Tag Archives: Mahe

Nesoenas picturata ssp. rostrata (Bonaparte)

Seychelles Turtle Dove (Nesoenas picturata ssp. rostrata)

The Seychelles Turtle Dove is a subspecies of the Madagascar Turtle Dove (Nesoenas picturata (Temminck)); as its name implies, it inhabited to Seychelles Islands in the Indian Ocean. It is known to have inhabited at least the islands of Cousin and Cousine, Mahé and Praslin, as well as Aride- and Bird Island, where the last pure-bred birds were found.

The form is sometimes considered a full species; it disappeared du to hybridization with (nominate) Madagascar Turtle Doves, that somehow reached the Seychelles, either by themselves or with human aid. No pure-bred birds are known to exist now; however, their genes live on in the turtle dove population that now inhabits the Seychelles.
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syn. Streptopelia picturata ssp. rostrata (Bonaparte)

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References:

[1] Julian P. Hume: Extinct Birds. 2. Edition. Bloomsbury Natural History 2017

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edited: 07.05.2022

Pachnodus velutinus (Pfeiffer)

Fleece Landsnail (Pachnodus velutinus)

The Fleece Landsnail was endemic to the island of Mahé in the Seychelles; it was specialized to the moist forests on the summits of the north-western part of the island.

The species disappeared sometimes around 1994 after invasive plants began altering its habitat, especially Cinnamon Trees (Cinnamomum verum J. Presl) and Vanilla Orchids (Vanilla planifolia Andrews) which now cover large areas of former native forest.

Predation by the introduced and invasive Tailless Tenrec (Tenrec ecaudatus (Schreber)) very likely also plays a role – many snail shells are found with conspicuous bite marks caused by this small mammal. 

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The reason for this species’ extinction is often said to be due to hybridization with a congeneric species from lower elevations, the Black Landsnail (Pachnodus niger (Dufo)); however, this assumption turned out to be wrong and the putative hybrids were found to be a completely distinct species.

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Depiction from: ‘Christian R. Altaba: Extinction through Climate Change: Review of Evidence and Analysis of Two Land Snails from the Seychelles Islands. Preprints 2022, 2022100315. https://doi.org/10.20944/preprints202210.0315.v1’

https://creativecommons.org/licenses/by/4.0/

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References:

[1] Justin Gerlach: Red Listing reveals the true state of biodiversity: a comprehensive assessment of Seychelles biodiversity. Phesluma 20: 9-22. 2012
[2] Christian R. Altaba: Extinction through Climate Change: Review of Evidence and Analysis of Two Land Snails from the Seychelles Islands. Preprints 2022, 2022100315. https://doi.org/10.20944/preprints202210.0315.v1

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edited: 29.01.2024