Interesting/Little Known introduced populations

Here's an interesting one - in 1964 a group of nine manatees were introduced to the Panama Canal in order to try and control invasive water hyacinth. The project was scrapped in 1966 when it became apparent that to have any effect on water hyacinth, there would need to be a herd of two thousand manatees. The animals already in the wild have bred, with a population of between 25-37 animals by the 1980s. This resulted, in September 2020, in the first ever sighting of a manatee in the Pacific Ocean.

Also quite interesting to note that although eight of the manatees (five males and three females, one of them pregnant on arrival) were Antillean manatees, the species native to Panama, the very first individual to arrive was a male Amazonian manatee imported from Peru. The researchers are currently studying tissue samples from the manatees in the Canal to determine if there are any hybrids between the two species.

The paper about this introduction can be seen in the link below:
https://onlinelibrary.wiley.com/doi...QVsOqc5EII8rdsxb4-LexBHzbQH5W8jdYER6AEDqSMXD4
 
DesertRhino150 said:
Here's an interesting one - in 1964 a group of nine manatees were introduced to the Panama Canal in order to try and control invasive water hyacinth. The project was scrapped in 1966 when it became apparent that to have any effect on water hyacinth, there would need to be a herd of two thousand manatees. The animals already in the wild have bred, with a population of between 25-37 animals by the 1980s. This resulted, in September 2020, in the first ever sighting of a manatee in the Pacific Ocean.

Also quite interesting to note that although eight of the manatees (five males and three females, one of them pregnant on arrival) were Antillean manatees, the species native to Panama, the very first individual to arrive was a male Amazonian manatee imported from Peru. The researchers are currently studying tissue samples from the manatees in the Canal to determine if there are any hybrids between the two species.

The paper about this introduction can be seen in the link below:
https://onlinelibrary.wiley.com/doi...QVsOqc5EII8rdsxb4-LexBHzbQH5W8jdYER6AEDqSMXD4
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This is perhaps the most interesting population mentioned on the thread so far. An introduced marine mammal! :eek:
 
Here's an interesting one which I don't think has been mentioned before. In a recent study of Bennett's Wallabies on the Isle of Man, a few individuals of Parma Wallabies were also detected by camera traps.

If this link doesn't work (to a draft copy of the paper), then it can be found via Google with the title "The distribution and trophic ecology of an introduced insular population of red-necked wallabies (Notamacropus rufogriseus)"
https://tspace.library.utoronto.ca/bitstream/1807/87270/1/cjz-2017-0090.pdf

The Parma Wallabies are only mentioned in passing on page 9, where it says that from camera traps they recorded 737 photos of Bennett's Wallabies and four of Parma Wallabies.

At the Curraghs Wildlife Park, from which the wallaby population originated via escapes, both species had been kept in the same enclosure.
 
birdsandbats said:
Pied Imperial-Pigeon is introduced on the island of New Providence in The Bahamas.
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Have you noticed how most people on the thread put a blue line of text in their post after saying that X species is introduced to X place? That's a link to a paper or article giving details on that introduction, which is really helpful so that other people don't need to trawl through Google to find information.

Here's an article about the Pied Imperial Pigeons in the Bahamas: Pied Imperial Pigeon in the Bahamas – 10,000 Birds
 
vogelcommando said:
Amethystine python seems to be an invasive species in South Africa :

https://invasives.org.za/fact-sheet-animals/amethystine-python/
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"Invasive species" is just a legislative term under NEMBA regulations, for reasons to do with import / export / permits, etc. It basically covers exotic species present in South Africa (in the wild or in captivity / agriculture / horticulture, etc) which have "demonstrable potential" for becoming established and causing ecological harm or harm to human interests. It also covers species native to South Africa but which have been transported to other non-native parts of the country (e.g. garden plants).

Some "invasive species" are entirely prohibited, while others (like Amethystine Python) are listed only for specific locations in the country, presumably due to environmental restrictions and usually not because that is where the species has actually become established.

So "invasive species" in South Africa covers species which are legitimately established in the country, and also species which have never been established in the wild there.
 
Chlidonias said:
"Invasive species" is just a legislative term under NEMBA regulations, for reasons to do with import / export / permits, etc. It basically covers exotic species present in South Africa (in the wild or in captivity / agriculture / horticulture, etc) which have "demonstrable potential" for becoming established and causing ecological harm or harm to human interests. It also covers species native to South Africa but which have been transported to other non-native parts of the country (e.g. garden plants).

Some "invasive species" are entirely prohibited, while others (like Amethystine Python) are listed only for specific locations in the country, presumably due to environmental restrictions and usually not because that is where the species has actually become established.

So "invasive species" in South Africa covers species which are legitimately established in the country, and also species which have never been established in the wild there.
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Thanks for this explination, didn't know that !
 
Chlidonias said:
Here's an interesting one which I don't think has been mentioned before. In a recent study of Bennett's Wallabies on the Isle of Man, a few individuals of Parma Wallabies were also detected by camera traps.

If this link doesn't work (to a draft copy of the paper), then it can be found via Google with the title "The distribution and trophic ecology of an introduced insular population of red-necked wallabies (Notamacropus rufogriseus)"
https://tspace.library.utoronto.ca/bitstream/1807/87270/1/cjz-2017-0090.pdf

The Parma Wallabies are only mentioned in passing on page 9, where it says that from camera traps they recorded 737 photos of Bennett's Wallabies and four of Parma Wallabies.

At the Curraghs Wildlife Park, from which the wallaby population originated via escapes, both species had been kept in the same enclosure.
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I wonder if there are any hybrids in this population? They have been known to cross on occasion
 
FBBird said:
I wonder if there are any hybrids in this population? They have been known to cross on occasion
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Quite unlikely. The reason these populations were suspicious in the first place is because they were recently discovered far from natural(-ish) populations of tree frogs in the Netherlands. The group also found other amphibians that were suspicious: the dune population of common spadefoot toad originates from eastern Europe and the common midwife toad is almost certainly introduced as well, given that the species only naturally occurs in the far south-east of the country. A population of great crested newt is also likely introduced, but it could also be a relict population from a time when the species was more widespread.
 
Mr. Zootycoon said:
Quite unlikely. The reason these populations were suspicious in the first place is because they were recently discovered far from natural(-ish) populations of tree frogs in the Netherlands. The group also found other amphibians that were suspicious: the dune population of common spadefoot toad originates from eastern Europe and the common midwife toad is almost certainly introduced as well, given that the species only naturally occurs in the far south-east of the country. A population of great crested newt is also likely introduced, but it could also be a relict population from a time when the species was more widespread.
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Sorry, I meant the wallabies:)
 
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