Eradication of Common Myna facilitates the establishment of insurance populations of island endemic birds

Birds of the islands and waters of the South Pacific.
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Michael Szabo
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Eradication of Common Myna facilitates the establishment of insurance populations of island endemic birds

Postby Michael Szabo » Thu Nov 25, 2021 9:01 pm

Eradication of a highly invasive bird, the Common Myna Acridotheres tristis, facilitates the establishment of insurance populations of island endemic birds.

FEARE, C., BRISTOL, R., & VAN DE CROMMENACKER, J. (2021). Eradication of a highly invasive bird, the Common Myna Acridotheres tristis, facilitates the establishment of insurance populations of island endemic birds. Bird Conservation International, 1-21. doi:10.1017/S0959270921000435

Summary

Common Myna Acridotheres tristis is considered to be among the world’s most damaging invasive species through disturbance, predation, competition pathogen introduction to native birds and other taxa. Claimed impacts on native birds have often been based on anecdotal reports. More substantive evidence of interference with small-island endemic birds has been reported, but impacts have rarely been quantified or subjected to experimental manipulation. On Denis Island (Seychelles), up to 10% of Seychelles Warblers Acrocephalus sechellensis, and small numbers of Seychelles Fodies Foudia sechellesis and Seychelles Paradise Flycatchers Terpsiphone corvina had head injuries following myna attacks, stimulating an eradication of the mynas. Populations of four species of Seychelles’ endemic birds, introduced to the island to establish insurance populations, were estimated before, during and after the completion of the eradication, permitting assessment of the impact of myna removal on populations of the endemics. Numbers of all four endemics increased following introduction, but increases in the numbers of Seychelles Magpie Robins Copsychus sechellensis and Seychelles Paradise Flycatchers accelerated after >90% of the mynas had been removed. All endemic populations continued to increase during and after completion of the eradication in 2015, and injuries to Seychelles Warblers, Seychelles Fodies, and Seychelles Paradise Flycatchers ceased. Habitat management within a designated conservation zone on the island, into which the endemics were released and subsequently spread to occupy most of the island, also contributed to the endemic birds’ global populations and to their improved conservation status. This study confirms that mynas negatively impact small island populations of endemic birds and suggests that their potential impact has been underestimated. Myna eradication should be considered vital before endangered endemic birds and other taxa susceptible to their negative impacts are translocated to small islands for conservation reasons.

Link: https://www.cambridge.org/core/journals ... RtR1EZk1TI
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Steps
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Re: Eradication of Common Myna facilitates the establishment of insurance populations of island endemic birds

Postby Steps » Fri Nov 26, 2021 8:19 am

I really love seeing these sorts of reports...

Claimed impacts on native birds have often been based on anecdotal reports.

When we where in Manurewa, establishing our native and tree gardens over the last 30yrs, in the 'early days' there was a large (protected) norfick pine not far away where magpies had set up house. Early 1 morning, several what I thought suppressed .22 shots rang out..mag pies has disappeared..none of the neighborhood complained.
Was not long after that the tui flock established in our banksia and totoara trees. Several families of fan tail, wax eyes, established Then the wood pigeons and Rosella came for the karaka and puriri trees. And a couple families of thrush and blackbird, that got quite tame in the veggie garden. And of cause the busy little sparrows
The Tui tended to keep the mynia under some sort of control over the yrs.

Now we have retired cashed up , developers bulldozzed everything, moved sth. We still have a resident tui fan tails, morepork, black bird , thrush and passing thru kaka kingfishers wood pigeon, Rosella, wax eyes.

Myna are few and far between, with magpies on the edge of town.
Issue now is wild pigeons in a phonex palm..which being a small town the neighbours around have no issues locals knocking them off with the air rifles.

Further out of town is the son, on a small rural block and a stand of protected kahikatea. Few yrs back magpies and mynia and little else. Again local culling, magpie, mynia, possum , rabbits... the fan tails, wax eyes and smaller birds came back quickly, and last a flock of kaka set up house in the trees..and remain set up this season... Wood pigeon and tui gone from passing thru to establishing... and a surprise, the suphur crested now fly over without stopping very often now.

Anecdotal reports.. yes , over near 40yrs in 3 locations...urban, rural town and rural lifestyle block and not uncommon events. All have trees.
I lot is put on possums, rabbits rats, birds like magpie mynia and wild pigeon little or nothing...
The latter should be made a bigger deal of and added with as much 'vehemence' to the list of rats, possums etc.
Confirming many things scientifically is good, but when the anecodotal reports are constant, and commonsense also says the same, I think local bodies, those whos budgets will be effected, tend to put off actually doing anything till the science over a few yrs confirms... Im the mean time we are loosing the small remaining populations that will re establish.
It seems strange, what is 'sitting in the tree outside our windows' and in our backyards gets pretty much ignored, but what crawls around at night un seen does..

PS should add Rosella to the list as well, we will then see kakariki (and likely other species ) reestablish and start to flourish, even in urban areas.
http://www.kakariki.net
My Spelling is NOT incorrect, it's Creative

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