Kea Creature of curiosity

Forest and Bird, Volume 21, Issue 3, 1 August 1990, Page 20

Kea Creature of curiosity

by

Kerry-Jayne Wilson

HE KEA is one of our most notorious birds. Loved by some, disliked by others, no-one is indifferent to this raucous clown of the mountains. By 1880 its intense curiosity had led this predominantly vegetarian parrot astray, and it was reputed to be a sheep killer. The truth of this has never been satisfactorily resolved, but reports are certainly much exaggerated. Today keas’ curiosity still leads them into trouble whenever people enter their alpine domain. Modern cars with their exterior gadgetry, anything rubber or polystyrene, tents, packs, boots and food can prove irresistible to kea whose strong, manipulative bill and feet can be used to human disadvantage.

Little Known

But these all too frequent encounters with kea give a false impression of their abundance and behaviour. Away from alpine villages, skifields, huts and carparks kea are not often encountered; in fact, for a species with such a high profile, surprisingly

little is Known about them. In 1986 I began to study what kea do when they are not around people. Since then, with the help of assistants, we have colour-banded 91 kea at Mount Cook National Park and, using radiopackages especially designed by SIRTRACK Electronics, radio-tagged eight of these. We have also banded over 120 other kea, at Arthur's Pass and Westland National Parks and Craigieburn Forest Park. In this article I will describe my findings on kea breeding, social habits, habitat and movements. The study will continue for at least two more years. Much is still to be discovered, and the views presented here are only preliminary. A graduate student, Ria Brejaart, has been studying the foods of kea and what they do at skifields and villages. Her work was assisted by a grant from Forest and Bird, and she will report on it in a subsequent article. New Zealand has some unusual parrots; the giant lek-breeding kakapo, sub-antarctic parakeets and the kea, the world’s only

‘alpine’ parrot. Kea occur only in the South Island mountains: the Southern Alps as well as most mountain ranges in Westland, Nelson and Marlborough. Although less numerous than they were 120 years ago, their overall distribution has changed little. Most likely they were formerly more evenly distributed through each mountain chain, whereas today their distribution appears to be fragmented. They are a timberline species by preference, and apparently occur most commonly either side of that ecological boundary. At Mount Cook, Governors Bush, one of the few areas Of forest, is a favoured haunt. In my main study area, the Tasman Valley, the taller and thicker the scrub, the more favoured the habitat. The steep valley sides are preferred, and kea spend little time on the valley floors. In the glacier-filled Tasman Valley the reason is obvious, but further down the valley and in the Hooker Valley, kea usually avoid the flat valley floors, even when these are well vegetated. At Craigieburn Forest Park, kea concentrate in the upper levels of the mountain beech forest and the lower slopes of the neighbouring sub-alpine herb fields, but we have seen them from mountain top to valley floor. Huts, villages and dumps readily entice kea down from their favoured haunts. So far we have found only three nests, two at Mount Cook and one at Arthur's Pass. The Mount Cook nests are approximately 100m and 250m in altitude above the valley floor. Both are beneath prominent landmarks and command superb views of the surrounding mountains. One is in a burrow between buried rocks. The other is beneath a huge rock. In both the nest chamber is at least 1.5m from the entrance, secure from the prying eyes of researchers. The Arthur's Pass nest is in a very different situation — in a hollow rata tree well below the bush line. Both Mount Cook nests have been used by the same pairs for two and probably three years. A previous study by Dick Jackson found that kea laid eggs between July and January. I have observed five clutches of kea eggs. Hatching dates of these eggs and the dates fledglings were first seen at Mount Cook, Arthurs Pass and Craigieburn suggest that most eggs were laid in July or August, but the eggs within a single clutch could have been laid over several weeks.

Female Sole Incubator

The female does all the incubating, leaving the nest only to take food from her mate. In well over 100 hours of observation at nests, I have never seen the father enter the nest, although I have twice seen other adult males briefly enter a nest. Adult females also occasionally enter other birds’ nests. Several times each day the male returns to a prominent perch, usually above the nest, and calls. The female emerges, takes food regurgitated by her mate, then quickly returns to her incubation duties. Initially this routine continues after the chicks hatch; all their food being gathered by their father, but conveyed from him to them by the mother. Once the chicks are several weeks old their demands can no longer be met solely by their father and the female begins foraging also. Even at this stage the male will not enter the nest. I once watched a male return to the nest while his mate was away foraging. He waited patiently outside for over half an hour, his frequent calls being answered by his hungry progeny. He finally gave up, left and returned with his mate an hour and a half later.

Both parents take a role in post-fledging care. Although fledglings quickly learn to forage for themselves, they will beg, usually unsuccessfully from their parents, whom they usually accompany for several months. While the nuclear family is the basic social group, kea are highly social animals and their groupings are remarkably fluid. At any time one or several of the family may be absent, or visitors, some of which are known to reside up to 5km away, may join the residents. In

spring, and less often in summer, groups of kea may even visit nest sites. In August 1989 I watched a group of eight adult kea visit one nest. Led by Geoffrey, the resident male, it included David, who was radio tagged a few months later and found to spend most of his time between 7 and 13 km down valley. Also present was Elizabeth, a female radio-tagged the previous season and resident directly across the valley 2.5-5 km away. The three other banded kea had previously been seen

within 3 km of the nest. During each February visit to Ball shelter | have been entertained by "kea conventions" when up to 20 kea, many banded, some up to 15km away, arrive for night long revelry. The significance of this extensive socialising and its role, if any, in their mating system, feeding ecology and home range, is part of my study. Kea are apparently non-territorial, but live in

overlapping home ranges that vary considerably in size. Known breeding birds, for example Baldrick, Geoffrey and probably Charles (see the accompanying figure), seldom move more than 1.5 km from their nests. Presumed non-breeders (for example David and Cedric) are far more mobile. David had a core area covering about 6 km of valley, but he has been located at points as far apart as Hooker Moraines and Ball Shelter. Some kea begin this vagrant life early. A fledgling, apparently a son of Charles, was seen on 16 February 1990 near the village, 14 km south of his probable birthplace. Next day he was seen at Ball Shelter 1 km north of his natal nest. At Mount Cook the greatest distance between sightings is about 25 km and movements of 10 km are not uncommon. However, Ria Brejaart has observed four of her banded kea move between Arthur's Pass and Mount Hutt, a distance of over 60 km.

While the family groups generally keep to the hills, other kea converge on skifields and villages. These ‘gangs’ are predominantly males of all ages, attracted by food handouts and the novelty of people with all the toys they bring with them. Having fed, usually on junk food, their curiosity leads them to explore and often damage vehicles or buildings. Sometimes these antics lead to their deaths. For the wellbeing of both kea and people, kea should not be fed and food scraps should be disposed of so that kea cannot get them.

Population Unknown

No one knows how many kea there are, and no reliable estimate is likely within the foreseeable future. The most often quoted figure is 5000, a rough estimate made by the Wildlife Service in 1986 but based on very little information. It would be more useful to establish an index that could be used to determine whether populations are increasing, declining

or stable. Ria and I have tried a number of approaches to this, the most promising being the relative proportions of fledglings, immatures and adults present in late summer. We have three years’ data for Mount Cook, Arthur’s Pass, and Craigieburn, but this material is not yet analysed. Kea are breeding successfully in each of the parks we have visited, but their tendency to concentrate in sites of human activity and to fly over several kilometres in large, noisy, conspicuous flocks gives a misleading impression of their abundance. Kea appear to be less common now than they were 100 years ago throughout their range, and they are less common at Arthur's Pass than they were 20 years ago. Kea exhibit those characteristics shared by so many New Zealand species that have declined in the face of competitors, predators and habitat change: delayed maturity, not all adults breeding each year, only one clutch per sea-

son and a small clutch size. There may be only a few hundred kea in each large protected area and each of these populations may well be genetically isolated. There are probably relatively few kea living outside these protected areas. Such species may be quite safe in the short term, but in the long term their futures can be uncertain. I plan to collect blood from kea at several parks, and by comparing DNA or blood proteins assess how isolated these populations are. One hundred years ago all New Zealand's parrots and parakeets were common, but all have declined. Today the kakapo is on the brink of extinction, on the mainland kaka are uncommon and declining, the orangecrowned parakeet is of uncertain status, redcrowned parakeets are scarce on the mainland and some island subspecies are extinct, and the yellow-crowned parakeet is now much restricted in distribution. Today, the kea is Our only parrot that is readily observable at

many localities on the main islands of New Zealand. Conservation is not just a question of endangered species. New Zealand has many species that are still locally common but whose populations are small and isolated. In the face of continuing habitat loss and habitat modification, their future is uncertain. The endangered kakapo and kaka grab our attention and resources, while kea and parakeets may be sliding downhill to join them. Long may the tranquility of the South Island mountains be shattered by the raucous screams of kea. #& If you see banded kea please record location, date and colour combinations. Take care to note which leg each band is on and whether the coloured bands are above or below the metal or other colour bands. If you can read the number on the metal band this is even better. Please send sightings to Kerry Wilson, Entomology Department, Lincoln University, Canterbury.

Acknowledgements

I wish to thank the staff at Mt Cook, Arthur's Pass and Craigieburn for the help they have given. Thanks to all the people who have helped band kea or reported sightings of banded birds. Rowan Emberson, Marnie Barrell and Ria Brejaart kindly commented on this manuscript. This research has been funded by the Lincoln University Research Fund and the Department of Conservation. Kerry-Jayne Wilson is a lecturer in ecology at Lincoln University. She is well known for her work on seals, carried out in the 1970s.