Western Golden Bay, around and west of Collingwood, is a bird-watchers paradise, with a wide variety of native, migratory and self introduced species. At and around Twin Waters Lodge we have an abundance of interesting birds. This is a story involving the harrier hawk, Maori name Kahu.
Land-based raptors are not widely represented in New Zealand, with the relatively common Australasian harrier hawk (Circus approximans; Kahu in Maori) being more prevalent and the smaller native New Zealand falcon (Falco novaeseelandiae) relatively uncommon. The much larger Haast eagle (Harpagornis moorei), the largest raptor ever known, has been extinct for several hundred years, owing to the extinction of its main prey, the flightless moa.
In Golden Bay, we have larger numbers of raptors than elsewhere in New Zealand, largely because of the absence of the Australian magpie, a vicious bird that attacks hawks and other birds (and people too!). It is not clear why we are free of magpies – probably an accident of geography, but a few that made their way to Upper Takaka a few years ago were promptly trapped and sent back over the Hill.
While New Zealand falcons can be seen throughout Golden Bay from time to time, the daytime skies over farmland and estuaries usually feature harrier hawks, patrolling, looking for unwary mice and rats, or crabs in the latter case. Their mastery of the air and skills in soaring, catching and using every available updraft, are awesome to see. Harrier hawks are both predators and carrion eaters, and a staple is road kill. Unwary hawks feasting on road kill can be rather slow to take off when a motor vehicle comes along, at risk of being injured or possibly becoming road kill themselves. This brings me properly to the story of Kahu.
A few months ago, Trish arrived home with an unexpected passenger: while driving back from town, she arrived on the scene immediately after another vehicle had hit a harrier hawk and found it flapping about on the roadside, unable to fly. Now this was not the first injured bird to be brought home. Unfortunately the previous example, a pukeko that had been too slow crossing the road, had too many broken bones and had to be put down, but that is another story.
It turns out that harrier hawks, as with other raptors, become quite docile when their heads are covered (hence the use of a hood in the practice of hawking) so covering the head with an old towel made the bird passive and easy to handle. We brought the injured hawk into the gallery, covered the floor with old sheets, and proceeded to examine him. An ironing board was pressed into duty as an examination table. At that time we named him “Kahu” – the Maori name for the species. We do not know whether Kahu was actually male or female, but as no eggs were laid during “his” stay, we assumed male. It was noteworthy in handling the bird, how light he was. For a bird with a wingspan of the order of 60 cm (2 ft) he weighed just a few hundred grams. The body and wings look larger than they really are due to feathers, and the bones are hollow to reduce their weight.
It quickly became clear that the only major injury to this bird was to its left wing. The bones all felt as if they were intact and he could flex the wing, but he was not carrying it properly and could not flap it at all. We decided that it had probably been badly sprained at the base of the wing, and there was surface damage and a suggestion of bruising too. A quick survey of several good veterinary web sites all indicated the same treatment: the wing must be immobilised for 2 weeks, in a position symmetrical with the good wing. This is achieved by a figure 8 bandage around the body.
We duly applied the bandage and housed the hawk in the gallery for a period of 1 week, feeding him pieces of meat and offal that he devoured – although only in our absence. A true wild creature, he went into defensive mode every time we came near the window, let alone in the room. This involves crouching as low as possible and raising the beak skyward (or roofward in this case) and opening it wide. How this is supposed to provide defence is not clear, but that is how he acted. During the first week of his convalescence it became apparent how important the wings are for balance, even when hopping and jumping – with one wing immobilised he presented a comical sight as he tried to hop and regularly fell over. Such loss of dignity!
After about a week, Kahu decided he had had enough and pulled the bandage loose, so we unwrapped it. He seemed to be carrying the wing better, so we decided to see if he had healed. Alas the wing quickly showed he was not ready to fly yet, so we had to re-bandage for a few more days. Five days later, Kahu decided he had really had enough and managed to shred a lot of the bandage and in the process get the adhesive tape that had been holding it in place stuck to his breast feathers. This time, after we removed the bandage and unstuck him, he demonstrated his recovery by flying across the room and trying to fly out through a closed window. We decided this time he really was better, so opened the door for him to leave – he refused, so we just left him there, with the outside door open. Twenty minutes later he was gone.
We do not know for sure what happened to Kahu. We hope he healed and went back to patrolling the fields and estuary for rodents and crabs. The one clue we did have was a couple of days later, we saw a hawk (one of several) soaring in the area, but a little erratically – as if favouring his left wing. It may have been Kahu, but we will never know.