Eric Spurr of Manly is the man behind the annual NZ Garden Bird Survey, which he started as a hobby project. A retired scientist from Landcare Research, Eric, aged 71, has been involved in a number of bird monitoring projects that have taken him from Ross Island in Antarctica to the Orkney Islands in northern Scotland. He spoke with Terry Moore.
I can remember as a kid being intrigued with birds. We had a hedge that the Dunnocks hopped around in on the dairy farm where I grew up – at Le Bons Bay on Banks Peninsula. We had lots of tui in our orchard, eating the plums, and rooks nesting in our walnut trees.
I started the NZ Garden Bird Survey as a hobby project 11 years ago, just before I retired – it’s a ‘citizen science’ project, which gives people in the community the opportunity to participate and take ownership of research that is done locally. At the time, NZ didn’t have a long-term monitoring programme for common bird species. We know that rare species such as Kiwi and Kakapo have been declining through loss of habitat and introduced predators but we don’t know about trends in species that are currently more common, such as Tui and Fantail. They are species that we see around us every day and are generally not concerned about, but they could become more scarce in the future. We definitely don’t want to see them get into the same situation as Kiwi or Kakapo.
On average, about 3500 people throughout the country have taken part in the Garden Bird Survey each year: Auckland has one of the lowest rates of participation, whereas Dunedin has the highest. More people in southern parts of the country feed birds over the winter and I think that makes them more interested in doing the survey. We would like a lot more people to participate because the more that take part, the more reliable and significant the data will be. The survey has shown that the most numerous garden bird nationally is the House Sparrow, followed by Silvereye, Blackbird, Starling, Myna, and Tui. However, there are regional differences – for example, Myna is the third most numerous species in Auckland, behind House Sparrow and Silvereye, and Silvereye is the most numerous species in Dunedin, ahead of House Sparrow. Bellbird is the fifth most numerous species in Dunedin, but Auckland has very few Bellbirds. There are also differences between urban and rural gardens, with rural gardens having a greater variety of birds and higher numbers of most species. Not surprisingly, there are more birds in gardens where people put out supplementary food such as bread, seeds, fruit, and sugar-water. Most species have not changed in abundance over the first 10 years of the survey but people have been commenting for several years that Song Thrush numbers appear to be declining. People have also noted anecdotally that Tui numbers are increasing, and attribute that to official and community pest control initiatives such as Shakespear Open Sanctuary and the local Forest and Bird’s Pest Free Peninsula campaign.
Over the years I’ve been involved in bird monitoring projects that have taken me from Ross Island in Antarctica to the Orkney Islands in Scotland. While doing my doctorate at Canterbury University, I spent four summers in Antarctica studying behavioural interactions and breeding biology of Adelie Penguins. I was there for two to three months each summer with my tutor and two other students, based in a forestry-type hut at a field station at Cape Bird on the northern tip of Ross Island. Cape Bird is known as the ‘Banana Belt’ because of its slightly warmer temperatures, which causes the snow to melt and sea ice to break out early in the summer. This allows the penguins to come ashore and build nests on the exposed ground. Although temperatures were above freezing during the day, they were below freezing at night. I remember waking up some mornings with my sleeping bag frozen to the wall. We melted ice on a two-burner primus to obtain water, and so had a bath only about every fortnight. The bath was a plastic tub, and because there was no room within the hut we bathed outside. We then used the bath water to wash our clothes. The clothes froze solid after we pegged them out, and then freeze-dried. About 40,000 pairs of penguins nest at Cape Bird, in large colonies. As part of a long-term monitoring programme, I helped count the number nesting there each year. It took four of us two to three days to count them all. After completing my doctorate, I spent a year doing post-doctoral research on Eider Ducks in the Sands of Forvie nature reserve, north of Aberdeen in Scotland. While in Scotland, I helped with a long-term monitoring project counting cormorants, fulmars, guillemots, gulls and other seabirds on Eynhallow, one of the Orkney Islands.
When I returned to NZ I worked for the Forest Research Institute’s Protection Forestry division, later renamed Landcare Research, based in Christchurch – a job I had for about 35 years. A lot of my work was organising bird surveys, mostly in relation to 1080 poisoning operations for possum control. I reckon I’ve done around 70,000 surveys either as research leader or working in the field. We used a technique called the Five Minute Bird Count before and after bait drops, to measure the non-target effect on bird numbers. There was a small ‘by kill’ of birds but populations recovered very quickly and improved in the absence of mammalian pests – possums, ferrets, stoats, weasels and rats. The birds that were poisoned – mainly Blackbirds, Chaffinches and some natives such as Tomtits – mostly ate the baits directly but some may have eaten insects that had eaten bait. Long term, the bait drops were positive for birdlife. I also did quite a bit of research on poison baits for wasp control. I started using protein baits – based on sardine catfood – because anything sweet also attracts bees. It was important to use a poison that can’t be detected by wasps. I had it commercially made for a couple of years and it was very effective. Others have since taken this further. I got involved with wasp baits initially because there were some logging gangs who cut into a tree which had a wasps nest in it and the guy with the chainsaw got badly stung – definitely not a safe situation when wielding a chainsaw!
Since moving to Whangaparaoa Peninsula four years ago, I’ve been helping Forest & Bird with monitoring the success of their Pest Free Peninsula campaign, using the Five Minute Bird Count technique. We’re also using Garden Bird Survey results from the Peninsula to help back that up. I am impressed with the numbers of birds on the Hibiscus Coast. There’s a big range – in my garden we have tui and can watch kereru do a lovely diving display from our windows. There’s a kingfisher that keeps an eye on our goldfish pond and they were breeding in our bank a couple of summers ago. I would be interested to know if anyone has seen nests of tui and kereru locally. We also keep an eye out for bellbirds. They put sugar water feeders at Shakespear Open Sanctuary a while ago to try and attract bellbirds and keep them here. Since then, there have been one or two reports of bellbirds on the peninsula.
The NZ Garden Bird Survey takes place June 24–July 2. Anyone can take part. All you need to do is choose a day within the above period, stay in one place for an hour, and record the largest number of each bird species you see. Info: http://gardenbirdsurvey.landcareresearch.co.nz