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 Researchgate.
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.
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
Based on fossil extinction records, 99.99% of extant species are DOOMED anyhow, so what’s the big deal?
;p
Willis now has instant come-back for any warmtwits who sneer that he’s “unpublished” in the field.
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.
But the models all show coming extinctions in the thousands…;)
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?
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.
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.
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.
Will S says:
October 25, 2011 at 9:01 pm\
Australia was included with the islands because the Australian extinctions were from the same cause as the island extinctions—introduced species.
w.
Brian H says:
October 25, 2011 at 9:16 pm
Actually, this is my fourth peer-reviewed publication in the field … including a “Communications Arising” in Nature.
w.
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.
DocMartyn says:
October 25, 2011 at 6:47 pm
Anna Lemma says:
October 25, 2011 at 9:26 pm
Robert Clemenzi says:
October 25, 2011 at 9:47 pm
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.
Worth remembering that there have been no marine extinctions this century – despite the urgent alarms.
http://www.anenglishmanscastle.com/archives/009807.html
No ocean is an island, so no problems with introduced predators or inability to move.
And of course the good news is that last year not one species went extinct officially according to the Red List. In fact one species (St. Helena Darter) went from extinct to unknown as while no one has seen one for nearly forty years no one has properly looked.
http://www.anenglishmanscastle.com/archives/009796.html
[snip – fake email address]
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…
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…
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).
grats to you Willis you deserve it and it just goes to show that blogs can make the science stronger. GREAT JOB!!!!!
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.
Congratulations WIllis
Are there any plans to get your thermostat hypothesis into print?
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.
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
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.
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.