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

 

Non-native species not the bad guys in a changing eco-system

Non-native species not the bad guys in a changing eco-system

April 17, 2014

University of Canterbury researchers are investigating some positive features of animals being introduced to New Zealand.

Exotic animals are generally considered to be a major threat to native species in New Zealand and worldwide.

Despite numerous examples of invasive species harming ecosystems, exotic species may actually be able to fill ecological gaps in their new home, such as those left by native species that have gone extinct.

Professor Jason Tylianakis says this is one of the first examples of exotic species filling the roles left by declining natives across a whole range of species.

"A collaborative research project between scientists at the University of Canterbury and University of Oviedo, Spain, has examined the role of exotic birds in dispersing the seeds of native New Zealand trees and shrubs.

"Many fruiting plants require birds to carry their seeds to new locations and drive the persistence and recovery of native forests.

"New Zealand fruit-feeding birds have historically suffered a strong decline of native birds but they have also gained new fruit-eaters in the form of introduced European birds such as blackbirds and song thrushes."

The Canterbury researchers studied the network of feeding interactions between different species of plants and birds in the North and South Islands. They found that the intermediate body and beak size of exotic birds allowed them to feed on a great variety of different fruits.

This allowed the birds to disperse seeds of plant species that were not frequently eaten by native birds at any given location and helped to stabilise seed dispersal across a whole range of plants.

Without introduced species, many native plants would not have their fruits eaten and their seeds would simply fall to the ground below the tree.

Another Canterbury researcher Dr Daniel Stouffer says exotic species were less discriminating in their fruit consumption patterns.

"Native fruit-eaters have developed strong affinities for or against consumption of particular native fruit species making our native communities vulnerable to loss of key bird species. On the contrary, the exotic species were more than happy to make equal use of all the fruits available, thereby spreading their benefit more widely."

Professor Tylianakis says people often consider invasions by non-native species as always being harmful.

"However, many of our native species have already gone extinct and sometimes we need new species to fill their role. Although they often do harm, we can’t always assume that non-native species are the bad guys in our constantly-changing ecosystems,” Professor Tylianakis says.

ENDS

© Scoop Media

 
 
 
Business Headlines | Sci-Tech Headlines

 


Reserve Bank: A least regrets approach to uncertainty

The Reserve Bank of New Zealand – Te Pūtea Matua makes decisions about official interest rates in a way that is robust in the face of uncertainty about the economy, Reserve Bank Assistant Governor Christian Hawkesby says in a speech published today*... More>>




Shocking Stuff: Lower Income Areas Paying More For Power

Analysis from Consumer NZ and Powerswitch has found major differences in electricity pricing depending on where you live, with those in lower income areas being hit the hardest... More>>



Science Media Centre: Understanding DDoS cyber attacks – Expert Reaction

Cyber attacks have hit several New Zealand organisations this month, disrupting their online services. The Distributed Denial of Service (DDoS) attacks were the same kind of cyber attack that affected the NZX around this time last year... More>>



Statistics: GDP rises in the June 2021 quarter

Gross domestic product (GDP) rose by 2.8 percent in the June 2021 quarter, following a 1.4 percent increase in the March 2021 quarter, Stats NZ said today. June 2021 quarter GDP was 4.3 percent higher when compared with the December 2019 quarter... More>>


Energy-from-waste: $350 Million Plant To Deliver Renewable Energy Considered

Investigations have begun into the viability of building an Energy-from-Waste plant that will safely convert 350,000 tonnes of waste, that would otherwise be dumped into South Island landfills annually, into renewable electricity... More>>

Olam: Confirms plans for commissioning of NZ dairy plant

OFI, a global leader in natural and sustainable food ingredient solutions, today confirmed plans to develop a new dairy processing facility at Tokoroa. It is now taking expressions of interest from potential farmer suppliers, employees, contractors, and general trade suppliers... More>>