Cockatoos win, swallows lose when roos come to town

February 16, 2016, Australian National University

Kangaroo grazing has a huge impact on grasslands and bird populations, potentially leading to population explosions of some species while others decline, a new study from The Australian National University (ANU) has found.

A study of 127 sites in ACT, NSW and Victoria found that large birds such as cockatoos and galahs prefer areas where there are large populations of kangaroos. In contrast, some smaller birds miss out on the insects they eat when the are grazed heavily.

"Kangaroos are ecosystem engineers and can completely change the structure of the grasslands," said lead researcher Mr Brett Howland from ANU.

"They're big animals and can have a huge effect on the other around them."

Mr Howland's research will help conservation bodies manage reserves to support the largest number of species.

The study found that when grasslands were not grazed at all, some bird species thrived, such as welcome swallows, dusky woodswallows and tree martens that feed on insects they catch in the air above the grass.

As the level of grazing increased other small birds, such as the superb fairy-wren fared better, and at the highest levels of grazing the dominant species were large , such as cockatoos and galahs.

"Building a successful conservation area is complex, you can't just lock reserves up, they need to be actively managed," Mr Howland said.

Mr Howland's research is being used to inform burning and trials currently underway in ACT grasslands reserves.

"Nature is complex, and so our management needs to also be complex," he said.

The article has been published in Biological Conservation.

Explore further: Kangaroos eating reptiles out of house and home

More information: Brett W.A. Howland et al. Birds of a feather flock together: Using trait-groups to understand the effect of macropod grazing on birds in grassy habitats, Biological Conservation (2016). DOI: 10.1016/j.biocon.2015.11.033

Related Stories

Non-native species are transforming grassland ecosystems

July 17, 2015

Non-native 'space invaders' are transforming the world's precious grassland ecosystems, with new research showing that they do far better than native plant species in the presence of fertiliser and large herbivores like kangaroos, ...

Combining techniques provides new insight into bird migration

December 30, 2015

Two complementary methods work together in a study forthcoming in The Auk: Ornithological Advances, producing more refined estimates of where individual Barn Swallows spend the winter. Using the methods separately comes with ...

Recommended for you

How winter temps can affect your spring fishing

January 16, 2018

Cold winter weather can play a key role in what you're allowed to fish for next spring. That point was driven home when low temperatures in early January led North Carolina to temporarily bar fishing for spotted seatrout ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.