Most Australian species have been significantly disadvantaged by the massive losses of habitat that has occurred over the last 200 years of colonisation. This includes many of our native birds. However, some native species have actually flourished in this altered landscape, increasing in abundance and influence. This includes the notorious Yellow-throated Miner.
This species thrives in the linear stripes of vegetation left after widespread clearing, forming aggressive colonies that actively displace smaller birds. This species also poses a hybridization threat to its close relative, the endangered Black-eared Miner. So we have to manage this species, and the best way to do that is to cull. But will a targeted cull that hopes to achieve one management outcome, also achieve another?
That’s what Thea and her team wanted to understand when told that Parks Victoria were going to remove some Yellow-throated Miner colonies around a reserve in order to protect the Black-eared Miners within. They asked whether the removal of these colonies would also advantage small birds in this landscape? So they conducted a bunch of bird surveys, at a bunch of sites, before and after the cull.
What they found was no immediate influx of small birds into those culled sites. Those small birds were already using those sites! Miner colonies elsewhere around the reserve were significantly impacting the small bird community, but not those sites that were culled. Why? Well those culled sites were literally the colonies right next to the reserve. That proximity to an intact reserve probably offered a close refuge for those small birds to use when the Miners were giving them grief. Meaning they were cool to move in and out of those sites as they pleased.
The take home message is you cannot assume that your management action will have other beneficial outcomes beyond what you are specifically trying to achieve. The Black-eared Miners were protected. But the small birds across the landscape didn’t even notice a change.
For the actual science of this story, you should definitely read the paper and contact the authors if you have any questions.
O’Loughlin T, O’Loughlin LS & Clarke MF (2017) No short-term change in avian assemblage following removal of Yellow-throated Miner (Manoria flavigula) colonies. Ecological Management & Restoration 18: 83-87.
K!E#29 by Luke S. O’Loughlin