Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 


First evidence of rhinos’ ability to correct sex imbalance

7 March 2017

First evidence of rhinoceros’ ability to correct gender imbalance


Research led by Victoria University of Wellington has demonstrated the ability of rhinoceros to modify the sex of their offspring to avoid the dominance of one gender and limit severe competition for breeding.

The study, led by Associate Professor Wayne Linklater from Victoria’s School of Biological Sciences, provides the first experimental evidence in the wild that unbalanced population sex ratios can result in a compensatory response by parents to ‘correct’ the imbalance.

“This is called a homeostatic sex allocation (HSA) response—a biological theory first proposed in 1930,” explains Associate Professor Linklater.

“Almost all population models assume birth sex ratio is fixed. Our evidence indicates that this may not be the case.”

The study, published today in Nature Ecology & Evolution, was co-authored by Dr Peter Law from Nelson Mandela Metropolitan University in South Africa, Pierre du Preez from Namibia’s Ministry of Environment and Tourism, and former Victoria University postdoctoral researcher Dr Jay Gedir.

The research team examined 24 years of rhinoceros data, gathered during the course of 45 reintroductions of the animals across southern Africa.

Sex-bias is especially important in rhinoceros populations due to their critically low numbers, says Associate Professor Linklater.

“But because of the evidence of HSA, we need not be so concerned about that misbalance, because parents appear able to ‘correct’ it when they breed.

“HSA has an especially strong effect when the gender imbalance is very large. In fact, the further it is from an even-sex ratio, the stronger the response is by parents.”

Associate Professor Linklater says that those populations where HSA is possible will be more resilient. “Their small populations will have improved establishment and greater viability. Such species will populate habitats faster, and be less susceptible to random demographic processes and genetic drift.”

Explaining the allocation of resources by parents among male and female offspring is a leading issue in evolutionary biology, says Associate Professor Linklater.

“Extreme sex ratios commonly occur, so the incidence of HSA will significantly impact our understanding of a range of ecological processes including invasion biology and conservation management.”

The study was completed with funding from the United States Fish and Wildlife Service’s Rhinoceros and Tiger Conservation Fund.

Associate Professor Linklater now plans to do further research into how an HSA response works in Australian brushtail possums. This includes how competition to breed triggers the effect and at what point in the reproductive process the mother is able to control the sex of her offspring.

“Possums are ideal subjects for such a study because their offspring are born into the marsupial pouch at an extraordinarily young age—very early in development—and so can be studied in great detail,” he says. “Possums are also invasive mammals in New Zealand. Understanding their reproductive processes can provide new ways of managing population numbers.”


ends

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Statistics: Business Research And Development Up 29 Percent

Computer services and machinery manufacturing firms led the way in an almost 30 percent lift in business spending on research and development (R&D) in 2016, Stats NZ said today. Businesses spent $1.6 billion on R&D in 2016, up $356 million (29 percent) from 2014. More>>

ALSO:

China Shopping: NZ-China FTA Upgrade Agreed Among Slew Of New Deals

New Zealand Prime Minister Bill English and China Premier Li Keqiang signed off a series of cooperation deals spanning trade, customs, travel and climate change and confirmed commencement of official talks on an upgrade to the nine-year old free-trade agreement between the two countries. More>>

ALSO:

Media: TVNZ Flags Job Cuts To Arrest Profit Decline

Chief executive Kevin Kenrick said the changes were aimed at creating "a sustainable future video content business for TVNZ in an ever-changing media market." More>>

ALSO:

Reserve Bank: Wheeler Keeps OCR At 1.75%

Reserve Bank governor Graeme Wheeler kept the official cash rate unchanged at 1.75 percent, as expected, and reiterated his view that the benchmark rate doesn't need shifting for the foreseeable future. More>>

ALSO:

Trade Plans: Prime Minister's Speech To International Business Forum

"The work to improve public services, build infrastructure, and solve social problems is possible only because we have enjoyed sustained, solid economic growth. A big reason for that is the Government’s consistent agenda of economic reform, and our determination to open up more opportunities for trade with the world." More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news