Chatham Islands, New Zealand

Over 30 years have passed since the remaining five black robins, including the last surviving fertile female "Old Blue", were translocated from Little Mangere to Mangere Island, in the beginning of a dramatic, 22-year long effort to rescue this endemic species from the brink of extinction. The conservation measures that were taken to save this species were successful and by 1998 two black robin populations had been restored including about 150 birds on Rangatira and 50 birds on Mangere Island. At this stage conservation managers decided that it was time to scale back the intense monitoring and management and to let the black robins recover unassisted.

While the descendents of "Old Blue" continued to lay eggs and raise their nestlings over the past 10 years, conservation biologists have become aware of another potential problem facing the remaining black robins. When populations decline to critical levels, individuals are forced to mate with close relatives and this can cause increased inbreeding and reduced genetic diversity. This has been the case with the black robin, which passed through a severe population bottleneck in the late 1970s, when numbers were reduced to five individuals (including only one fertile breeding pair). Of greatest concern is the loss of genetic variation, which in turn can lead to increased levels of reproductive failure, decreased resistance to diseases, and even a reduced ability to adapt to novel environmental changes.

To address this concern, University of Canterbury researchers Melanie Massaro and Jim Briskie www.biol.canterbury.ac.nz have launched a project to study whether the severe bottleneck the robins passed through in the 1970s is affecting the post-bottlenecked black robin population in ways that reduces its viability over the long term. In collaboration with DoC, Melanie and her team have just completed their second field season on Rangatira Island. They are assessing rates of nesting failure, parasite loads and developmental abnormalities. To this effect, Melanie's team followed over 50 black robin nests throughout the past breeding season. First results show that many black robin eggs fail to hatch because they are infertile or due to early embryonic death. High rates of hatching failure are typical for species that have passed though severe bottlenecks. Despite these difficulties, 2008 appears to have been a reasonably good breeding season as over 40 black robin nestlings were successfully raised to fledging.

As the black robin is such an iconic bird species and the story of its dramatic rescue captivated the interest of both the Chatham Islanders and other New Zealanders, a science communication project that follows Melanie's research on Rangatira Island has been launched concurrently. This outreach project takes a close look at all life on the island, uncovers what it is like to be a field scientist and, details the "why" and "how" of data collection. Through films and photographs students in classrooms all over New Zealand will be able to follow the successes and failures of black robin families, see how female tomtits determinedly defend their nests, explore the island from the tree tops to under the ocean's surface and understand some of the mysteries of ecological interactions in the natural world. By May 2009, the project will have a website set up offering interactive resources for the classroom, beautiful photographs and film clips from the field season and information on the science behind the black robin project.