Noisy Miners

["Philip Veerman" <>]

Always good to go to the source of info on the GBS, which reveals (as below) that long-term, the abundance is at its highest in May, which might be part of the reason for this observation, although I suspect Martin has only been at that site recently, so that isn't a lot to go on. Also the May peak is not a strong trend. Trends could easily be notably different in areas that are of different habitat type (as Martin's abode may be compared to typical Canberra. That is why it is best not to include very much outer areas in the GBS. Though I don't anything about the location described below. Early in the GBS history we had a site from "the Mullion" that was not included in the GBS analysis, the info was mentioned separately in the ABR. That was a wise move. Sometimes the idea has been overlooked. It can distort trends. But then again, this distortion can highlight interesting patterns, such as what the GBS Report shows about the annual abundance and distribution of the White-eared Honeyeater and my comments about site 246. 

 

I also attach (below) the abstract of the talk given by Kris French at the BE seminar that Geoff Dabb & I went to on 25-3-2006. That gives a different perspective of the Noisy Miner from one that may be appropriate here, because (as the GBS Report points out), it is not a major part of Canberra?s suburban avifauna.

Noisy Miner Manorina melanocephala

This species is known to be successful at becoming dominant at disturbed sites. It has a strong social system and colonies will establish at particular sites and tend to exclude other species. It is a conspicuous and bold species. Some sites have many repeat observations of similar sized groups lasting over several weeks or many years and others have just a few observations of small numbers of them. At 0.2% of total birds, it is not a major part of Canberra?s suburban avifauna. The monthly pattern has changed. In the first about eight years, seasonal fluctuations were marked. With a minimum in September, numbers climbed fairly smoothly to a May peak then declined again. Since then this variation has reduced dramatically. When all years' results are pooled, that monthly trend still shows but is not strong. The same happened with the Red Wattlebird and for probably the same reasons, although this species is on about one tenth abundance scale. After high numbers in the first two years, the long-term abundance has fluctuated. .........Graphs on page: 98, Rank: 64, Breeding Rank: 37, A = 0.15932, F = 19.00%, W = 50.0, R = 4.603%, G = 3.46.

End of GBS Report extract

"Do we have species that control the avian diversity in urban areas? ? Evidence for Noisy Miners and Common Mynas.

Kris French

Institute for Conservation Ecology, University of Wollongong

There is a great deal of discussion amongst councils and the community about how our conservation dollar should be spent in cities to conserve our wildlife. More recently there has been a push by some groups to spend dollars controlling Common Mynas that they consider to be one of the causes of loss of birds in cities. How do governments weigh up these various viewpoints to achieve good conservation outcomes for their communities?

What evidence can science add to the debate?

The Common or Indian Myna is considered a pest species in many parts of the world because it damages fruit and grain crops and their noise and smell can be annoying where they are in large numbers. They are street wise and cheeky, becoming fearless of people and interfering in picnics etc. They are considered to be a problem for biodiversity because they nest in hollows which are in short supply due to agricultural clearing. In a study in Canberra, they fought for nest hollows with two species of parrot. In the BIBY Survey we found that Common mynas occurred in 80% of gardens. However, parrots also occurred commonly, suggesting that that they may not be a problem for parrots in these coastal cities. Furthermore, the Birds in Backyards survey found that none of the seven small birds surveyed were negatively related to the presence of Common mynas.

Noisy Miners are a native cooperatively breeding species that has colonies of individuals that rigorously defend feeding territories from all species of birds. It traditionally occupied open grassy woodland. Research in agricultural remnants in Victoria has found that there is an increase in species richness in remnants following removal of Noisy Miners. There are also studies along roadsides in the Southern Highlands and in the Wimmera, documenting negative relationships between noisy miners and species richness. We have also found a similar pattern occurring in cities in both remnants (Wyong study) and in the streets (Illawarra study). Noisy miners overlap with many small birds in terms of both foraging and nesting requirements so it is not surprising that the BIBY survey found a strong significant negative relationship between the presence of small birds in gardens and the presence of Noisy Miners.

We have some good evidence that one of the most important influences determining which birds occur in urban areas is the presence of noisy miners. We have yet to prove that spending conservation dollars on removing or controlling these birds is worthwhile. We must weigh up their native status and the expense of catching and removing them ?and we need to know if it will work. We must weight up other measures such as changing our gardens. However, I think it is time that we undertook the main test. We need a trial removal from some suburbs to see if we can encourage small birds back again.

I don?t think there is the evidence to spend money on Common Mynas. Spend aesthetic dollars or even health dollars if evidence is gained. But let?s stop picking on the non-native, just because it is abundant!!"

End of quote

Philip