A little while ago I wrote this post in response to an article by Tim Caro and Paul Sherman about why behavioural biologists avoid involvement in conservation science. You can read about my thoughts on the divide that Caro and Sherman highlighted between theoretical and applied science here, but our conclusions were the same: that,
“many studies of animal behaviour are relevant to solving conservation problems, and we therefore encourage behaviourists to contribute more strongly to finding practical solutions to the contemporary conservation crisis.”
Having made it something of a pet project to find examples of behavioural studies being applied to conservation issues, I’m always delighted to come across lovely work like this new study that’s just come out online in the Journal of Applied Ecology: Conservation implications of song divergence between source and translocated populations of the North Island Kōkako.
Never heard of the Kōkako? Neither had I until this morning – but it has a distinguishing feature that will ensure you remember it. Check out this video (courtesy of BushTellyTV) and listen out for its call: like a cross between a harmonica, and a creaky window…
This beautiful songbird is found only in New Zealand. Like many of New Zealand’s endemic birds that have darted around the forest floor for hundreds of years, it has suffered from the introduction of ground-dwelling carnivores like rats and possums, as well as substantial habitat loss. Currently there are only 22 populations – 11 surviving, and 11 reintroduced.
The ability to successfully translocate individuals of this species is therefore crucial to its survival. This paper looks at the success of translocation in a source population, and two translocated populations in the North Island of New Zealand, by investigating the effect of translocation on song.
The importance of song for mate attraction and territory establishment in bird species has been well established; likewise, spatial variation in song patterns is a known phenomenon. But how might local song diversity affect the success of translocation attempts? If there is variation in song structure between translocated populations, and each population has a preference for its own song, the resulting divergence could lead to a reduction in gene flow and genetic diversity. For the endangered kōkako, this could do more harm than good.
The study found that in the three populations (the source population, and the two translocated populations), song structures and phrasing differed significantly, suggesting the potential for these populations to diverge in preference. Luckily for the future of translocated kōkako, however, there didn’t seem to be discrimination against foreign songs when individual birds were played songs of birds from the same, and different locations.
This is good news for the conservation of the species, as continued introductions of new birds is important for population persistance, as it maintains a healthy level of genetic diversity. The authors suggest, however, that introduced birds should be from as close to the original population as possible to maintain cultural homogeneity.
Overall, despite songs diverging over distance, the kōkako is on track for a successful translocated future. Worth making a song and dance about.