Size is not everything when you are a seal
Tuesday 08 September 1998
Scientists at the Sea Mammal Research Unit, at St Andrews University, are mystified by their latest findings, which seem to show that the weight of a seal after it is weaned from its mother does not affect its chances of surviving its first year.
Evolutionary theory would suggest that, if weight makes no difference, then the mothers should not invest the extra time and energy required to feed pups with their incredibly fatty milk - one of the richest produced by any animal, which in just one month can quadruple a pup's weight.
But Ailsa Hall, of the St Andrews research unit, said yesterday that though the weights of pups after weaning could vary from 25kg to 50kg around an average of 39kg, "size isn't everything".
About 60 per cent of pups survive their first year, during which they must learn to fish, evade predators and cope with disease and injury.
To track the seals, from the Isle of May in the Firth of Forth, the scientists stick bright yellow or green plastic caps, each with two letters, to the fur on their heads.
The caps allow researchers to observe the seals from some distance. Members of the public can also jon in by taking tour boats to the seals' sites and reporting the codes on any caps they see.
The caps do not in themselves seem to affect survival, Dr Hall said: "We have animals from the same birth group with flipper tags, and they have the same survival rate."
Nor do the caps affect their social standing - as far as the researchers can tell. The hat falls off after a year when the pup moults its fur.
So far, the St Andrews scientists have data on about 40 per cent of the 209 pups born last December. Dr Hall said: "We have done autopsies on the few bodies washed up and the cause of death isn't starvation.
"In fact, they're in pretty reasonable condition, except that they're dead."
Other factors may be at work, and Dr Hall is now investigating the possibility that pollutants or other environmental factors could affect the survival of pups.
- 2 Pope Francis issues top 10 tips for happiness – including don’t try to convert other people
- 3 Arturo Vidal to Manchester United: Midfielder set to force through move to Louis van Gaal's Red Devils - reports
- 4 Disney heiress Abigail disowns her share of family profits in West Bank company
- 5 Israel's propaganda machine is finally starting to misfire
Russell Brand accuses FOX News anchor Sean Hannity of terrorism after aggressive Israel-Gaza debate
Pope Francis issues top 10 tips for happiness – including don’t try to convert other people
Sabina Altynbekova, the girl branded 'too good looking' for volleyball, says social media obsession with her is a 'bit much'
Justin Bieber posts Instagram photo of Orlando Bloom crying after Ibiza fight 'over Miranda Kerr'
Disney heiress Abigail disowns her share of family profits in West Bank company
The secret report that helps Israel hide facts
Land for gas: Merkel and Putin discussed secret deal could end Ukraine crisis
Woman and two children killed by mob in riots over 'blasphemous' Facebook post in Pakistan
A day in the life of Vladimir Putin: The dictator in his labyrinth
Putin is 'thuggish, dishonest and reckless', says British ambassador to US
Richard Dawkins tweets: 'Date rape is bad, stranger rape is worse'
- < Previous
- Next >
£35000 - £40000 per annum + competitive: Progressive Recruitment: .Mid Level V...
£40000 - £45000 per annum + Competitive Benefits: Progressive Recruitment: Dig...
£40000 - £50000 per annum + Car, Medical, Fuel + More!: Progressive Recruitmen...
£50000 - £60000 per annum + benefits: Progressive Recruitment: An absolutely o...