A bit more info:
Most of these findings were done using surveys, i.e. point counts. The species they tested for interspecific aggression were Willie Wagtail and Magpie Lark. Hollows were detected from occupancy, that is they surveyed an area and followed all hole-nesting species (from Lorikeets to Cockatoos they say) to ascertain the number of hollows used (as a proxy for the number present). They then have lots of bar graphs that show that common mynahs essentially do things in the same proportions as other species relative to their abundance. Most of this work in the October-February period.
I suspect that a longitudinal study of shifting behaviour within a site over time during which a change in abundance of Common Mynahs will yield different outcomes (which is what I assume Kate's work is doing).
Damien
Date: Sun, 18 Sep 2011 14:13:18 +1000 From: To: CC: ; Subject: Re: [canberrabirds] “Do Common Mynas significantly compete with native birds in urban environments?” new paper
I'll be interested to see
whether Kate Grarock's findings support or contradict this study.
If the Common Mynas really "have little competitive impact", then
surely that's good news?
John Brannan (who's not likely to stop trapping them anytime soon)
On 18/09/11 1:19 PM, martin butterfield wrote:
Alas. If we only had a spare Euro34.95 we might know
whether these folk are serious or not.
Martin
On Sun, Sep 18, 2011 at 1:06 PM, Robin
Hide <>
wrote:
A controversial new
paper?
Robin Hide
Lowe, K. A., C. E. Taylor and R. E. Major (2011). “Do Common
Mynas significantly compete with native birds in urban
environments?” Journal of Ornithology 152(4):
909-921.
Keywords: Common Myna - Acridotheres tristis -
Competition - Aggression - Urban.
Abstract: In Australia, the introduced Common Myna (Acridotheres
tristis) is commonly believed to aggressively displace
native birds and outcompete them for food and nest
resources. However, the current paucity of scientific
evidence makes it difficult to devise appropriate management
strategies for protection of urban bird populations. This
study investigates the way in which the Common Myna uses the
urban environment and interacts with other species while
foraging and nesting in Sydney, Australia. The bird
community varied between habitat types along an urbanisation
gradient, and the abundance of the Common Myna increased
significantly with the degree of habitat modification.
Surveys of the frequency of interspecific interactions
revealed that the Common Myna did not initiate a
significantly greater number of aggressive encounters than
did other species. Focal observations of two potential
native competitors showed that despite foraging in close
proximity, the Common Myna rarely interfered with feeding
activity. Assessment of natural tree hollow occupancy found
that Common Mynas used significantly fewer tree hollows than
did native species. Analysis of nest site selection
indicated that Common Mynas chose to nest in more highly
modified habitats, and in artificial structures rather than
in vegetation. These findings suggest that, in this study
area, Common Mynas have little competitive impact on
resource use by native bird species in the urban matrix. The
logical conclusion of these results is that the substantial
efforts currently directed towards culling of Common Mynas
in heavily urbanised environments is misdirected, and
resources would be better directed to improvement of natural
habitat quality in these areas if the purpose of control is
to enhance urban bird diversity.
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