The distribution of this small native passerine is interesting. In Golden Bay it is most usually associated with pākihi and low scrublands, however, it is also present around the fringes of some estuaries, on Farewell Spit and in high altitude vegetation such as Gouland Downs. While known to be vulnerable to predation and habitat changes it also crops up in surprising places. The ability of fernbird to disperse and colonise new areas is at odds with their seemingly poor flight. In Tasman Bay the strongest population is at the Cable Bay estuary where the sudden increase in numbers coincides with intensive planting and trapping by a community group.
In Abel Tasman National Park it has been recorded from several estuaries, most commonly at Awaroa and Totaranui. There appears to be large areas of good habitat and one might expect that once predator control swings into action they will become far more evident.
A good way to know whether there is an increase in fernbird would be to start recording their presence now as a baseline against which future change can be measured. The usual way of detecting fernbird is hearing their metallic call—check out the recordings on What Bird? It’s not a very obvious call—at least, not for me, so it might be helpful to become familiar with the recording and then listen quite actively.
I strongly encourage bach owners and visitors to these estuaries to submit observations to eBird.
This way we can all share in the information of where they are. As a picture develops this can also prompt us to search harder in the locations where they are apparently absent.