In this month’s Incredible Creatures we start in Indonesia, recounting a search for the largest species of bee in the world. A species that hasn’t been seen in 38 years. On a similar theme, we then learn about a species of tortoise in the Galápagos islands that was feared extinct, but biologists were hot on the trail to see if any remaining populations could be found. We then turn our attention to Australia, to a mammal that is feared extinct as water levels rise and its habitat disappears. These are some of the stories of the lost and found of the animal kingdom.
The Search for the Biggest Bees
Imagine the thrill of finding an insect so rare that the species has only been seen twice in the past 170 years. That is what happened recently when a team of researchers from Australia, Canada and the US found a species known as Wallace’s giant bee (Megachile pluto). This species of bee is not only incredibly rare, but it is also the largest species of bee in the world. They found this rare species in a termites’ nest. It had not been seen since 1981 and was feared extinct. Wallace’s giant bee is native to Indonesia, and has been recorded by scientists only three times in history. The first time was by the English entomologist Alfred Russell Wallace, after whom it is named, during a visit to the Indonesian island of Bacan in the 1850s. He described it as “a large black wasp-like insect, with immense jaws like a stag-beetle”. It was then not seen again until 1981 when on this expedition it was seen on three other islands by the entomologist Adam Messer.
Despite several more recent expeditions, the bee wasn’t seen again until January 2019, when it was found by an international team from Australia, the US, and Saint Mary’s University in Nova Scotia. This most recent specimen was found in the North Moluccas, living in a termite nest suspended from a tree branch about 2.5 metres above the ground. The bee is among the 25 “most wanted lost” species that are the focus of Global Wildlife Conservation’s “Search for Lost Species” initiative.
Wallace’s giant bee has a wingspan of more than six centimetres. This makes it even more remarkable that the bee has not been seen for so long. Wallace’s giant bee builds their nests inside nests of a tree-dwelling species of termite. This may help hide their existence.
One goal from this rediscovery is to elevate this bee to a symbol of conservation in this part of Indonesia. Wallace’s giant bee has only been found on three islands of the North Moluccas in Indonesia: Bacan, Halmahera and Tidore. It seems to be restricted to primary lowland forests. These islands have become home to oil palm plantations that now occupy much of the former native habitat. This has caused the International Union for the Conservation of Nature to label this species as Vulnerable.
Giant Tortoise Rediscovered
A similar discovery occurred recently when a species of tortoise not seen in more than 110 years, and feared to be extinct, was recently found in a remote part of the Galápagos island of Fernandina. An adult female of the Fernandina giant tortoise (Chelonoidis phantasticus) was spotted on February 17, 2019, by a joint expedition of the Galápagos National Park and the US-based Galapagos Conservancy.
Investigators think there may be more members of this tortoise on the island because of tracks and feces they found. The Fernandina giant tortoise is listed as critically endangered and possibly extinct. The only other living member of the species was found in 1906. Since then, expeditions have encountered tortoise feces and bite marks on cacti, and there was a possible unconfirmed sighting in 2009. But the recent discovery was the first confirmed sighting. The female that was found is estimated to be roughly 100 years old. Giant tortoises can live up to 200 years, so by tortoise standards, she is just middle-aged.
Fernandina is the third largest Galapagos island and has the La Cumbre volcano, one of the most active in the world. In listing the Fernandina tortoise as possibly extinct, it was thought that the species may have succumbed to the frequent volcanic lava flows that nearly cover the island.
The team that found the tortoise decided to take her to a breeding centre on Santa Cruz Island. This was decided because the area where she had been living had few food sources nearby. And if left on Fernandina, finding her again would have been difficult. Now I guess the next big challenge will be finding a male Fernandina giant tortoise. Anyone heading south looking for a little adventure? The team came across more tortoise tracks in soil just over a mile from where they discovered the female and is planning another expedition to the island later this year.
There are several species of tortoise threatened with extinction in the Galápagos. And there is a reason why this matters. As one of the team members put it “tortoises in the Galápagos are like ecosystem engineers. They contribute to seed dispersal and mold the ecosystem. That ecological role is so important.”
Rats – a Mammal Gone Extinct
If enough of an animal’s habitat can be preserved, the chances of the species surviving increase, although there are things other than habitat loss that cause species extinction. A recent example of an animal that is now believed to be extinct because its habitat disappeared is the Bramble Cay melomys (Melomys rubicola), a small rodent that lived only on a single island off Australia. It is named after its home on Bramble Cay, a small coral island that is at most 10 feet above sea level, located in the Torres Strait between Queensland state and Papua New Guinea. The government of Australia now officially recognizes this rodent as extinct. It was last seen by a fisherman in 2009 but failed attempts to trap any in late 2014 prompted scientists to say it is likely extinct. There were several hundred there as of 1978. So what happened? Since 1998, the part of the island that sits above high tide has shrunk from 9.8 acres to 6.2 acres. That means the island’s vegetation has been shrinking, and the rodents have lost about 97 percent of their habitat. Sea level rises have become a major concern, of which scientists are documenting.
Around the world, sea level has risen by almost eight inches between 1901 and 2010, a rate unparalleled in the last 6,000 years. For an area like Bramble Cay this is a big deal. Scientists reporting on this rodent commented that this is likely the world’s first mammal to be a casualty of climate change.
It is very encouraging that we do see some species previously considered extinct being rediscovered, even if they are still under threat of extinction. Ensuring that species have appropriate habitat to thrive is a continual challenge. The way we plan our cities, industrial and agricultural practices, and the ways we live our lives all have a major impact. But done well, these decisions and actions can help mitigate the problem. And hopefully, there will be more encouraging stories like the Wallace’s giant bee and the Fernandina giant tortoise.
Incredible Creatures is a monthly contribution to provide information on some of the common yet often not well-known creatures that we share space within Manitoba and abroad. John Gavloski is an entomologist living in Carman.