Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Seals gamble with their pups' futures

21.11.2012
Some grey seal mums adopt risky tactics when it comes to the future of their young, a strategy that can give their pup a real advantage, according to scientists.

Researchers from Durham University, UK, and the University of St Andrews, looking at grey seal colonies in Scotland, found that some seal mothers are flexible in the parenting style they adopt and 'gamble' on the outcome of their actions, whilst other play it safe and steady.

The study is the first to demonstrate how variation in personality traits in large marine mammals in the wild can persist, rather than a single, successful, personality type dominating the population.

The research shows that some seal mothers have a very fixed approach to looking after their pups, and tend to behave in a similar fashion whatever the local conditions on the breeding colony are; whether they are in a crowded and busy location, or in a less disturbed situation. These mums tend to achieve average success in terms of their pups' weight gain (crucial to the future survival of the pup), so that, by-and-large, they generally do well. These mums seem to have a 'play it safe' approach to life.

Some seal mothers have a very different approach. These mums are more flexible and try to adjust their mothering behaviour according to the local conditions. In potentially unpredictable situations, this can be risky; sometimes they get it right and their pups fare very well, but other times they might get it wrong and their pups do rather badly.

The findings, published in the journal PLoS One, show that individual animals can differ markedly in their ability to adjust their behaviour to their local environmental conditions and that large variations in behavioural strategies can persist within a species.

According to the researchers, the results for both extremes of personality show how different types can be maintained by selection. This retains behavioural diversity within a species, potentially making the species more resilient to environmental change.

The results are relevant to environment and conservation policies that use a one-size-fits-all approach, as these may need to be re-evaluated to take into account individual differences in animal personality, the researchers say.

Lead author, Dr Sean Twiss, School of Biological and Biomedical Sciences, Durham University, said: "Some mums have a very fixed way of caring for their pups, come what may, whilst others are more flexible. "Seals that 'gamble' and try to fit their behaviour to their immediate surroundings can do very well, if they get it right! However, being flexible can be risky - a mum might 'mis-judge' the conditions and fail to match her behaviour to the prevailing conditions.

"In either resting or disturbed situations, seal mums behaved in very individual ways, some showing high levels of maternal attentiveness, others showing low levels. Some behaved the same when disturbed as they did at rest while other individuals changed their behaviour dramatically when disturbed."

These differences in mothers' behaviour, either fixed or flexible, can have profound effects on their pups. After about 2 weeks of being looked after by their mothers, all pups are left to fend for themselves, and have to teach themselves to feed. The fatter a mum leaves her pup, the more time the pup has to learn, and its chances of surviving are better.

The scientists observed seals on the Scottish island of North Rona during the breeding season over two years. The team observed seals in their natural habitat to analyse responses to unusual stimuli (disturbances) and to assess seal behaviour at rest.

Co-author Dr Paddy Pomeroy said: "What's really interesting about these short term tests is the way behavioural types map onto individual measures of reproductive success. If more flexible mothers are better and worse pup rearers, one of our next tasks will be to see how breeding successes and failures are apportioned over lifetimes, which can only be done in this type of study."

The research has been part-funded by NERC, The Living With Environmental Change partnership, and the Esmée Fairburn Foundation.

How they did it: The researchers ran 30-minute observations on 14 females to see how they behaved at rest. The team measured the attentiveness of the mothers towards their pups during these periods by recording the number of pup checks made (where the mother raises her head off the ground and moves it in the direction of her young to check their well-being).

Repeating these observations twice on each seal showed that mothers varied considerably, and consistently, in their behaviour, with some showing low levels of maternal attentiveness, whilst others checked their pups much more often.

The team then used a remote controlled vehicle (RCV) with a fitted video camera to test how seals reacted to mild disturbance, including approaches by the RCV and wolf calls played from the vehicle.

The seals varied in their responses to the RCV from almost completely ignoring its presence to pushing it with their muzzles. Again, mothers varied considerably in the number of pup checks they made during these disturbances.

The team also measured and weighed each seal mum and pup before and after each test and observation. Comparing these measurements for the behaviourally 'fixed' and 'flexible' seals, the team found an intriguing pattern: All mums with the 'fixed' approach had very average pup growth rates, while some of the 'flexible' mums did really well, with their pups growing at twice the rate of others, but the rest did rather poorly, with pup growth rates well below average.

The researchers can identify individual seals using their unique and varied patterns on their fur and this allows them to observe maternal behaviour over multiple years as seals generally return to the same site to breed.

Carl Stiansen | EurekAlert!
Further information:
http://www.durham.ac.uk

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>