515 species on the brink of extinction

RatioTile

RatioTile

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A recent review paper in PNAS has made news headlines for detailing the sixth mass extinction. The authors of the paper compiled this list based on IUCN knowledge of 515 species with less than 1000 wild individuals. I think zoos should focus on collecting these species for captive breeding programs. Also, many of the species on the list are already well established in zoos and aquariums, which reduces the risk of them going extinct in 20 years. Would anyone like to peruse the list and tabulate which species already have captive populations, and which ones are missing from collections but could theoretically be established?

https://www.pnas.org/content/pnas/s...86117.DCSupplemental/pnas.1922686117.sapp.pdf
 
As far as the 70 listed Mammal species are concerned:

In Captivity / Successful Ex-Situ Breeding Programmes (21):
(* indicates re-introduced to wild)
Dibbler*
Gilbert's Potoroo*
Numbat*
Carpentarian Rock Rat
Vancouver Island Marmot*
Pygmy Hog*
Visayan Spotted Deer
Bawean Deer
Dama Gazelle*
Slender-horned Gazelle
Addax*
Arabian Oryx*
Wild Bactrian Camel* (breeding programme at Zakhyn Us, Mongolia)
African Wild Ass
Przewalski's Wild Horse*
Black-Footed Ferret*
Giant Panda*
Iberian Lynx*
Red Wolf*
Black Lion Tamarin
Golden Lion Tamarin*

Well Managed In-Situ Programmes / Semi-Captive Sanctuaries Exist (6):
(the establishment of captive groups for most species also in varying stages of development)
Northern Hairy-Nosed Wombat (? possibly now a small captive group too)
Scott's Tree Kangaroo? (no plans for captivity; wild managed pop. rising)
Mount Claro Rock Wallaby
Ethiopian Wolf
Hirola (48+ in fenced conservancy)
White-Headed Langur (3 also in captivity; no breeding)

Only Further Ex-Situ Programme Development Required (1):
Madeira Pipistrelle

Good Targets for Captive Breeding Programmes (No Current Captive Individuals) (9):
Central Rock Rat (previous captive colony established, but died out 2011)
Santa Catarina's guinea pig (captive individuals kept previously; current?)
Walia Ibex
Saola (at least, a managed semi-captive population)
Tamaraw (Mindoro Dwarf Buffalo) (a failed captive programme attempted late '90s)
Northern Muriqui (given success with Southern Muriqui in captivity)
Cozumel Raccoon
Blond Titi Monkey? (success with other Callicebinae sp.)
Bonin Flying Fox (previously attempted at Tama Zoo, Tokyo)

Possibly Suitable for Ex-Situ Breeding Programmes? (Never in Captivity) (13)
(alas, my understanding of bat biology and captive husbandry is lacking, many of the bats here may actually be difficult / unsuitable)
Cozumel Harvest Mouse
Jico Deer Mouse
San Quintin Kangaroo Rat
Riverine Rabbit
Perrier's Sifaka?
Bulmer's Fruit Bat
Fernandez's Sword-Nosed Bat
Flat-Headed Myotis
Jamaican Flower Bat
Kolar leaf-nosed bat
Seychelles Sheath-Tailed Bat
Yemeni Mouse-Tailed Bat

Population Too Low to Consider Ex-Situ (3):
(Number of captures required for captive pop. too considerable a proportion of existing 'steady' ex-situ population)
Hainan Gibbon
Cao-vit Crested Gibbon
Javan Rhino (borderline, given Ujung Kulon pop. nearing carrying capacity; some transfer to semi-captive conditions may soon be required)

Diet-Restrictive / Too Difficult for Ex-Situ (1):
Northern Sportive Lemur

Data-Deficient / Biology and/or Pop. Poorly Known (6):
(considerably more in-situ work required first)
Golden-Mantled Tree Kangaroo
Fijian Monkey-Faced Bat
Dryas Monkey (? or 'possible ex-situ')
Andean Caenolestid
Cohen's Horseshoe Bat
Myanmar Snub-Nosed Monkey

Likely Already Extinct (and last confirmed sighting) (11):
Wondiwoi Tree-Kangaroo (1928)
Dwarf Hutia (1937)
Little Earth Hutia (1978)
Christmas Island Shrew (1985)
Kouprey (1969-1970)
Puebla Deer Mouse (1957)
Telefomin Cuscus (~1997)
Montane Monkey-Faced Bat (1990)
Emperor Rat (1888)
Guadalcanal Rat (1888)
Malabar Large-Spotted Civet (1990)

____

With that quick assessment, that's about 10-15ish species currently not held in captivity that we know would likely benefit from, and result in, a reasonably successful ex-situ breeding programme (e.g. ethiopian wolf, hirola, walia ibex etc.).

Then there's those species (e.g. a number of rodents, bats and a sifaka) that may just about cut it too, all things considered (current population, known biology and diet, comparison with similar captive species etc. unless I'm mistaken). The rest are species whose husbandry we understand and already fare well in captivity or, in contrast, generally species we know far too little about to adequately assess suitability.

Let me know if anything needs correcting, folks. Will be constantly updating as I find more information.
 
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As for the Amphibians (62 species):

Currently in Captivity (1):
Mountain Chicken

IUCN Recommended / Planned Ex-Situ Breeding Programmes (3):
Bleeding Toad
Mindo Harlequin-Toad (Rediscovered 2019)
Rancho Redondo Frog

Highly Managed In-Situ Programme (1):
Hamilton's Frog

Some In-Situ Conservation (1):
Krokosua Squeaking Frog

No Current Targeted Conservation Work (6):
Atelopus exiguus
Carchi Andes Toad
Costa Rica Brook Frog
Quito Stubfoot Toad (Rediscovered 2016)
Resplendent Shrubfrog
Rough Moss Frog
Telmatobius fronteriensis

Data-Deficient (1):
Small Bush Frog (Described in 2009; no pop. information known)

Possibly / Likely Extinct (and last confirmed sighting) (49):
Angelito Stubfoot Toad (2000)
Arico Water Frog (1976)
Argelia Robber Frog (1981)
Atelopus ardila (2000)
Atelopus chocoensis (1998)
Atelopus eusebiodiazi (1997)
Atelopus gigas (?)
Atelopus guanujo (1998)
Atelopus monohernandezii (1982)
Atelopus onorei (1992)
Atelopus orcesi (1988)
Atelopus podocarpus (1994)
Atelopus quimbaya (1990)
Atelopus sernai (2001)
Atelopus simulatus (2003)
Atelopus sonsonensis (1996)
Bogota Stubfoot Toad (1993)
Cacao Robber Frog (2001)
Carabaya Stubfoot Toad (2004)
Colombian Stubfoot Toad (1985)
Du Toit's Torrent Frog (1960)
Flat-Spined Atelopus (1985)
Forest Stubfoot Toad (2003)
Gastrotheca antomia (1997)
Green Poison Frog (2005)
Hulia Stubfoot Toad (1992)
Jacobson's Bubble-Nest Frog (1912)
Jambato de Lynch (1984)
La Planada Poison Frog (1990s)
Mindo Robber Frog (1995)
Morona-Santiago Stubfoot Toad (1998)
Niceforo's Stubfoot Toad (1998)
Northern Darwin's Frog (1981)
Pacific Marsupial Frog (1990s)
Painted Stubfoot Toad (1996)
Paramo Toad (2003)
Peru Stubfoot Toad (1998)
Peter's Stubfoot Toad (1998)
Pristimantis albericoi (1986)
Pristimantis chrysops (1997)
Pristimantis deinops (2001)
Pristimantis diogenes (1993)
Pristimantis xylochobates (2004)
Rana Saltarina de Brazalete (1998)
Rio Calima Marsupial Frog (1993)
Rio Calima Robber Frog (1993)
San Isidro Stubfoot Toad (1963)
Schmidt's Stubfoot Toad (1990)
Sugar Robber Frog (1983)
Uribe Robber Frog (1999)

Makes for much grimmer reading - most species are New World anurans likely already extinct following chytrid fungus incursion into their native range. A couple species may persist in isolated groups, and may yet be rediscovered. Otherwise, a single species is currently bred in captivity; three more might follow soon-ish. The rest are mostly still fending for themselves, many of which may be potential candidates for captive breeding programmes.
 
Of the 42 listed Reptile species:

Currently in Captivity (17):
(* indicates re-introduced to wild)
Burmese Roofed Turtle
Campbell's Alligator Lizard
Chinese Alligator*
Española Giant (Galápagos Giant) Tortoise*
Fernandina Island (Galápagos Giant) Tortoise (Extinct in Wild)
Geometric Tortoise
Gharial*
Grand Cayman Blue Iguana*
Jamaican Iguana*
Northern River Terrapin
Red-Crowned Roofed Turtle
Orinoco Crocodile*
Pinzón Giant (Galápagos) Tortoise*
Philippine Crocodile*
Psychedelic Rock Gecko (Described 2010)
Siamese Crocodile*
Yunnan Box Turtle

Well Managed In-Situ Programmes (3):
Eastern Santa Cruz (Galápagos Giant) Tortoise
Sierra Negra Giant (Galápagos Giant) Tortoise
Volcán Darwin Giant (Galápagos Giant) Tortoise

IUCN Recommended for Ex-Situ Breeding Programmes (6):
Arnhem Land Gorges Skink
Carrot Rock Skink (if not already extinct; 2-3 seen in 2000)
Conception Bank Silver Boa (Discovered 2016)
Galápagos Pink Land Iguana
Hoge’s Side-Necked Turtle
Key New Caledonian Gecko

Possibly Suitable for Ex-Situ Breeding Programmes? (5):
Boavista Wall Gecko
Censky's Ameiva
Hellmich's Tree Iguana
Pedra Branca Cool-Skink
Phrynocephalus golubewii

Data-Deficient / Biology and/or Pop. Poorly Known (5):
Cape Melville Leaf-Tailed Gecko (Discovered 2014)
Cyrtodactylus chrysopylos
Karst-Dwelling Rock Gecko (Described 2008)
Long-Necked Northern Leaf-Tailed Gecko
Psychedelic Rock Gecko (Described 2010)

Likely Extinct (and last confirmed sighting) (6):
Jamaica Giant Galliwasp (1840)
Jamaican Racer (Early 20th Century)
La Vega Racer (?)
Hispaniolan Two-Lined Skink (1937)
Hispaniolan Ten-Lined Skink (1985)
Saint Croix Racer (Late 19th - Early 20th Century)

That's about 10ish species for which the establishment of a captive breeding programme may benefit / be suitable.

Anywho, that's me done. There are too many birds. Eek.
 
Tea_and_Biology said:
Of the 42 listed Reptile species:

Currently in Captivity (17):
(* indicates re-introduced to wild)
Burmese Roofed Turtle
Campbell's Alligator Lizard
Chinese Alligator*
Española Giant (Galápagos Giant) Tortoise*
Fernandina Island (Galápagos Giant) Tortoise (Extinct in Wild)
Geometric Tortoise
Gharial*
Grand Cayman Blue Iguana*
Jamaican Iguana*
Northern River Terrapin
Red-Crowned Roofed Turtle
Orinoco Crocodile*
Pinzón Giant (Galápagos) Tortoise*
Philippine Crocodile*
Psychedelic Rock Gecko (Described 2010)
Siamese Crocodile*
Yunnan Box Turtle

Well Managed In-Situ Programmes (3):
Eastern Santa Cruz (Galápagos Giant) Tortoise
Sierra Negra Giant (Galápagos Giant) Tortoise
Volcán Darwin Giant (Galápagos Giant) Tortoise

IUCN Recommended for Ex-Situ Breeding Programmes (6):
Arnhem Land Gorges Skink
Carrot Rock Skink (if not already extinct; 2-3 seen in 2000)
Conception Bank Silver Boa (Discovered 2016)
Galápagos Pink Land Iguana
Hoge’s Side-Necked Turtle
Key New Caledonian Gecko

Possibly Suitable for Ex-Situ Breeding Programmes? (5):
Boavista Wall Gecko
Censky's Ameiva
Hellmich's Tree Iguana
Pedra Branca Cool-Skink
Phrynocephalus golubewii

Data-Deficient / Biology and/or Pop. Poorly Known (5):
Cape Melville Leaf-Tailed Gecko (Discovered 2014)
Cyrtodactylus chrysopylos
Karst-Dwelling Rock Gecko (Described 2008)
Long-Necked Northern Leaf-Tailed Gecko
Psychedelic Rock Gecko (Described 2010)

Likely Extinct (and last confirmed sighting) (6):
Jamaica Giant Galliwasp (1840)
Jamaican Racer (Early 20th Century)
La Vega Racer (?)
Hispaniolan Two-Lined Skink (1937)
Hispaniolan Ten-Lined Skink (1985)
Saint Croix Racer (Late 19th - Early 20th Century)

That's about 10ish species for which the establishment of a captive breeding programme may benefit / be suitable.

Anywho, that's me done. There are too many birds. Eek.
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If you want, I could do the birds. If you are already doing it, it is okay.
 
Volcan Darwin tortoise is at the Bronx Zoo. Not sure if the individuals are old enough to breed yet. Also Psychedelic rock gecko is bred in Europe and possibly at iZoo in Japan, where I saw it.
 
When you’re done, I’m thinking about annotating the list and sending it to the IUCN, AZA, EAZA, WCS, and other relevant institutions.
 
Tea_and_Biology said:
Diet-Restrictive / Too Difficult for Ex-Situ (1):
Northern Sportive Lemur
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I'd be inclined to suggest this may not be the case, considering the population of Red-tailed Sportive (Lepilemur ruficaudatus) at Paris survived for 7 years, and we have an additional 30 years of husbandry advances in how to care for primates with specialist diets.

Tea_and_Biology said:
Likely Already Extinct (and last confirmed sighting) (11):
Wondiwoi Tree-Kangaroo (1928)
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Try 2018 :p

Tea_and_Biology said:
Malabar Large-Spotted Civet (1990)
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This one quite possibly never existed - the latest thinking is that it was probably a translocated population of Viverra megaspila.

 
Jungle Man said:
If you want, I could do the birds. If you are already doing it, it is okay.
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Ahh, I should probably not procrastinate any further, paha. Knock yourself out!


TeaLovingDave said:
I'd be inclined to suggest this may not be the case, considering the population of Red-tailed Sportive (Lepilemur ruficaudatus) at Paris survived for 7 years, and we have an additional 30 years of husbandry advances in how to care for primates with specialist diets.
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Perhaps? I based the judgement on this extract in Ranaivoariosa et al. (2013): "The folivorous diet of the northern sportive lemur and this species' predilection for leaves complicates any attempts or plans to maintain it in captivity. There is no record of a sportive lemur held in any zoological park, as all known attempts to maintain them in captivity have failed on average within one week of capture. In situ conservation programs and community-based interactions are therefore the only viable solutions" and the MBP's Project Objectives.

I can't speak much on Northern sportive lemurs, but in general, sportive lemurs seem to tend to be rather specialist, many feeding predominantly on a few Alluaudia species, and relying heavily on a germane gut microbiome. Given the Northern sportive lemur population is estimated at ~50 (though only 19 known individuals), I can't say they're a good species to start experimenting on. Perhaps a semi-captive or highly managed in-situ reserve like the Indri at Analamazaotra Reserve might be possible. Else, I'd consider them 'population too low for ex-situ'; in-situ support seems the only real solution, all things considered.

I'd agree having another crack at the captive husbandry of other sportive species might not be a bad idea though.
 
Tea_and_Biology said:
There is no record of a sportive lemur held in any zoological park, as all known attempts to maintain them in captivity have failed on average within one week of capture.
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Well, as noted Paris kept them (no breeding though) from 1986 to 1993 so that paper is plain wrong to say there's no record of it having happened :p we even have members here who saw them!
 
Lets make one more list: a list of species which local bureaucrats consistently refuse to start a conservation breeding program.

Potentially, we could also make a list which of these species were discussed on Zoochat for such a program before. For example, Ethiopian wolf was discussed several times. ;)
 
RatioTile said:
A recent review paper in PNAS has made news headlines for detailing the sixth mass extinction. The authors of the paper compiled this list based on IUCN knowledge of 515 species with less than 1000 wild individuals.
Click to expand...
The paper itself, a more useful link than to just a naked list of species, is here: Vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction


The inclusion of Giant Panda was interesting to me, as in 2016 the species was dropped from Endangered to Vulnerable based on the wild population now being c.2000 individuals. I looked on IUCN just now to see what it says, and it gives the population as "500-1000" for the number of mature individuals. However the text within the page says something almost but not quite the same:

The Fourth National Survey (2011-2014) produced an estimated range-wide population of 1,864 Giant Pandas, excluding dependent young <1.5 years of age (State Forestry Administration 2015). Although no formal demographic analysis is available, there are demographic data available to enable estimation of age-related population composition (Sichuan Forestry Department 2015): if the population consists of 9.6% cubs, then the total population of Pandas is approximately 2,060. Mature adults are estimated to compose 50.5% of the total population, yielding an estimate of 1,040. Although this estimate does not contain confidence intervals, clearly the lower confidence interval would fall below 1,000 mature individuals, which meets the small population size criteria (D1) for Vulnerable.

I thought maybe the "500-1000" was a hold-over from the previous rating which they had forgotten to change, but the old one was actually higher at "1000-2000".
 
Tea_and_Biology said:
Northern Hairy-Nosed Wombat (? possibly now a small captive group too)
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There is no captive population of which I'm aware. There has been talk of setting one up for ages, and various people are interested, but it has not yet happened as far as I know.
 
I’m also surprised extinct in the wild yet reintroduced species aren’t on the list.
 
Jurek7 said:
Lets make one more list: a list of species which local bureaucrats consistently refuse to start a conservation breeding program.

Potentially, we could also make a list which of these species were discussed on Zoochat for such a program before. For example, Ethiopian wolf was discussed several times. ;)
Click to expand...

In regards to the Ethiopian wolf I think it would be relatively hard to start up a captive population. This is a species of canine that is relatively unique in behavior and physiology and every possible death is a risk to the survival of the population. I'm sure scientists can figure it out don't get me wrong but I think there should be a larger effort to protect the natural parks so that the populations can grow a little more but that's just my opinion. I do think the Walia Ibex can have a captive population set up with the Nubian Ibex used as a reference guide since both species live in Ethiopia and the Walia currently have a growing population which isn't all good since the mountain range they live can only hold around 2,000 individuals so it wouldn't be a bad idea to start trying to work with the ibex. That's just my thoughts though.
 
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