Talk:Christmas Island shrew

Latest comment: 2 years ago by Tzali in topic Christmas Island shrew range map

Suggested change to text regarding its distinction as a species

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I would suggest changing the wording "but morphological differences and the large distance between the species indicate that it is an entirely distinct species" to more clearly denote it as a distinct species due to DNA analysis, rather than just because of "morphological differences and the large distance between the species." As noted on the linked website (4):

"DNA analysis of museum specimens indicate that all collections are from the same taxon and that the Christmas Island Shrew cytb is divergent at the species level." (webpage: http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=86568)

I would suggest changing the text to:

"It was placed as subspecies of the Asian gray shrew (Crocidura attenuata) or the Southeast Asian shrew (Crocidura fuliginosa), but DNA analysis indicate that it is an entirely distinct species."

- and changing the link to the Australian government webpage: http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=86568.

My apologies, but I don't know how to do that so shall leave it to those who are more experienced in this regard. Tzali (talk) 17:39, 13 October 2022 (UTC)Reply

Clarification needed: Trypanosoma disease and Gecarcoidea natali

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TRYPANOSOMA DISEASE

The paragraph is unclear and needs to be clarified.

In the first sentence is the author trying to say:

"Both Durham (1908) and Pickering and Norris (1996) theorized that the Christmas Island shrew population may have been impacted by the same infection that caused the decline of two endemic rat species, as they occurred around the same time."

- add references/links to those documents/papers.

What is the comment about the "local researchers?" If the researchers were not Durham, and Pickering and Norris, should the text be clarified or removed?

In the second sentence, the text reads: "first thought to have vanished by 1908"

Who first thought that? Is that Durham, or Durham, Pickering and Norris, or someone else? Some clarification here perhaps.

The continuing text could also be clarified: "probably due to a trypanosoma disease carried by introduced black rats, which is also considered a likely cause of the extinctions of Maclear's rat and the bulldog rat."

- use "possibly" instead of "probably?" Update text to:

"...possibly as a result of a trypanosoma disease carried by introduced black rats, which likely caused the extinction of Maclear's rat and the bulldog rat. There is no conclusive evidence that either the black rat and/or the parasite caused the Christmas Island shrew's decline."

GECARCOIDEA NATALIS

I found this paragraph confusing and had to reread it to understand it more clearly, e.g.:

"Another theory on the decline of Crocidura trichura is linked to the demise of the two endemic rats, and the competition left amongst the Christmas Island shrew and the Christmas Island red crab (Gecarcoidea natalis) for leaf litter resources."

How is the demise of the two endemic rats linked to the leaf litter resources? This should be referred to later, after explaining that there'd been a rise in the population of the crabs.

Instead may I suggest updating the paragraph to read:

"An increase in the population of the Christmas Island red crab (Gecarcoidea natalis) may have impacted the Christmas Island Shrew as the two different species competed for leaf litter. While the number of Christmas Island red crabs had been controlled by the island's two predatory rat species, Maclear's rat and the bulldog rat, their extinction resulted in a rise in the crab population. This may have forced the shrew into new habitats such as tree canopies, or sites with low crab abundances and ultimately impacted on their numbers. Alternately, greater numbers of crabs may have resulted in their consumption of larger numbers of the shrew's vulnerable young, eventually leading to the shrew's extinction."

ALL THEORIES

I note there are several theories about reason for the shrew's demise in the paragraph prior to these two. Should the remaining theories have their own paragraph, under "Other Theories?" Tzali (talk) 19:07, 13 October 2022 (UTC)Reply

References

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I note some of the reference links appear to be problematic, specifically:

3. This links to the Wikipedia page rather than any document/book/webpage outside of Wikipedia

6. This simply jumps back to the earlier reference on this page but has no link that I could find to any document/book/webpage outside of Wikipedia

7. This link goes to the site where the "Page cannot be found"

10. Should this be the link at 6?

12. This appears to be linked to an unrelated page on the NSW Department of Planning and Environment website. Tzali (talk) 19:23, 13 October 2022 (UTC)Reply

Christmas Island shrew range map

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The map showing the Christmas Island shrew range would suggest that it can be found on a large number of islands including Indonesia and Malaysia! The tiny Christmas Island is lost in the image. While I understand that the other islands are likely included to clarify the island's location, it also suggests that the shrew has a huge range when it's confined to just that one island. Tzali (talk) 19:51, 13 October 2022 (UTC)Reply