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:12/22/2016)... , December 22, 2016 SuperCom (NASDAQ: ... secure solutions for the e-Government, Public Safety, HealthCare, and Finance sectors ... SuperCom, has been selected to implement and deploy a community-based supportive ... Northern California , further expanding its presence in the ... This new ...
(Date:12/16/2016)... DUBLIN , Dec 16, 2016 Research ... Access System Market - Global Forecast to 2021" report to ... ... projected to grow at a CAGR of 14.06% from 2016 to ... 2016, and is projected to reach 854.8 Million by 2021. The ...
(Date:12/15/2016)... , Dec. 15, 2016 ... driving experience, health wellness and wellbeing (HWW), ... one in three new passenger vehicles begin ... recognition, gesture recognition, heart beat monitoring, brain ... monitoring, facial monitoring, and pulse detection. These ...
Breaking Biology News(10 mins):
(Date:1/19/2017)... NY (PRWEB) , ... January 19, 2017 , ... FireflySci ... an exponential rate. The tremendous growth is accounted to two main factors. ... table and the expanding network of vendors supplying FireflySci products all around the world. ...
(Date:1/19/2017)... , Jan. 18, 2017 Acupath Laboratories, ... announces the formation of an Executive Committee that will ... beyond. John Cucci , a 15-year ... from Director of Business Development to Chief Sales ... Mr. Cucci served in senior sales leadership roles at ...
(Date:1/18/2017)... 18, 2017   Boston Biomedical , an industry ... target cancer stemness pathways, will feature data from two ... the 2017 ASCO Gastrointestinal Cancers Symposium, held from January ... Napabucasin is an orally-administered investigational agent designed ... Cancer stem cells (CSCs) possess the property of ...
(Date:1/18/2017)... ... January 18, 2017 , ... Total Orthopedics ... implanted SpineFrontier’s A-CIFT™ Solofuse-P™. The operation took place on Wednesday, January 11, 2017 ... procedure was an anterior cervical discectomy and fusion on a 42 year old ...
Breaking Biology Technology: