Election of committee

It has long been known that many birds sing in regional dialects. But, if you're an outsider, how important is it to sing like a local if you want to attract a mate? Morag Fordham and Kay Milton look at what we know from the behaviour of the kōkako that have been translocated to Tiritiri Matangi since 1997.

In March this year the international press showed brief interest in a report that a rare Australian bird, the regent honeyeater, was losing its song. Its population had become so sparse that there weren’t enough adults for young birds to listen to and learn from. There was speculation that this might prevent them from attracting mates.

It is widely accepted that young songbirds learn to sing by listening to adults of their species. In birds that are able to produce a wide range of calls, and especially when populations become isolated, this can produce different regional dialects, a phenomenon well-known, for instance, in tūī, korimako/bellbird, tīeke/saddleback and kōkako.

Conservationists have long been interested in what happens when birds from different regions, with different song dialects, are brought together through translocations. Do they, for instance, learn each others’ dialects and, if so, how long does this take? And do they have difficulty attracting mates whose dialects are different from their own? In this article we consider these questions in relation to the kōkako population on Tiritiri Matangi.

The population was founded by Te Koha Waiata (male) and Cloudsley Shovell (female), who were about nine months old when they were translocated to the Island in August 1997. Te Koha Waiata was bred in captivity at Pukaha National Wildlife Centre, Mount Bruce, and Cloudsley Shovell was raised in the wild at Mapara. We cannot know what early influences helped to shape their song, but we do know that, after moving around the Island, they settled in Wattle Valley and started singing.

Over the following 10 years, this original pair, their descendants, and the brothers of Te Koha Waiata (who arrived from Mount Bruce in March 1998) established what we recognise as the Tiritiri dialect. This has changed over the years, but has remained distinctive, at least to human ears. Although the local residents will have heard unfamiliar calls from at least five of the birds who arrived later, these do not appear to have entered the local dialect.

On 30 June 2007 two females, Pukaha and Te Rae, and one male, Parininihi, all of whom had been bred at Pukaha/Mount Bruce from a wild-caught Taranaki male, were released onto the Island. Waipapa (male) and Māwhero (female), two wildcaught birds from the Waipapa region of Pureora forest, arrived on the same day.

The two Taranaki females, Pukaha and Te Rae, quickly paired up with young Tiritiri males (Moby and Chatters respectively) in their already-established territories, and were heard singing the Tiritiri dialect during their first season. Parininihi did not establish a territory and attract a partner until the following year, but when he did, his song was also in the local dialect.

Meanwhile, Waipapa and Māwhero hung around together for a while but didn’t establish a territory and did not sing. By late 2010 Māwhero had joined Kikorangi, a younger male, and was singing the Tiritiri dialect with him. Waipapa was not heard singing until he started holding a territory with Awatea in 2016, when he too sounded like a local.

On 30 August 2008 another three birds were released. Crown (male) and Pureora (female) were both wild-caught Pureora Forest birds. They stayed together and, by the winter of 2009, had established a territory. Their song was mostly in the Tiritiri dialect but, for at least two years following their arrival, it included notes from their original dialect.

The bird released with Crown and Pureora was Poutama (male), another Taranaki bird who had hatched at Pukaha/

FEATHERED DAME MALVINA: A female kōkako, in this case Keisha, singing a magnificent aria. Photo / Simon Fordham