Navigation Links
Bats split on family living
Date:1/24/2013

For the tiny Daubenton's bat, the attractions of family life seem to vary more with altitude than with the allure of the opposite sex.

For more than a decade, a team led by Professor John Altringham from the University of Leeds' School of Biology has studied a population of several hundred bats along a 50-km stretch of the River Wharfe. They monitored roosts in Ilkley and Addingham, upstream in the market town of Grassington and higher still in the villages of Kettlewell and Buckden.

The researchers found that all Daubenton's bats in nursery roosts in lowland areas of Wharfedale during the spring and summer were females and their offspring.

Male bats were mostly restricted to a windier, Heathcliff-like existence in roosts at the top of the Dales.

But the researchers were surprised to find a small oasis of cohabitation in Grassington, sandwiched between the bustle of the women-only childrearing in the lowlands and the more relaxed lives of the bachelors in the highlands.

Professor Altringham said: "Low down the dale, the females appear not to tolerate males and we assume they won't let them in the roost. They don't want anything to do with them. High in the dales, all the roosts are bachelor pads. But in the middle, at Grassington, males and females live togetherthe social structure changes with the environment"

"One possible reason for not finding males low down the valley could be that the mothers just want to avoid competing with males for food. It takes a lot of insects to make the milk needed to feed their young," Professor Altringham said.

"But it is also possible that the males choose not to roost with the females. When you look at the nursery colony in Ilkley, mothers and pups often have a lot of ectoparasites like ticks and mites. In a warm, crowded nursery, parasites can thrive, especially if there's less time for good personal hygiene. Parasites not only make life uncomfortable but can affect a bat's health. The males that live by themselves are usually very clean in their bachelor pads, so you can understand why they might not want to move in," he added.

At Grassington, which is deep in the Yorkshire Dales National Park but not as high as Buckden and Kettlewell, the bats have a completely different social structure. Both male and female bats live with the young throughout the spring and summer in roosts in the stonework of the old Dales bridges and in holes in ash trees.

"Females may roost as high up the dale as Grassington because they have these warm, cuddly males to bunk up with. This way, females use less energy keeping warm and babies grow faster," Professor Altringham said. "In these marginal conditions, they may just tolerate a few males to keep them warm. Otherwise they kick them out. Why do the males co-habit if they are going to get parasites all over them? Well, that may be down to the usual answer: sex."

Although male and female Daubenton's bats usually live apart throughout the spring and summer, they meet when they begin flying to caves in late summer.

Professor Altringham said: "In and around these caves the bats gather in huge numbers to mate, in a behaviour known as swarming. This is clubbing for bats, with males displaying to females in lengthy acrobatic chases. As winter closes in, these caves will ultimately be their hibernation sites.

"There are nearly 2,000 cave entrances and hundreds of kilometres of cave passages in the Dales and these attract bats from all over Yorkshire, Lancashire, Cumbria and beyond for mating and hibernation. The males in Grassington may be giving themselves the opportunity to mate with the females late in the summer before they even get to the caves."

The researchers have built up a detailed picture of social and sexual behaviour by genotyping hundreds of individuals. The evidence gathered from this supports the theory that the Grassington males enjoy an advantage in mating.

"At Grassington, most of the fathers of bats born there spent the summer with the females. If we look at pups in Addingham and Ilkley, their dads were males caught when swarming at caves. So, as well as two different mating systems, you have distinct social groupings. A bachelor from Buckden is always a bachelor from Buckden. He doesn't pop down to Grassington to visit the females in the summer. His only option seems to be to go clubbing in the autumn," Professor Altringham said.

The Daubenton's bat, named after the 18th Century French naturalist Louis-Jean-Marie Daubenton, is widespread across the United Kingdom and specialises in hunting insects over water. Full-grown adults weigh only 7 to 12 grams, but they can live for 20 years or more.

"These bats are the size of a shrew but have a very different lifecycle. A shrew typically spends its entire life in a few metres of hedgerow, eats and breeds with a ferocious intensity, for a year if it is lucky, and then dies. In contrast, these bats lead a complex life over a huge area and females produce only one pup a year," Professor Altringham said. "This makes bats particularly vulnerable to the problems of habitat fragmentation and climate change."


'/>"/>

Contact: Chris Bunting
c.j.bunting@leeds.ac.uk
44-113-343-2049
University of Leeds
Source:Eurekalert

Related biology news :

1. UCSB scientists report new beginning in split-brain research, using new analytical tools
2. ATP splitting in membrane protein dynamically measured for the first time
3. Where we split from sharks: Common ancestor comes into focus
4. Low-cost nanosheet catalyst discovered to split hydrogen from water
5. Scientists study the catalytic reactions used by plants to split oxygen from water
6. Networking ability a family trait in monkeys
7. All in the family: A genetic link between epilepsy and migraine
8. Bloomberg School receives $28 million for family planning advocacy
9. CEVA, Rubidium Partner to Deliver Speech Processing Solutions based on the CEVA-TeakLite Family of DSPs
10. Millipede family added to Australian fauna
11. Helping family is key for social birds
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/7/2016)... , June 7, 2016  Syngrafii Inc. and ... business relationship that includes integrating Syngrafii,s patented LongPen™ ... project. This collaboration will result in greater convenience ... credit union, while maintaining existing document workflow and ... ...
(Date:6/1/2016)... NEW YORK , June 1, 2016 ... Biometric Technology in Election Administration and Criminal Identification to ... According to a recently released TechSci Research report, " ... Sector, By Region, Competition Forecast and Opportunities, 2011 - ... $ 24.8 billion by 2021, on account of growing ...
(Date:5/9/2016)... DUBAI , UAE, May 9, 2016 ... choice when it comes to expanding freedom for high ... Even in today,s globally connected world, there ... online conferencing system could ever duplicate sealing your deal ... are obtaining second passports by taking advantage of citizenship ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... WI (PRWEB) , ... June 23, 2016 , ... ... supplements, is pleased to announce the launch of their brand, UP4™ Probiotics, into ... for over 35 years, is proud to add Target to its list of ...
(Date:6/23/2016)... June 23, 2016 /PRNewswire/ - FACIT has announced ... biotechnology company, Propellon Therapeutics Inc. ("Propellon" ... commercialization of a portfolio of first-in-class WDR5 inhibitors ... such as WDR5 represent an exciting class of ... precision medicine for cancer patients. Substantial advances have ...
(Date:6/23/2016)... , June 23, 2016 Houston ... with the Cy-Fair Sports Association to serve as ... the agreement, Houston Methodist Willowbrook will provide sponsorship ... and connectivity with association coaches, volunteers, athletes and ... with the Cy-Fair Sports Association and to bring ...
(Date:6/23/2016)... 2016  The Prostate Cancer Foundation (PCF) is pleased to announce ... cures for prostate cancer. Members of the Class of 2016 were selected from ... Read More About the Class of 2016 PCF Young Investigators ... ... ...
Breaking Biology Technology: