London, Oct 29 (ANI): Australian scientists have discovered a new method to measure a whale's sex hormones without harming it - stockings.
For the first time, testosterone and progesterone-two key hormones that signal whether whales are pregnant, lactating or in the mood to mate-have been extracted from whales' lung mucus, captured in nylon stockings dangled from a pole over their blowholes as they surface to breathe.
According to the researchers, this method could allow scientists to study whales without having to slaughter them, and could be used to simply give them a pregnancy test to try to learn why some species aren't breeding.
To find out if it was possible to collect sex hormones from whales non-invasively, Carolyn Hogg of the Evolution and Ecology Research Centre at the University of New South Wales in Sydney, Australia, and her colleagues collected "blow" samples from 35 humpback whales off Queensland, Australia, and 18 North Atlantic right whales in the Bay of Fundy on the border of Canada and the US.
They noted the whales' gender by sight, where possible. Back at the lab, liquid chromatography mass spectrometry was used to measure the blow's testosterone and progesterone content.
They found that whale blow - previously assumed to be no more than a mix of air and water - also contains measurable levels of sex hormones.
"Hormones in the whale's blood are probably diffusing across the lung wall, which is rich in blood vessels, into the mucous lining on the other side," New Scientist quoted Patrick Miller, a co-author based at the University of St Andrews, UK, as saying.
To their surprise, the researchers found that female humpback whales returning to polar waters from the tropics, where they are thought to breed and give birth, produce the "breeding" hormone progesterone.
"It was surprising to find that these whales were sexually receptive, given that they had calves with them and were departing from their breeding grounds. It raises a serious question over how much we know about these animals," Miller added.
Phillip Clapham at the National Marine Mammal Laboratory in Seattle, Washington, said: "This is an exciting and promising technique which potentially adds one more method to the toolbox of those studying living whales."
The study appears in the Journal Marine Mammal Science. (ANI)