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Question 2.

Our second criterion is that the effective extinction date (EED) must be confirmed as falling within recent times. The studies on recently extinct fish and mammals defined this time as covering from AD 1500 to the present. We felt that AD 1500 represented a justifiable start date for surveying recent extinctions for two reasons: following this date, human exploration of the globe became more prevalent, and reliable evidence for the loss of other species in association with human movement and activities began to be recorded widely. Do you agree that this is a sensible date from which to start a survey such as this? If not, how much further back in time do you think the survey should go?

  • Comments by CREO Chairman, Ian Harrison, have been added to some of the responses below -- in underlined text.

    Amphibians Advisory Panel

    Comment 1: agrees with AD 1500.

    Comment 2: agrees with AD 1500.

    Comment 3: AD 1500 is far too early for reliable data for frogs. The date must be that for which there is adequate extinction data for any group. Data for amphibians are too thin to be of any use prior to about AD 1800 in Europe and North America.

    Comment 4: AD 1500 seems about the best along a continuum; some might argue for earlier in the Mediterranean Basin.

    Birds Advisory Panel

    Comment 1: suggested starting at AD 1600 to conform with the most widely used lists for birds; certainly no later than AD 1500.

    Comment 2: would accept AD 1500 but suggests it should be about 1000 years earlier to catch some of the more devastating effects in Madagascar and the Pacific islands. Notes that an earlier date would probably also be good for mammals, to account for pygmy hippos and giant sloth-like lemurs from Madagascar. Suggests AD 1 as a starting date.

    Comment 3: suggests that an earlier date, to account for Pacific extinctions, would be wise.

    Comment 4: AD 1500 is artificial for places like New Zealand and the Pacific, as there is equal knowledge for taxa that went extinct before and after 1500. AD 1000 might be more appropriate by being more inclusive of extinctions and so reducing the number of extinctions that are excluded from the survey on the basis of an arbitrary date. The 14C record is too coarse to make decisions on much of the extinct fauna, most of which survived past AD 1000.

    Comment 5: accepts AD 1500.

    Coleoptera Advisory Panel

    Comment 1: no reason to go beyond AD 1500. For invertebrates, one would be lucky to get historical information much earlier than the 19th century, and most if not all documented insect extinctions have occurred since 1900. One of the primary advantages to using insects to such ends is their acute sensitivity to environmental change, acting as fine mesh filter for identifying vulnerable groups and areas.

    Comment 2: for insects, much later than AD 1500 is appropriate. As the major insect surveys were first run in the late 19th century, EEDs of 50 and 100 years work very well.

    Comment 3: while the rationale is clear, the data on most invertebrates is too recent to matter even on this scale.

    Fishes Advisory Panel

    Comment 1: agrees with AD 1500.

    Comment 2: agrees with the suggested EED, although doubts that for freshwater fish we have reliable data before c. 1800 for Europe and probably c. 1920 for Asian fish. (Data started becoming thin through the 1800s when Stiassny and I made the preliminary survey for fishes - although for other groups this is less of a problem. People on other panels have commented that accurate data does not extend back to AD 1500 for their taxa) If we go back to AD 1500 and are comprehensive about documenting missing species, what should we do with all the mermaids, gorgons etc. described by Gessner 1535?.

    Comment 3: agrees with AD 1500; no reason to go earlier.

    Lepidoptera Advisory Panel

    Comment 1: data from c. 1500 would be very difficult to find.

    Comment 2: AD 1500 could be retained as a starting date - but there will be no sound biological information on Lepidoptera until at least the middle of the 19th century, with most concerns arising only in last few decades.

    Mammals Advisory Panel

    Comment 1: extinctions should be surveyed over a longer time than since AD 1500, otherwise one loses too much information on the last episode of extinction processes. Surveys starting from an earlier date permit a better (more complete) description of the patterns and effects of extinctions on the Earth's biodiversity of the Earth. A uniform date for all extinctions will not work: for islands and later colonized continents, the time of arrival of first settlers could be used (but avoid being Eurocentrically biased.); for Africa and Eurasia it is more difficult, and some other artificial consensus date should be used, such as (a) birth of agriculture and civilization, 10,000 YBP; (b) extinction of Homo neanderthalensis associated with spread of H. sapiens as unique human species living on Earth, 30,000 YBP; or (c) birth of writing, c. 6000 YBP. Then, define "recent" as within the total period, eg. 30,000 YBP-present day, and "very recent" or "last phase of recent extinction" for post AD 1500. Any survey starting before AD 1500 requires wider criteria and must account for upper Pleistocene faunas.

    Comment 2: AD 1500 is acceptable.

    Comment 3: agrees with AD 1500 - no criteria to support evidence of extinctions caused by native American and Caribbean peoples on fauna.

    (Comments 2 and 3 also added that, in some cases, regional fauna are either not sufficiently known, scientifically, earlier than European settlement, or there is no evidence of extinctions caused by native human populations earlier than AD 1500. (However, this is not the case for all faunas)).

    Comment 4: AD 1500 seems sensible, otherwise the surveys must include dozens of species that became extinct during the mid-Holocene (6000-5000 YBP).

    Molluscs Advisory Panel

    Comment 1: generally OK although in N. America, Australia, and many other parts of the world, the advent of "modern colonizers" a few hundred years ago created a separate wave of extinction from that of the earlier human inhabitants. It seems that, in most areas of the world, there are two separate major effects that would be worth recording and they will be location dependent, and the first of these human impacts were much earlier than AD 1500. In Australia, for example, one would not look at anything older than about 250 years ago to see the impacts of European colonization whereas the impact of aboriginal colonization started 30-40000 years ago. We should not suggest that pre-European human populations did not cause modification of the environment and extinctions.

    Reptiles Advisory Panel

    Comment 1: generally agrees but notes that older Melanesian and Polynesian extinctions, and perhaps some others, should also be included. (Several people have commented on the importance of including these older, Pacific extinctions).

    Comment 2: agrees with AD 1500 start date.

    Comment 3: agrees with AD 1500 start date.

    Comment 4: agrees with AD 1500.

    Comment 5: AD 1500 seems like a sensible start date. It will however eliminate some very clear cases of human mediated extinctions that took place in the Pacific over the last 3,000 years. Because of the relative 'simplicity' of these Pacific island systems (and oceanic island systems in general) these faunal extinctions have been very useful for understanding the role humans in mediating extinctions.