Moreporks are iconic New Zealand birds that are instantly recognisable from their distinctive calls. They are known to inhabit many different habitats in New Zealand, however, comparatively little is known about urban morepork populations.
The overall goal of the possum and rat control that we do in bush areas near the city is to improve the survival of all our native birds, and we were very pleased to learn some good news about the morepork population in Hamilton, as the report below from the Ornithological Society of New Zealand (www.osnz.org.nz(external link)) says. [Our thanks to the society for allowing their findings to be summarised here.]
The Ornithological Society of New Zealand (OSNZ) is committed to encouraging, organising and promoting the study and enjoyment of birds, and has 17 regions across the country.
As part of the Waikato region’s 2011 programme, a morepork survey of Hamilton was organised as a fun way to involve and expose many different people to ornithology. It was also the first time such a survey had been conducted in a New Zealand city. Fortunately, Moira Pryde from the Department of Conservation had developed a method for surveying moreporks that community groups could use, though it had so far been untried.
The survey was organised primarily by Dai Morgan, OSNZ, and Andrew Styche (Department of Conservation). Twenty different Hamilton sites were selected and, for five nights between 24-28 October 2011, people went to each of these sites to record moreporks for an hour after sunset.
Preliminary findings were quite encouraging – 16 of the 20 sites detected moreporks at least once over the five night survey. Of these 16 'successful' sites, 13 detected moreporks on two different nights and five managed to have birds counted every night, despite some noisy traffic and one evening of weather that was less than pleasant.
Moreporks were detected at the 13 sites by the second night of the survey, suggesting that a bird is likely to be counted quickly. On at least one of the nights the birds were counted at the beginning of the survey, suggesting the counting was being done at the ‘right’ time of the night.
But, what does this all mean? Well, before we did the survey, there were no other studies that had attempted to count moreporks in a New Zealand city. This makes comparisons with other areas a little difficult. However, moreporks are classed as ‘widespread and moderately common’ throughout the rest of New Zealand and this also appears to be true for Hamilton too! The fact that we detected moreporks in so many sites is, perhaps, not so surprising as we intentionally chose areas that should support them; e.g., gullies, parks and other green spaces.
It is likely that the moreporks detected at sites on most or all nights are probably resident there. Birds only detected at a site on one or two nights may have been transients that were just passing through, or perhaps the count site was on the edge of their home-range, so they only visited the area where they were counted sporadically.
It is impossible to determine this level of detail from the data we collected; however, the fact that a bird was detected there is good enough for our purposes. When we repeat the survey, it will be interesting to see if those sites still have birds detected.
We also found that 11 of the 16 ‘successful’ sites had two or three birds present. This is great news as it implies that breeding within the city is probably occurring too (especially when two or more birds were counted at a site during most/all nights). Looking at how successful these breeding birds are would be very interesting, and may be picked up by a post grad student at some stage - the data we have collected would be very useful in such a study.
Where to from here? The first thing that we’ll do is fully analyse the data. We are sure that more interesting findings will come out of this with a closer inspection. Next, we’ll look to put the study within the public domain through publication in New Zealand’s only bird focused scientific journal, Notornis (http://notornis.osnz.org.nz/(external link)). This study was done under the OSNZ umbrella, and other regions across the country have expressed an interest in doing surveys in their cities - this will be great for future comparisons.
We will want to repeat the survey again in Hamilton at a later date .
It was amazing to see how many people were keen to give up their time each night to count moreporks, and thrilling that people brought their kids along to help out too. Officially, we had 56 people on the list, but I know partners, friends and relatives were brought in as well - so it was a big effort. We counted 20 sites on five occasions - that is 100 hours of work! It is really encouraging that Hamiltonians have a keen interest in conservation, which can only result in good things for the future!