麻豆淫院

The discovery of yet another unique animal species from R膿kohu Chatham Islands illustrates how the physical qualities of an animal are influenced by its surroundings.

New research led by the University of Otago鈥斉宼膩kou Whakaihu Waka describes a new, extinct shelduck whose ancestors arrived on the islands 390,000 years ago.

While this may seem like a short period of time, co-lead author Associate Professor Nic Rawlence, Director of the Otago Paleogenetics Laboratory, says it is long enough to impact the species.

"In that time, the R膿kohu shelduck evolved shorter, more robust wings and longer leg bones, indicating it was going down the pathway toward flightlessness," he says.

These changes were due to a range of factors, such as an abundance of food, lack of ground-dwelling predators, and windy conditions, so flying was not the preferred option.

Co-lead author Dr. Pascale Lubbe, also of the Otago Paleogenetics Laboratory, says in a case of "use it or lose it, the wings start to reduce."

"Flight is energetically expensive, so if you don't have to fly, why bother," she says. "The longer leg bones are more robust to support more muscle and create increased force for take-off鈥攏ecessary when you have smaller wings."

Researchers used ancient DNA and analyzed the shape of the bones to determine the R膿kohu shelduck is most closely related to the p奴tangitangi paradise shelduck from Aotearoa New Zealand.

The R膿kohu shelduck spent more time on the ground than its cousin and became extinct prior to the 19th century due to over-hunting and predation.

The is published in the Zoological Journal of the Linnean Society and adds to the islands' rich history as a home to many species of waterfowl before human settlement.

The shelduck's scientific name (Tadorna rekohu) and common name (R膿kohu shelduck) were gifted to researchers by the Trust who are tchieki (guardians) of the plants and animals on R膿kohu Chatham Islands, with which they are interconnected through shared hokopapa (genealogy).

Hokotehi Moriori Trust CEO Levi Lanauze says "this discovery is great for R膿kohu as a whole and helps connect imi (tribe) Moriori with miheke (treasure) of the past."