Interesting/Little Known introduced populations

Chinese francolins have been introduced on Mauritius and Réunion and after they were first quite succesfull on both islands , they now have disappeared again.
The same species was also introduced on Luzon ( Philippines ) and there still a population seem to be present.

 

About five years ago I was able to film wild francolins on Mauritius. They were fairly easy to see at that time.

 

So they are still there ?!

 

Any idea where on Luzon please? In case I ever get back there....

 

Near Manila.

 

The francolins on Mauritius are Grey Francolin, they are very common.

 

For anyone in North America wishing to see European Goldfinch, I think this eBird checklist may be of interest (I can't believe those numbers, either):

https://ebird.org/view/checklist/S51718654

 

Japanese burrowing cricket in the North America :

Introduced Japanese burrowing cricket (Orthoptera: Gryllidae: Velarifictorus (Velarifictorus) micado) range continues to expand in North America

 

In the dunes around Den Haag - the Netherlands during 2017 a number of Western gopher snakes were found. I don't know if the small population has reproduced but from climate it would be possible.

 

Blue-And-Yellow Macaw in Florida.
Graylag Goose in Southern California.
Western Meadowlark in Hawaii.
Muscovy Ducks in Texas (in spots other than the Rio Grande) as well as Louisiana.
Black Swan in Florida.
Hill Mynas in Florida.
Spectacled Caiman in Florida.
Nilgai and Blackbuck in Texas.
Mariana Swiftlet in Hawaii.
Rosy-Faced Lovebird in Arizona...

Wow. The US is filled with odd invasives.

 

Nile tilapia on Bawean island...... :

First record of the invasive Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758) (Perciformes, Cichlidae), on Bawean Island, Indonesia

 

False widow spider to conquer the world :

Steatoda nobilis, a false widow on the rise: a synthesis of past and current distribution trends

 

While some use the terms "exotic" and "invasive" interchangeably, I think in general there's a distinction to make. For example, in the Netherlands the Japanese knotweed completely dominates everywhere it grows, choking the far more biodiverse native vegetation. As it threatens biodiversity among other things it is invasive. However, the Black swan is also a non-native species that lives and breeds in the Netherlands in low numbers (around 70 pairs if I'm not mistaken). While it may compete to some extent with our native swans, it's biology and low density make it a reasonably "harmless" exotic.

Of course, an exotic can turn invasive, but it doesn't have too. Invasives are also not necessarily exotic, as native species can turn invasive too (Molinia cearulea, Purple moor-grass, comes to mind, but I'm sure there are better examples).

 

The work invasive is an odd one to me. Sometimes I use the word distinctively to refer to exotics that threaten an ecosystem, and sometimes I use it interchangeably. However, I personally never use the word to refer to native species.

White-Tailed Deer is a good example from this side of the pond.

 

Exotic: Any species that is not native in a region. Completely unrelated to the fact of being in the wild, captive or absolutely non existent in this region. Example: Narwhal is exotic in Buenos Aires.

Introduced: Any species that is not native in a region, and that is thriving in the wild in that region. Example: any of the species that popped up in this thread. Completely unrelated to the fact of being invasive or not, tough often both concepts come together.

Invasive: Any species that poses serious threats to other species or ecosystems. Completely unrelated to the fact of being native or exotic, tough almost all invasive species are also introduced in the concerning region. But there are also invasive species in native regions, for example the Yellow-legged gull in Mediterranean coast or the crown-of-thorns starfish in Great Barrier. Often native species became invasive if the ecological factors that kept them in a non-invasive status until recently, are disturbed or destroyed.

 

In the UK 'invasive' is used by Government law to describe and control some spp which are only theoretically such and not actually found in the wild at all, and as such can of course have absolutely no impact whatsoever on other species or ecosystems; whereas others are not such listed or controlled at all. The priority species in the UK which 'poses a serious threat' to a native animal, is the domestic cat....

 

Not surprising, as domestic cats kill billions of birds each year.

 

Not really an introduced population, but I thought I would mention in it anyway, as it is little known. In Wisconsin, there is a small but steadily growing population of Fallow Deer x White-Tailed Deer crosses. They may begin to spread similar to Coywolves...

 

I’d like to see a reference supporting this. I would think a Whitetail Fallow Hybrid would not be possible, but I’ve been wrong about a lot of things. I know that Sika have been crossed with both Red Deer and Wapiti...and that Wisconsin has (or had) a small population of Sika...is it possible that’s the source of this information?