1. PRIMATES IN PERIL
The World’s 25 Most Endangered Primates
2012–2014
Russell A. Mittermeier, Christoph Schwitzer, Anthony B. Rylands,
Lucy A. Taylor, Federica Chiozza, Elizabeth A. Williamson and Janette Wallis
Illustrations by Stephen D. Nash
2012

2. Published by:
IUCN/SSC Primate Specialist Group (PSG)
International Primatological Society (IPS)
Conservation International (CI)
Bristol Conservation and Science Foundation (BCSF)
Copyright: ©2012 Bristol Conservation and Science Foundation
All rights reserved. No part of this report may be reproduced in any form or
by any means without permission in writing from the publisher.
Inquiries to the publisher should be directed to the following address:
Russell A. Mittermeier, Chair, IUCN/SSC Primate Specialist Group,
Conservation International, 2011 Crystal Drive, Suite 500, Arlington, VA
22202, USA
Citation: Russell A. Mittermeier, Christoph Schwitzer, Anthony B. Rylands, Lucy A.
Taylor, Federica Chiozza, Elizabeth A. Williamson and Janette Wallis (eds.).
2012. Primates in Peril: The World’s 25 Most Endangered Primates 2012–
2014. IUCN/SSC Primate Specialist Group (PSG), International
Primatological Society (IPS), Conservation International (CI), and Bristol
Conservation and Science Foundation, Bristol, UK. 40pp.
Illustrations: © Stephen D. Nash, Conservation International, Arlington, VA, and
Department of Anatomical Sciences, Health Sciences Center, State
University of New York at Stony Brook, NY, USA
Available from: Anthony B. Rylands, Conservation International, 2011 Crystal Drive, Suite
500, Arlington, VA 22202, USA
e-mail: a.rylands@conservation.org; website: http://www.primate-sg.org
Front cover photos (clockwise from top left):
Madame Berthe’s mouse lemur (Microcebus berthae) © John R. Zoanarivelo
Tonkin snub-nosed monkey (Rhinopithecus avunculus) © Tilo Nadler
Northern brown howler monkey (Alouatta guariba guariba) © John J. Tschirky
Roloway monkey (Cercopithecus roloway) © West African Primate Conservation Action (WAPCA)
Back cover photo:
Golden-headed langur or Cat Ba langur (Trachypithecus poliocephalus poliocephalus) © Tilo Nadler

3. Contents
Acknowledgements ............................................................................................................................. ii
The World’s 25 Most Endangered Primates: 2012–2014................................................................. 1
Africa ................................................................................................................................................... 4
Rondo dwarf galago (Galagoides rondoensis) .................................................................................. 5
Roloway monkey (Cercopithecus roloway) ...................................................................................... 6
Bioko red colobus (Piliocolobus pennantii pennantii) ...................................................................... 7
Tana River red colobus (Piliocolobus rufomitratus) ......................................................................... 8
Grauer’s gorilla (Gorilla beringei graueri) ....................................................................................... 9
Madagascar ........................................................................................................................................10
Madame Berthe’s mouse lemur (Microcebus berthae) ....................................................................11
Sclater’s black lemur or Blue-eyed black lemur (Eulemur flavifrons) .............................................12
Red ruffed lemur (Varecia rubra) ....................................................................................................13
Northern sportive lemur (Lepilemur septentrionalis) .......................................................................14
Silky sifaka (Propithecus candidus).................................................................................................15
Indri (Indri indri) .............................................................................................................................16
Asia .....................................................................................................................................................17
Pygmy tarsier (Tarsius pumilus) ......................................................................................................18
Javan slow loris (Nycticebus javanicus) ...........................................................................................19
Simakobu or Pig-tailed snub-nosed langur (Nasalis concolor) ........................................................20
Delacour’s langur (Trachypithecus delacouri) .................................................................................21
Golden-headed langur or Cat Ba langur (Trachypithecus poliocephalus poliocephalus) .................22
Western purple-faced langur (Semnopithecus vetulus nestor) ..........................................................23
Grey-shanked douc monkey (Pygathrix cinerea) .............................................................................24
Tonkin snub-nosed monkey (Rhinopithecus avunculus) ..................................................................25
Cao-Vit or Eastern black-crested gibbon (Nomascus nasutus) .........................................................26
Neotropics ...........................................................................................................................................27
Variegated or Brown spider monkey (Ateles hybridus) ....................................................................28
Ecuadorian brown-headed spider monkey (Ateles fusciceps fusciceps) ...........................................29
Ka’apor capuchin monkey (Cebus kaapori) .....................................................................................30
San Martín titi monkey (Callicebus oenanthe).................................................................................31
Northern brown howler monkey (Alouatta guariba guariba) ..........................................................32
References........................................................................................................................................33
Editors’ addresses ............................................................................................................................39
i

4. Acknowledgements
The 2012–2014 edition of the World’s 25 Most Endangered Primates is, for the second time,
presented in the form of species fact sheets. For this edition, we have summarized and updated the
species profiles from the 2008–2010 and 2010–2012 editions of the World’s 25 Most Endangered
Primates for those species remaining on the list, and added additional profiles for the new species.
We would like to thank all of the contributing authors to the 2008–2010 version for their work, which
forms the basis of the fact sheets in the new edition. Each profile from the 2008–2010 edition is cited
on the fact sheets:
Simon K. Bearder, Thomas M. Butynski, Liliana Cortés Ortiz, Dong Thanh Hai, Jörg U. Ganzhorn,
Ha Thang Long, Paul E. Honess, M. Cecília M. Kierulff, Le Khac Quyet, Andrés Link, Karmele
Llano Sanchez, Long Yongcheng, David N. M. Mbora, W. Scott McGraw, Pierre Moisson, Alba
Lucia Morales-Jiménez, Tilo Nadler, K. Anne-Isola Nekaris, Vincent Nijman, John F. Oates, Lisa M.
Paciulli, Erwin Palacios, Erik R. Patel, Andrew Perkin, Phan Duy Thuc, Clément J. Rabarivola,
Martina Raffel, Guy H. Randriatahina, Iary B. Ravaorimanana, Christian Roos, Rasanayagam Rudran,
Yves Rumpler, Daniela Schrudde, Nora Schwitzer, James S. Thorn, Bernardo Urbani, Sylviane N. M.
Volampeno, Janette Wallis, Ananda Wanasinghe, Kanchana Weerakoon, Indah Winarti and Alphonse
Zaramody.
We would also like to express our thanks for the additional contributions by Stuart Nixon, on Grauer’s
gorilla, and Ross Fuller, for help with literature accumulation and proof reading.
ii

5. The World’s 25 Most Endangered Primates: 2012–2014
Here we report the seventh iteration of the biennial listing of a consensus of the 25 primate species
considered to be among the most endangered worldwide and the most in need of conservation
measures. The 2012–2014 list was drawn up during an open meeting held during the XXIV Congress
of the International Primatological Society (IPS), Cancún, 14 August 2012. It is a joint effort by the
IUCN/SSC Primate Specialist Group, the International Primatological Society, Conservation
International, and the Bristol Conservation and Science Foundation.
The 2012–2014 list of the world’s 25 most endangered primates has five species from Africa, six from
Madagascar, nine from Asia, and five from the Neotropics (Table 1). In terms of individual countries,
Madagascar tops the list with six species. Vietnam has five, Indonesia three, Brazil two, and China,
Colombia, Côte d’Ivoire, the Democratic Republic of Congo, Ecuador, Equatorial Guinea, Ghana,
Kenya, Peru, Sri Lanka, Tanzania and Venezuela each have one.
The changes made in this list compared to the previous iteration (2010–2012) were not because the
situation of the nine species that were dropped (Table 2) has improved. In some cases, such as, for
example, Varecia variegata, the situation has in fact worsened. By making these changes we intend
rather to highlight other, closely related species enduring equally bleak prospects for their future
survival. An exception may be the greater bamboo lemur, Prolemur simus, for which recent studies
have confirmed a considerably larger distribution range and larger estimated population size than
previously assumed. The severe threats to this species in eastern Madagascar remain, though.
Table 1. The World’s 25 Most Endangered Primates 2012–2014
Africa
Galagoides rondoensis Rondo dwarf galago Tanzania
Cercopithecus roloway Roloway monkey Côte d’Ivoire, Ghana
Piliocolobus pennantii Bioko red colobus Equatorial Guinea (Bioko Is.)
pennantii
Piliocolobus rufomitratus Tana River red colobus Kenya
Gorilla beringei graueri Grauer’s gorilla DRC
Madagascar
Microcebus berthae Madame Berthe’s mouse lemur Madagascar
Eulemur flavifrons Sclater’s black lemur Madagascar
Varecia rubra Red ruffed lemur Madagascar
Lepilemur septentrionalis Northern sportive lemur Madagascar
Propithecus candidus Silky sifaka Madagascar
Indri indri Indri Madagascar
Asia
Tarsius pumilus Pygmy tarsier Indonesia (Sulawesi)
Nycticebus javanicus Javan slow loris Indonesia (Java)
Nasalis concolor Pig-tailed langur Indonesia (Mentawai Is.)
Trachypithecus delacouri Delacour’s langur Vietnam
Trachypithecus poliocephalus Golden-headed or Cat Ba langur Vietnam
Semnopithecus vetulus nestor Western purple-faced langur Sri Lanka
Pygathrix cinerea Grey-shanked douc monkey Vietnam
Rhinopithecus avunculus Tonkin snub-nosed monkey Vietnam
Nomascus nasutus Cao-Vit or Eastern black-crested China, Vietnam
gibbon
Neotropics
Ateles hybridus Variegated spider monkey Colombia, Venezuela
Ateles fusciceps fusciceps Ecuadorian brown-headed spider Ecuador
monkey
Cebus kaapori Ka’apor capuchin monkey Brazil
Callicebus oenanthe San Martín titi monkey Peru
Alouatta guariba guariba Northern brown howler monkey Brazil
1

6. Nine primate species were added to the 2012–2014 list (Table 3). Seven of them were placed on the
list of the world’s 25 most endangered primates for the first time. The Tana River red colobus and the
Ecuadorian brown-headed spider monkey had already been on previous iterations of the list, but were
subsequently removed in favor of other highly threatened species of the same genera. The 2012–2014
list now contains two members each of these genera, thus particularly highlighting the severe threats
they are facing.
During the discussion of the 2012–2014 list at the XXIV Congress of IPS in Cancún in 2012, a
number of other highly threatened primate species were considered for inclusion (Table 4). For all of
these, the situation in the wild is as precarious as it is for those species that finally made it on the list.
Table 2. Primate species included on the 2010–2012 list that were removed from the 2012–2014 list.
Africa
Piliocolobus epieni Niger Delta red colobus Nigeria
Madagascar
Prolemur simus Greater bamboo lemur Madagascar
Varecia variegata Black-and-white ruffed lemur Madagascar
Asia
Tarsius tumpara Siau Island tarsier Indonesia (Siau Is.)
Macaca silenus Lion-tailed macaque India
Pongo pygmaeus pygmaeus Northwest Bornean orangutan Indonesia (West Kalimantan, Borneo),
Malaysia (Sarawak)
Neotropics
Cebus flavius Blond capuchin monkey Brazil
Callicebus barbarabrownae Barbara Brown’s titi monkey Brazil
Oreonax flavicauda Peruvian yellow-tailed woolly Peru
monkey
Table 3. Primate species that were added to the 2012–2014 list. The Tana River red colobus and the
Ecuadorian brown-headed spider monkey were added to the list after previously being removed, and
the other seven species are new to the list.
Africa
Piliocolobus rufomitratus Tana River red colobus Kenya
Madagascar
Microcebus berthae Madame Berthe’s mouse lemur Madagascar
Varecia rubra Red ruffed lemur Madagascar
Indri indri Indri Madagascar
Asia
Tarsius pumilus Pygmy tarsier Indonesia (Sulawesi)
Neotropics
Ateles fusciceps fusciceps Ecuadorian brown-headed spider Ecuador
monkey
Cebus kaapori Ka’apor capuchin monkey Brazil
Callicebus oenanthe San Martin titi monkey Peru
Alouatta guariba guariba Northern brown howler monkey Brazil
2

7. Table 4. Primate species considered during the discussion of the 2012–2014 list at the IPS Congress
in Cancun that did not make it onto the list, but are equally highly threatened.
Africa
Piliocolobus preussi Preuss's red colobus Cameroon, Nigeria
Gorilla gorilla diehli Cross River gorilla Nigeria, Cameroon
Pan troglodytes ellioti Nigeria-Cameroon chimpanzee Nigeria, Cameroon
Madagascar
Cheirogaleus sibreei Sibree’s dwarf lemur Madagascar
Hapalemur alaotrensis Lac Alaotra bamboo lemur Madagascar
Eulemur cinereiceps White-collared brown lemur Madagascar
Propithecus perrieri Perrier’s sifaka Madagascar
Asia
Nasalis larvatus Proboscis monkey Indonesia (Borneo)
Presbytis comata Grizzled leaf monkey Indonesia
Rhinopithecus strykeri Myanmar snub-nosed monkey Myanmar, China
Nomascus hainanus Hainan black-crested gibbon China (Hainan)
Nomascus leucogenys Northern white-cheeked black- Laos, Vietnam, China
crested gibbon
Neotropics
Chiropotes satanas Black bearded saki Brazil
Leontopithecus caissara Black-headed lion tamarin Brazil
Saguinus bicolor Brazilian bare-faced tamarin Brazil
Callicebus caquetensis Caquetá titi monkey Colombia
3

8. 4

9. Rondo dwarf galago
Galagoides rondoensis (Honess in Kingdon, 1997)
Tanzania
Top 25: 2006, 2008, 2010, 2012
Biology1: o R
 Weighs ~60g2 u
 Distinct from other dwarf galagos in a
its bottle-brush-shaped tail, its w
reproductive anatomy, and its a
distinctive “double unit rolling call” 2-4
 Mixed diet of insects and fruit F
 Often feed close to the ground and R
move by vertical clinging and leaping
in the shrubby understory 4
 Build daytime sleeping nests5
 Predation from owls and other k
nocturnal predators2 m
 Emerging evidence that the northern ²
and southern populations may be
phylogenetically distinct
 Sympatric with a number of other
galagos
Estimated population1:
 Unknown
Range1:
 Estimated density:
 Extremely limited and fragmented
o 3–6/ha at Pande Game
 Range in a number of remnant patches
Reserve9
of Eastern African Coastal Dry Forest
o 8/ha at Pugu Forest Reserve10
in Tanzania2, 6
 Relative abundance from encounter
o Zaraninge forest (06º08'S,
38º38'E) in Sadaani National rates
Park o 3–10/hr at Pande Game
Reserve and Pugu/
o Pande Game Reserve (GR)
Kazimzumbwi Forest
(06º42'S, 39º05'E),
Reserve9, 10
o Pugu/Kazimzumbwi (06º54'S,
39º05'E), o 3.94/hr at Rondo Forest
Reserve2
o Rondo (10º08'S, 39º12'E),
o Litipo (10º02'S, 39º29'E)
o Ziwani (10º20'S, 40º18'E)
forest reserves (FR) Threats1:
o Chitoa FR (09º57'S, 39º27'E)  Very small and fragmented range in
o Ruawa FR (09º44'S, 39º33'E) remnant forest patches
 Total area known to occur does not  Forest loss
exceed 101.6 km² 1, 7, 8 o Agricultural encroachment
o Pande GR: 2.4 km², o Charcoal production
o Rondo FR: 25 km², o Logging
o Ziwani FR: 7.7 km²,
o Pugu/Kazimzumbwi FR: 33.5
km², Justification for the Top 25:
o Litipo FR: 4 km²  Highly threatened by the logging of
o Zaraninge forest: 20 km², remaining small forest fragments
Chitoa FR: 5 km²
5

10. Roloway monkey
Cercopithecus roloway (Schreber,
1774)
Ghana and Côte d’Ivoire
Top 25: 2002, 2006, 2010, 2012
Biology11:
 Closely related to
Cercophithecus diana12
 Distinguished from C.
diana by its broad white
brow line, long white beard
o 14 years ago found in the
and yellow thighs
Yaya Forest Reserve, the
 C. roloway is more seriously Tanoé Forest adjacent to the
threatened with extinction Ehy Lagoon and the Parc
 Largely arboreal species13 National des Iles Ehotilé16-18
 Occurs in canopy of primary and old o Now only found in the Tanoé
secondary lowland moist forest, and forest18, 19
riverine and gallery forest13
 Rare in degraded forest, but can
survive in lightly logged forest where Estimated population11:
the canopy remains13  Unknown
 Decline exceeding 50% (potentially
exceeding 80%)14
 Numerous local extinctions
Range11:
 Found to the east of the Sassandra
River in Côte d’Ivoire to the Pra River
in Ghana13 Threats11:
 Considerable amount of primary  Hunting for the bushmeat trade
habitat loss over the past ~30 years14 o Relatively large size and value
 Ghana of its meat and skin makes it a
o Steadily extirpated from both preferred game species13
protected and unprotected  Forest loss
areas and is nearing extinction o Logging
o Several surveys have failed to o Agriculture
find this species in any o Charcoal production20
western reserves  Population fragmentation and isolation
o Possibly exists in the Ankasa
Conservation area15
 Côte d’Ivoire
o Not known in any protected Justification for the Top 25:
areas  Extirpation and continuing decline
6

11. Bioko red colobus
Piliocolobus pennantii pennantii (Waterhouse, 1838)
Equatorial Guinea (Bioko Island)
Top 25: 2004, 2006, 2010, 2012
Biology21, 22:
 Previously four subspecies of
Piliocolobus pennantii recognized: P.
p. pennantii; P. p. bouvieri; P. p.
preussi; and P. p. epieni
 Debated whether all should be
elevated to species level
 P. p. epieni at least is considered
elevated to species level
 P. p. pennantii is largely arboreal
 Found in lowland and mid-montane
tropical moist forest and marsh forest
 Form groups of more than 30 animals
 Often found in polyspecific
associations23
Range21, 22:
 Very restricted range on the island of
Threats21, 22:
Bioko, Equatorial Guinea
 Heavy hunting
 Restricted mainly to the south-west of
o Most notably from the early
the island
1980’s when a commercial
 Range of less than 500km2 24-26 bushmeat market appeared in
 Confined to the Gran Caldera and the town of Malabo24
Southern Highlands Scientific Reserve o Bushmeat considered a
(510km2) ‘luxury food’26
 Perhaps still at Pico Basile National  Limited range
Park (330km2)  Habitat degradation
 None of the ranges are well protected o Especially sensitive to habitat
degradation27-29
Estimated population21, 22: Justification for the Top 25:
 Less than 5,000 individuals  Heavily hunted in a very restricted
 45% decline in numbers between 1986 range
and 200626
7

12. Tana River red colobus
Piliocolobus rufomitratus (Peters, 1879)
Kenya
Top 25: 2002, 2004, 2006, 2008, 2012
Biology30, 31:
 Previously Procolobus rufomitratus
rufomitratus
 Piliocolobus separated from
Procolobus32
 Elevated to species level32
 Inhabits gallery forest dominated by
Pachystela and Barringtonia
 Not observed moving between habitat
patches during the day
 Some movement at night which
appears to be helping to ensure the
continued survival of the groups in the
seemingly isolated patches
 Broadly sympatric with Cercocebus
galeritus and Cercopithecus mitis
albotorquatus, and narrowly
sympatric on the forest edges with
Papio cynocephalus ibeanus and
Cercopithecus pygerythrus
Range30, 31:
 Found only on the levees of the lower Threats30, 31:
Tana River in Kenya  Habitat loss, degradation and
 Total known range is 60 km from fragmentation36
Kipende in the north to Mitipani in the o Forest clearance for
south, where the Lamu–Garsen road agriculture
enters the Tana River floodplain o Fires eroding levee forests
 Restricted to ca. 34 patches of o Degradation due to livestock
fragmented gallery forest, notably and wood collection
Guru South, Sifa East, Baomo South, o Selective felling of Ficus trees
Mnazini East, Bubesa West 1, Hewani for canoes
South 2 forests33  Habitat change
 All of these forests are small, ranging o Drastic changes in vegetation
in size from <1 ha to c.500 ha. due to dam construction,
irrigation projects, and water
diversion which changed the
Estimated population30, 31: water table
 Estimated at 1,100–1,300, down from  Hunting37
an estimated 1,200–1,800 in 197533-35  Parasites38, 39
 At least 86 groups occur in 34 forest
patches32, 33
 Mean group size has declined by Justification for the Top 25:
about 50% since the 1970s  Small extent and increasingly smaller
and more isolated patches of habitat
8

13. Grauer’s gorilla
Gorilla beringei graueri (Matschie, 1914) Contributing author:
DRC Stuart Nixon
Top 25: 2010, 2012
Biology40:
 One of two subspecies of eastern
gorilla (Gorilla beringei)
 The largest, on average, subspecies of
gorilla
 Inhabits lowland tropical rainforest
habitat through transitional forests to
Afromontane habitat of 600 to 2,900m
asl
 Feeds mainly on herbaceous
vegetation; fruit preferred when
available
 Groups consist of 2–36 multi-aged
individuals led by a single
“silverback” male  Southern Maïko populations exist in a
region occupied by Simba rebels
Range40:  Northern Maïko populations remain
 Endemic to eastern DRC unknown since 1992 due to lack of
 Historical range ~52,000km2 41 park infrastructure and the presence of
 Three broadly defined populations: militia
Maïko-Tayna (Maïko National Park,  Mt Tshiaberimu population dropped to
Tayna Nature Reserve, Kisimba-Ikoba 14 individuals in 2009
Nature Reserve and the Usala Forest),  Now estimated to number 2,000–
Kahuzi-Kasese (Kahuzi-Biega 10,000 individuals in 14
National Park (KBNP) lowland sector subpopulations48
and adjacent forest) and the Itombwe
Massif (Itombwe Natural Reserve) Threats40:
 Isolated populations in the KBNP  Massive forest loss and fragmentation
highland sector, Masisi and on Mt o Agriculture
Tshiaberimu in Virunga National Park o Pastoral activities
 Habitat destruction and fragmentation  Illegal mining
widespread o Bushmeat hunting
 52% reduction of suitable range since  Illegal capture of infants
199042  Ongoing political unrest and military
activity
Estimated population40: o Bushmeat hunting43, 49-51
 In 1995 estimated at 16,900  Continuous low-level extractive
individuals43, 44 activities
 Many populations have disappeared o Charcoal production
during the last 30 years o Bamboo harvesting
 KBNP highland population dropped o Wood cutting
from ~270 in 1996 to only ~140  Future challenges may include
animals in 200045 concessions for timber, minerals and
 Preliminary surveys in KBNP possible petroleum52
lowlands indicate 75–80% decline
since 199546 Justification for the Top 25:
 Local extinctions on the north bank of  Drastic and continuing population
the Lowa River and Masisi47 decline compounded by continuing
civil unrest and widespread insecurity
9

14. 10

15. Madame Berthe’s mouse lemur
Microcebus berthae (Rasoloarison, Goodman
& Ganzhorn, 2000)
Madagascar
Top 25: 2012
Biology53:
 World’s smallest primate (average
31g54)
 Inhabits dry deciduous forest
 0–150m asl
 Solitary forager characterized by
extensively overlapping ranges55
 Male ranges larger than females and
more prone to seasonal fluctuation55
 Daily torpor, but no prolonged torpor
during the dry season
 Sympatric with the larger Microcebus
murinus across some of the range56, 57
 Avoids interspecific competition by
spatial segregation, making
distributions of both species patchy57
 Feeds on fruit and gum58
 Relies on sugary excretions from
insects during the harsh dry season58
Estimated population53:
 <8,000 potentially breeding
individuals57
Range53:  Densities of 100/km2 recorded in
 Menabe region in southwest patches, which suggests high localized
Madagascar, south of the Tsiribihina densities
River56, 57  Overall generalized density ~30
 Area ≤900km2 individuals/km257
 Kirindy/CFPF forests and Ambadira  None in captivity
 Believed to also occur in the forests of
Analabe, but the forest has been
heavily degraded, so it is uncertain if Threats53:
it still occurs there59  Habitat loss and fragmentation
 Formerly occurred in the o Illegal logging
Andranomena Special Reserve, but it o Slash-and-burn agriculture
is not known if it still occurs there57
 Range is severely fragmented
Justification for the Top 25:
 Decline in the area and quality of
habitat  Small and severely fragmented range,
which has seen a drastic decline in
extent and quality of remaining
habitat, especially since the illegal
transfer of power in Madagascar in
early 2009
11

16. Sclater’s black lemur or
Blue-eyed black lemur
Eulemur flavifrons (Gray, 1867)
Madagascar
Top 25: 2008, 2010, 2012
Biology60:
 Rediscovered in 198361, 62
 Initially regarded as a subspecies
of E. macaco
 Elevated to species level because
of consistent morphological
differences and pairwise genetic
distances comparable to other
Eulemur species pairs63, 64
 Inhabits primary and secondary
forest fragments61, 65-67
western dry deciduous forest region in
 Home range size and use differs the south
between primary and secondary forest
 Largest remaining population in forest
fragments, indicating secondary forest
fragments on and adjacent to the
is less suitable68
Sahamalaza Peninsula71
 E. flavifrons has been recorded to
consume 72 different plant species Estimated population60:
from 35 families, of which 52.3%
 In 1999, the estimated population of
were fruits and 47.7% were leaves
the Sahamalaza Peninsula was 450–
 Also feeds on flowers, insects, insect 2,300 wild individuals and had
exudates and fungi69 declined by 35.3% in three years72
 Bimodal activity pattern70  Estimated total population,
 Multi-male multi-female groups, extrapolated from density73, 74 and area
ranging in size from 6 to 10 estimates, of 2,780–6,950 severely
individuals, including 4 to 7 adults fragmented wild individuals
 Both sexes disperse, but only males  80% wild population reduction
have been seen moving into a foreign estimated and predicted over 35 years
social group  30 captive individuals75
 The sex ratio at birth varies strongly
between years and could be male- Threats60:
biased  Very small range
 Births occur between late August and  Forest loss
October, at the end of the dry season. o Slash-and-burn agriculture
 During two successive birth seasons, o Selective logging
infant mortality was 22.7%.  Hunting and trapping
o Bushmeat
Range60: o Live capture for the pet
 Very small area of 2,700km² in trade72, 76
northwest Madagascar, south of the o Trap density of up to 570
Andranomalaza, north of the traps/ km2 73
Maevarano, and west of the
Sandrakota rivers61, 65-67 Justification for the Top 25:
 Transition zone between the humid  Highly fragmented population in very
Sambirano region in the north and the small range that is almost totally
deforested
12

17. Red ruffed lemur
Varecia rubra (E. Geoffroy, 1812)
Madagascar
Top 25: 2012
Biology59, 77:
 Diurnal
 Inhabits tropical moist lowland forests
 Apparent need for tall primary forest
o Primarily inhabiting primary
forest
o Prefers high forest and is often
observed in the crowns of
large feeding trees
 Sea level to 1,200m asl
 Moves quadrupedally through the
canopy, leaping occasionally
 Largely frugivorous (75–90%), with
flowers, nectar and leaves
 Home range size: 23–58ha78
 Multi-male, multi-female communities
of 5–31 individuals78
 Mating season May–July Estimated population59, 77:
 Births from September–early  Density estimates:
November o 31–53 individuals/km2 in
 Gestation period: 102 days Andranobe83
 Inter-birth interval: 2 years o 21–23 individuals/km2 in
 Mean litter size: Ambatonakolahy84
o Wild: 2.1179  Captive population of 590 in 2009
o Captivity: 2.2280
Range77: Threats77:
 Very restricted range  Habitat loss
 Masoala Peninsula and the region o Slash-and-burn agriculture
immediately north of the Bay of o Human encroachment
Antongil in northeastern Madagascar81 o Illegal logging
 4000km2 o First lemur to disappear from
degraded forest
 Antainambalana River appears to
separate this species from V.  Hunting
o Heavily hunted in its entire
variegata, but the western and
range
northern limits of the red ruffed
lemur’s range remain unclear59
 Westernmost distribution near the
Justification for the Top 25:
confluence of the Antainambalana and
 Small distribution range that is under
Sahantaha rivers82
severe threats of hunting and habitat
loss
13

18. Northern sportive lemur
Lepilemur septentrionalis (Rumpler and Albignac, 1975)
Madagascar
Top 25: 2008, 2010, 2012
Biology85:
 Originally described based on
cytogenetic and morphometric
characteristics86
 Supported by more detailed studies
since, especially molecular data87-89
 Small grayish-brown sportive lemur
with not very prominent ears90
 Nocturnal
 Sleeps in tree holes during the day
 Little known about its ecology and
behavior
Range59, 85:
 Strictly limited to a few small patches
of dry forest in extreme northeastern
o Sahafary (degraded forest patches
Madagascar, just to the south of
in Western Sahafary, Sahafary
Antsiranana on the east coast
East, Sahafary North, Andravina,
 Very small remnant forest patches:
Sahandrano, Andranomadiro, and
o Near the villages of Madirobe
Analalava) - about 100 individuals
and Ankarongana in the
 In 2012 probably only 19 individuals
Sahafary region
remaining in total
o In the immediate vicinity of
Andrahona, a small mountain
about 30 km south of Threats59, 85:
Antsiranana, east of Route  Very small fragmented range
Nationale 6 o Most habitat already gone
o Does not occur in protected
areas
Estimated population59, 85: o Uncertain if remaining
fragments are of sufficient
 Total population unknown, but very
small size to warrant protection
 A survey in 2007 provided the  Habitat destruction
o For Eucalyptus plantations
following estimates:
o Firewood collection
o Andrahona (forest patches and
o Charcoal burning
gallery forests of Andrahona,
Analajanana, and  Hunting
Analanjavavy) - 20  Most restricted and least protected
individuals lemur
o Ankarakataova (forests of
Ankarakataova Be and
Ankarakataova kely) - none Justification for the Top 25:
found  Combination of small population,
small range and rapidly decreasing
suitable habitat, with high pressure
from hunting
14

19. Silky sifaka
Propithecus candidus (Grandidier, 1871)
Madagascar
Top 25: 2000, 2002, 2004, 2006, 2008, 2010, 2012
Biology91:
 Large, white sifaka from northeastern
Madagascar
 Recently raised to full species level 59,
92, 93
 This species does not occur with other
sifakas and cannot be confused with
other lemurs
 Found mainly in tropical montane
forest
 Group size: 2–9
 Home ranges 34–47ha94, 95
 Quarter of time travelling between
foraging sites
 Folivorous and granivorous,
 A few groups have been found in the
consuming fruits, seeds and leaves
from a large number of plant groups Makira Forest Protected Area at two
sites: Andaparaty (central-east
 Mating occurs just a few days a year
Makira) and Manandriana, 44 km to
in November and January
the northwest, adjacent to the
 Young born in June or July94
Anjanaharibe-Sud Special Reserve).
 Well-developed olfactory
 Also found in the Betaolana Corridor
communication
that connects Anjanaharibe-Sud and
 Scent-marking of territory Marojejy, and the unprotected
 Males gouge trees prior to scent- Tsaratanana Corridor to the northwest
marking
Estimated population91:
 Less than 250 individuals96
Range91:  Marojejy: 40 inidviduals/km2 and 90
 Restricted range in northeastern individuals/km2 97
Madagascar
 Includes the humid forest belt Threats91:
extending from Maroantsetra to the  Habitat destruction
Andapa Basin and the Marojejy o Slash-and-burn agriculture
Massif o Illegal logging of precious
 Precise limits unknown woods, including rosewood96
 Marojejy National Park is the northern o Firewood
limit of its known distribution and the o Occurs in and adjacent to
forests of Makira and the protected areas they are found
Antainambalana River are regarded as in98-100
the southern limit96  Hunted throughout range
 300–1,875m elevation
 Patchy distribution and low densities Justification for the Top 25:
 Majority of the remaining population  Small fragmented population under
found in two protected areas: Marojejy extensive pressure from habitat
National Park and Anjanaharibe-Sud destruction and hunting
Special Reserve
15

20. Indri
Indri indri (Gmelin, 1788)
Madagascar
Top 25: 2012
Biology59, 101:
 Largest extant species of lemur
 Vertical clinger and leaper, with
long hind limbs
 Identified by its eerie wailing
song
 Male indri are slightly larger than
females
 Males and females can also be
distinguished by song
 Inhabits tropical moist lowland
and montane forests
 Usually found at low elevations,
but ranges up to 1,800m102
 Lives in groups of 2–6
individuals, usually consisting of
a monogamous adult pair
 Groups in fragmented habitats tend to Estimated population101:
be larger103, 104  Low population density
 Primarily feeds on immature leaves,  5.2–22.9 individuals/km2 106
with flowers, fruit, seeds and bark also  50% reduction over the past 36 years
consumed105
 Descends from canopy every day to
consume soil, which may help
detoxify seeds consumed105, 106 Threats101:
 Home range size 18ha in fragmented  Habitat loss
forest, up to ~40ha in pristine forest o Forest loss for fuel and timber
 Reproduction is highly seasonal, with o Slash-and-burn agriculture
a single offspring born in May or June  Hunting
 Birth interval: 2–3 years o Previously considered a taboo,
but now significant in some
 Reproductive maturity: 7–9 years 107
areas
o Hunted for skins and meat
o Unsustainable108
Range59, 101:
 Eastern rainforests from
Anjanaharibe-Sud in the north to
Anosibe An’ala Classified Forest in
Justification for the Top 25:
the south
 High rate of habitat destruction and
 Not found on the Masoala Peninsula
or in the Marojejy National Park unsustainable hunting
 Subfossil evidence indicates that indri
were once widespread across
Madagascar
16

21. 17

22. Pygmy tarsier
Tarsius pumilus (Miller and Hollister, 1921)
Indonesia (Sulawesi)
Top 25: 2012
Biology109, 110:
 Largely data-deficient
 Prior to 2008, known only from three
specimens from 1916, 1930 and
2000111, 112
 Thought to be extinct until the 2000
specimen was found dead in a rat trap
 In 2008, 3 individuals were captured
and 1 additional individual was
observed110
 Mean body mass: 50g, less than half
of adult lowland tarsiers110
 Nocturnal
 Largely arboreal
 Lives in small groups
 Returns to the same sleeping tree each
morning110
 Unlike lowland tarsiers, pygmy tarsier
groups contain multiple adult males,
and they rarely vocalize or scent-
mark110
 Found at high altitudes (~1,800–
2,200m asl)
 Adapted to colder, montane cloud
forests112
 Arthropod based insectivorous diet
Range109:
Threats109:
 Southern and central Sulawesi,
 Habitat encroachment and destruction
Indonesia
o Expanding human population
 Specimen 1 (1916): 1,800 m from
 Human conflict
Rano Rano, in the mountains between
o Some areas of Central
Palu and Poso
Sulawesi near known sites are
 Specimen 2 (1930): 2,200 m on Mount
conflict zones
Rantemario in South Sulawesi
o Factional fighting has seen the
 Specimen 3 (2000): 2,200 m on the dislocation of large human
flank of Mount Rorekatimbu111 populations that are then
 2008 capture: Lore Lindu National resettled in refugee camps
Park, Central Sulawesi110
Justification for the Top 25:
Estimated population109:  Highly fragmented and isolated
 Unknown populations threatened by human
 3 museum specimens encroachment and conflict
 3 captured and 1 additional
observation in 2008110
18

23. Javan slow loris
Nycticebus javanicus (Geoffroy, 1812)
Indonesia
Top 25: 2008, 2010, 2012
Biology113:
 Recognized as a species in 2006
 Nocturnal and arboreal
 Found in both primary and secondary
forest114
 Requires arboreal connectivity
between trees, via vines and lianas
 Feeds on sap, floral florescence, gum
and insects114
 Found at elevations of 0–1,600m but
more common at higher elevations114
Threats113:
 Habitat loss
o Deforestation
Range113: o After an area is cleared,
 Western and central Java, Indonesia lorises are collected as they
 Less than 10% of the original forest remain clinging to the trees115
remains, most covering the higher  Hunting
slopes of the central mountains o Traditional medicines
o Pet trade116, 117
 Less than 20% of suitable habitat
o Not always the intended target
remains
but are picked up when found
 17% of the potential distribution is
o Numbers in animal markets
protected
exceed the ability for
population numbers to recover
o Front teeth removed at
markets
o Most lorises die of dental
Estimated population113:
abscesses, pneumonia or
 Unknown
malnutrition
 Very low population densities (0.02– o Unable to eat preferred gum
0.20 animals/km2 113 and exhibit important social
 5–10 km must be walked to see a behavior118
single loris o Confiscated animals unlikely
 Small population of confiscated to survive in the wild
animals in rescue centers but 95%–  Roads and human disturbance119, 120
100% mortality has been reported due  Intrinsic risk: slow-reproducing121
to health conditions associated with
captivity Justification for the Top 25:
 Intensive hunting pressure
19

24. Simakobu or Pig-tailed
snub-nosed langur
Nasalis concolor (Miller, 1903)
Indonesia
Top 25: 2002, 2004, 2006, 2008,
2010, 2012
Biology122:
 Two subspecies:
o Nasalis concolor
concolor (Millar,
1903)
o Nasalis c. siberu
(Chasen and Kloss,
1927)  N. c. siberu ~6,000–15,000 in Siberut
 Very little published on behavior and National Park
ecology  Total population down from 26,000 in
 Found in swamp forests and lowland 1980
rainforests and primary forests on  Maximum decline of 75% in 20
hillsides123-125 years124
 Diurnal124  Population densities also reduced,
 Semi-terrestrial124 indicating a 73–90% decline in 10
 Almost equal time resting (46%) and years128-130
feeding (44%) and less time moving
(7%)126
 Primarily folivorous124 Threats122:
 Birth season from June to July125  Hunting
o Preferred game species in
some areas130, 131
Range122: o Hunting pressure increased
 Endemic to Indonesia with improved access and
 Confined to the Mentawai Islands off replacement of bows with air
the western coast of Sumatra124 rifles128
 N. c. concolor o In 1987, estimated that twice
o Inhabits Sipora, North Pagai, as many individuals were
and South Pagai Islands and hunted as were born in the
several small islets off South Pagai islands123
Pagai o Pet trade
o Remaining forest cover on the  Forest loss
Pagai islands ~826km2 127 o Commercial logging124, 128 –
 N. c. siberu particularly sensitive130
o Only on Siberut Island o Conversion to palm oil
o 190,500ha Siberut National plantations and cash crops124,
128
Park covers 47% of Siberut
Island o Human encroachment
o Remaining 53% outside of o Forest clearing and extraction
protected areas by local people124, 128
Estimated population122:
 N. c. concolor two estimates: ~3,347 Justification for the Top 25:
individuals on the Pagai islands127 and  Heavy hunting and commercial
700–1,800 total population128 logging
20

25. Delacour’s langur
Trachypithecus delacouri (Osgood,
1932)
Vietnam
Top 25: 2000, 2002, 2004, 2006,
2008, 2010. 2012
Biology132:
 Restricted to limestone
karst forest habitat, with
additional records of
secondary forest in
limestone areas133, 134
 Up to 1,000m asl135  Two protected areas with important
 Caves thought to offer protection from subpopulations showed a decline of
predators and temperature extremes136 20% in 5 years from 2000 to 2004
 Diurnal and crepuscular  Four protected areas showed a
 Degree of terrestriality is habitat- dramatic decline during 2009137
dependent135  Approximately 6 locations extirpated
 60–80% of the diet consists of leaves,  Current total population unknown, but
with 20–40% shoots, fruit, flowers and likely to be a maximum of 250 wild
bark135 individuals
Threats132:
Range132:  Small population size
 Very restricted area in north Vietnam  Hunting
 5,000km² between 20º–21ºN and o Traditional medicines
105º–106ºE o Meat
 Distribution closely related to the  Fragmentation
limestone mountain ranges in the o Only the largest population of
provinces Ninh Binh, Thanh Hoa, Hoa 68–70 individuals is thought
Binh, and Ha Nam133 likely to survive136, 137
 17 isolated locations totaling less than o Inbreeding may result in loss
400–450km² (size estimates from 18 of genetic viability
locations)136, 137  Minor threat: Forest loss and
degradation
o Illegal grazing of goats
Estimated population132: o Limestone quarrying138, 139
 1999/2000 estimated 281–317136  Potential threat: Tourism and
 320 hunted individuals over 10 years, associated development135
but actual number undoubtedly higher
 60% of total population in isolated
subpopulations with less than 20 Justification for the Top 25:
individuals133  Critically small, fragmented
 Largest subpopulation, in the only population under hunting pressure
well guarded forest, has increased and
totals ~68–70 individuals133, 138, 139
21

26. Golden-headed langur or
Cat Ba langur
Trachypithecus poliocephalus
poliocephalus (Trouessart, 1911)
Vietnam
Top 25: 2000, 2002, 2004, 2006,
2008, 2010, 2012
Biology140:
 Inhabits tropical moist
forest on limestone karst
hills
 70–100m asl, possibly 0–200m141
 Six to seven taxa of the T. francoisi
group share range
Threats140:
 Caves thought to offer protection from
predators and temperature extremes,  Small population size
but are accessible by human hunters136 o Fragmentation resulting in
inbreeding in subpopulations,
 Diurnal
which could compromise
 Arboreal and terrestrial142
genetic viability
 60–80% of the diet consists of leaves, o Limited mate choice
with 20–40% shoots, fruit, flowers and o Susceptible to natural or
bark135 human disaster causing total
extinction142, 143
 Hunting
Range140:
o Traditional medicines
 Confined to the island of Cat Ba in the o Bushmeat
Gulf of Tonkin, northeastern Vietnam o Driven by increasingly
 Further restricted to ~100km2 area of attractive commercial gains
occupancy143  Habitat disturbance and fragmentation
 Mostly in Cat Ba National Park, which o Increasing human population
covers more than half of the main o Tourism and associated
island143 development
 Wildlife protection deficient o Rampant fires due to honey
 Divided into seven isolated collectors142 144
subpopulations due to habitat
fragmentation143
Estimated population140: Justification for the Top 25:
 60–70 individuals (64 in 2006142)  Critically low population size and low
 3–4 all-female, non-reproducing reproductive output, with threats from
groups143 hunting
 Reproductive output low
 Stagnated at 1–2 offspring per year143
22

27. Western purple-faced
langur
Semnopithecus vetulus nestor
(Bennett, 1833)
Sri Lanka
Top 25: 2004, 2006, 2008, 2010,
2012
Biology145:
 Inhabits lowland tropical
rainforest
 Refugee populations
presently inhabit semi-
urban and rural home
gardens, rubber plantations and areas
with adequate canopy cover146
 Highly arboreal Estimated population145:
 Fragmentation forces this species to  Unknown
the ground for which it is ill-  Believed to have undergone a decline
adapted147 of more than 80% over three
 Folivorous generations151
 Fragmentation and urbanization in  Extirpation151
most of this species’ range has
resulted in a diet mainly consisting of Threats145:
fruits from residential gardens148  Habitat loss and fragmentation152, 153
 Nutritional consequences of urban diet o Urbanization, including
unclear, but feeding on fruits long- human settlement and
term may be detrimental as they are infrastructure and industry
not adapted to a frugivorous diet and o Agriculture, particularly crop
fruits tend to occur seasonally plantations
o Deforestation
 Dependent on gardens for survival
Range145:  Dangers from power lines and
 Western Sri Lanka, from the north of roads147, 151, 152
the Kalu Ganga as far north as the  Dogs147
rainforest limit149  Occasional hunting
 Ranges up to 1,000m asl146 o Pet trade
 Inhabits an area of high human density o Persecution for crop-raiding154
 81–90% of the entire historic range o Local trade for meat, but not
deforested and urbanized147, 150 significant152
 Only recorded as present in 43% of o Becoming more tolerant to
eastern (n=23) and 78% in the western humans which is putting them
(n=27) halves of the historical range147 at increased risk153
 Population fragmentation and isolation
 Largest inhabited forests, with a total Justification for the Top 25:
area of 21km2, surround two reservoirs  Habitat loss, fragmentation and
(Kalatuwawa and Labugama)147 urbanization
23

28. Grey-shanked douc monkey
Pygathrix cinerea (Nadler, 1997)
Vietnam
Top 25: 2000, 2002, 2004, 2006, 2008, 2010,
2012
Biology155:
 Mostly found in primary mountain
evergreen forest156
 Altitude of 900–1,400m asl
 Canopy cover of 80–90%156
Range155:
 Central Vietnam between 13º30' and
16ºN
 Recorded in five provinces: Quang
Nam, Quang Ngai, Kon Tum, Gia Lai,
and Binh Dinh136, 156
 Occurrence confirmed in eight
protected sites: Song Thanh Nature
Reserve, Ngoc Linh Nature Reserve,
Ba To Cultural and Historical Site, An o Snares common
Toan Nature Reserve, Kon Cha Rang o Degraded habitats increase the
Nature Reserve, Kon Ka Kinh risk of being caught in snares
National Park, Mom Ray National whilst travelling
Park and A Yun Pa Nature Reserve o Hundreds of traps installed in
trees frequently used by
monkey groups
Estimated population155: o Trapped animals are often
severely injured or mutilated
 600–700 individuals156
o Less than one quarter of
 Fragmented
hunted animals are
 Some areas with assumed occurrence
confiscated alive155
not yet surveyed156
 Forest loss
 Endangered Primate Rescue Center o Agricultural expansion
has begun a breeding program with
o Illegal logging
confiscated animals
o Firewood collection
o Almost 10,000ha of forest are
selectively logged every year
Threats155:
in the central highlands156
 Hunting
o Meat
o Traditional medicine
o Pets156
o Problem inside protected areas Justification for the Top 25:
o Response to hunting is to hide
 Intensive logging and hunting
motionless rather than fleeing,
which makes them more
susceptible136
24

29. Tonkin snub-nosed monkey
Rhinopithecus avunculus (Dollman,
1912)
Vietnam
Top 25: 2000, 2002, 2004, 2006, 2008,
2010, 2012
Biology157:
 Described in 1912
 Collected on no more than two
occasions over the next 50–60
years
 Presumed extinct
 Rediscovered in 1989
 Tropical evergreen forests
associated with karst
limestone hills and
mountains158, 159 o 2006: No evidence, but local
 Largely restricted to primary forest160 reports suggested 8–12
 200–1,200m asl158  TSM conservation area, Ha Giang
 Selective feeder consuming young Province
leaves, unripe fruits and seeds159, 160 o 2001: estimated 30–40 based
 Diurnal161 on interviews164
o 2006: observed about 81
 Arboreal and terrestrial159
animals; estimated 90158
Range157:  Tung Vai Commune of Quan Ba
District close to the border with China
 Northeastern Vietnam149
o 60 individuals
 Historically occurred east of the Red
 Total population: estimated around
River136
200–250+ individuals throughout
 Due to widespread deforestation and
range157, 159
intensive hunting, its distribution has
become severely restricted136
Threats157:
 Currently, five completely isolated
 Hunting pressure159
localities known
o Traditional medicines136, 158
 Small forest patches in Tuyen Quang, o High pressure158
Bac Kan, Ha Giang and Thai Nguyen o Hydroelectric power project
Provinces136 increases number of people
and demand for meat136, 158
Estimated population157: o Not shy and do not necessarily
 Tat Ke sector158 flee when encountered161
o 1993: 72 individuals  Habitat degradation
observed, 80 estimated160 o Firewood
o 2005: far lower densities, 17– o Timber exploitation
22 estimated158 o Shifting cultivation
 Ban Bung sector158 o Collection of non-timber
o 1993: 23 observed, 50 forest products for
estimated160 commercial purposes
o No verifiable information for o Roads159
2005158
 Cham Chu Nature Reserve Justification for the Top 25:
o 1992: survey with locals  Critically small fragmented population
estimated 20–40 individuals162 under hunting pressure
o 2001: 70 estimated163
25

30. Gibbons in Peril:
 Three species of gibbon were considered for this edition: Nomascus hainanus, N. leucogenys
and N. nasutus
 N. hainanus was recently listed on the ZSL/IUCN list of 100 most threatened species
(Priceless or Worthless), with just 23–25 individuals remaining
 For the World’s 25 Most Endangered Primates 2012–2014, we have selected N. nasutus as a
flagship species to highlight the plight of other gibbons
Cao-Vit or Eastern black-crested
gibbon
Nomascus nasutus (Kunkel d'Herculais, 1884)
China, Vietnam
Top 25: 2008, 2010, 2012
Biology165:
 Historically one of two subspecies, but
both elevated to species level166, 167
 Inhabits montane and limestone
forests in a wet tropical monsoon
climate168
 500–900m asl168
 Primarily fruivorous (86.6%), but also
consumes leaves (4.7%), animal
matter (0.5%) and undetermined food
class (8.2%)169, 170
Range165:  2002: estimated 26 individuals in five
 Historical range was east of the Red groups171, 172
River in China and Vietnam  2004: 37 individuals in eight groups173
 Current range very restricted  Total population estimated at 110
 Sino-Vietnam border, northeastern individuals living in 18 groups173
Vietnam167, 171, 172
o 48km² Threats165:
o 22º55'N 106º30'E  Habitat loss and disturbance
o Includes the northern Phong o Cleared for cultivation
Nam-Ngoc Khe forests (about o Pasture for livestock
30km²) of Trung Khanh o Firewood collection
District, Cao Bang Province, o Charcoal production
Vietnam o Already restricted range170
 Jingxi County, Guangxi Zhuang  Small population
Autonomous Region, southeastern o Inbreeding effects
China167, 171, 172 o Poor mate choice
o Area immediately adjacent to o Human or natural disaster167,
170
Vietnam
o ~18km²  Hunting 170
Justification for the Top 25:
Estimated population165:  Small range and population size, with
 Feared extinct until a survey a large threat from habitat loss and
rediscovered a population in the disturbance
limestone forest of Phong Nam-Ngoc
Khe Communes171, 172
26

31. 27

32. Variegated or Brown spider
monkey
Ateles hybridus (I. Geoffroy, 1829)
Colombia, Venezuela
Top 25: 2004, 2006, 2008, 2010, 2012
Biology174:
 Two subspecies:
o Ateles hybridus brunneus
o A. h. hybridus175
 Large size
 Slow reproductive rate of a single
offspring at 3–4-year intervals
 Spider monkeys are generally
highly frugivorous (83%), but also
eat young leaves and flowers176
 They form groups of up to 20–30
individuals176
Range174:
 A. h. brunneus
o Restricted to Colombia
 Potential extirpation
o Between the lower Ríos Cauca
and Magdalena in the  Held in captivity in zoos and rescue
Departments of Bolívar, centers in Colombia
Antioquia and Caldas177
o Small geographic range where Threats174:
forest loss, degradation and  Habitat loss and increasing
fragmentation are widespread fragmentation
o Surrounded by human o Agriculture and cattle
populations o Human expansion
o 9% of potential range remains o Land clearing
continuous forest o Logging
 A. h. hybridus o Conversion to secondary
o Right bank of the Río forest
Magdalena extending into o Potential corridors at risk
western Venezuela175, 178  Hunting
o Extremely fragmented, with o A. h. hybridus a favourite
small populations game species in the Perijá
Mountains179
Estimated population174:  Pet trade
 Unknown
 Low population densities
Justification for the Top 25:
 A. h. hybridus extremely fragmented
and there may be few populations of  High rate of habitat loss and hunting
an adequate size to be viable in the
mid- to long-term175, 177
28

33. Ecuadorian brown-headed
spider monkey
Ateles fusciceps fusciceps (Gray, 1866)
Ecuador
Top 25: 2006, 2012
Biology180:
 Tropical and subtropical human
forests from 100 to 1,700m
asl181
 Diurnal
 Strictly arboreal, preferring the
uppermost levels of the canopy
 Group size of up to 35
individuals
 Diet consists mainly of ripe fruit
(83%), but also flowers and a
number of species of leaves182
 Slow reproductive rate of one
offspring at up to 3-year
intervals183
Range22, 180: Estimated population22, 180:
 Endemic to Ecuador in the north, west  Unknown
of the Andes, in the Province of  Population density of 1.2
Esmeraldas, and, at least historically it individuals/km2 in Cotacachi-
would seem, south as far as the Cayapas184
Cordillera de Colonche  80% decline due to habitat loss185
 Very small distribution, which is
highly fragmented
 Two populations remaining:
o North of the Rio Mira, in the
“Reserva Etnica Awá” close Threats22, 180:
to the Colombian border22  Habitat loss and fragmentation
o To the south, largely within o High rate due to
the limits of the “Reserva deforestation185
Ecológica Cotacachi-  Hunting
Cayapas” and the o Strong pressure185
neighbouring forest (north),
mainly in a private reserve:
“Reserva Biológica Los
Cedros” 22
 It has been suggested that A. f. Justification for the Top 25:
fusciceps may be found in southern  Restricted distribution with high
Colombia, continuous with the fragmentation, and small population
populations in Ecuador178, but there is size
still no evidence to support this
29

34. Ka’apor capuchin
monkey
Cebus kaapori (Queiroz, 1992)
Brazil
Top 25: 2012
Biology186:
 Arboreal quadrupeds,
typically found in the
lower to mid-canopy and
understorey187-189
 Undisturbed and slightly
disturbed dense lowland
Amazonian high forest
 Estimated density:
 Altitudes of 200m or less190
o 0.98 individuals/km² in the
 Can also be found in edge habitat in Gurupí Biological Reserve192
the transition with the Zona dos o 0.99 groups/10 km in the
Cocais Fazenda Cauaxi in
 Frugivorous and insectivorous diet, Paragominas191
they are manipulative and extractive  Three groups in 480km walked in the
scavengers Gurupí Biological Reserve197
 Groups observed to be 1–7
individuals191 Threats186:
 Males disperse  Habitat loss
 Both sexes take up linear hierarchies, o Forests in southern Pará and
the top ranking male being dominant Maranhão have been
over the top ranking female187 extensively destroyed
 Sympatric with Cebus apella, causing o Region with the highest
inter-species competition192 human population density and
the highest level of
deforestation and habitat
Range186: degradation in the entire
 Northwest Maranhão and northeast Brazilian Amazon191
Pará in the Brazilian Amazon190 o Occurs in only one protected
 Ranging from east of the lower Rio area, which has lost half of its
Tocantins to the bank of the Rio forest
Grajaú where it enters the Zona dos o Selective logging of trees
Cocais190, 191, 193-196 providing fruit that are a
 Now absent east of the Rio Grajaú 193 significant part of the diet197
 Hunting
 Pet trade190
Estimated population186:
 Unknown Justification for the Top 25:
 Drastic decline of at least 80% over  Extreme threat from deforestation and
the past three generations hunting causing drastic population
decline
30

35. San Martín titi monkey
Callicebus oenanthe (Thomas, 1924)
Peru
Top 25: 2012
Biology198:
 Able to survive in a wide variety of
habitats including, at least in the short
term, in forest fragments199, 200
 Monogamous
 Found in small family groups of two
to six
 Females usually give birth to one
offspring per year
 Diet consists primarily of insects and
fruit
o Liana species and fruits from
the mistletoe family are
particularly important
o Insects form a larger portion
of the diet than in most other
titi monkey species201
Range198:
 Found in the upper Rio Mayo Valley,
extending to the south into the Bajo
Mayo and Huallaga central o This is largely the cultivation
 At least 60% of the original habitat of rice and coffee
has been lost202 o Cattle ranching and selective
 Additional surveys are required in all logging also occur
potential habitats in San Martin o Rapid rates of deforestation
 Not found in any protected areas have caused the loss of 40%
of the forest over the last 20
years
Estimated population198: o Construction of a two-lane
 Estimated density of 1.4 individuals asphalt road has further
/ha increased human activity in
 Remaining populations extremely the area
fragmented and in small groups  Also hunted for bushmeat 200, 202, 203,
 Groups observed in fragments as small with pressure likely to increase as
as 2ha199 other game becomes scarce and forest
 Estimated decline of 80% over the last fragmentation increases access.
25 years  Popular as pets 200, 202-204
Threats198: Justification for the Top 25:
 Habitat loss and fragmentation200, 203  Massive deforestation of this species’
o Major agrarian program has preferred habitat resulting in a drastic
attracted huge numbers of population decline
immigrants to the area
31

36. Northern brown howler
monkey
Alouatta guariba guariba
(Humboldt, 1812)
Brazil
Top 25: 2012
Biology205, 206:
 Validity as a subspecies in
question
 Inhabits lowland,
submontane and montane
forest
 Prehensile tail
 Communicates with howls which can
Estimated population205, 206:
be heard up to 2km away207
 Unlikely to be more than 250 mature
 Group size is usually four or five, but
individuals
can be up to eleven
 No subpopulation above 50 mature
 Usually only one dominant male,
individuals is thought to exist
occasionally two
 Quite small and broadly overlapping
home ranges, of 5ha up to 45ha,
depending on the type of habitat208
 Leaf-based diet Threats205, 206:
 The only New World primates to  Hunting
regularly include mature leaves in  Deforestation
their diet, though younger leaves are o Hunting is a larger threat as
preferred groups can survive in small
 Molar teeth are particularly adapted forest fragments if they are
for chewing leaves through shearing not hunted
 Mature fruit is also an important part o Selective logging
of the diet  Disease epidemics
Range205, 206: Justification for the Top 25:
 Restricted to a small area north of the  Very small population under a number
Rio Jequitinhonha of threats
32