I was wonder what BIBY members think of the Noisy Miner, in particular their own experiences with the bird and thoughts on possible conservation strategies (if any) relating to the species.
i was in part spurred by this comment by Amateur in another thread:
... if you want to target your conservation funding most effectively it seems it would be best directed at controlling the native noisy miner rather than the well-known exotic pest of the Common Myna, let alone the Common Blackbird whose effects remain to a large extent unquanitified.
It seems it's been getting some bad press
Indeed, the Victorian government's position is now to regard the NM as a 'Key Threatening Process' (for comparison other recognised KTPs include land clearance and foxes)
http://www.environment.gov.au/cgi-bin/sprat/public/publicgetkeythreats.pl
I've personally tended to view the species' overabundance as a side effect of human land modification. the train of thought i'd been aware of has been construction of many urban parks with large eucalypts whilst being devoid of mid- and understory vegetation, which replicates its favoured habitat.
another purported reason for the increase i've heard is the increase in popularity of large-flowering native cultivars. particularly Grevilleas, which flower all year round providing a near-continuous food source.
NMs have also been suggested for a seeming decline in resident small native birds in gardens on the east coast. at a local nature reserve several formerly resident native honeyeaters have been locally extirpated for over a decade, NMs are superabundant.
I also wonder about the impacts on the NM on raptor species. while providing in some cases a food source (i believe there has been an increase/influx of Square-tailed Kites on parts of the east coast as they were able to take advantage of the ready availability of miner nests), adult birds are also predated (i've seen hobbies and brown goshawks take them). however the keen eye of the bird and its rapidly-communicated alarm calls serve to alert all birds in the immediate vicinity to potential threats, perhaps in some cases interfering with predator hunting success and maybe even protecting some species from raptors (though they would then have to coexist with miners).
I'm a bit tired right now, but there are quite a few papers published regarding the impact of Noisy Miners. I'll read them in-depth tomorrow and try provide a succinct summary of their findings (and methods).
I agree with Zosterops in that the main issue is indead clearing of understory and the like creating too much habitat suited for the Noisy Miners to rule and defend. Rather than the culling which is being trialled in some locations, I believe we should be tackling the problem at its root, by re-vegetating habitat overrun with Noisy Miners
Ryu
Canberra
Aiming for DSLR-quality shots with a bridge camera
It was the general view when I was a member of Birds SA that destruction of understorey produced open woodlands which favoured Noisy Miners. This general view was supported by my own observations of birds in Adelaide's parklands & at Milang in SA where there is very little understorey but plenty of relatively large trees. I saw further evidence of this in several places in NSW where understorey had been destroyed by feral goats & livestock. Noisy Miners were by far the predominant bird species in these places. In addition, my several readings about Noisy Miners have contended that understorey clearance is a critical factor in Noisy Miner abundance but don't ask me to cite the readings.
It's concerning to me that the Victorian government seems to be painting the Noisy Miner as the bad guy. Surely the focus should be on the understorey destroyers & this would suggest that if we wish to do something about Noisy Miner overabundance then we need to be restoring indigenous understorey. The beauty of such a strategy is that it would have a number of biodiversity benefits.
Scientists like to simplify everything, that is reasonable, but often biological issues are so complicated that the simplifications are no longer very useful. Trying to attribute a cause for the decline of small native birds is difficult, blaming the NM is easy. In my area I have lots of small honeyeaters, they are mostly very aggressive birds which can easily hold their own if the conditions are right. We also have NMs and they don't cause any problems.
How's the understorey, Greg?
In some areas we have plenty of understory, plenty of wattles and biddy bush also exotic shrubs. The small honeyeaters seem just as happy, or happier with rosebushes and the like. In other areas there is just woodland with groundcover mainly grasses native and exotic. I have planted lots of Eucalyptus viminalis which are very popular with insects that eat the leaves, the leaves seem to be more edible than most Eucalypts. This makes them good habitat for insectivorous birds such as honeyeaters, they are a good birdwatchers tree if you don't mind the mess they drop. Viminalis has a wide distribution, they are native to most parts of SE Australia.
I can subscribe to all your points Zosterops.
In my area I have native NM that are present but don't seem to gang up on others that much. Rather they seem to co-habitate however they are also the smallest bird generally and do make a fuss ocassionally. I live on a park not far from large parts of lesser touched bush but don't have small birds anywhere except swallows. Secondory meat eaters magpies, currawongs, butcher birds, magpie larks, kookaburras, are for the most amongst swarms of Rainbow Lorikeets. Down the road where understory is present and a bat colony exists, there is a clan of Inian miners that don't seem to come up this end. I have not had a look down there for little birds but would assume something will be there.
Is the native NM more aggressin than the Indian. Or is it preferred habitat, or another bunch of conditions.
Interstingly I observed on the fringe of the park, bordering an industrial estate, in a nature stip along a powerline cutting; rainbow lorikeets, scally breasted parots, galahs, and native NM all having a conversation for some time over a dead tree that had lost more of it's upper limbs in storm damage. In the air and on the ground there was not identifiable breeding holes or even possible opportunities.
It was not the only dead tree, there were several similar trees within 100m. Maybe it's an observation tree, and like Greg says identifing a cause is very complicated.
Ipswich Shire Eastern flanks
According to this paper
http://www.waverley.nsw.gov.au/__data/assets/pdf_file/0003/43491/Common_mynas_2011.pdf
"Noisy Miners act as a ‘reverse keystone species’, structuring bird communities in the human-modified environments in which they are most common. In Sydney suburban gardens, Parsons et al. (2006) found negative correlations between the presence of the Noisy Miner and that of several small bird species in Sydney gardens, while none were negatively correlated with the presence of the Common Myna. Thus, the perception in the public arena that the Common Myna is a highly aggressive species may be misplaced and attributable to identity confusion with the Noisy Miner. "
"The Red Wattlebird and Noisy Miner initiated more interactions than the Common Myna and showed significantly higher levels of aggression than any other species. "
LM
That is very interesting, i didn't know that about no negative correlation between common mynahs and other small native birds.
My back yard and surrounds are full of the common mynas, there are large trees, exotic and native, some understory not a lot, (it is housing commission, no planned planting at all). At a large park nearby that has been planted with a lot of native trees, and some bushes, a lot of grevillias there are no common mynas but many noisy miners.
They were coming in my window when i didn't have a fly screen eating my fruit, when i was out, and when i caught them they paniced, i paniced, they didn't know how to get out and left droppings all over my bed.
Elizabeth
elizabeth
Thanks for the understorey description, Greg. Do you think your understorey has any affect on Noisy Miner numbers &/or behaviour?
i think the study found an apparent lack of correlation between Common Myna presence and native bird presence, which as implied above isn't necessarily to say there is (or isn't) one in some circumstances
the 2011 study does seem rather lenient on the species compared to some news reports
http://www.dailytelegraph.com.au/news/nsw/call-for-volunteers-as-science-takes-the-fight-to-invading-myna-birds/news-story/88ddb397f75b88e0071d380219c054c0
'He added that birds at the vanguard of these invading flocks were naturally the strongest, most dominant mynas. They were therefore the ones most likely to meet and mate with dominant mynas at the spearhead of other flocks, producing genetically superior offspring with even greater talents for invasion than the previous generation.
Multiply that by many generations and the possibility exists for a kind of supercharged myna, capable of flying further, harassing an ever-expanding list of native birds and creating havoc in Australia’s delicate ecosystems.'
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i thought some of the concern relating to perceived common myna impact revolved around their occupying the increasingly scarce nesting hollows available on the urban fringe, which was believed to have some impact on parrot breeding success.
from my observations they seem to much prefer holes in houses to natural tree hollows (though admittedly i don't see many natural hollows in the burbs where myna density is seemingly greatest). mynas are usually described as nesting hollow-dependent species yet i've seen them utilising dense cypress foliage for nesting sites.
yes many people (apparently) can't tell the two miner/myna species apart
i've also heard some of the birds referred to as 'african mynas',
and also red wattlebirds identified as 'mynas' by more than one individual
there are clearly some local common names for both birds in use (+ misidentifications).
Oconnnore the Common Mynas much prefer closer proximity to human built environments (whether trees are present or not) NMs prefer open park woodland dominated by eucalypts.
as for Noisys i certainly see more aggression from NMs, particular instances that come to mind include a party of ~9 dragging a roosting Little Pied Cormorant out of a tree by the tail and wings, pinning it the ground and plucking feathers from it. i've also seen a spotted pardalote killed and NMs killing one of their own kind on two occasions.
interestingly i don't recall seeing aggression from NMs towards lorikeets or butcherbirds despite sharing ostensibly similar habitat preferences, ravens and currawongs on the other hand seem very prone to harassment.
That's interesting Zosterops, I've never seen behaviour like that, I wonder how widespread it is? I can see how it would upset people, native animals are supposed to be cute and cuddly, There is a good joke about it in this cartoon;
http://wondermark.com/c1196/
I don't see what can be done about it, I presume NMs are protected like most native birds, and there are a lot of NMs that never cause any harm. Human settlement causes all sorts of weird animal behaviour and problems with the balance of the ecology.
It seems to me at least one solution to the problem of Noisy Miner dominance is to re-establish the natural understorey in places where the natural understorey has been destroyed.