Seabirds beyond the Mountain Crest: The history and natural history and conservation of Hutton’s shearwater by Richard J. Cuthbert.
Dunedin: OUP (2017).
RRP: $45. Pb, 212pp.
Reviewed by Mary Cresswell.
Hutton’s shearwater (Kaikōura tītī) is an endemic bird which – unusually for seabirds – breeds in an alpine environment. The last two wild colonies, located in the 1960s, are high in the Kaikōuras. This readable and entertaining book reports on the author’s three years living with the shearwaters, observing them, their environment, and their behaviour.
The two colonies were found by Geoff Harrow, officially an ‘amateur’ ornithologist but hardly that in practice, fifty years ago when not only the home turf but also the taxonomic status of the birds and specimens was uncertain. Harrow’s persistent observations eventually led to steps towards preserving this species, steps made by the Department of Conservation and its predecessors as well as the author and workers involved in this particular project.
Names are named, dates are given, and the saga unrolls. There is careful detail about Cuthbert’s three-year field work: investigating, the site, setting up camp, sorting tracking methods and surveying methods, assessing predation in the colonies.
Several chapters cover the various dramas behind identifying and properly naming the Hutton’s shearwater: which museum specimens have the right labels, which labels are properly applied. Who was the bird mentioned in an 1883 newspaper article as (shock! horror!) nesting in high mountains, where seabirds “just don’t go”.
The shearwater colonies decreased drastically in number from Harrow’s first observations, presumably from predation. Cuthbert’s team looked at falcons and harriers, noting a niche expansion of harriers, but they had no major impact. Keas? They take a few birds. The obese chicks (weighing a third more than their parent) are preferred, as they give more ‘value for money’ than scrawny breeding adults; thus, the breeders survive and the colony can stay fairly stable. Stoats were one favoured candidate until it was proved that they also preferred the porky chicks but, as well, had a population crash of their own each winter.
The major predators were pigs, as it turned out. The two surviving wild colonies are the only colonies showing no signs of feral pigs. Extinct colonies, all at lower altitudes than the two colonies studied, were wiped out completely, and the main sign of their existence today is a particular green sedge that seems to grow only in shearwater colonies and is diagnostic of colony sites.
And that takes us almost up to the present. Cuthbert gives us the most readable kind of natural history: the field notes have become research papers, the research papers have become survey articles and project reports – and the lot have turned into a comprehensive stash of information that lets him tell us a really good story, in his own way and in his own time.
The modern story continues with the establishment of a third, and backup, shearwater colony on the Kaikōura Peninsula. Te Rae O Atiu colony was established in 2005 by the Hutton’s Shearwater Charitable Trust (http://www.huttonsshearwater.org.nz ). Translocated chicks are now returning to the new site and show signs of breeding.
Just in time, too. The 2016 earthquake caused major damage to the two wild colonies. The Trust estimated 10-15% landslide damage and a significant degree of damage owing to collapsed burrows. It has been unsafe to get close up to now – perhaps the summer of 2017/18 will allow an accurate assessment of damage.
This is an elegantly planned and written book – Cuthbert brings in background and logistic details from an impressive variety of disciplines and angles to end up with a story for armchair travellers and outdoor conservationists alike. And in a world where ‘citizen science’ is becoming a buzz phrase, it’s a fine illustration of the value of having both formally and informally trained scientists on deck and working together.
Mary Cresswell is from Los Angeles and lives on the Kapiti Coast. Fish Stories, a collection of ghazals and glosas, was published by Canterbury University Press in 2015. Field Notes, a satiric miscellany, was published by Submarine Books Mākaro Press in 2017.