New paper from Loehle & Eschenbach shows extinction data has been wrongly blamed on climate change due to island species sensitivity

Dodo, based on Roelant Savery's 1626 painting ...

One of the most famous extinctions -The Dodo, a flightless bird endemic to the Indian Ocean island of Mauritius – Image via Wikipedia

Guest post by Dr. Craig Loehle

Last year, Willis Eschenbach had a WUWT post about extinction rates being exaggerated in the literature. I offered to help him get this published, and it is now out. We conclude that the extinction crisis for birds and mammals is very specific to island fauna which are uniquely sensitive to human impacts, including our pets and commensals like rats. It is not valid to extrapolate these extinctions to either the problem of deforestation on continents or to future impacts of climate change.

The process of getting this published was relatively painless which is surprising given how much we counter conventional wisdom in it. The paper is available free at NCASI.

I would argue that blogs CAN be a real part of the scientific process. I would recommend that people follow up on good ideas they see and get them into print as this example illustrates.

Loehle, C. and W. Eschenbach. 2011. Historical Continental Bird and Mammal Extinction Rates. Diversity & Distributions DOI: 10.1111/j.1472-4642.2011.00856.x

Methods: We examined historical extinction rates for birds and mammals and contrasted island and continental extinctions. Australia was included as an island due to its isolation.

Results: Only six continental birds and three continental mammals were recorded in standard databases as going extinct since 1500 compared to 123 bird species and 58 mammal species on islands. Of the extinctions, 95% were on islands. On a per unit area basis, the extinction rate on islands was 177 times higher for mammals and 187 times higher for birds than on continents. The continental mammal extinction rate was between 0.89 and 7.4 times the background rate, whereas the island mammal extinction rate was between 82 and 702 times background. The continental bird extinction rate was between 0.69 and 5.9 times the background rate, whereas for islands it was between 98 and 844 times the background rate. Undocumented prehistoric extinctions, particularly on islands, amplify these trends. Island extinction rates are much higher than continental rates largely due to introductions of alien predators (including man) and diseases.

Main Conclusions: Our analysis suggests that conservation strategies for birds and mammals on continents should not be based on island extinction rates, and that on islands the key factor to enhance conservation is to alleviate pressures from uncontrolled hunting and predation.

Loehle_Eschenbach_table1

Table 1: Extinctions since 1500 according to IUCN and CREO, with per species and per unit area rates.

Abstract:

Loehle, Craig, and Willis Eschenbach. 2011. Historical bird and terrestrial mammal extinction rates and causes.
Diversity and Distributions. doi: 10.1111/j.1472-4642.2011.00856.x

We examined historical extinction rates for birds and mammals and contrasted island and continental extinctions. Australia was included as an island because of its isolation. Only six continental birds and three continental mammals were recorded in standard databases as going extinct since 1500 compared to 123 bird species and 58 mammal species on islands. Of the extinctions, 95% were on islands. On a per unit area basis, the extinction rate on islands was 177 times higher for mammals and 187 times higher for birds than on continents. The continental mammal extinction rate was between 0.89 and 7.4 times the background rate, whereas the island mammal extinction rate was between 82 and 702 times background. The continental bird extinction rate was between 0.69 and 5.9 times the background rate, whereas for islands it was between 98 and 844 times the background rate. Undocumented prehistoric extinctions, particularly on islands, amplify these trends. Island extinction rates are much higher than continental rates largely because of introductions of alien predators (including man) and diseases. Our analysis suggests that conservation strategies for birds and mammals on continents should not be based on island extinction rates and that on islands the key factor to enhance conservation is to alleviate pressures from uncontrolled hunting and predation.

Copyright © 2011 by Blackwell Publishing Ltd. All rights reserved. Article posted on this website with permission.

Download the paper (Adobe PDF) Loehle & Eschenbach2011

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102 thoughts on “New paper from Loehle & Eschenbach shows extinction data has been wrongly blamed on climate change due to island species sensitivity

  1. The continual drip drip of calm corrections of wild alarmist claims is starting to have an impact. More of these extended well argued posts on this and other sites should be peer reviewed and published.

  2. Congratulations Craig and Willis!
    Since you are incomparably more competent than the “delinquent teenagers” to prepare the IPCC-AR, they’ll recruit you for AR6??

  3. Congratulations!

    Will we next be seeing a paper on the economic benefits of CO2 and increased crop yields. Surely there is a relationship between food production, population and economic output.

  4. The Great Auk, or gairfowl (Pinguinus impennis) became extinct in the mid-19th century.
    The Passenger Pigeon or Wild Pigeon (Ectopistes migratorius) became extinct at the end of the 19th century.
    The Arabian gazelle (Gazella arabica) was hunted to extinction in about 1830.
    Hensel’s field mouse (Rhagamys orthodon) disappeared from Britain and Ireland in the last 50 years.
    This week the last Vietnamese rhinoceros was killed by poachers, shot through the legs and horn sawed off.

  5. I hope that we will be able to bring back some of these extinct creatures someday, such as the dodo and passenger pigeon. I’m sure we have DNA of each.

  6. Minor grammatical note. In the first paragraph is the line

    “We conclude that the extinction crisis for birds and mammals is very specific to island fauna which are uniquely sensitive to human impacts, including out pets and commensals like rats.”

    I have many gay and lesbian friends, but I’ve yet to see any of our pets come out. Or did you mean “our pets”? ;)

    Congratulations too on being published by the way.

    JE [Fixed ... and very funny too.]

  7. I remember the original “Where are the corpses?” article. Good to see it’s in the literature now. Congratulations.

  8. “Island extinction rates are much higher than continental rates largely due to introductions of alien predators (including man) and diseases.”

    One idea could be to show negative Anthropogenic influences weighed against positive Anthropogenic influences on extinction rates. Modern Humans for the first time as far as we know in earths entire history are the only species ever to be actively involved in the prevention of other species from extinction, and contribute to the introduction of species to new environments, that in-turn insure the increase of survival rates and growth of their populations. I believe this to be a fact, and therefore I don’t think humans should be just lumped together along with diseases and other predators. I despise the idea, but if you feel that humans [are] or [not] similar to a disease, It would be fair to add some further elaboration on this either way.

  9. The great shame of the AGW who-ha is that it detracts attention from the real causes of what is happening.

    There are some changes in the environment that are adverse, from a human perspective.
    Some of those adverse changes can be reduced or even eliminated.

    Spending huge amounts of money, attention and effort of fairy tale solutions on problems that are just stormy night nightmares of no real substance, just detract from the effort that should be made to created real improvement to our position.

  10. Sparks.

    We are predators pure & simple.

    Unfortunately, we are cursed with what passes for intellect and a conscience.

    We see things we perceive as being wrong, (eg extinction of species,) then have the hubris to think we can fix it.

    Take for instance kites & magpies. They’re now protected & everyone’s wondering what’s happening to all the songbirds. No-one seems to have figured out they’re the prey of kites & magpies!

    Animal Liberation Front released loads of mink & then wonder what happened to the otters, similar thing.

    If we’re a disease, so are kites, magpies, polar bears, wolves, foxes and any number of other predators, it’s just that they don’t think about it because they’re to busy trying to survive, same as many primitive humans.

    DaveE.

  11. Haha, oh wow

    Including Australia as an “island” sure is convenient when it also happens to have one of the highest extinction rates, don’t you think?

  12. David A. Evans says:
    October 25, 2011 at 8:42 pm

    Take for instance kites & magpies. They’re now protected & everyone’s wondering what’s happening to all the songbirds. No-one seems to have figured out they’re the prey of kites & magpies!

    Animal Liberation Front released loads of mink & then wonder what happened to the otters, similar thing.

    The obvious solution is to “protect” songbirds and otters, too. Then restraining orders can be issued, and all will be returned to natural …

    Oh, wait.

  13. Not only is this a great analysis of the data, it’s also a very interesting read. Thank you.

  14. Based on fossil extinction records, 99.99% of extant species are DOOMED anyhow, so what’s the big deal?
    ;p

  15. Willis now has instant come-back for any warmtwits who sneer that he’s “unpublished” in the field.

  16. My great thanks to Dr. Craig Loehle for taking on this project and pushing it to completion. Although I contributed much of the basic ideas and text, he was the driving force behind expanding, editing, adding new ideas, re-writing and getting it into the journal. In addition to his writing abilities and knowledge, he has the PhD and the credentials, which shouldn’t make a difference but always does. However, the PhD and the credentials didn’t get it published. The good ideas, plus lots of writing, re-writing, improvements, revisions, and hard work on his part are what got it into print.

    Best to all, and particularly to my friend and co-author, Craig.

    w.

  17. DocMartyn, would you please remove your hat so we might see yer point?

    How do these five extinctions over the past 150 years support/confirm/call into question/disprove Loehle & Eschenbach’s paper?

  18. The original article was an eye-opener.
    Great to hear that your new article was published so easily. Because you do indeed counter ‘conventional wisdom’. That is hopeful.

  19. RayG

    A friend of mine got to walk in the All Blacks’ victory parade in Wellington. She is quite proud. She said she had a chance to chat with Richie McCaw, and that Brad Thorn let her touch the Webb Ellis Cup. She’s seems to be walking on air today.

  20. Will S says:
    October 25, 2011 at 9:01 pm\

    Haha, oh wow

    Including Australia as an “island” sure is convenient when it also happens to have one of the highest extinction rates, don’t you think?

    Australia was included with the islands because the Australian extinctions were from the same cause as the island extinctions—introduced species.

    w.

  21. Brian H says:
    October 25, 2011 at 9:16 pm

    Willis now has instant come-back for any warmtwits who sneer that he’s “unpublished” in the field.

    Actually, this is my fourth peer-reviewed publication in the field … including a “Communications Arising” in Nature.

    w.

  22. Robert Clemenzi says: October 25, 2011 at 9:47 pm

    Uhhh, and just how do these examples refute the paper? I don’t believe that Craig and Willis wrote that no continental species became extinct, rather they showed that island species tended to have a higher rate of extinction and that it had little to do with climate change and much more to do with human encroachment on habitat, hunting, and the introduction (inadvertant or otherwise) of invasive species. So just what is your point?

    I didn’t think so.

  23. DocMartyn says:
    October 25, 2011 at 6:47 pm

    The Great Auk, or gairfowl (Pinguinus impennis) became extinct in the mid-19th century.
    The Passenger Pigeon or Wild Pigeon (Ectopistes migratorius) became extinct at the end of the 19th century.
    The Arabian gazelle (Gazella arabica) was hunted to extinction in about 1830.
    Hensel’s field mouse (Rhagamys orthodon) disappeared from Britain and Ireland in the last 50 years.
    This week the last Vietnamese rhinoceros was killed by poachers, shot through the legs and horn sawed off.

    Anna Lemma says:
    October 25, 2011 at 9:26 pm

    DocMartyn, would you please remove your hat so we might see yer point?

    How do these five extinctions over the past 150 years support/confirm/call into question/disprove Loehle & Eschenbach’s paper?

    Robert Clemenzi says:
    October 25, 2011 at 9:47 pm

    Alagoas Curassow – Brazil
    Barbary Lion
    Atlas Bear
    Bachman’s Warbler
    Several more extinct in the wild
    This list could go on. You have a good start.

    Please read the paper, and consider the criteria we used. The paper was about extinct species, not locally extinct species or extinct sub-species or “extinct in the wild”. Then take a look at the official lists of extinctions that we used (CREO for the mammals and the Red List for birds). The article was extensively researched and peer reviewed. We may have made mistakes, but not heaps of stupid mistakes as you assume. For example, the Barbary Lion and the Atlas Bear are both sub-species, not species. This doesn’t mean that their extinction is unimportant. It wasn’t what we were measuring, which was the extinction of species. In the same way, the Arabian gazelle is listed by CREO as “Currently extant under valid species name”. If you dispute that categorization, you’ll have to take it up with the boffins at the American Museum of Natural History, they did the CREO classification.

    You may not like our criteria, of CREO’s criteria, and that’s fine. Make up your own criteria and do your own analysis, there’s always more to learn. Claiming we should have included the Barbary Lion, however, misunderstands the situation. That wasn’t the analysis we were doing.

    w.

  24. Thanks to Craig and Willis for this thoughtful paper. Here in the NW of Western Australia, we are about to go through major species reduction due to the advancing cane toad, foxes have just reached the Kimberley, camels and donkeys are now widespread, and introduced weeds are spreading rapidly, it just seems like a never-ending invasion…

  25. Despite the threatened species in Australia, new species are still being discovered which includes insects, reptiles and amphibians, as well as a number of plant species…

  26. DocMartyn says:
    October 25, 2011 at 6:47 pm

    You’ve pointed out five extinct Animals, I’ll see your five and raise you 106 Animals Assumed Extinct That Were Rediscovered “Lazarus species”.

    Animal Extinctions maybe over exaggerated.

    1. The Pygmy Tarsier
    2. The Okapi
    3. Dwarf Cloud Rats
    4. The Nelson’s small-eared shrew
    5. Laotian Rock Rats
    6. The Cuban Solenodon
    7. Worcester’s Buttonquail
    8. The Arakan Forest Turtle
    9. The Mountain Pygmy Possum
    10. The Terror Skink
    11. The Coelacanth (Once thought to have gone extinct 65 million years ago)
    12. The Woolly Flying Squirel
    13. The La Palma Giant Lizard
    14. Javan Elephants
    15. The lagoon spire snail
    16. Yellow-spotted Bell frogs
    17. Chacoan peccary
    18. Lord Howe Island stick insect (land lobsters)
    19. Takahe
    20. Giant Palouse earthworm
    21. Large-billed reed-warbler
    22. New Caledonian crested gecko
    23. New Holland Mouse
    24. Gracilidris
    25. Bermuda Petrel
    26. the Guadalupe fur seal
    27. The Bahian tree rat
    28. The nailtail wallaby
    29. Gilbert’s potoroo (small marsupial)
    30. Leadbeater’s possum
    31. Harpy eagle
    32. Caspian Horse
    33. La Gomera Giant Lizard
    34. Madagascar Serpent Eagle
    35. The White-plumed Antbird
    36. short-tailed albatross
    37. The Vegas Valley leopard frog
    38. kunimasu salmon
    39. capricorn beetle
    40. Rhodacmea filosa (Limpet)
    41. Cave Splayfoot Salamander (Chiropterotriton mosaueri)
    42. Mount Nimba Reed Frog (Hyperolius nimbae)
    43. Omaniundu Reed Frog (Hyperolius sankuruensis)
    44. Horton Plains slender loris
    45. The solitary bee Halictus eurygnathus
    46. nodulose Coosa (River snail)
    47. cobble elimia (River snail)
    48. Cahaba pebblesnail
    49. The female turtle (a river terrapin turtle, Thailand)
    50. The baiji (white flag dolphin)
    51. Xylotoles costatus, New Zealand longhorn beetle
    52. Nothomyrmecia macrops (Australian ant)
    53. Canterbury knobbed weevil (Karocolens tuberculatus)

    More Amphibians —
    54. Armoured Frog (Litoria lorica) 55. Painted frog (Atelopus ebenoides marinkellei) 56. Atelopus laetissimus 57. Atelopus nahumae 58. Bufo cristatus 59. Bufo sumatranus 60. Isthmohyla rivularis 61. Ixalotriton niger 62. Philautus chalazodes 63. Taudactylus rheophilus 64. Thorius minutissimus 65. Telmatobufo venustus

    More Mammals —
    66. Fernandina rice rat (Nesoryzomys fernandinae) 67. Bavarian pine vole (Microtus bavaricus) 68. Woolly flying squirrel (Eupetaurus cinereus) 69. Yellow-tailed woolly monkey (Lagothrix flavicauda) 70. Gilbert’s Potoroo (Potorous gilbertii) 71. Central Rock Rat (Zyzomys pedunculatus) 72. New Holland Mouse (Pseudomys novaehollandiae) 73. Brazilian Arboreal Mouse (Rhagomys rufescens) 74. Philippine bare-backed fruit bat (Dobsonia chapmani) 75.Flat-Headed Myotis (Myotis planiceps) 76. Tammar Wallaby (Macropus eugenii eugenii) 77.Leadbeater’s Possum (Gymnobelideus leadbeateri).

    More Birds —
    78. Ivory-billed woodpecker (Campephilus principalis) 79. Jerdon’s Courser (Rhinoptilus bitorquatus) 80.Madagascar serpent-eagle (Eutriorchis astur) 81. Grand Comoro scops-owl 82.Forest Owlet (Heteroglaux blewitti) 83. Night Parrot (Pezoporus occidentalis) 84. Edwards’s Pheasant (Lophura edwardii) 85. Bruijn’s Brush-turkey (Aepypodius bruijnii) 86. Madagascar Pochard (Aythya innotata) 87. Kaempfer’s Woodpecker (Celeus obrieni) 88. Cone-billed Tanager (Conothraupis mesoleuca) 89. White-winged Guan (Penelope albipennis) 90. Large-billed Reed-warbler (Acrocephalus orinus) 91. Utila Chachalaca (Ortalis vetula deschauenseei) 92. São Tomé Fiscal (Lanius newtoni) 93. Tresemann’s Bristlefront (Merulaxis stresemanni) 94. Banggai Crow (Corvus unicolor) 95. White-collared Kite (Leptodon forbesi) 96. São Tomé Grosbeak (Neospiza concolor) 97. Long-legged Warbler (Trichocichla rufa) 98.Bahia Tapaculo (Eleoscytalopus psychopompus) 99.Cebu Flowerpecker (Dicaeum-quadricolor) 100. Berlepsch’s Parotia (Parotia berlepschi) 101. Golden-fronted Bowerbird (Amblyornis flavifrons) 102. Noisy Scrub-bird (Atrichornis clamosus) 103. Beck’s Petrel (Pseudobulweria beckii) 104. Fiji Petrel (Pseudobulweria macgillivrayi) 105. Silvery Pigeon (Columba argentina) 106. Cuban Kite (Chondrohierax wilsonii).

  27. Well done and congratulation to the authors.
    Don’t know much about extinctions, but I know that Dr. Loehle did great work with the two millennia temperature reconstruction

    http://www.ncasi.org/publications/Detail.aspx?id=3025

    giving one more confirmation to my hypothesis of a possible common cause for the global temperature changes and the changes in the geomagnetic field:

    http://www.vukcevic.talktalk.net/LL.htm

    two parallel and independent outputs of the same input. The coincidence isn’t perfect, but it gets better closer the data is to the present, the usual result of reconstructions, here of both temperature and geomagnetic.
    Short quote from one of the BEST papers:
    We find that the strongest cross-correlation of the decadal fluctuations in land surface temperature is not with ENSO but with the AMO
    if correct, and the authors need to demonstrate it clearly (perhaps another project for Dr.Loehle), is exactly what is needed to link two events firmly together.

  28. An important point, I think, is that many models of extinction rates are based on the work of Edwin Wilson who extrapolated island extinction mechanisms to the continents. This might be part of why why they overestimate the numbers. See Kellow, A.(2007) Science and public policy: the virtuous corruption of virtual environmental science. Edward Elgar, Northampton.

  29. Some time ago I started to watch one of the otherwise excellent programs about Darwin, made by Andrew Marr for the BBC. Right at the beginning, Marr said something like: “Today we’re in the midst of a great extinction”.
    Of course, this is a lie. To hear this outrageous lie linked to Darwin was too much, and I instantly switched off.
    As Willis said in his original piece, if so many animals are going extinct, where are the corpses?
    Quite so. That was an excellent article and I’m very happy to see it become a part of peer-reviewed science.
    Warmest congratulations to both Willis and Dr. Loehle.
    Chris

  30. The paper not surprisingly finds that extinction risk on islands is higher than on the mainland. And then correctly argues than the uncertainty about the number of extinct species is not high enough to materially affect the relative risk of extinction for continental and island species. So far so good. But the uncertainly in the number of extinct species is high enough to affect the comparison with the background rate.
    This makes the most important conclusion of the paper very susceptible to questions like “Is the ivory-billed woodpecker extinct?” If it is extinct, that bird alone would increase your continental extinction rates by 1/6.
    The paper argues that the long-history of deforestation should mean that extinction debt can be excluded as a possibility. Certainly Europe has a long-history of deforestation, but in many other regions, especially in the wet tropics, extensive deforestation is a late 20th century phenomenon. Far too recent to exclude extinction debt as a cause of low extinction rates.

  31. Willis, the semantics of what exactly a species is is complex. However, the The Great Auk (Pinguinus impennis) and Passenger Pigeon (Ectopistes migratorius) were definitely species which are extinct. Neither were localized in small niches.
    After the great Auk was made extinct attempts were made to reintroduce Penguins from the Southern hemisphere into the Northern range that the Auk had lived, these failed.
    The Passenger Pigeon ranges across the whole of North America.
    Both were Continental species and both are extinct.

  32. Craig & Willis:
    Well done. I have been saying that human influence >>> climate for a long time, in fact I always challenge people to name one species that has been wiped out because of climate change, and have never yet had a satisfactory example given me. Where attribution is known, it’s normally got our name on it somewhere.

    DocMartyn: you mention the Javan rhino. The thought occurs that maybe WWF could have spent a few tens of thou on full time armed guards and shaved a bit off climate advocacy spending.
    But one rhino is, in the end, the last of a locally extinct species. They should have tranq’d it and sent it to Java, where the last 50 may be *just* viable. It would be ironic indeed if we have room for 7,000,000,000 people but not 50 rhinos, eh?

    Sparks: Think about it. We accidentally introduced rats to a lot of islands where they were unknown. That alone was devastating for local fauna. Other introductions, planned or accidental, have been equally painful. Then there’s hunting. Including by idiots who think rhino horn is magic or somethin’. (See above.)
    Your list includes the lagoon spire snail. This was never thought to be *globally* extinct, only in the *UK*. Haven’t the time to check the other 105 – happened to know a little about the snail! But you do raise a philosophical point. When do we declare a species “deceased”? Easier to do with a rhino than a minute snail. For many species this will be “presumed” for a long time – hence the “Lazarus” list.

  33. Tom Harley says:
    October 25, 2011 at 11:48 pm
    Thanks to Craig and Willis for this thoughtful paper. Here in the NW of Western Australia, we are about to go through major species reduction due to the advancing cane toad, foxes have just reached the Kimberley, camels and donkeys are now widespread, and introduced weeds are spreading rapidly, it just seems like a never-ending invasion……………
    ————————————Tom, imagine how the Aborigine felt.

  34. For a creature to be known to have become extinct, first it must have been known to exist. Is it possible that an island’s fauna is more likely to be documented than that of the the interior of a continent and that this might affect the outcome of the research?

  35. Congratulations! I read the paper and it makes perfect sense to me. Once again, models have been proved to be lacking. Seems sad that the present era might be known in the future as “The Age of Modelling Hypochondriasis”.

    Well done!

    Best,

    J.

  36. “richardjamestelford says:
    October 26, 2011 at 3:22 am

    …….This makes the most important conclusion of the paper very susceptible to questions like “Is the ivory-billed woodpecker extinct?” If it is extinct, that bird alone would increase your continental extinction rates by 1/6………”

    That’s a “what if” not supported by the available data and therefore outside the scope of their paper. I am a photographer and one of my specialties is Avian photography. I’ve delved quite a bit into the Ivory-billed woodpecker situation and have been tempted to go on a search for it. It seems to be alive and well in Arkansas: http://www.birdinginarkansas.com/birding/ivory-billed-woodpecker.aspx

    And, it is almost impossible to mistake the Ivory-billed with the common Pileated by anyone with enough bird-watching and avian photography experience . Here is an image sequence of a Pileated made by yours truly: http://www.josesuroeditorial.com/Nature/Nonpasserines/Woodpeckers/2791726_kZdGMn#424297743_BqSUA-O-LB

    It looks nothing like an Ivory-billed…..

    Best,

    J.

  37. … and that on islands the key factor to enhance conservation is to alleviate pressures from uncontrolled hunting and predation.”

    AND the introduction of non-native species of animals and plants.

  38. Someone asked what about Australia: we did calculations both ways (shows they did not read the paper), but if you count australia as a continent you have to ask why most of the mammal extinctions are marsupials. Marsupials are the losers when they encounter modern mammals, as happened when North & South America joined up 2 million yrs ago and modern mammals moved south.

  39. People are listing various species extinct to make some sort of point. Many of those listed are subspecies, like a rhino, bear, lion that were mentioned. Some are not officially confirmed–we used a standard database to avoid subjectivity. Many species thought extinct are later found again.

  40. Jit, if you ever want an example of the complexity of existence and the inability of humans to forecast the future, think on this: The greatest factor in the survival of the rhinoceros over the last 20 years has been the development of a failed heart drug.
    Prior to the emergence of Viagra, powdered rhino horn was the de facto anti-impotence treatment throughout the Middle East and South East Asia. Viagra works much better than sympathetic magic and the price of rhino horn dropped through the floor.
    However, don’t think that anti-impotence sympathetic magic was restricted to the third world and we sophisticated Westerners didn’t fall for it. The introduction of Viagra also destroyed the market for many psychiatrists and psychotherapists who managed to convince middle aged men that all their troubles stemmed from childhood sexual conflicts.
    Amazingly, the same practitioners now focus their laser sharp minds, and peddle their sympathetic magic, on childhood behavioral problems.

  41. Congratulations Craig and Willis. After reading the (excellent) paper I agree with your conclusions. A well written piece and logically laid out.
    One quibble I have concerns the separation of island and continent. It is obvious (from your paper) that island extinctions are dramatically higher and those extinctions cannot be used to estimate continental ones. After all, on a continent there is the greater possibility of movement to a new (similar) habitat compared to islands.
    However, there are continental features (and oceanic ones) that for awhile may support the long term adaptation of a species but then suddenly can disappear. For example, within a valley blocked by mountains in which a catastrophe (volcano, land-slide from earth quakes, man-made lake for hydro power etc) occurs, species could be wiped out instantly. Another example would be marine life living along the continental shelf where over-fishing occurs, eventually wiping out the species because they can only survive on the shelf.
    I raise this issue (that continents can have island-like habitats) because as humans increase their influence over the earth’s surface, this will increase the likelihood of extinctions as certain species are pushed into a corner from which they cannot adapt. We (humans) are creating more continental island-habitats. It would make sense to quantify the adaptability of a species and protect the habitats of the ones that cannot adapt (if we even want to be in the species preservation game).

  42. Craig, I understand your point, but submit that your classification is too narrow.
    I agree that the actual definition of a species and an ‘island’ is problematic.
    However, one would suspect that any potential extinction stress would be better modeled using a power law whereby one estimates the actual size of the ecological niche and the species specialization.
    Extinction events occur much more frequently in specialist species than in generalist species.
    Extinction events occur much more frequently in geographically isolated species than in geographically dispersed species.
    I will point out that both the Great Auk and the Passenger Pigeon were generalist and geographically dispersed species. These two species are extinct due to the impact of humans and are not included in your list.
    You may not think that this is unimportant or an illegitimate criticism. I would however like to know why you think that to be the case.
    One of the major criticisms leveled at various papers issued by proponents of CAGW is the issue of ‘cherry-picking’. I believe that one can make the same criticism of your criteria for species selection.
    I think it reasonable they you address these criticisms, in my own case, why did you not include the Great Auk and the Passenger Pigeon?

  43. Craig Loehle says:
    October 26, 2011 at 6:40 am

    People are listing various species extinct to make some sort of point. Many of those listed are subspecies, like a rhino, bear, lion that were mentioned. Some are not officially confirmed–we used a standard database to avoid subjectivity. Many species thought extinct are later found again.

    It does not matter how good your methods are, if the raw data are inadequate, the results may be meaningless. Many mammal species are listed by the IUCN as data deficient. You have assumed that none of these are extinct. If this enormous assumption is seriously violated, your conclusion that species are robust to habitat loss will be unsupportable.

  44. As someone who has actually worked in the endangered species conservation field, I have to second other commenters here on the waste of attention and resources spent on climate change.
    The CO2 obsession has taken up a lot of money that could’ve been far more effectively spent, and I’ve been tearing my hair out over it for years. I’ve even talked to “environmentalists” who said they would knowingly advocate for wind turbines that kill endangered birds and bats because the problem of CO2, Satan’s molecule, is so much more urgent.

  45. Craig Loehle said in his lead-off post,

    ” [ . . . ] The continental mammal extinction rate was between 0.89 and 7.4 times the background rate, whereas the island mammal extinction rate was between 82 and 702 times background. The continental bird extinction rate was between 0.69 and 5.9 times the background rate, whereas for islands it was between 98 and 844 times the background rate. [ . . . ]”

    From the Loehle & Eschenbach 2011

    “These [mammal] numbers are subject to great uncertainty
    because of difficulty in estimating past extinction rates
    (Boyajian, 1986; Jablonski, 1994; Boucot, 2006).”

    “Comparison to background extinction rates is difficult for
    birds because so many of them are small, with bones that
    preserve poorly.”

    Craig,

    Have you tried to express quantitatively the uncertainties of the background rates of extinction?

    John

  46. The point of including Australia as an island is to identify the CAUSES of extinction. The primary cause of extinction is the introduction of foreign species that can take over the ecosystem with no competition. In the past 200 years, dogs, horses, cows, and camels have all been introduced to Australia. Rats killed the majority of Pacific Island flightless birds, and dogs have taken care of much of the rest. The point is that you cannot extrapolate these extinction rates to say X acres of forest loss means Y number of species go extinct.

    John, I think that the order of magnitude range in percentage of background rate is a good indication about just how well we know that rate.

  47. John Whitman: we could find no way to quantify the uncertainty of background rates of extinction. We listed all the estimates we could find. They are all very squishy.

  48. Craig Loehle says:

    October 26, 2011 at 8:45 am

    @John Whitman: we could find no way to quantify the uncertainty of background rates of extinction. We listed all the estimates we could find. They are all very squishy.

    Craig,

    Thank you for your quick reply. OK, squishy.

    Here is a little humorous personal anecdote wrt squishy.

    My father used to say, “You are born screaming. Then life is squishy. Then you die.” He would pause solemnly for a minute to let the somber thought sink in. Finally, he would smile and say, “But the squishy part is really, really nice.”

    John

  49. Craig, I do apologize, I need new glasses. I didn’t read Table 1 correctly.

    I was looking for E. migratorius

    In Table 1 you have

    Passenger pigeon (C. carolinensis)

    Conuropsis carolinensis is of course the extinct Carolina Parakeet (Conuropsis carolinensis) mentioned two places above.

    The extinct Passenger pigeon would be correctly labeled Ectopistes migratorius.

    The Great Auk ranged from Newfoundland, Greenland, Iceland, Ireland, Scotland, Norway and Finland.
    One could make the argument that all the nesting sites were coastal and they favored islands, but I do not think that they can be counted as an Island species.

  50. jamie says:
    October 26, 2011 at 1:58 am

    Congratulations WIllis

    Are there any plans to get your thermostat hypothesis into print?

    It was published last year, in Energy and Environment.

    w.

  51. @DocMartyn,

    Why don’t you take the data from the paper and reanalyze it the way you want and show if the results change significantly, or not.

    Also, definition of species is not difficult. Any two organisms that can interbreed and produce live offspring are a species. There are some caveats that have been used to inflate the number of species by saying some sub populations don’t overlap in geography/breeding time enough to allow proper mixing, but in the end they still do interbreed.

    None the less, you can always use -whatever definition you want- and re-do the analysis under those new criteria, and then come to us with the results, why don’t you. I see absolutely nothing in your arguments that were not already considered and addressed both by this paper and the curated source data it’s based on. In short, all you’re saying has no merit as far as I can see, and it’s up to you to prove otherwise with factual data points and outlined criteria.

  52. @DocMartyn,

    By “live” offspring, I meant to say “viable”. That is, the offspring can produce offspring, ensuring biological continuity.

    Also, I think the main point of it all, is if you change your criteria for analysis, the numbers for -both- continental and island are going to be changed. Are you proposing the ratio between island and continent would significantly change under new criteria away from the results of this paper? Show us the evidence by doing the analysis if you believe so.

  53. vicepapr says:
    October 26, 2011 at 11:18 am

    Willis Eschenbach is a retired polymath
    what is a polymath?

    My dictionary says

    polymath: a devastatingly handsome, blazingly smart gentleman that all the ladies fawn over.

    But I hit the age ceiling, so I retired.

    w.

    PS—Actually, that’s a slight exaggeration. Before I hit the age ceiling, I could no longer pass the physical … but don’t mention that to the babes, vicepapr, keep that part between us, OK? …

  54. Congratulations! Publications always feel good, and I hope that you feel good about this one. Keep up the good work.

  55. Ged, this is a rather complex area and I am trying to be analytically critical, not being critical for its own sake.
    I acknowledged that I had not caught the typo in Table 1 where the mislabeling of the Passenger Pigeon.
    I dispute that the Great Auk is not included as a trans-continental species, but as an Island species.
    I do not accept you facile definition of species; for instance my own species, Homo sapiens, successfully mated with Homo neanderthalensis and I carry about 7% neanderthalensis.
    The Common Chimpanzee, Pan troglodytes and the Bonobo, Pan paniscus have also been successfully mated.
    Durum wheat is a species that resulted from the hybridization of two different diploid grass species, Triticum urartu and Aegilops speltoides.

    Speciation events are more likely to occur in islands, compared to continents. The depth of the genetic pool, the sum of the genetic diversity within a species, will be very much lower in island species than compared with MOST continental species; but not always.
    The cheetah, Acinonyx jubatus is a large continental animal, and is also a specialist.
    It fills a very narrow niche. The cheetah almost went extinct in the very recent past, we know that this species was subject to a very tight evolutionary bottle-neck 10,000 years ago, barely avoiding extinction at the end of the last ice age.
    Top predators are in terms of niche size, island species, regardless of their physical range. Though you may not believe it, the extinction rate of top specialized predators is very high.
    One should note that for grass eating herbivores selection pressure selects large animals, the large they get the more efficient they are at extracting energy from their food, the more successful the males are in fighting for females and the less predation they suffer.
    Thus, over evolutionary time the size of herbivores increases. This leads to an arms race with predators. To be able to predate the large herbivores the predators need to get larger and become more specialized.
    The animal we think of as a saber-toothed tiger is really a large number of sub-species of the machairodontine, when through various cycles of specialization from a generalist medium sized big cat into top large mammal predator to extinction. The cycle of size/sepcialization followed the size of the herbivore, and this followed the ecology, which was triggered by the climate.

    http://www.behav.org/student_essay/evol/dorgai_Smilodon.pdf

    I MY opinion, analyzing the rate of extinction in terms of depth of genetic pool, physical and nutrient niche size would be much better than classifying animals as either Island/Continent species. I say this because whilst these terms may mean something, in some cases, in other they do not. For instance, Proteus anguinus is a cave salamander found in Europe. These occupy a very small island niche, even though they are a continental species. The same goes for the Texas Blind Salamander,Eurycea rathbuni) which is a rare cave-dwelling amphibian native found only in the San Marcos Pool of the Edwards Aquifer.

  56. “Ged says:

    Are you proposing the ratio between island and continent would significantly change under new criteria away from the results of this paper? Show us the evidence by doing the analysis if you believe so.”

    If the Great Auk were included then the number of continental species would change by 7/6, so the ratios would be modified somewhat.
    The use of a ‘soft’ group of species, like the great Auk which do not fall conveniently into either island/continental classification would allow one to use a statistical estimate.
    I did not want to rain on anyone’s parade, nor do I wish to attack either Craig or Willis.
    However, I think their classification is too simplistic and lacks the input from an evolutionary biologist/ecologist.
    Some nodding aquatance with Hutchinson’s hypervolumic niche description would have greatly helped this paper. With luck this publication will lead an ecologist to build on this work by Craig or Willis.

    My criticisms are in no way personal, but if we are going to dissect papers we have a fundamental disagreement with, shouldn’t we do the same to other ones we find general merit with?

  57. DocMartyn: I AM an ecologist. Defining terrestrial “islands” like caves is much more subjective than physical islands, and these islands are only isolated genetically, not from predators or competitors (with very few exceptions). We do not claim to have exhausted the subject–lots more still to do. 6/123 does not differ appreciably from 7/123.

  58. DocMartyn, the Red List says of the Great Auk:

    The last known pair were killed on Eldey Island, Iceland, in 1844, and the last live bird was seen off the Newfoundland Banks in 1852. Historically, birds bred only on remote, rocky islands, probably due to early extirpation in more accessible sites.

    In other words, it is basically an island species. And this, of course, is the reason it went extinct. Humans went to those remote islands that had no natural predators, and predated the Auk into oblivion. So it was an island living species.

    More to the point, however, it was an island breeding species. As this is the time when birds are most vulnerable to extirpation, we listed birds that bred on islands with the island species. That information was included in early versions of the paper, although it seems to have been lost in one of the many rewrites. However, we list that among the reasons for considering islands separate from continents:

    The reasons for greater extinction risk on islands are asserted to be the result of species naive about predators (Cronk, 1997), ground nesting by birds on predator-free islands (e.g. Duncan & Blackburn, 2004), less competition because of reduced species richness (Corlett, 2010), perhaps reflected in slower rates of evolution (Wright et al., 2009), and smaller geographic ranges.

    In the same way, bird species that bred on the continents were counted as continental species, despite the fact that they might spend some part of their lives on islands.

    And the Great Auk, because it “ground-nested … on predator-free islands”, was included with the island birds.

    HTH,

    w.

  59. Craig Loehle & Willis Eschenbach,

    Congratuations on your good work and achieving publication in a journal.
    I look forward to reading your published paper this weekend.

  60. Craig wrote:
    Defining terrestrial “islands” like caves is much more subjective than physical islands, and these islands are only isolated genetically, not from predators or competitors (with very few exceptions).

    The problem here, as DocMartyn has so patiently pointed out, is that vulnerable continental species almost uniformly inhabit “island” habitats. The nine continental extinctions listed in Table 1 include at least five species that inhabited very discrete islands of suitable habitat. Craig’s statement gets dangerously close to circular reasoning (partly because the concept of “habitat” is dangerously close to circular). Because of the prevalence of “island” extinctions on continents, what the paper actually shows is that island/continental is a false dichotomy. This terrain has all been covered in the literature on serpentine specialization, with most of the important work being done in Willis’ home state of California.

  61. Matt Skaggs says:
    October 27, 2011 at 7:26 am

    Craig wrote:

    Defining terrestrial “islands” like caves is much more subjective than physical islands, and these islands are only isolated genetically, not from predators or competitors (with very few exceptions).

    The problem here, as DocMartyn has so patiently pointed out, is that vulnerable continental species almost uniformly inhabit “island” habitats. The nine continental extinctions listed in Table 1 include at least five species that inhabited very discrete islands of suitable habitat. Craig’s statement gets dangerously close to circular reasoning (partly because the concept of “habitat” is dangerously close to circular). Because of the prevalence of “island” extinctions on continents, what the paper actually shows is that island/continental is a false dichotomy. This terrain has all been covered in the literature on serpentine specialization, with most of the important work being done in Willis’ home state of California.

    As Craig pointed out, it’s easy to tell Hawaii from Nebraska. Why? It’s an island.

    And although DocMartyn doesn’t see it, it seems to make a fundamental difference in the extinctions of birds and mammals. Birds and mammals on islands, where there is little exchange with the outside world, are extremely vulnerable to introduced species. These introduced species have caused ~95% of the world’s extinctions.

    Now, it is tempting to call some restricted range for some continental species an “island”. You say:

    The nine continental extinctions listed in Table 1 include at least five species that inhabited very discrete islands of suitable habitat.

    But that’s just a misuse of language. All you mean is that they have geographically defined ranges. But that’s not what makes an island species vulnerable. For the current purposes, the thing that makes a real island different from an “island” on the continent is that (except humans) predator don’t have boats. So those islands (the real ones) were free of certain predators for millions of years.

    But predators, from shrews to tigers, happily cross and recross the borders of what you wrongly name “islands” of defined geographical ranges on the continent. There’s nothing stopping them.

    It is that exclusion of predators, for millions of years, that has made the island species vulnerable. And no matter if you call a continental animal’s range an “island”, with very few exceptions it doesn’t have that complete isolation from predators that we find in actual islands.

    So when you say:

    The problem here, as DocMartyn has so patiently pointed out, is that vulnerable continental species almost uniformly inhabit “island” habitats.

    I can only answer that we didn’t discuss “island” habitats, we discussed island habitats. It’s like the old joke. How many legs does a cow have, if you call a tail a leg?

    Four. Calling a tail a leg doesn’t make it a leg. And in the same way, no matter how patient DocMartyn might be, calling a chunk of a continent an island doesn’t make it an island.

    w.

  62. Willis,
    Reading from your paper, the Atitlan grebe went extinct because of the introduction of the exotic largemouth bass into the one lake that comprised its entire habitat. As far as the grebe was concerned, that lake surrounded by land was exactly analogous to an island habitat. In your paper, you called that tail a leg when you lumped it with the passenger pigeon and not the dodo. That is why your paper will draw a yawn from the folks actually trying to understand this stuff.

  63. “although DocMartyn doesn’t see it, it seems to make a fundamental difference in the extinctions of birds and mammals. Birds and mammals on islands, where there is little exchange with the outside world, are extremely vulnerable to introduced species. These introduced species have caused ~95% of the world’s extinctions”

    Whereas the Great Auk was widespread going from New England, Eastern Canada, Greenland, Iceland, Great Britain and Ireland and the Scandinavian nations. We know that more than 100,000 years ago Neanderthals hunted Great Auks as their bones/egg shells have been found at Neanderthal sites.
    The Great Auks were killed off very slowly, by Polar Bears and by Humans. Their eggs and down was so valued by humans that they ended up with only a few Island refuge’s. They were hunted by native North Americans, the colonists, the Inuit,

    “All you mean is that they have geographically defined ranges. But that’s not what makes an island species vulnerable”

    What makes a species vulnerable? 1) highly restricted location (Island, lake or cave species), 2) shallow genetic pool (Island, lake and cave species), 3) High specialization (not unique to continent or island), 4) Immunological/defensively naivety toward predation (continent or island) and 5) Genetic diversity/population size.
    4) is a big one. Dutch Elm disease, loss of the American Chestnut, loss of the European wine-vine, loss of many potato species, loss of much of the Native American population. Introduction of rats into island does wipe out ground nesting birds. However, introducing large fish into lakes can also wipe out birds.
    5) the background level of a neutral genetic polymorphism in a population is about 6%. The larger number of individuals you have the wider and deeper the genetic pool. Genetic diversity is the currency of speciation/survival. Richard Lenski’s demonstration of the evolution of a E. Coli citrate utilizing strain was probably the best best example of this.

    http://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment

    Some time around generation 20,000 there was established a genetically neutral change in one of his populations that predisposed them to being able to utilize citarte, at some future data; around generations 31,000 and 31,500.
    The bigger you population, the wider and deeper your genetic pool and the higher the species elasticity.
    The species specific size of an ELE will, amongst other things, depend on the ‘range’ of the species, not necessarily where the range is. A cave system, an isolated lake, the Paris underground system represent ‘Islands'; but the nesting of the Great Auk on island does not make them an Island species.
    This is why I disagree with your exact methodology.

  64. DocMartyn: it is not that the Great Auk was isolated genetically but that it had the habit of nesting on islands without predators, so it was vulnerable to predation (specifically humans). If small population size and/or restricted habitat was sufficient to cause extinction there would surely be more extinctions on continents since many birds and mammals have small populations and/or restricted ranges. Also, to try to a priori categorize continental species as “island” species using this method of identification is very subjective. Many authors and the Endangered Species Act in USA essentially identify all rare species as endangered, but forecasts based on this assumption are not coming true yet.
    And yes, of course introducing diseases and pests like dutch elm disease is a really bad idea, but island species are probably even more susceptible.

  65. Matt Skaggs says:
    October 27, 2011 at 11:31 am

    Willis,
    Reading from your paper, the Atitlan grebe went extinct because of the introduction of the exotic largemouth bass into the one lake that comprised its entire habitat. As far as the grebe was concerned, that lake surrounded by land was exactly analogous to an island habitat. In your paper, you called that tail a leg when you lumped it with the passenger pigeon and not the dodo. That is why your paper will draw a yawn from the folks actually trying to understand this stuff.

    OK, throw out the Atitlan grebe entirely, and class it with the dodo. I actually had considered doing that, since it lived on an island in the lake. I eventually decided to leave it in so people wouldn’t complain I was incorrectly lowering the number of continental extinctions … but of course, I hadn’t reckoned with your amazing ability to snatch triviality from the jaws of knowledge …

    It doesn’t change one jot or tittle of our conclusions if we class the grebe with the island species. In fact, it makes our argument stronger, it means less continental extinctions. In other words, you are insulting me and wasting perfectly good electrons over a meaningless point that is actually in favor of our arguments.

    Color me unimpressed with your claims and your attitude. If what you were on about were anything important you might be justified in your passion.

    But getting all snarky over the grebe, which makes no difference to the conclusions of the paper? OK, remove the grebe entirely, it makes no difference, in fact it improves our argument to leave it out. That’s why I left it in, to be scrupulously fair. But heck … take it out. I’m reminded by your attitude of why university politics is so nasty.*

    w.

    PS—I love the part where you are concerned by the methods/conclustions of the paper, and you tell us that DocMartyn has been patient in re-explaining what his point is about the paper, and you think it’s an issue that is important enough to discuss at length and to passionately restate your point several times … and then you claim that the paper will just “draw a yawn from the folks actually trying to understand this stuff …

    These two facts you have presented leave us, as far as I can see, with only two possible conclusions:

    1) You are wrong about the paper just drawing a yawn, or

    2) You are not “actually trying to understand this stuff”

    I’m voting for 1) myself, but it’s your choice, report back.

    * Because there’s so little at stake.

  66. People wonder how long it takes to get an idea into print. The first draft of this paper was written in 2002.

    In The Diversity Of Life (Wilson 1992), E. O. Wilson postulated that we are in the midst of the sixth great wave of extinctions. He based this claim on the “species/area relationship”, which was said to mathematically relate the size of an area to the number of species it could hold. The claim was that reducing the area would drive a large number of species extinct.

    This claim has been picked up and repeated in many scientific and popular papers. The source of these extinctions is said by Wilson to be the reduction of forest habitat, both tropical and temperate. In 1992 claimed that at that point, some 27,000 species were already going extinct every year from forest habitat reduction.

    Being the untrusting fellow that I am, not long after reading that I decided to research it. I didn’t think that life was that mathematically simple, and the parts I’d been in contact with had been uniformly hard to kill.

    So I got the Red List and the CREO list of extinctions. Because birds and mammals are the most visible and most studied forms of life, and because Wilson himself said (and reasonably so) that larger creatures were more likely to go extinct, I decided to study those two kinds of beings. Birds and mammals.

    The problem is the numbers are nowhere near to adding up. We know the approximate numbers of bird and mammal species, and we know the number of total species that Wilson used for his estimates. So we know what percentage of the putative 27,000 extinctions per year should be birds and mammals. Wilson’s figures clearly say we should have already seen hundreds of extinctions of both birds and mammals, even accounting for a long lag in the extinctions. Naive fellow that I was then, I set out to look for Wilson’s claimed extinctions, those animals gone extinct from reduction of their forest habitat.

    Since I had the inestimable advantage of knowing nothing about the field, I started by looking at all of the extinctions. I soon realized that a tiny area of the world (those areas not visited by outsiders in hundreds of thousands of years) held almost every one of the extinctions. They all occurred either on islands or on Australia, and in almost every case for a simple reason—introduced species. Humans, of course, but also foxes, rabbits, rats, dogs, a huge spectrum of diseases, and the under-appreciated bird-and-beast killing and definitely not extinct House Lion, felix domesticus.

    But despite humans cutting forests for hundreds of years, I couldn’t find any extinctions from forest habitat reduction.

    What was even more surprising to me (being unacquainted with the numbers) was that in all of Asia, and Africa, and Europe, and North America, and South America, there were only 9 extinct species in 500 years. I would have guessed many, many more than that on the continental land masses. Only nine.

    I found that astonishing. So I wrote it all up. I submitted it to some journal. They kicked it back with comments from the reviewers that totally discouraged me. Knowing what I know today I might have forged ahead, but then, the theme was “you’re an amateur, leave it to the professionals, we know that the species/area relationship to predict extinctions is correct.” It was also written as I write, not in dense, compressed blocks of text like the journals want. I tried to crunch it together like that, but you could see the seams …

    Since my paper showed that the species/area relationship is not correct, even if I re-wrote it, I could read the writing on the wall. I circulated it privately, and put it with my other studies to let it mellow like good wine.

    Some seven years later I resurrected it and made it into a blog post. Craig Loehl agreed with the analysis and offered to work with me to turn it into a journal paper. I gratefully accepted (and have other papers and blog posts worthy of journal articles, if anyone else wants to offer to do a huge pile of work like Craig did, you get to be lead author.)

    Now, remember my intention was to overthrow the use of the species/area relationship to predict extinctions. It doesn’t work. In my opinion, this is because life is sneaky and underhanded and incredibly tenacious and will sneak through hidden gaps and grow up through the concrete if it has to.

    I consider the publication of this paper to be a signal achievement, particularly for an amateur scientist like myself. At a stroke I have shown that a long-held mathematical relationship, the “species/area relationship” used to predict extinctions, is incorrect and is contradicted by observations.

    I have also shown that the modern continental extinction rates are not significantly different from historical extinction rates. This means that the oft repeated claim that we are in a “sixth wave of extinction” has no scientific foundation. The “sixth wave of extinction” claim was fabricated entirely and completely on the “species/area relationship”, and it is thus also overthrown.

    Not bad for a reformed cowboy off a cattle ranch, I’d say, but my bias is obvious …

    w.

  67. Willis,
    Calm down. Your main conclusion was “conservation strategies for birds and mammals on continents should not be based on island extinction rates and that on islands the key factor to enhance conservation is to alleviate pressures from uncontrolled hunting and predation.” My point is that at least five of the nine continental extinctions were functionally island extinctions, and that conflicts with your conclusion. If you want to understand the extinction of the slender-billed grackle, the Omilteme cottontail rabbit, or the Atitlan grebe, you want to approach these extinctions as island-type events (staying away from extra quotation marks here).

  68. DocMartyn says:
    October 27, 2011 at 1:10 pm

    … but the nesting of the Great Auk on island does not make them an Island species.
    This is why I disagree with your exact methodology.

    You are 100% correct, Doc … but it does make them vulnerable to introduced species on those islands.

    And that is why we classed birds by where they breed, not by where they lived. Actually, there’s another reason, is that it is a “bright line” distinction. A bird may live over its lifetime in many habitats. But typically, they breed in only one kind of habitat.

    This gave us a clear method of distinguishing between “island” birds and “continental” birds, by dividing them based on nesting location. So it was a clear distinction as well as a useful one, putting the those birds at risk of extinction from introduced species on their island breeding sites in with the “island” group. And that is why the Auk is classed with the “island” rather than the “continental” group.

    Here’s the point. Whether or not the Auk should be counted “continental” or “island”, it is not one of E. O. Wilson’s claimed extinctions from habitat reduction. It was driven extinct by predation.

    So whichever way you class it doesn’t matter. It doesn’t even change the continental bird extinction rate appreciably, it increases by one part in six. But that leaves it still well within the uncertainty of the historical rates of extinction.

    Now Doc, if you want to divide birds on some basis other than where they nest, be my guest. You could divide them based on where they eat, or where they congregate, or where they fly over. The division we used is both clear and useful, in that it puts birds at risk from introduced species all in one group. But if you want to class them based on where you find them in June, go for it.

    My point is that we used ex ante, clear criteria for dividing them into “island” and “continental” groups, based on where they nest. Those criteria revealed interesting things. Claiming we should have used other criteria? Sure, we could have done a host of things differently … but then we wouldn’t have found out what we did.

    w.

  69. Willis, you are not taking it this well. I think you and Craig are essentially correct, but I think your classification leaves much to be desired.
    I have not being attacking you, Craig nor your approach or goal.
    What I actually think you are describing is the propensity of species to develop a ‘glass-jaw’.
    Normally, the majority of selection pressure is within a species, not without. Almost every aspect of a species morphology, behavior and biochemistry represents a metabolic/temporal opportunity cost. Cave species show that the removal of a selective advantage from a niche rapidly leads to genetic/phenotypic atrophy; cave species lose eyes, pigmentation and the repair mechanisms for repairing uv induced DNA damage.
    Humans, and other great apes, are the result male sexual selection.
    Monkeys gain an enormous advantage in their ability to climb trees, they are able to evade predators and access food sources unavailable on the ground.
    The cost is big brains, long tails and forward facing eyes.
    Monkeys also have a problem with sex. There is male competition for females, and the largest males tend to have more progeny. In the long run, males become larger and larger. The tail can no longer support the Super-Sized Monkey and becomes a bit of a pin in a Male-Male fight, so that goes. After a while the males are so big they can hardly (Chimps/Bonobos) or simply can’t climb trees (Humans, Gorillas and Orang’s). Luckily, the arboreal small to medium size transition seems to have allowed the apes to leap the majority of predators, and in our case the big brains came in very useful.
    Male African elephants use their tusks in fighting other males, they are a product of sexual selection.African elephant populations have been very damaged by Ivory hunters, some 13% of males now do not have Tusks. Having tusks is the largest negative selection pressure on the elephant and the length of tusks in the tusk has collapsed over the last 150 years. The elephants are losing their ‘glass-jaw’. They could, because they had a very large number of starting numbers, a deep/wide genetic pool and can physically move about.
    Island species typically lose a major predator or many major predators, so there is often a switch from tree to ground nesting and a major down regulation in their immune systems. One would expect that intraspecies selection pressure would be much greater than in larger niches, especially sexual selection.
    These species become fitted to their, very small, niche and so a change in their niche can be devastating.
    I absolutely agree that a small rise in temperature is completely different from suddenly be presented with a new super predator. I also think it reasonable to attempt to try to estimate how different these selection pressures are. However, I think you classification system if not as useful as it could be.
    I actually think the best way to do this would be experimentally.
    Myself, I would grow bacteria, take 10 single founder E. Coli cultures and 10 genetically diverse E. Coli cultures. Grow them on a really, really rich medium for a year, under the same every other day splitting routine.
    After a year test their sensitivity to a range of diverse stressors; pH, heat, Paraquat, osmotic stress, salinity, e.t.c.
    At worst, this will give you an idea of the loss of elasticity one gets from a founder effect.

  70. DocMartyn says:
    October 27, 2011 at 4:07 pm (Edit)

    Willis, you are not taking it this well. I think you and Craig are essentially correct, but I think your classification leaves much to be desired.
    I have not being [been?] attacking you, Craig nor your approach or goal.

    Thanks for that, Doc. I’m still not clear what your point is. For a while it was Great Auks. Now it’s genetically diverse E. Coli cultures.

    What’s not clear is what that has to do with what we have shown. For all the faults you perceive in our method, we have demonstrated and provided evidence that:

    1) The species/area relationship doesn’t work to predict extinctions, and

    2) The claims of a “sixth wave of extinction”, which are based on the species/area relationship, are false.

    3) The extinction rates on the continents are not statistically different from the historical rates.

    I don’t have a clue how the evolution of blind cave animals or of E. Coli has anything to do with those three things. We presented a paper on the historical extinction record. It demonstrated some pretty amazing things.

    Now you tell us that we should have studied E. Coli and we didn’t include the “glass-jaw” and we failed to consider that in elephants “the length of tusks in the tusk has collapsed over the last 150 years” … say what???

    Sorry, Doc, I’m not following you at all. How would any of that have improved or even changed what we set out to show? Our paper has provided extensive evidence overturning two decades of “species/area” extinction nonsense, what more do you want?

    w.

  71. O.K. Willis. I give up. You win. Trying to understand species robustness and sensitivity to extinction stressors is obviously not at all of interest.

  72. DocMartyn says:
    October 27, 2011 at 5:17 pm

    O.K. Willis. I give up. You win. Trying to understand species robustness and sensitivity to extinction stressors is obviously not at all of interest.

    Not true. I am interested. I’m interested enough in the subject to research and write a paper about it. It’s something I care about. I’ve discussed speciation with experts, I’m curious about it.

    Which is why I took the trouble to read and re-read what you wrote. But I couldn’t understand it. I’m sorry, but it wasn’t at all clear what your point was. I mean the words were clear, but I didn’t understand what it had to do with my paper on bird and mammal extinctions.

    So I wrote to say I wasn’t following you. I asked how what you were explaining would have changed or improved our paper.

    Let me pause here and look at the situation. You can respond to that in a variety of ways. You can answer my questions. Or restate your three main points in three sentences. Or ask me questions to find out where from your perspective I’m going off the rails. Or explain what you think I misunderstand.

    There’s lots of things you can say in response to my post. However, you can’t accuse me of not being interested, Doc. That’s simply not true.

    w.

  73. As for “species robustness”, that’s one of the major areas of revision in the field. It seems to be much higher in general than assumed by the boxy constrained habitat parameters of all the best models.

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