Navigation Links
Older killer whales make the best mothers

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
BioMed Central

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:
(Date:5/20/2016)... 20, 2016  VoiceIt is excited to announce ... By working together, VoiceIt and VoicePass ... and VoicePass take slightly different approaches to voice ... security and usability. ... new partnership. "This marketing and technology ...
(Date:4/28/2016)... , April 28, 2016 Infosys ... (NYSE: INFY ), and Samsung SDS, a global ... that will provide end customers with a more secure, fast ...      (Logo: ) , ... but it also plays a fundamental part in enabling and ...
(Date:4/15/2016)...  A new partnership announced today will help ... in a fraction of the time it takes ... life insurance policies to consumers without requiring inconvenient ... Diagnostics, rapid testing (A1C, Cotinine and HIV) and ... weight, pulse, BMI, and activity data) available at ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... June 23, 2016  The Prostate Cancer Foundation (PCF) is pleased ... and faster cures for prostate cancer. Members of the Class of 2016 were ... Read More About the Class of 2016 PCF Young ... ... ...
(Date:6/23/2016)... OTTAWA, ON (PRWEB) , ... June 23, 2016 , ... ... former DNA Technical Leader at the Arkansas State Crime Laboratory, has joined STACS DNA ... joining the STACS DNA team,” said Jocelyn Tremblay, President and COO of STACS DNA. ...
(Date:6/23/2016)... 2016 Andrew D ... Published recently in ... from touchONCOLOGY, Andrew D Zelenetz , discusses ... care is placing an increasing burden on healthcare ... therapies. With the patents on many biologics expiring, ...
(Date:6/23/2016)... ... June 23, 2016 , ... Velocity Products, a division of ... and optimized exclusively for Okuma CNC machining centers at The International Manufacturing Technology ... among several companies with expertise in toolholding, cutting tools, machining dynamics and distribution, ...
Breaking Biology Technology: