Navigation Links
Older killer whales make the best mothers
Date:2/3/2009

Killer whales (Orcinus orca) nearing the menopause may be more successful in rearing their young. New research published in BioMed Central's open access journal Frontiers in Zoology shows that estimated survival rates for calves born to these older mothers were 10% higher than those for other calves.

Eric Ward from the Northwest Fisheries Science Center, Seattle, USA, coordinated a team of researchers who studied killer whales inhabiting the inland and nearshore waters of Washington state (USA) and British Columbia (Canada). They used a 30-year dataset collected by the Center for Whale Research and Canada's Department of Fisheries and Oceans. He said, "During annual photographic surveys, nearly every individual in the population has been recorded. Each animal has unique pigmentation, scars, and fin shapes, allowing us to track the survival and reproductive performance of each female over time".

The authors aimed to investigate what benefits killer whales derive from the menopause. One theory, termed the "attentive mother hypothesis", is that giving birth to calves and then losing the ability to reproduce helps the mother to focus on bringing up her offspring, without wasting time and energy on further pregnancies. The authors' results support this theory to an extent in that during a calf's first year of life, having a mother who was nearing menopause increased chances of survival. According to Ward, "We found that the oldest mothers may also be the best mothers. Older females may be more successful in raising young because of maternal experience, or they may allocate more effort to their offspring relative to younger females".

Killer whales are extremely long lived, with one female believed to be more than 90 years old. Males rarely live past 50, but female life expectancy is considerably longer. Females can produce their first calf as early as age 10, and continue to produce offspring until their early 40s.


'/>"/>

Contact: Graeme Baldwin
graeme.baldwin@biomedcentral.com
44-020-707-94804
BioMed Central
Source:Eurekalert

Related biology news :

1. Gardening gives older adults benefits like hand strength and self-esteem
2. Gardening gives older adults benefits like hand strength and self esteem
3. Research finds older women who are more physically fit have better cognitive function
4. Pain is in the eyes of the beholder
5. Older people who diet without exercising lose valuable muscle mass
6. BIO-key(R) Issues Open Letter to Shareholders
7. Testosterone replacement theraphy beneficial in men 60 and older
8. RING finger protein 5 may guide treatment for muscle disease in older adults
9. Stakeholders use science to find common ground on wood supply from forests
10. Worlds largest investor coalition seeks further disclosure on climate change and shareholder value
11. High blood pressure in older adults traced to genes effects in blood vessels
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/20/2016)... , Jan. 20, 2016  Synaptics Incorporated (NASDAQ: ... interface solutions, today announced sampling of S1423, its ... wearables and small screen applications including smartwatches, fitness ... Supporting round and rectangular shapes, as well as ... performance with moisture on screen, while wearing gloves, ...
(Date:1/13/2016)... 2016 --> ... market report titled - Biometric Sensors Market - Global Industry ... 2023. According to the report, the global biometric sensors market was valued ... reach US$1,625.8 mn by 2023, expanding at a CAGR ... volume, the biometric sensors market is expected to reach ...
(Date:1/11/2016)... Jan. 11, 2016  higi, the leading retail ... retail locations, web and mobile, today announced it ... from existing investors. --> ... to further innovate higi,s health platform – its ... portal – including expanding services and programs to ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... ASAE is introducing a hybrid membership model which will ... of joining or renewing through an organizational purchasing model. ... every employee in any size association or AMC office ... member benefits.   John H. Graham, IV ... allow organizations of any size and their employees to ...
(Date:2/10/2016)... plc (NYSE: AGN ) a leading global pharmaceutical ... CEO and President, will be featured as the keynote ... Capital Markets Healthcare Conference on Tuesday, February 23, 2016 ... Hotel in New York, NY . ... accessed on Allergan,s Investor Relations web site at ...
(Date:2/10/2016)... ... February 10, 2016 , ... HOLLOWAY AMERICA, ... Pharmaceutical Engineering (ISPE) Rocky Mountain Chapter 21st Annual Vendor Exhibition on Thursday, February ... than 100 tables for its annual event, which will run from 3:00 p.m. ...
(Date:2/10/2016)... San Mateo, CA (PRWEB) , ... February 10, ... ... Registry of Multiplex Testing (PROMPT), a research registry built on the secure online ... in September 2014. More than 1,600 participants have joined the PROMPT study, which ...
Breaking Biology Technology: