Interesting/Little Known introduced populations

I have seen this 2020 paper talking about the history of olms in the UK - a species that, if it ever occurred in the wild at all in the UK, is certainly absent now:
https://www.thebhs.org/publications...ave-olms-i-proteus-anguinus-i-in-england/file

There is an alleged case of some olms from the Zoology Department at the University of Bristol being released into a cave in the Mendips, but because the animals were quite old at release, the cave water has very different chemical properties to those the salamanders are used to and the absence of a high diversity of cave invertebrates, it is likely they quickly died out.

It also addresses the case of Kent's Cavern in Devon, falsely stated in several sources online to be home to olm. The confusion may stem from another cave in south Devon that kept a tank of white axolotls in the 1970s.
 
A recent study has suggested that a recent cluster of sightings of red-billed leiothrix in Wiltshire and Somerset could mean the species is establishing itself in Britain (there have been other sightings elsewhere in England as well). They have also established successfully elsewhere in Europe (Italy, France, Spain and Portugal) as well as on Japan and Hawaii.

More information can be found in the link below:
Non-native songbird 'could change Britain's dawn chorus' - BirdGuides
 
Not sure if its been covered in the past.

Squirrels in Australia.

In Perth Western Australia and in Sydney New South Wales.
Both populations escaped from zoos and seem to not be thriving.

The rise and fall of Perth's palm squirrels
Neither population escaped from zoos - they were released by the zoos. The Sydney ones were eliminated about fifty years ago. The Perth ones are mostly (perhaps entirely) gone now through a recent eradication programme.
 
Neither population escaped from zoos - they were released by the zoos. The Sydney ones were eliminated about fifty years ago. The Perth ones are mostly (perhaps entirely) gone now through a recent eradication programme.

Which species was ( were ? ) involved ?
 
I can remember seeing them both in Sydney and in Perth. Eastern grey squirrels were also introduced into Melbourne and Ballarat. Both populations eventually died out.

Do you have many nut-producing trees in Australia? Being as nuts are a major staple for gray squirrels, maybe that's a key factor in why they were unsuccessful unlike in Europe where they are quite invasive?
 
Do you have many nut-producing trees in Australia? Being as nuts are a major staple for gray squirrels, maybe that's a key factor in why they were unsuccessful unlike in Europe where they are quite invasive?
Both Melbourne and Ballarat have substantial inner suburban areas with European style gardens, as well as plantings of European trees in streets and parks. The squirrels certainly did not spread into surrounding rural and bushland areas.
 
Do you have many nut-producing trees in Australia?
Actually I did not read your question properly. The dominate trees in Australia are eucalypts and acacias, so no, there are very few nut-producing trees.
 
A new non-native species has recently been discovered in Britain - the rockrose prickly leaf beetle Dicladispa testacea. The first specimen was found in a garden in Surrey, with another population discovered almost simultaneously in London's Kew Gardens. Social media reports suggest another population may be present in southwest London.

Fortunately, it seems the species will not be likely to cause any harm - it is a specialist of a single plant genus - the Cistus rockroses, which are not native to Britain and only occur as ornamental plants in gardens. Because it has poor dispersal abilities, it would have had to have colonised Britain either in plant pots or inside the plants themselves (the larvae of this species is a leaf-miner).

More information can be found in the link below:
Prickly leaf beetle is found in the UK for the first time
 
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