, it seems that they are not able or do not know how to appropriately fend off the non-native mice. The mice often work together, attacking at night, quickly gnawing through the nest and straight into the chicks body.

With such low numbers of surviving chicks, Tristan Albatrosses are very close to the brink of extinction. Relatively slow breeders, pairs only nest every other year, producing a single chick each time. Adults are further threatened by the long-line fishery. Fishing boats towing miles of fishing line, with thousands of hooks baited with squid or fish, often attract Albatrosses, who attempt to snag the bait and become entangled or hooked and drown.

"Tristan Albatross is being hit by a double whammy. The chicks are predated by mice and the adults and juveniles are being killed by longline fishing vessels," said John Croxall, chair of BirdLife's Global Seabird Programme. "Unsustainable numbers are being killed on land and at sea. Without major conservation efforts, the Tristan Albatross will become extinct."

Is there any hope? Some. In New Zealand, similar situations with rats have been successfully dealt with by dropping rat poison from helicopters. The RSPB has done preliminary studies indicating that a similar solution would solve the mice problem on Gough Island, and is encouraging the British government to come up with the needed funds.

You can help. Get involved with the Save the Albatrosses Campaign.

Donate to Bird Life International's Preventing Extinctions Program.

If you live in the UK, you can contact your representatives and ask them to support funding for wildlife in the UK Overseas Territories.

You can also donate to Sea Shepherd Conservation Society, which works against the illegal use of long line fishing.

02 December 2008

Baby Goliaths Can't Hide

Goliath Grouper (Epinephelus itajara), Critically Endangered

The Critically Endangered Goliath Grouper is the largest grouper in the Atlantic, growing more than 2 meters (6 feet) long, weighing more than 450 kg (1000 lbs), and living up to 40 years. Recently, the Ocean Research & Conservation Association (ORCA) used an underwater acoustic camera system (similar to the sonar dolphins or bats use) to visualize baby Goliaths among the murky waters of mangrove roots. Baby Goliaths, up to 1 meter long, spend the first 5-6 years of their lives, almost exclusively in and amongst the waters around mangroves.

Conservation action began in 1990 when the US placed a moratorium on fishing, and the Caribbean did the same in 1993. Though the population has increased it will take many years for numbers to recover to previous levels. Additionally, in some areas, fishing continues despite the bans. It is sometimes difficult to accurately assess the recovery of the species, in part because of the inability to visualize Baby Goliath numbers in murky and cloudy waters. The new camera system used by ORCA should alleviate this problem, and make surveys of Goliath populations easier.

Read an article here.

Donate to Ocean Futures, an Ocean Conservation that has worked to conserve the Goliath Grouper in the past.