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Question 10.
In general, can you think of any other criteria or sub-criteria that would be helpful for assessing extinctions in your group?
Amphibians Advisory Panel
Birds Advisory Panel
Comment 1: separate out extinctions possibly pre-dating 1500; extinctions in the last 50 years; 'true' resolved extinctions between 1500 and 50 years ago. Then modify these categories according to taxonomic problems, undescribed status, or the possibility of survival; ie., apply modifiers rather than a dichotomous key. See the first comment under Question 11 for further details on this protocol. Coleoptera Advisory Panel
Comment 1: for insects we must apply a rarity rule; i.e. it is far easier to document loss of a dominant species than a rare one. Lepidoptera Advisory Panel
Comment 1: Where such information is available, loss/rate of loss of key habitat and resources is the main factor in decline and loss and could be used as a more effective surrogate index of urgency. Mammals Advisory Panel
Comment 1: we need to discuss cases with domesticated mammals. An example we have now some extinct species in the wild but numerous recent domesticated descendants, which are now referred to another species: for example, Bos primigenius - Bos taurus; Equus gmelini - Equus caballus. Some systematists united extinct ancestors and domesticated recent animals in one species. Maybe new subcriteria can be used for such cases. (This seems to be in part a species concept issue; if the domesticated forms are viewed as different species then there is an extinction; if not there is no extinction. However, domestication might be viewed as driving evolution so that, although the species still exists (as a domesticated version) the original form has disappeared. Maybe there is a way of recognizing this by recommending that, if the domesticated form is conspecific with the original wild form, it is recognized as such and classified as "domestic extant" or something similar, but it is not covered any further than that by CREO?). Reptiles Advisory Panel
Comment 1: size (eg. area) of known intact habitat type remaining within the range of the species (and therefore the possibility of the persistence of the particular species.) |
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