Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 

Native Bats Thrive After Predator Control

New Zealand’s native bats/pekapeka are thriving at sites in Fiordland and the central North Island due to Department of Conservation (DOC) predator control.

Long and short-tailed bats were once common in Aotearoa but have disappeared from many areas due to habitat loss and being eaten by rats, possums, stoats, and feral cats. These tiny mammals roost together and rear their young in hollow trees, where they are especially vulnerable to attack.

Close monitoring of bats over many years in the Eglinton valley near Te Anau and Pureora Forest Park west of Lake Taupō has shown a significant upswing in populations of short-tailed bats due to predator control, says DOC Principal Science Advisor Colin O’Donnell.

“Short-tailed bats in the Eglinton valley have done really well since predator control began in the late1990s with the population increasing on average by 8% per year.

“At Pureora, where we’ve tracked short-tailed bats for the past eight years, predator control has allowed the population to grow by 10% annually.”

However, Colin O’Donnell says long-tailed bats appear particularly sensitive to rat predation, requiring very low rat numbers over large areas for them to thrive.

“Ten years ago, long-tailed bat survival in the Eglinton valley was dropping after each beech mast when predator numbers soared. But since 2010, predator control over larger areas, timed to suppress rat plagues, has allowed many more bats to survive.

“In 25 years of monitoring we’ve seen the long-tailed bat population turn around—from declining at 5% to increasing by 4% per year.”

Unfortunately, the long-tailed bats at Pureora appear to still be in decline. Long-tailed bats can fly up to 20 km a night and at Pureora range widely across farm and forestry land where they are at greater threat from predators.

“Research shows that large-scale predator control over at least 3500 ha, keeping rats to very low levels, is needed to protect long-tailed bats. Linking up forest areas and other habitats with predator control may be key to the survival of long-tailed bats at Pureora,” Colin O’Donnell says.

Rat and stoat numbers in the beech forest-clad Eglinton valley spike after each beech mast (seeding) but remain low between masts, while in the warmer mixed podocarp and hardwood forest at Pureora predators tend to be consistently high.

DOC controls predators in the Eglinton valley using combinations of sustained trapping, ground-based toxins, and periodic aerial 1080 over large areas to prevent predator plagues following beech masts.

In Pureora, toxins in bait stations are used to protect bats over 900 ha, timed for when they are raising their young in maternity roosts. Predator control at nearby Waipapa will also be helping to protect their wider habitat.

Monitoring bats is intensive work and involves catching a sample of bats from a colony and either attaching identifying bands or PIT tags (passive integrated transponders). In following years, the bats are either recaptured or logged as they enter or leave maternity roosts. Annual survival is estimated from the number of marked individuals detected year by year. DOC staff that monitor bats are specially trained and take hygiene precautions when handling bats, including hand washing and using gloves.

The Eglinton valley and Pureora are two of the few places where both species of bats remain. The Eglinton has one of only two populations of short-tailed bats on mainland South Island, with the other in the Murchison Mountains. Pureora is a stronghold for the central sub-species of short-tailed bat, which is in decline.

Bat populations continue to decline at unmanaged sites.

DOC also monitors bats at other sites around the country including Puketi Forest, Rangataua and Whirinaki in the North Island, and Ōpārara, Te Maruia, south Canterbury and the Murchison Mountains in the South Island.

© Scoop Media

 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell: On The Demise Of The Tokyo Olympics

As the Covid vaccines roll out around the world, the Tokyo Olympics are looming as a major test of when (and whether) something akin to global normality can return – to international travel, to global tourism, to professional sport and to mass gatherings of human beings. Currently though, it looks like a forlorn hope that Japan will be able to host the Olympics in late July. Herd immunity on any significant scale seems possible only by December 2021, at the earliest... More>>

 

New Zealand Government: Cook Islanders To Resume Travel To New Zealand

The Prime Minister of New Zealand Jacinda Ardern and the Prime Minister of the Cook Islands Mark Brown have announced passengers from the Cook Islands can resume quarantine-free travel into New Zealand from 21 January, enabling access to essential services such ... More>>

ALSO:

A New Year: No politicians at Rātana in 2021

Annual celebrations at Rātana pā will be different this year, amid a decision to hold an internal hui for church adherents only… More>>

ALSO:

Government: Pre-Departure Testing Extended To All Passengers To New Zealand

To further protect New Zealand from COVID-19, the Government is extending pre-departure testing to all passengers to New Zealand except from Australia, Antarctica and most Pacific Islands, COVID-19 Response Minister Chris Hipkins said today. More>>

ALSO:

Covid: Border Exception for 1000 International Students

The Government has approved an exception class for 1000 international tertiary students, degree level and above, who began their study in New Zealand but were caught offshore when border restrictions began....More>>

ALSO:

 
 
 
 
 
 

LATEST HEADLINES

  • PARLIAMENT
  • POLITICS
  • REGIONAL
 
 

InfoPages News Channels