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Going, Going, Gone: A 15-Year History of the Decline of Primates in Forest Fragments near Kibale National Park, Uganda


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Given accelerating trends of deforestation and human population growth, immediate and innovative solutions to conserve biodiversity are sorely needed. Between 1995 and 2010, we regularly monitored the population size and structure of colobus monkey populations in the forest fragments outside of Kibale National Park, Uganda. Through this monitoring we assessed the monkeys’ gastrointestinal parasites and fecal cortisol levels. Over 15 years, we documented a rapid decline in the number of fragments that supported primates, largely as a result of tree removal. Fecal cortisol levels of primates found in the fragments were consistently higher than in populations found in the continuous forest of the national park. The fragment populations also harbored gastrointestinal parasites rarely found in the main forest and exchanged bacteria with nearby people and livestock at high rates, suggesting that fragmentation facilitates disease transmission. Fragments supported the fuelwood needs of an average of 32 people living immediately adjacent to the fragment, and partially supported families up to three farms away (~400 m, representing 576 people). Intensive fuelwood harvesting occurred when neighboring households engaged in brewing beer (an average of 9.6 % of the households), distilling gin (8.8 %), or producing charcoal (14.5 %). Our data suggest that the future of small and unprotected forest fragments is bleak; a scenario that is unfortunately typical outside protected areas in many tropical regions.
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Abstract Given accelerating trends of deforestation and human population growth,
immediate and innovative solutions to conserve biodiversity are sorely needed.
Between 1995 and 2010, we regularly monitored the population size and structure
of colobus monkey populations in the forest fragments outside of Kibale National
Chapter 7
Going, Going, Gone: A 15-Year History
of the Decline of Primates in Forest Fragments
near Kibale National Park, Uganda
Colin A. Chapman , Ria Ghai , Aerin Jacob , Sam Mugume Koojo ,
Rafael Reyna-Hurtado , Jessica M. Rothman , Dennis Twinomugisha ,
Michael D. Wasserman , and Tony L. Goldberg
C. A. Chapman (*)
Department of Anthropology , McGill School of Environment, McGill University ,
855 Sherbrooke St West, Montreal , QC , Canada H3A 2T7
R. Ghai A. Jacob
Department of Biology , McGill University , 1205 Dr. Penfi eld ,
Montreal , QC , Canada H3A 1B1
S. M. Koojo D. Twinomugisha
Makerere University Biological Field Station , P.O. Box 967 , Fort Portal , Uganda
R. Reyna-Hurtado
Investigador Titular A, ECOSUR-Campeche , Avenida Rancho s/n,
Poligono 2, Lerma , Campeche 24500El , Mexico
J. M. Rothman
Department of Anthropology , New York Consortium in Evolutionary Primatology, Hunter
College of the City University of New York , 695 Park Avenue , New York , NY 10065 , USA
M. D. Wasserman
Department of Anthropology , McGill University , 855 Sherbrooke St West,
Montreal , QC , Canada H3A 2T7
T. L. Goldberg
Department of Pathobiological Sciences , School of Veterinary Medicine,
University of Wisconsin-Madison , Madison , WI 53706 , USA
L.K. Marsh and C.A. Chapman (eds.), Primates in Fragments: Complexity
and Resilience, Developments in Primatology: Progress and Prospects,
DOI 10.1007/978-1-4614-8839-2_7, © Springer Science+Business Media New York 2013
Park, Uganda. Through this monitoring we assessed the monkeys’ gastrointestinal
parasites and fecal cortisol levels. Over 15 years, we documented a rapid decline in
the number of fragments that supported primates, largely as a result of tree removal.
Fecal cortisol levels of primates found in the fragments were consistently higher
than in populations found in the continuous forest of the national park. The frag-
ment populations also harbored gastrointestinal parasites rarely found in the main
forest and exchanged bacteria with nearby people and livestock at high rates, sug-
gesting that fragmentation facilitates disease transmission. Fragments supported the
fuelwood needs of an average of 32 people living immediately adjacent to the frag-
ment, and partially supported families up to three farms away (~400 m, representing
576 people). Intensive fuelwood harvesting occurred when neighboring households
engaged in brewing beer (an average of 9.6 % of the households), distilling gin
(8.8 %), or producing charcoal (14.5 %). Our data suggest that the future of small
and unprotected forest fragments is bleak; a scenario that is unfortunately typical
outside protected areas in many tropical regions.
Tropical habitats around the world are experiencing increasing stress; the majority
of which results from direct (e.g., deforestation) or indirect (e.g., climate change)
human activities. This increased stress is largely due to human population growth:
our species has grown by 3.7 billion people in the last 50 years (Potts 2007 ) and is
expected to reach between eight and ten billion people in the next 50 years (United
Nations 2009 ). The majority of this growth will occur in tropical countries (Potts
2007 ) and will substantially increase the demands for environmental products and
services (Houghton 1994 ). For example, the net loss in global forest area between
2000 and 2005 was ~7.3 million ha per year (~200 km
2 of forest per day, (FAO
2005 )). This does not consider the vast areas being selectively logged or the forests
degraded by fi re. For example, during the 1997/1998 El Niño, seven million ha of
forest burned in Brazil and Indonesia alone (Chapman and Peres 2001 ). Even when
the physical structure of the forest remains intact, subsistence and commercial hunt-
ing can have a profound impact on forest animal populations. For example, it is
estimated that 3.8 million primates are eaten annually in the Brazilian Amazon
(Chapman and Peres 2001 ).
In the face of these threats, parks and protected areas have become the main tools
of most national strategies to conserve biodiversity and ecosystem processes (Bruner
et al. 2001 ). Tropical forest parks are thought to be particularly important in protect-
ing biodiversity since they contain over half of the world’s known species (Wilson
1992 ). However, these statistics invoke the question: What about the remaining half
of the world’s biodiversity? Such questioning has led a number of researchers to
examine the conservation value of disturbed lands (Brown and Lugo 1994 ), the
potential of restoration (Chapman and Chapman
1999 ; Lamb et al. 2005 ), and,
given their increasing frequency of occurrence, the conservation signifi cance of
C.A. Chapman et al.
forest fragments (Chapman et al. 2007 ; Harcourt and Doherty 2005 ; Hartter and
2009 ; Marsh 2003 ). However, when conservation strategies rely on
unprotected forest fragments to conserve biodiversity, a number of assumptions are
inherent and the validity of these assumptions is largely unknown. Two of the most
critical assumptions are (1) that the fragments will maintain their value to conserve
biodiversity over time and (2) that the animal populations within the fragments will
be healthy.
A principal objective of our research program over the last 15 years has been to
test whether these assumptions are valid. We conducted our investigations in a series
of community-owned forest fragments adjacent to Kibale National Park, Uganda
7.1 ). We focused our research on two species of colobus monkeys: red colobus
Fig. 7.1 Twenty forest patches surveyed outside of Kibale National Park, Uganda, starting in 1995
( note : this does not represent all forest patches in the region). 1 = Kiko #3; 2 = Kiko #4; 3 = Kiko #2;
4 = Kiko #1; 5 = Kasisi; 6 = Rusenyi; 7 = Kyaibombo; 8 = Durama; 9 = C. K.’s Durama; 10 = Rutoma
#1; 11 = Rutoma #4; 12 = Rutoma #3; 13 = Rutoma #2; 14 = Nkuruba—fi sh pond; 15 = Nkuruba—
lake; 16 = Ruihamba; 17 = Lake Nyanswiga; 18 = Dry Lake; 19 = Lake Nyaherya; 20 = Lake
Mwamba. In 2010 only Lake Nyaherya, Ruihamba, Lake Nkuruba, and CK Durama still supported
colobus monkeys
7 Going, Going, Gone: A 15-Year History of the Decline of Primates in Forest…
( Procolobus rufomitratus ) and black-and-white colobus ( Colobus guereza ). These
species were chosen because the red colobus is endangered, neither species moves
among forest fragments, and noninvasive methods can be used to monitor their
physiological status and health (Chapman et al. 2005 ), making these species a valu-
able study system.
Forest Fragments Near Kibale National Park, Uganda
Kibale National Park (hereafter Kibale) can itself be considered a large fragment as
it is 795 km
2 surrounded by agriculture, grazing land, and tea plantations. It is a
mid-altitude, moist evergreen forest in central-western Uganda, Africa (0 13–0
41N and 30 19–30 32E), in the foothills of the Ruwenzori Mountains (Struhsaker
1997 ; Chapman and Lambert 2000 ). Kibale was designated a Forest Reserve in
1932 and became a National Park in 1993 (Fig. 7.2 ). Most of the area inside the
boundary was protected to at least some degree after becoming a forest reserve
(Chapman and Lambert 2000 ), but forested areas outside the boundary were not.
Historically the Kibale region was noted for its extensive forest and abundant big
game (Naughton-Treves 1999 ). Historians describe western Uganda’s forests as
sparsely populated before the twentieth century (Osmaston 1959 ). The Game
Department archives of 1934 state: “ The Toro district is the most diffi cult of the con-
trol areas and will be hard work for many years to come . There are some thirty to
forty herds of elephant totaling fully 2000 animals , the majority of which live in close
proximity to settlements and cultivation . This is only made possible owing to the
appalling nature of the country and the density and height of the grass ” p. 319
(Naughton-Treves 1999 ). However, this situation soon changed and by early 1959 the
area had been converted to a series of community-owned forest fragments immersed
in a matrix of agricultural lands (as substantiated by early aerial photographs). These
fragments tended to persist in areas unfavorable for agriculture, such as wet valley
bottoms and steep hillsides; today they contain remnant populations of four of the
nine diurnal primate species found in the park (Onderdonk and Chapman 2000 ).
We would like to stress that much of the previous work on primates living in
fragmented habitats involves fragments protected from human use (Laurance and
Bierregaard 1997 ; Tutin et al. 1997 ). In reality, most fragments are not protected;
they are on land managed by private citizens who depend on them for resources.
People around Kibale use these forest fragments for activities ranging from forest
product extraction (e.g., timber, charcoal, medicinal plants) to slash-and-burn agri-
culture. In the Kibale region, previous studies have shown that fragments supported
the fuelwood needs of an average of 32 people who lived immediately adjacent to
the fragment, and partially supported families up to three farms away (~400 m),
representing 576 people. Fuelwood harvesting was most intensive when neighbor-
ing households were engaged in brewing beer (an average of 9.6 % of the house-
holds), distilling gin (8.8 %), or producing charcoal (14.5 %; Naughton et al. 2006 ).
C.A. Chapman et al.
While domestic consumers use the most plant species for fuelwood (>50), their
consumption is potentially sustainable because they generally harvest fast- growing
species from fallows on their own land or their neighbors’ land. In contrast, com-
mercial charcoal producers prefer old-growth hardwood species and are responsible
for the greatest loss of natural forest. They access forests by fi nding landholders
who, either willingly or through coercion, allow trees on their lands to be cleared.
The impact of charcoal production is exacerbated by a license system in Uganda
that undervalues natural forests and rewards rapid harvesting across large areas
(Naughton et al. 2006 ).
Fig. 7.2 A typical forest fragment surrounding a crater lake neighboring Kibale National Park,
7 Going, Going, Gone: A 15-Year History of the Decline of Primates in Forest…
The Fate of Fragments and Primate Populations
In 1995 we censused 20 forest fragments near Kibale that had been isolated for at least
36 years (Onderdonk and Chapman 2000 ). In each fragment we determined the pres-
ence or absence of all diurnal primate species, and estimated the population size of
black-and-white colobus (since 1995) and red colobus (since 2000). We measured the
fragment area, distance to the nearest fragment, distance to Kibale, and counted the
number of food trees. We recensused the same fragments in 2000 (Chapman et al.
2007 ), 2003, and 2010. From 1995–2010 there was a drastic decline in the number of
fragments occupied and in population size for both colobines (Fig. 7.3 ).
In 2000 and 2003 we measured all the trees (>10 cm DBH) in each fragment
including all red colobus food trees to examine changes in the food available to each
population. All fragments showed evidence of forest clearing; however, the extent
of clearing was extremely variable (Chapman et al. 2006b ). The average size of the
fragments containing red colobus in 2000 was 4.4 ha (range 1.2–6.4, n = 8). In 2000
there were on average 99 trees/ha in each fragment (range 27–259 trees/ha), while
in 2003 there were 86 trees/ha (range 30–230 trees/ha). The basal area of trees in the
fragments averaged 9002 m
2 in 2000 (range 1981–39,012 m
2 ) and 5293 m
2 in 2003
(range 1772–28,397 m
2 ). The cumulative basal area of red colobus food trees was
915 m
2 in 2000 (range 317–2,430 m
2 ) and 535 m
2 in 2003 (42–2387 m
2 ). Thus,
although forest change was highly variable between fragments, on average the basal
area of food trees declined by 29.5 % over the 3 years. In 2000, exotic species, pri-
marily Eucalyptus grandis , constituted 16 % of the food tree basal area, while in
2003 this value had risen to 28 % (Chapman et al. 2006b , 2007 ).
Fig. 7.3 The population size of re d ( squares ) and black -and- white ( diamonds ) colobus in a series
of forest fragments adjacent to Kibale National Park, Uganda. The number above each point is the
number of fragments that the species were found at that time
1995 1997 1999 2001 2003 2005 2007 2009
Black and White Colobus
Red Colobus
Population Size
16 11
C.A. Chapman et al.
The changes in the forest fragments had dramatic consequences on the resident
primate populations. Black-and-white colobus populations declined by 60 %
between 1995 and 2010, while red colobus populations declined by 83 % between
2000 and 2010 (Fig. 7.3 ). Over the 15 years many of the initial fragments were
largely cleared and resident primate populations were no longer present. In fact by
2010, 92 % of the colobus monkeys were found in only two fragments, and 65 % of
all the monkeys were found in one specifi c fragment—Lake Nkuruba. This site is
unique because in 1991 a small-scale ecotourism operation, established by
C. Chapman, L. Chapman, and M. Steenbeek, maintained the forest and improved
the local communities’ welfare. After a short period of external input, the ecotour-
ism operation was turned over to the local community that it is still protecting this
forest fragment.
Health of the Primates in the Fragments
The Kibale EcoHealth Project ( )
was founded in 2004 by Tony Goldberg as an ecological study of animal and human
health in the Kibale region. The project is an attempt to evaluate the “ecohealth
paradigm” using scientifi c rigor. Ecohealth refers to the idea that human and animal
health are inherently connected to each other and to the physical environment
(Goldberg et al. 2012 ). Thus, improving the health of any component of the animal
health, human health, and environment triangle will improve the health of the
other two.
Some of our initial studies focused on gastrointestinal parasites. We documented
that elevated parasite infections were associated with logging or an increase in the
proportion of forest edge (Chapman et al. 2006a , 2010 ; Gillespie et al. 2005 ). When
we turned to studying forest fragments, we discovered that indices of animal health
were affected in a number of ways. We were particularly interested in whether food
availability and parasite infections synergistically affected red colobus abundance
and if these animals showed physiological signs of stress. We monitored gastroin-
testinal parasites, evaluated faecal cortisol levels (an indicator of physiological
stress), and determined changes in food availability in eight fragments between
2000 and 2003. During this time, the red colobus populations in fragments declined
by 21 %. The change in red colobus population size was correlated both with food
availability and a number of indices of parasite infections. In addition, the stress
levels of groups inhabiting the fragments were approximately 3.5 times greater than
those living within Kibale. In fact, red colobus from Kibale seldom had cortisol
values as high as the lowest values of those in fragments (Chapman et al. 2006b ).
Our interest in the ecohealth concept led us to focus on possible human–
primate disease transmission. Microscopic evaluation of gastrointestinal hel-
minths is inadequate for understanding cross-species transmission because many
helminths are host specifi c, yet morphologically indistinguishable at the spe-
cies level. This was clearly illustrated by elegant studies of nodular worms,
7 Going, Going, Gone: A 15-Year History of the Decline of Primates in Forest…
Oesophagostomum bifurcum , in West Africa: Traditional parasitological analyses
suggested a transmission link between humans and nonhuman primates, but sub-
sequent molecular analyses demonstrated that the parasites infecting nonhuman
primates were entirely distinct from those infecting humans (Gasser et al. 2006 ,
2009 ). We therefore turned to the common gastrointestinal bacterium Escherichia
coli , which inhabits the gastrointestinal tracts of all vertebrates, but is highly vari-
able genetically and clinically (Donnenberg 2002 ). Using this system we docu-
mented that people living near forest fragments harbored E . coli bacteria
approximately 75% more similar to bacteria from primates living in these frag-
ments than to bacteria from primates living within Kibale (Goldberg et al. 2008b ).
Furthermore, genetic similarity between bacteria from human, livestock, and
primates increased by approximately threefold as anthropogenic disturbance
within fragments increased from moderate to high (Goldberg et al. 2008b ).
While E . coli is typically not pathogenic, other microbes can cause signifi cant
clinical effects (Bonnell et al. 2010 ; Garcia 1999 ). For example, we found the patho-
genic gastrointestinal protozoans Giardia duodenalis and Cryptosporidium parvum
in red colobus living in fragments (Salzer et al. 2007 ). In the case of G . duodenalis ,
molecular analyses indicated two genotypes: one (assemblage B IV) appears to
move from people to red colobus, while the other (assemblage E) appears to move
from livestock to red colobus (Johnston et al. 2010 ). Of perhaps even greater con-
cern for public health, we have subsequently identifi ed novel pathogens in this sys-
tem (Goldberg et al. 2008a ; Goldberg et al. 2009 ). We found evidence of a previously
uncharacterized Orthopoxvirus in Kibale red colobus; this pathogen is similar but
distinct from cowpox, vaccinia, and monkeypox viruses (Goldberg et al. 2008a ).
With further investigations, we found three novel simian retroviruses in these red
colobus (Goldberg et al. 2009 ), related to viruses in West Africa that are known to
be zoonotic (Wolfe et al. 2004 ; Wolfe et al. 2005 ). This last fi nding is particularly
troublesome since primates in the forest fragments near Kibale have regular antago-
nistic interactions with people that can result in people receiving bites and scratches
(Goldberg et al. 2006 ; Skorupa 1988 ). As a result, this setting appears to be ideal for
novel zoonotic transmissions to occur.
Our results paint a grim picture of the conservation value of the fragmented land-
scape near Kibale National Park, Uganda. As a result of resource extraction, most
fragments did not last more than the 15 years of the study. Furthermore, the pri-
mates in these fragments were generally unhealthy and physiologically stressed.
Because most fragmented landscapes are not in protected areas, but are locally
owned and used by the communities for extractive purposes, our results are gener-
ally representative of other landscapes with similar human density and demo-
graphic trends (Jacob et al. 2008 ). However, for other primate species that can use
the matrix more effectively or are not forest dependent our fi ndings may not prove
C.A. Chapman et al.
general. The fragmented landscape near Kibale is therefore of little conservation
value for tropical forests and forest-dependent species, such as colobus monkeys.
However, these fi ndings raise fi ve interesting questions.
First, while the fragmented landscape near Kibale appears to be of limited con-
servation value, it raises the question of when conservation effort should be applied
to such habitats. In the case of the Kibale region, there is no evidence that the frag-
ments support wildlife that is not present within the national park. Therefore, it
seems reasonable to suggest that conservationists should concentrate their efforts to
sustaining the protected area, rather than the surrounding fragments. In the case that
endemic species are present within fragments, an argument can be made to protect
these fragments. A similar argument could be made if particular fragments have the
additional value of facilitating movement corridors. Our study demonstrates the
problems associated with protecting small areas of habitat, especially with regard to
the declining health and fi tness of its inhabitants. However, given the threat of infec-
tious disease, isolated fragmented populations may hold value as safeguards against
future epidemics that could occur in larger populations. In the Kibale situation
translocations of the red colobus is not an option because there are no known suit-
able habitat nearby to translocate the animals to. Similarly, it is not possible to man-
age this region as a metapopulation because it is habitat clearing that causes single
populations in the metapopulations to go extinct, thus, there is no habitat remaining
to recolonize.
Second, our study raises the question of what minimum fragment size will per-
mit the long-term health and survival of primates in forest fragments. This question
has been of interest since the conservation value of fragments was fi rst considered
(Lande 1995 ; Soule 1987 ). Our data can be used to evaluate this question over 15
years. This is insuffi cient to address any genetic issues; however, a large and rela-
tively stable population continued to exist in the one fragment where the canopy
trees were not cut: Lake Nkuruba. The persistence of this population suggests that
the most essential short-term issue for survival of colobus populations is simply to
maintain the forest as intact as possible.
A third question that arises from our study is what primate species are most resil-
ient to living in fragmented landscapes. During the last census in 2010, we asked
local agriculturalists if they had seen primates in the study fragments. Many reported
that while colobus were no longer present, red-tailed monkeys ( Cercopithecus asca-
nius ) frequently visited the fragment. Unlike colobus, red-tails travel among frag-
ments and can forage and persist successfully in the agricultural matrix outside of
the fragments. Similarly, Pozo-Montuy et al. ( 2011 ) reports that howler monkeys
( Alouatta palliata ) in Southern Mexico are capable of using very modifi ed land-
scapes that have very small fragments and few native trees. They survive by travel-
ling among trees and shrubs (even travelling along barbed-wire fences) and using
exotic trees as food sources.
Fourth, our research leads to the question of what conditions create unhealthy
primates. In the fragments outside Kibale, poor nutrition is associated with increased
stress levels, which are both related to elevated gastrointestinal parasite infections
(Chapman et al.
2006b ). Similarly, we have demonstrated that contact with humans
7 Going, Going, Gone: A 15-Year History of the Decline of Primates in Forest…
and livestock can lead to the acquisition of benign and pathogenic parasites by red
colobus (Goldberg et al. 2008b ; Johnston et al. 2010 ). Future studies should exam-
ine how other human-induced or mediated factors may lead to elevated stress and
disease in fragments (e.g., hunting, shared water sources, selective harvesting of
food trees).
Lastly, to successfully protect community-owned fragments we need to know
what leads community members to degrade forest fragments and what can be done
to prevent such activities. This is stepping out of the classical framework of biologi-
cal research, but such interdisciplinary research is needed to conserve fragmented
landscapes where socioeconomic conditions create demands for forest products and
new arable land.
To conclude, our study documented a dramatic rate of fragment clearing and colo-
bus decline in 15 years. The primates in this group of fragments were physiologically
stressed and had high disease levels, some of which were clearly transmitted among
humans, livestock, and primates. We expect that all colobus will disappear from these
fragments within the next few years; the only exception is the fragment at Lake
Nkuruba that is protected by a small-scale ecotourism operation. The persistence of
the forest and primates at this site highlights the potential role that community- based
conservation projects can play in protecting forests and wildlife. If current or future
researchers fi nd themselves in the situation that we happened upon 15 years ago, they
need to think carefully about the appropriate action to take. Reversing the trends of
clearing forest and declining primate populations, such as the ones we documented,
requires a major conservation effort on a scale and nature that is rarely feasible.
Specifi cally, halting fragment clearing requires the cooperation of local people. To do
this, alternative sources of income must be found (e.g., ecotourism), fuelwood sup-
plies from elsewhere must be made available (e.g., a large scale woodlot project, or
solar stoves could be provided), and a great deal of effort must be placed on educa-
tion and outreach. In reality, it is unlikely that a project of this magnitude could be
initiated unless the fragments contained species of very special value. Sadly, we
believe that this is the reality of biodiversity conservation outside of protected areas
in many tropical areas of the world. Thus, if the situation in fragments is well illus-
trated by the title “Going, Going, Gone” and this pattern is general, the question
needs to be asked, should conservationists just place their efforts into protected areas?
While the logical extension of our study would suggest that the answer to this ques-
tion is yes, we have hope that in some locations and at some future time the situations
will be different, so that conservation of such community-owned fragments will
become a profi table conservation strategy. As we conduct more research into com-
munity needs and restoration methods, this may become a reality.
Acknowledgments Funding for this research was provided by the Wildlife Conservation Society,
National Science and Engineering Research Council (NSERC, Canada) and the National Science
Foundation (NSF, grant number SBR-9617664, SBR-990899) to CAC and the Morris Animal
Foundation (award number D07ZO024) to TG. Permission to conduct this research was given by
the Offi ce of the President, Uganda, the National Council for Science and Technology, and the
Uganda Wildlife Authority. Lauren Chapman and Tom Struhsaker provided helpful comments on
this research.
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... This species occurs in a wide variety of forest types, including riparian and gallery forest, forest-miombo savanna mosaic, old-growth lowland, mid-altitude, and montane moist rainforest and Euphorbia cloud forest, degraded secondary forests, and regenerating forest. 7,116,[163][164][165] However, it has been extirpated in nearly all forest fragments surrounding Kibale National Park 7,165 and in some forests on the Ufipa Plateau. 163 Total population size for the Ashy red colobus is greater than 25,000 individuals and is thought to be stable. ...
... This has countered dramatically declining encounter rates in the middle of the park due to chimpanzee predation as well as the extirpation of red colobus in most fragments outside the park. 7,165,171,172 At Gombe National Park, the population is also thought to be stable despite chimpanzee predation. 173,174 On the Ufipa Plateau, poor forest protection has led to forest loss, extirpation of red colobus from some forests, and precipitous declines in populations in other forests. ...
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Ranging from forests in Senegal to the Zanzibar Archipelago, red colobus monkeys (Piliocolobus spp.) are the most threatened group of African monkeys. According to the IUCN Red List of Threatened SpeciesTM in 2020, every form of red colobus monkey is threatened with extinction, and 14 of the 18 taxa (>75%) are listed as Critically Endangered or Endangered. Despite their conservation status, only a few populations have been studied in any detail and the general public is largely unaware of these monkeys and their plight. Following over two decades of calls to prioritise red colobus conservation efforts, this publication finally brings together the knowledge of experts on these monkeys and African wildlife conservation to identify the populations in most urgent need of conservation and to develop priority conservation actions for each taxon and across the red colobus’ geographic range.
... While pollution is a direct threat to animal health, it also interacts with a range of other anthropogenic impacts on habitats. To illustrate how chemical contaminants could interact with the changing environment, we consider a tropical system where primate populations inhabit forest fragments that are adjacent to agricultural land; a tropical system some of us have worked on for many years (Chapman et al., 1999;Chapman et al., 2013;Chapman et al., 2007a;Chapman et al., 2006c). Forest loss and fragmentation is a global problem affecting most tropical terrestrial mammals. ...
Sixty years ago, Rachel Carson published her book Silent Spring, which focused the world's attention on the dangers of pesticides. Since that time human impacts on the environment have accelerated and this has included reshaping the chemical landscape. Here we evaluate the severity of exposure of tropical terrestrial mammals to pesticides, pharmaceuticals, plastics, particulate matter associated with forest fires, and nanoparticles. We consider how these environmental contaminants interact with one another, with the endocrine and microbiome systems of mammals, and with other environmental changes to produce a larger negative impact than might initially be expected. Using this background and building on past conservation success, such as mending the ozone layer and decreasing acid rain, we tackle the difficult issue of how to construct meaningful policies and conservation plans that include a consideration of the chemical landscape. We document that policy solutions to improving the chemical landscape are already known and the path of how to construct a healthier planet is discernible.
... All things considered, increased anthropogenic disturbance can reduce available patch size and increase resource competition, potentially leading to negative changes in primate abundance (Anderson et al. 2007;Chapman et al. 2013). In fact, many local elders around WWNSF mentioned that they had subjectively noticed a declining guereza population trend in the area, which they believe is due to the high level of anthropogenic disturbance-including habitat degradation, livestock grazing, human settlement, and agricultural expansion-over several decades (D. ...
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Given the current rate of habitat degradation and loss in the tropics, data on primate population densities and habitat use are indispensable for assessing conservation status and designing feasible management plans for primates. The Omo River guereza (Colobus guereza guereza) is a subspecies of the eastern black-and-white colobus monkey endemic to the western Rift Valley forests of Ethiopia. Their restricted distribution along with habitat loss and hunting within their range render them vulnerable to local extirpation and extinction. Furthermore, there are no published data available on the population status and habitat use patterns of the Omo River guereza. We therefore aimed to assess the population size of Omo River guerezas in diferent habitats (Erica-Juniperus mixed forest, mixed plantation forest, undisturbed natural forest, disturbed natural forest) using transect surveys at Wof-Washa Natural State Forest (WWNSF) in central Ethiopia. Our surveys covered a cumulative distance of 88.5 km in four diferent habitats, during which we recorded a total of 140 Omo River guereza groups. The average group density was 14.3 groups/km 2 , average individual density was 94.4 individuals/km , and we estimated the total population size within WWNSF to be 2549 individuals. The sex ratio of the population was split evenly between males and females, though the age classes skewed strongly towards adults. Of the habitats surveyed, the highest group encounter rate (1.83 groups/km) occurred in the disturbed natural forest. However, the highest individual density (110.1 individuals/ km 2 ) was recorded in undisturbed natural forest. Still, sizable densities (group and individual) were recorded in three of the disturbed habitats (disturbed natural forest, mixed plantation forest, and to a lesser extent Erica-Juniperus mixed forest). Our study ofers the irst baseline information with which to compare future population density estimates and habitat use in the range of Omo River guerezas.
... Several studies on folivorous and arboreal primates have predicted higher extinction probabilities for small fragmented populations; for example, the Mexican mantled howler monkeys (Alouatta palliata mexicana) in Los Tuxtlas, Mexico, have been found to have a 60% probability of local extinctions if fragmented areas are less than 15 ha. Similarly, Colobus Monkey populations in Kibale National Park in Uganda have been found to have higher extinction probabilities with high disease levels (Mandujano and Escobedo-Morales, 2008;Chapman et al., 2013). Hence, it is important to assess the impacts of disturbance intensity (frequency of human visitation in forest fragments, rate of deforestation/logging, etc.), patch characteristics (patch size, heterogeneity among tree composition, etc.) of forest fragments and landscape matrix features on the dispersal of individuals (Bicca-Marques et al., 2020). ...
Trachypithecus geei Khajuria, 1956 or Golden langur are an endangered colobine primate species that are distributed in the transboundary region of Bhutan and India. The species is severely threatened because of increasing habitat fragmentation and isolation across its entire range, especially the populations in Assam, India. The distribution range of the species has not been updated for the last two decades, nor is there any proper evaluation of the habitat requirements for the species. Therefore, we mapped the habitat suitability for the species across its entire distribution and projected its habitat suitability on the simulated landscape for the future (2031). The results indicate that out of the total range extent (66,320 km²), only 12,265 km² (18.49%) is suitable for the species at present, which will further be reduced to 8884 km² by the year 2031, indicating major range contraction. These suitable habitats are largely scattered and fragmented in southern range of the species. Among the predictors used, the distance to evergreen and deciduous broadleaf forest was the strongest predictor out of the 35 used for model building. Moreover, land use and land cover were found to be more informative than the climatic variables. Much of the suitable habitats of the species are located outside the protected area network in the landscape. Therefore, we identified landscape configurations and suitable habitat areas for the future conservation and monitoring of Golden Langur in the protected areas of its range.
... Human population and the attendant increase in consumption rates are drivers of forest loss and fragmentation (Kalbitzer and Chapman, 2018). Many primate species are now found in fragmented forests which can hardly sustain them (Chapman et al., 2013). In order to conserve mona monkeys in fragmented forests around periurban areas of Ikorodu, it is important to understand the trend in the land-use changes in these areas so as to identify areas that would continually remain as their habitats. ...
This chapter reviews current knowledge of the red colobus, Piliocolobus, a polytypic widespread colobine living in sub-Saharan African forests, woodlands, mangroves, and riparian forests. The taxonomy of Piliocolobus has undergone many changes and is still unresolved, resulting in confusion and possibly hindering conservation efforts. Red colobus is known for being the favourite prey of chimpanzees in many locations, and in several populations red colobus associate with guenons to reduce predation risk. Less well-known are their sexual swellings, which vary greatly in size across the genus, and their graded vocal repertoire that lacks a long call, but in some cases includes female mating calls. Noisy, large multi-female multi-male groups, female dispersal, philopatric males that form coalitions, and lack of female allomothering are considered the norm for the genus but these are not universal. Red colobus is facing extirpation in many locations due to human hunting and forest destruction. Various serious diseases and parasites are also reported for many populations and are often associated with human encroachment into their habitat. Much about the social behaviour is yet to be studied, especially in the less-studied central African species assemblage.
As deforestation progresses in the tropics, wildlife populations are increasingly restricted to forest fragments. Here we study genetic population structure in the endangered Ashy red colobus (Piliocolobus tephrosceles) population in the forest fragments surrounding Kibale National Park, Uganda. Subsequently, we use landscape features (elevation, road data and distance to the park) to design a feasible strategy to restore forest in a fashion suitable for both the dispersal patterns of the species and land use practices of the local people. A lack of association between geographic distance and pairwise genetic relatedness among localities, the presence of first degree relatives across localities, and a low global Fst value suggest that red colobus individuals have migrated across this landscape in the recent past. Thus, a series of “stepping stone” forests from the fragments to the park will likely maintain viability of red colobus fragment populations. In this area, low-lying valleys are legally protected to prevent flooding and are considered of low-economic value to local people. We identify such valleys for development of community-based forest restoration efforts that will aid in red colobus conservation and provide various ecosystem services. Our study outlines how genetics and community-based restoration can be integrated to provide realistic conservation solutions.
Habitat loss and fragmentation are major threats to primate populations globally. The Endangered golden monkey Cercopithecus mitis kandti is only found in two small forest fragments: the Virunga massif in Rwanda, Uganda and the Democratic Republic of the Congo, and the Gishwati Forest in Rwanda. Little is known about the abundance and distribution of this subspecies, or threats to its survival. During 2007–2018, we collected data along 893.7 km of line transects and 354.2 km of recce trails in Volcanoes National Park and in Gishwati–Mukura National Park to estimate golden monkey density and examine any threats. In Volcanoes National Park, golden monkeys were found almost exclusively in the bamboo zone, and in Gishwati–Mukura National Park they occurred only in the remnant tropical montane Gishwati Forest. In Volcanoes National Park, density was estimated to be 7.89 (95% CI: 3.85–16.19), 5.41 (2.64–11.08), and 5.47 (3.68–8.14) groups per km ² in 2007, 2011 and 2017–2018, respectively. This corresponds to a total of 4,331 individuals (95% CI: 2,723–5,938) in 2007, 4,487 (2,903–6,071) in 2011 and 4,626 (4,165–5,088) in 2017–2018. In Gishwati Forest, group density averaged 1.98 (95% CI: 1.27–3.16) per km ² , corresponding to 172 (95% CI: 154–190) individuals in 2017–2018. Survey results from Volcanoes National Park suggest that the golden monkey population has been stable during 2007–2018. Limited habitat, illegal activities such as harvesting of bamboo and firewood, and the presence of feral dogs, threaten the golden monkey in Rwanda and require continued monitoring. The development of a conservation action plan is a priority to protect this species.
Many primates exhibit behavioral flexibility which allows them to adapt to environmental change and different habitat types. The golden monkey (Cercopithecus mitis kandti) is a little-studied endangered primate subspecies endemic to the Virunga massif and the Gishwati forest in central Africa. In the Virunga massif, golden monkeys are mainly found in the bamboo forest, while in the Gishwati forest they live in mixed tropical montane forest. Here we describe and compare the diet of golden monkeys in both fragments. Over 24 consecutive months from January 2017 we used scan sampling to record feeding and ranging behavior of two Virunga groups and one Gishwati group totaling ca. 240 individuals. We also examined the phenology of bamboo and fruit trees, key seasonal food plant species for the monkeys. Golden monkeys fed on more than 100 plant species. The Virunga groups were mostly folivorous (between 72.8% and 87.16% of the diet) and fed mostly on young bamboo leaves and bamboo shoots, while 48.69% of the diet of the Gishwati group consisted of fruit from 22 different tree and shrub species. Bamboo shoots and fruit are seasonally available foods and were consumed regularly throughout the period when they were available. Despite being the smallest of the three study groups, the Gishwati group had a larger home range area (150.07 ha) compared to both Virunga groups (25.24 and 91.3 ha), likely driven by the differences in availability and distribution of fruit and bamboo in the habitats. Like other blue monkey subspecies, golden monkeys appear to have a flexible dietary strategy enabling them to adjust diet and ranging behavior to local habitats and available food resources. Additional studies and continuing conservation efforts are needed to better understand how variation in feeding and ranging ecology affects reproduction, population growth, and carrying capacity.
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Dietary responses to the habitat heterogeneity resulting from anthropogenic disturbance vary among primates. Some species alter their foraging strategy and continue to thrive in human-modified habitats while others are unable to modify their diets sufficiently to cope with such disturbance. Over a 12-mo period, we investigated the feeding ecology of the Omo River guereza (Colobus guereza guereza), a subspecies of black-and-white colobus monkeys endemic to Ethiopia, in a large continuous forest (Munessa: LC group), a smaller modified continuous forest (Wondo Genet: SC group), and a tiny forest fragment (Aregash: F group). We found that the forest fragment had higher tree stem densities but lower overall tree basal area than the continuous forests. In all three forests, guerezas were mostly folivorous (LC group: 83%; SC group: 65%; F group: 62%) and consumed young leaves in accordance with their availability. However, in addition to these broad dietary similarities, there were several differences between forests suggesting strategies guerezas may use to cope with habitat heterogeneity in southern Ethiopia. We found that guerezas in anthropogenically altered forests relied less on mature leaves and more on whole fruits (F group) or flowers (SC group) than guerezas in large continuous forest (LC group). Guerezas also devoted large percentages of their feeding time to exotic species in disturbed forests (SC group: 49.0%; F group: 20.6%) but not in the large continuous forest (LC group: 0.0%). Lastly, guerezas in disturbed forests had richer diets (F group, N = 37 species, SC group, N = 32) than those in the large continuous forest (LC group, N = 27). Thus, our study found that within the folivorous dietary strategy of guerezas, there is considerable dietary variability among even neighboring populations experiencing different degrees of habitat fragmentation and degradation. This dietary flexibility may explain the relatively high tolerance of guerezas to human disturbance across their geographic distribution.
This volume was created initially from a symposium of the same name presented at the International Primatological Society's XVIII Congress in Adelaide. South Australia. 6-12 January 2000. Many of the authors who have contributed to this text could not attend the symposium. so this has become another vehicle for the rapidly growing discipline of Fragmentation Science among primatologists. Fragmentation has quickly become a field separate from general ecology. which underscores the severity of the situation since we as a planet are rapidly losing habitat of all types to human disturbance. Getting ecologists. particularly primatologists. to admit that they study in fragments is not easy. In the field of primatology. one studies many things. but rarely do those things (genetics. behavior. population dynamics) get called out as studies in fragmentation. For some reason "fragmentation primatologists" fear that our work is somehow "not as good" as those who study in continuous habitat. We worry that perhaps our subjects are not demonstrating as robust behaviors as they "should" given fragmented or disturbed habitat conditions. I had a colleague openly state that she did not work in fragmented forests. that she merely studied behavior when it was clear that her study sites. everyone of them. was isolated habitat. Our desire to be just another link in the data chain for wild primates is so strong that it makes us deny what kinds of habitats we are working in. However.
Talking about all the diagnostic of general Parasites
The author summarizes 20 years of research in the Kibale forest in Uganda. The main body of the book demonstrates the adverse effects of logging on community structure and other aspects of forest ecology. The author provides evidence that future logging must be done at far lower intensities than is currently the norm, if intact ecosystems are to be maintained. Detailed recommendations for harvest plans compatible with the conservation of biodiversity and ecological integrity are outlined. Struhsaker addresses the underlying causes of tropical deforestation and concludes that although there are numerous proximate factors, the ultimate causes are rapidly increasing human populations and rates of consumption per capita. Comparisons with relevant studies elsewhere in the tropics are drawn and specific recommendations to address the problems are offered.
Two contrasting vegetation types occur in the Lopé Reserve in central Gabon: tropical rain forest dominates but areas of savanna containing natural forest fragments also exist. How forest mammals use the forest fragments has broad implications for conservation and management of tropical ecosystems because the natural landscape at Lopé mimics the fragmentation of forests produced increasingly by human action. The Lopé savannas result from climate induced vegetation changes over the past 20,000 years and are currently maintained by active management because, without regular burning, they are colonized by forest. Forty-five species of large mammal (body weight ≥2 kg ) have been recorded at Lopé and, although none are savanna specialists, some use the savanna habitat. Sweep censuses were conducted monthly over 2 years in 13 forest fragments. The census sites were small (0.4–11 ha), completely or largely surrounded by savanna, and up to 450 m from continuous rain forest. Population density and biomass were calculated for the 26 species of mammals encountered (nocturnal species were rarely seen) and compared to data previously collected in adjacent continuous forests. Total biomass (6010 kg km⁻²) was highest in the forest fragments. Compared to adjacent, continuous forest, elephants ( Loxodonta africana) were less common whereas buffalo (Syncerus caffer) and red river hog ( Potamochoerus porcus) were much more numerous. Of eight species of diurnal primates, four were more common, two occurred at similar densities, and two were much less common in the fragmented habitat. Most mammalian species moved between continuous forest and the fragments but two species of guenon and six species of duiker appeared to reside permanently in some fragments. The diversity and high biomass of large mammals found within the forest outliers at Lopé is surprising and suggests that fragmentation per se will not be catastrophic for most of these species.