Watching icarus

Forest and Bird, Issue 312, 1 May 2004, Page 16

Watching icarus

JASON ELSWORTH

tells how satellite

technology is revealing the life story of the New Zealand falcon.

omewhere in the central North S Island, "Big Brother’ is watching Icarus. She’s not a character in some Orwellian nightmare, but part of a hightech research project being led by Dr John Holland of Massey University. Dr Holland and his team are using a tiny solarpowered transmitter and a weather satellite to track a female New Zealand bush falcon that they've named Icarus. By using this technology they can collect and analyse more data, with far more accuracy, than was ever possible before. The results of the research could play a significant role in the long-term conservation of the threatened New Zealand falcon. The little falcon is the only remaining bird of prey peculiar to New Zealand. It is

about three-quarters the size and little more than half the weight of the far more common Australasian harrier. The falcon is a variable species with three distinct forms. The bush falcon (smaller, dark bird), frequents the North Island’s and northwest South Island’s native forest. The South Island’s eastern falcon (a larger, paler form), is a bird of the tussock and farmland in the hills along the eastern side of the Southern Alps. The southern falcon, intermediate in size and colour between the eastern and bush falcons, is found in the southwest of the South Island, on Stewart Island and the Auckland Islands. Dr Holland became involved in researching the New Zealand falcon after working ‘a lot’ with falcons in Africa. ‘T found that there was a need for work

to be done in New Zealand, and the fact that the falcon was a species in trouble meant that I wanted to get involved, he explains. The Department of Conservation lists the New Zealand falcon as a threatened species — its second-highest priority for conservation. The eastern falcon is listed as ‘in gradual decline’. The more-threatened bush falcon and southern falcon are respectively ‘nationally vulnerable’ and ‘nationally endangered’. Raptor expert Dr Nick Fox did the ‘most recent work’ on falcon population levels, back in 1978. He estimated there were around 3100-3200 pairs of eastern falcon, 450-850 pairs of bush falcon and 140-280 pairs of southern falcon. Today population levels of the New Zealand falcon are not well understood, but its continued existence is certainly vulnerable. The New Zealand falcon is under threat for some of the same reasons as many of our native birds — disappearing native forest and predation by pest species. Also, according to New Zealand’s leading raptor conservation organisation, Wingspan Birds of Prey Trust, deliberate shooting by farmers to protect poultry, and by pigeon fanciers to protect their birds, remains the biggest cause of injured falcons delivered to them. Dr Holland introduced the idea of using satellite tracking with falcons when he met Steve Lawrence, chairman of the Raptor Association of New Zealand, and Noel Hyde of the Wingspan Birds of Prey Trust. ‘We got together and thought what can we do? Banding is relatively useful, but would still leave us with a big gap in our knowledge about the falcon’ Satellite tracking seemed to be the ideal method to fill this gap — Dr Holland was already using it with elephants in Africa. But a much smaller transmitter was needed for a highly manoeuvrable bird like the falcon. ‘What I had in my mind was that the bird had to have the equivalent of Nike Airs, not tramping boots, Dr Holland says. Eventually he found those ‘Nike Airs’ in a transmitter the size of his thumb, solar powered and weighing only 18 grams, about the weight of one and a half twenty cent coins. It was perfect for the job, but this kind of technology isn’t cheap. Luckily 2001 was the tenth anniversary of the company that made the transmitter and to celebrate they were encouraging schools worldwide to submit a proposal to win one. Massey University and Palmerston North Girls’ High School put a proposal together and came in first. Since

then the school has continued to be closely involved with the project. Thanks to the winning proposal the project now had a transmitter. Next, a government grant provided funding for the satellite time, but they still needed to find the right bird. Eventually, after much effort, they were able to track down an adult-female bush falcon, surprisingly found nesting on the floor of a clear-felled exotic pine plantation in Kaingaroa Forest. This ability of bush falcons to adapt to new habitats could be a potential plus for the species. The timber companies have been extremely supportive of falcon research in their forest and the Wingspan Trust, along with Massey University, has been studying falcons there for a number of years. Recently 22 falcon nest sites were found. Once found, the falcon was trapped and the transmitter attached in mid-February 2002. It was named Icarus. The transmitter does not appear to have affected the bird in any way, and she successfully produced three chicks in the 2002-3 season. Once in place the transmitter started to send its signal to a satellite. From the satellite the signal is sent to a base station and from there to the researcher via the internet. The data, including location, time, date, solar-charge level and if the falcon is moving or stationary, is downloaded and fed into sophisticated mapping and analysis software.

Rob Murray, a colleague of Dr Holland, showed me the mapping and analysis system in action. On a big screen, which was initially displaying a list of the kind of equations that make most of us break out in a sweat, Rob showed me an area east of Taupo, where hundreds of yellow dots showed where Icarus had travelled each day. Another click of the mouse and we were looking at a map combining wind speed with the position of Icarus. The map clearly showed that, just like us, on blustery days she likes to stay near home. Other weather data that can be combined

with the falcon’s position includes temperature, wind direction, rainfall and humidity. Finally, another click of the mouse brought up a real crowd pleaser. I was now looking at a 3D representation of Icarus’s territory. Rob worked his magic and suddenly I was getting a falcon’s eye view of Icarus’s travels. Amazingly, as we swooped across the screen, I could see what she saw. So what has been learnt from all this so far? It’s still early days and findings are only preliminary, but during the first week or so Icarus flew an average of about 40

kilometres per day. Since then though she has settled into a daily average of about seven kilometres. Once a month, however, she appears to go on a ‘walkabout; sometimes venturing 80 kilometres from home before returning within 24 hours. In the longer term the research will start to fill in many of the gaps in knowledge about falcon behaviour. We will understand the size of their territories, how fast they travel, whether they stray nomadically or occupy a well-defined area and how far they fly each day. Most importantly we will begin to understand the influence of weather conditions and human activity on behaviour. The first results will be published this year and then the plan, depending on the availability of funding, is to retrieve the transmitter and attach it to a juvenile bush falcon. The future of the New Zealand falcon though isn’t just about the high-tech world of transmitters and satellites. In New Zealand there is a small group of highly committed people, including the

team at Massey, the Wingspan Birds of Prey Trust and the Raptor Association of New Zealand, working closely together to help New Zealand falcon. Central to this is a technique called ‘hacking’ Hacking was pioneered with falcons in New Zealand by the Wingspan Trust, and involves the release of young raptors, managed to be true wild birds. Hacking has been so successful with peregrine falcons in America that they have now been officially down-listed from the status of an endangered species. In hacking, captive-bred falcon chicks are initially hand reared before being put into the ‘hack box’. Once in the box they are fed via a tube, so that they don’t see and ‘imprint’ on humans as a food source. Next, the front of the box is opened during feeding, so that the birds begin to link their food to the environment. Finally, food is slowly moved farther and farther away from the box. Once the box has been opened the birds are free to start learning to hunt, but

during this time food continues to be supplied until they are fully independent. The ‘hack box’ provides a safe haven as the birds find their feet in the real world. For each of the last four years the Wingspan Trust has successfully released falcons into the wild using *hacking. Also Dr Holland, in conjunction with Steve Lawrence of the Raptor Association, has also recently released three young falcons at a site near Massey University in Palmerston North. Meanwhile Icarus is still out there, oblivious to the sophisticated technology being used to research her daily life. Such research, along with the efforts of a small group of highly committed individuals, could lead to a brighter future for the New Zealand falcon.

— JASON ELSWORTH is a freelance journalistphotographer based in Wellington. GEOFF MOON who took the nesting and flight photographs is, coincidentally, patron of the Wingspan Birds of Prey Trust.