Navigation Links
When to have kids: A complex question for hazel dormice
Date:4/27/2012

Claudia Bieber from the Research Institute of Wildlife Ecology (FIWI) of the University of Veterinary Medicine, Vienna, and fellow scientists analysed a capture-recapture data set on common dormice (Muscardinus avellanarius) to investigate the life-history strategy of this species. These small rodents are about the size and weight of a wood mouse (Apodemus sylvaticus), but, unlike their rodent cousins, they hibernate usually from late September/October to April/May. This is reflected in rather different life history strategies: While wood mice may reproduce any time between February and October and have multiple litters in one season, common dormice give birth to young either as early as possible after waking up from hibernation, or as late as possible, just in time to get the young fit for hibernation. The research findings are published in the current issue of the international journal Oecologia.

According to life-history theory, a species reproductive strategy (e.g. time of sexual maturity, first reproduction, litter size, and other factors) is evolutionarily adapted to the environmental constraints encountered by that species in its natural habitat, such as availability of food resources and predictability of the environment. The aim generally is to produce the largest possible number of surviving offspring under particular conditions.

The researchers observed in a wild dormouse population in Lithuania two peaks of reproduction within the active season. About one third of the litters were born early in the year (June), but the majority were born late in the active season (August/September). In mid-summer, however, only a small fraction of females gave birth to litters, although environmental conditions did not impair investment into reproduction in this time frame. While wood mice, for example, have what is generally known as a "fast" life history, common dormice apparently have some flexibility to adjust their life history tactics (early versus delayed reproduction) to circumstances. Dr. Claudia Bieber and her fellow scientists hypothesized that the ability to hibernate may explain this unusual bimodal birth pattern in the hazel dormouse.

So far relatively little is known about hibernation and survival rates of small hibernators, such as common dormice. By means of a long-term mark and re-capture study, the researchers were able to determine that, unlike previously thought, survival rates were high during the hibernation period for all age-groups. Thus, even animals born late in the active season face a period with high survival probability during the upcoming winter season.

By comparing lifetime reproductive success (the number of juveniles produced in a females' lifetime) the scientists found that the early-born juveniles outpace their late-born counterparts. The May-born cohort often manages to raise their first litter in the same year. In populations under high predation pressure, like the one in Lithuania, this "fast" life history strategy seems to convey an advantage. However, only females that already have a high body-mass in the spring manage to invest into early reproduction for females with lower body-mass it is better to delay reproduction until late in the active season, which maximises the chances of survival of their young. This is referred to as a "slow" life history strategy. "Most interesting is the fact that we observed "fast" and "slow" life histories occurring within the same population," says Claudia Bieber, lead author of the study. "It turns out that life histories are much more flexible within a species and even within a population than so far expected."


'/>"/>
Contact: Dr. Claudia Bieber
claudia.bieber@vetmeduni.ac.at
43-148-909-15230
University of Veterinary Medicine -- Vienna
Source:Eurekalert

Related medicine news :

1. Codeine After Surgery Could Endanger Certain Kids: Study
2. Measles Vaccines Wont Raise Seizure Risk in Young Kids: Study
3. Genes Play a Role in Drug Abuse Risk Among Adopted Kids: Study
4. Safety-First Playgrounds Linked to Bored, Inactive Kids: Study
5. Some Asthma Drugs Raise Risk of Complications, Especially in Kids: Study
6. Milk better than water to rehydrate kids: McMaster study
7. Cell Phones Dont Seem to Pose Cancer Risk to Kids: Study
8. Couch-Potato Kids: It Shows in Their Eyes, Researchers Say
9. Parents Want Genetic Testing for Kids: Study
10. Social Media Has Good and Bad Effects on Kids: Experts
11. Xolair Reduces Seasonal Asthma Attacks for Inner City Kids: Study
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/27/2017)... ... March 27, 2017 , ... The Anaheim Hills office ... First National Capital has added 10 new sales professionals over the past 6 months ... by 15 additional new hires over the course of 2017. , “This new ...
(Date:3/27/2017)... Orange, Texas (PRWEB) , ... March 27, 2017 ... ... celebration at the GTEC Orange facility from 8:00am-10:00am on Monday, April 3rd to ... giveaways and will be an opportunity for area-residents to celebrate two great years ...
(Date:3/26/2017)... ... March 26, 2017 , ... Local physician Dr. Justin ... a prestigious award honoring the top influencers on RealSelf—the most trusted online destination ... doctors and clinics. , In 2016, more than 82 million people visited RealSelf ...
(Date:3/24/2017)... ... March 24, 2017 , ... Vighter ... the same time by providing Prehospital Trauma Life Support (PHTLS) course scholarships to ... premier prehospital trauma education developed in cooperation with the American College of Surgeons ...
(Date:3/24/2017)... ... ... The Radiology Business Management Association (RBMA) has named the nine winners ... year, are among the most prestigious in radiology marketing because a panel of radiology ... recognize achievements in both large budget (over $5,000) and small budget (under $5,000) campaigns. ...
Breaking Medicine News(10 mins):
(Date:3/27/2017)... BOSTON , March 27, 2017 ... pharmaceutical company and Paratek Pharmaceuticals, Inc. (Nasdaq: PRTK), ... commercialization of innovative therapies based upon tetracycline chemistry, ... sarecycline for the treatment of moderate to severe ... Sarecycline is a once-daily, oral, narrow spectrum tetracycline-derived ...
(Date:3/27/2017)... 2017  Impax Laboratories, Inc. (NASDAQ: IPXL)today announced that ... Bisaro as Impax,s President and Chief Executive Officer ... 27, 2017. Mr. Bisaro will succeed J. Kevin ... Chief Executive Officer since December of 2016. ... experience, Mr. Bisaro, 56, is an accomplished global business ...
(Date:3/27/2017)... 27, 2017  PhaseRx, Inc. (NASDAQ: PZRX), a ... liver diseases in children, today reported financial results ... December 31, 2016 and provided an update on ... to make progress during the fourth quarter of ... our non-human primate safety study, and with our lead ...
Breaking Medicine Technology: