Do we really need to put a fence on a property that was purchased to protect a bird? That was a question many supporters and donors asked us, mainly as a new fence can be an obstacle to taxonomic groups that fly or glide. However, fences are a requirement in pastoral rangelands, by neighbouring properties, to manage and separate cattle from areas they should or shouldn’t graze.
From a conservation perspective, fences are vital infrastructure to keep large feral herbivores from reserves, and help eliminate their impacts on vegetation and critical habitats.
At Pullen Pullen we did construct a fence, but knowing that there was going to be some debate about this, Bush Heritage in collaboration with University of Queensland students addressed potential benefits or costs. A blog on the high visibility tape on the new fence was published previously.
Firstly, Nick Leseberg, our PhD student, undertook some systematic sampling along the new fence and old fence, to understand the risk of bird strike. This data was in addition to information collected by Dr Steve Murphy over the past three years on bird strike risk from existing fences in that area.
Secondly another PhD student, Al Healy, was helping Nick understand the dynamics of the floodplain vegetation, the changes in the feeding grounds of the Night Parrot in response to small amounts of rainfall, and how the exclusion of grazing affected the food plants.
The initial results are very encouraging. Data from fence surveys indicated that the number of birds effected are low, and almost all were pigeons, a bird that flies low and fast. Where there was woody vegetation, birds rarely hit the fence.
And the vegetation response on either side of the fence was dramatic – the cover, and more importantly the presence of seeds and seed heads was significantly higher on the cattle-free side.
These seeds are critical food sources for the Night Parrot in the dry season, and if reduced the parrots are likely to need to fly further to feed, reducing their foraging efficiency and fitness.
This is a classic conservation conundrum – the benefits of one action can have some negative consequences – so we need to make decisions on how to reduce the effect of fence strike (i.e. high visibility fencing) while conferring advantages to our target threatened species – the Night Parrot.
Al Healy is also looking at the speed of vegetation response to rainfall on each side of the fence. There’s nothing dull about watching the grass grow, especially in an arid environment like Pullen Pullen Reserve. Al recently visited the reserve as part of his doctoral research to set up time-lapse cameras to monitor how vegetation responds to rainfall.
Here's a post on his work: Watching the grass grow at Pullen Pullen.
Our work at Pullen Pullen to protect the Night Parrot is supported by the Queensland Government’s Nature Assist program.