New Evidence of Giant Deer Extinction

Back about 11,000 years ago, a huge deer (Megaloceros giganteus), sometimes called the Irish deer or Irish elk (wiki), ceased to wander the forests of Ireland.

At first, scientists conjectured that man hunted them to extinction. However, there was a problem with that theory in that people did not arrive in Ireland until after most, if not all, of the deer were gone.

A search was made forother predators but none were found that could account for the disappearance.


Enter the team from the University College at Dublin. Using ratios of carbon and oxygen isotopes, they analyzed the teeth of the great ungulates and found that the most likely culprit was a change in weather.

The ratios of isotopes revealed that the ecosystem in which the deer lived became stressed by drought.

As a result it changed from being covered in forest to being more open and tundra-like.

"There's an overall trend of general vegetation decline," says Ms Chritz.

The deer also appeared to be born in spring or early summer. But at the time of their extinction, temperatures dropped.

"Giant deer would probably have had a hard time coping with cooler mean annual temperature and a shortened growing season," says Ms Chritz.

That would be particularly bad news for young deer. Most young animals are born in spring precisely because temperatures are warmer and there is more food available.

"It would be very difficult for young deer to cope with all these changes brought on by the Ice Age, as well as support the energetic demands of their growing bodies," concludes Ms Chritz, who is now studying for her PhD in palaeoecology at the University of Utah in Salt Lake City, US.