Distribution, status, and conservation needs of the golden-crowned
sifaka (Propithecus tattersalli)
Astrid Vargasa, Ignacio Jimeneza,*, Francisco Palomaresb, Marıa Jesus Palaciosc
a
Species and Spaces International, Carlota Alessandri 69, Apt. 10, Montemar 29620, Málaga, Spain
Department ofApplied Biology, Doñana Biological Station, Avda. de Maria Luisa s/n, Pabellón del Perú, Sevilla 41013, Spain
cConsejerı´a de Medio Ambiente, Dirección General de Medio Ambiente, Avda. Virgen de Guadalupe 42, Cáceres 10001, Spain
b
Abstract
The golden-crowned sifaka is considered one of the world’s most endangered primates. To evaluate the species’ current conservation status we established its actual distribution and abundance, and assessed current threats that affect its survival. Study
methods involved direct sifaka observations and interviews to local villagers. Propithecus tattersalli’s distribution is restricted to the
region comprised between the Loky and Manambato rivers. Throughout its range, the species is abundant and it can even be found
in small forest fragments, although it was never observed at elevations above 700 m.a.s.l. Major threats to the species include
habitat destruction through slash-and-burn agriculture, grass fires, wood and gold extraction, and poaching. Total population
estimates range from 6100 to 10,000 individuals, with an effective population size of approximately 2500–4000 sifakas. Though
sensitive to forest destruction, the species seems to be resilient to current levels of landscape fragmentation. We recommend the
establishment of a system of protected areas throughout the Loky-Manambato region and the implementation of a ‘‘Flagship
Species Program’’ utilizing the golden-crowned sifaka as a catalyst for a regional Conservation Management Plan.
Keywords: Golden-crowned sifaka; Propithecus tattersalli; Distribution; Abundance; Flagship species
1. Introduction
Madagascar is considered one of the world’s biodiversity hotspots due to its high level of endemisms
(Mittermeier and Goettsch, 1999). Among the unique
fauna found in the island, lemurs represent a complete
adaptive radiation of non-human primates (Mittermeier et al., 1992, 1994). Of the existing lemur taxa, the
family Indriidae contains the largest and, perhaps,
the most spectacular lemur species. Within this
family, the genus Propithecus comprises nine different
taxa, of which only one species, Propithescus tattersalli,
is monotypic (Mittermeier et al., 1994). This primate
was first noted by Tattersall in 1974 (Tattersall, 1982)
but it was not scientifically described until 14 years
later (Simons, 1988).
The golden-crowned sifaka is one of the smallest
representatives of the genus Propithecus, with an average adult weight of 3.5 kg and a total body length of
approximately 90 cm (Meyers, 1993; Mittermeier et al.,
1994). The species is primarily diurnal, although it can
*Corresponding author. Tel./fax: +34-96-360-33-85.
E-mail address: i_jimenez_perez@yahoo.es (I. Jimenez).
also display early morning and crepuscular activity
bouts during the rainy season (Meyers, 1993). During
dry season, it also tends to feed and rest on higher parts
of the canopy (Meyers, 1993), which makes it more
visible from observation points outside of the forest.
Group size ranges from 3 to 10 individuals that occupy
territories of 9–12 ha (Meyers, 1993).
Previous studies estimated that the geographic distribution of Propithecus tattersalli was limited to forest
fragments between the Loky and the Manambato Rivers, in northeast Madagascar (Meyers and Ratsirarson,
1989; Randrianarisoa et al., 1999). These surveys
focused mainly on the three largest forest patches present in the region (Meyers and Ratsirarson, 1989; Mittermeier et al., 1992; Meyers, 1993; BIODEVFANAMBY, 1998), with the community of Daraina
being the center point of surveyed fragments. Almost no
surveys had taken place on smaller, neighboring patches. Given the highly fragmented and limited distribution of P. tattersalli, this species has been classified as
one of the 25 most critically endangered primates in
the world (IUCN, 1997). The golden-crowned sifaka is
also listed as highest priority rating (6) by the Primate Specialist Group, Species Survival Commission,
International Union for the Conservation of Nature
(Mittermeier et al., 1992).
Throughout the last decade, there have been multiple—yet unsuccessful—efforts and recommendations to
try to establish a 20,000–30,000 ha protected area within
the Daraina region to help protect the golden-crowned
sifaka (Meyers and Ratsirarson, 1989; Mittermeier et al.
1992, 1994; Randrianarisoa et al., 1999; BIODEVFANAMBY, 1998; ANGAP, 2000). However, there has
been no systematic evaluation of the actual conservation
status of the golden-crowned sifaka. This information is
the first step towards the development of a Conservation
Plan for the species, ultimately supporting ongoing
efforts towards establishing a protected area in the region
of Daraina. In this study, we evaluated the conservation
status of P. tattersalli, focusing on the following two
objectives: (1) to establish the species’ actual distribution
and abundance, (2) to assess current threats that can
affect the species’ survival. Results from earliermentioned objectives were later used to evaluate the
golden-crowned sifaka Red List status based on IUCN
current criteria (IUCN, 2001), and to provide management recommendations to ensure its long-term protection.
2. Methods
2.1. Study area
The Daraina region (12o 500 –13o 190 S and 49o 250 –
E) lies within the subregion of Vohemar (Iharana), in the Tsaratanana hydrogeographic region, province of Antsiranana, northeast Madagascar. Previous
information suggested that P. tattersalli occurred in
forest patches delimited by the Loky and the Manambato Rivers, within the Daraina region (Fig. 1;
Simons, 1988; Meyers and Ratsirarson, 1989). The
region comprises approximately 245,000 ha and it contains a mosaic of anthropogenic savanna, dry scrub,
agricultural land, gallery forests, and forest fragments
that vary on degree of deciduousness. Four types of forest (ranging in size between 1 and 14,000 ha) are found in
the region: dry deciduous forest covering the lower hills,
semi-evergreen forest and pre-montane evergreen forest
covering hills and mountain tops, respectively, and the
coastal forest of Sahaka, within the region of Nosy Be.
Throughout the region, an extensive network of gallery
forests, which appear highly degraded in some areas,
connects many forest fragments. Altitude ranges from
100 m in the lowlands of Bekaraoka up to the 1170 m
of Binara, the highest point in the region. Climate is
seasonal, with a dry period that lasts an average of 8
months—April through November—and a 4-month wet
season, from December to March, that coincides with
the Austral summer (Meyers, 1993). No forest within the
region enjoys a legal protection status.
49o 550
The study area includes 18 rural communities, each
composed of small villages that vary between 6 and
2000 people (Rajaobelina, personal communication),
which primarily depend on a subsistence economy
dominated by slash-and-burn agriculture, cattle-raising,
extraction of forest products, as well as fishing around
the coastal and lake areas of Sahaka. The most intensive
form of agriculture is dry rice cultivation in the interior
forests and wet rice farming around Lac Sahaka (Safford, 2000). Gold mining also plays a role in the local
economy, being mostly exploited by immigrant miners
(Meyers and Ratsirarson, 1989). In spite of the region’s
severe fragmentation, the important levels of biological
diversity encountered between the Loky and the Manambato Rivers explain why the Daraina region has been
repeatedly designated as a high priority area for biodiversity conservation (Ganzhorn et al., 1997; ZICOMA,
1999; ANGAP, 2000).
2.2. Geographic distribution
To determine the presence of P. tattersalli in forest
fragments we used two main methods: interviews and
direct observations. These techniques were used
throughout the region comprised between the Loky and
the Manambato Rivers and in bordering forests
and villages located on opposite sides of both river
drainages. Interviews aimed at obtaining preliminary
information on the presence of sifakas in the area as
well as at acquiring knowledge regarding human activities in the surrounding forests and, most importantly,
at increasing local awareness and pride regarding the
importance of the golden-crowned sifaka as a unique,
endemic species to the region. Interviews to local villagers always preceded forest surveys, and target groups
mostly included local middle-aged and young men that
worked in the forests who, therefore, were knowledgeable of the surrounding wooded areas and the possible
presence of sifakas. Interviews were carried out in a
brief, unstructured, and informal fashion covering the
three following issues: (1) presentation of a poster with
all the sifakas of Madagascar to ensure proper species’
identification and, inquiries about the existence of sifakas in nearby forest fragments, (2) inquiries about the
relative abundance of the species in those fragments,
and (3) activities carried out in the surrounding forests
that could threaten this primate (slash and burn agriculture, wood extraction, mining, and hunting).
Actual distribution of the golden-crowned sifaka was
subsequently confirmed through surveys of individual
forest fragments, which were identified a priori using a
LANDSAT TM 1:50,000 image of the region taken in
1994 and FTM 1:100,000 maps based on aerial flights
taken in 1949. A forest fragment was defined as any
piece of forested landscape with an area larger than 4 ha
and a minimum width greater than 50 m. When a forest
Fig. 1. Golden-crowned sifaka presence throughout its distribution range.
of these characteristics presented areas narrower than
50 m, these tracts were considered part of the same
fragment only if their length did not exceed 100 m.
Longer, narrow areas with trees were not considered
forest fragments if isolated, but they were classified as
corridors when they served as a connection between
forest patches.
Forest fragments were surveyed using two methods:
observation points and forest transects. For any surveyed fragment we established an observation point at
high and/or medium altitude sites that allowed maximum
visibility of the area. Distances from each observation
point to the targeted forest fragment ranged between
200 and 1500 m. Once an observation point was established, each survey team—composed of one to two
people—searched for sifakas with binoculars for a
maximum period of two hours or until the first individual was detected. Three factors converged to allow a
high detectability of the species from distant areas: (1)
local landscape is rugged, allowing for visual access of
large forested areas from specifically chosen high and
medium altitude points, (2) our study was conducted
during the dry season, when most forests within the
study area had lost a significant number of leaves, and
(3) golden-crowned sifakas have a bright white coat that
provides a sharp contrast with other forest features
when observed from afar. Our fragment survey-scheme
prevented the possibility of counting the same group of
sifakas in different fragments. Preliminary observations
indicated that the times of highest activity levels, and
thus the optimal observation periods to detect goldencrowned sifakas, was between 8:00 and 12:00 and 15:00
to 17:30 h.
Transects were established in forest fragments where
the existence of sifakas could not be verified from
observation points. This method was used mostly in
small fragments (4–20 ha) located on flat areas, and
with limited visibility from distant points. In such cases,
the forest was transected along its two main axes. Each
surveyed fragment was given one of the following values
regarding the occurrence of P. tattersalli: present,
absent, and undetermined. Golden-crowned sifakas
were considered present in a forest when at least one
individual of the species was observed by a member of
our team. The species was considered absent when its
presence could not be confirmed through direct observations and the following criteria where met: (1) more
than 2 h of observation were dedicated to the fragment
and the whole fragment was transected at least along its
longest axis, (2) weather conditions during observations
were appropriate (i.e. absence of rain), and (3) no
interviewees reported having ever observed the species
in the forest patch. When no sifakas were seen in a
fragment and at least one of the previous criteria was
not met, such forest was classified as undetermined.
Area of occupancy and extent of occurrence were
calculated by digitizing each positive forest fragment
from the LANDSAT TM image on MAPINFO GIS.
Extent of occurrence was measured by a minimum
complex polygon that included all the known sites of
present occurrence of the P. tattersalli. Area of occupancy is commonly defined as the area within a species
extent of occurrence, which is occupied by a taxon,
excluding cases of vagrancy (IUCN, 2001). We calculated area of occupancy by adding the areas of all positive fragments in the GIS database and subtracting
those mountain areas whose altitude precluded the
presence of the species. To estimate species abundance,
we multiplied minimum and maximum density estimates
by the area of occupancy of P. tattersalli.
2.4. Threats to the species
We provide a descriptive evaluation of threats, which
was conducted through interviews to local leaders,
guides, ad hoc interviews with villagers (young and
middle-aged men working in the forest), and direct
observations. Besides questions regarding the presence
and relative abundance of the species (see earlier), we
inquired about activities carried out in forests fragments
that could threaten P. tattersalli, such as hunting, slashand-burn agriculture (tavy), firewood production, gold
mining, and logging activities. When talking to village
elders, we also posed questions relative to changes that
might have taken place overtime in the surrounding
area. In addition, we took notes of the various human
pressures (tavy, wood extraction, etc.) that we encountered while surveying forest fragments and their surrounding matrix.
2.3. Species abundance
2.5. IUCN Red List status
Density estimates were obtained from five representative sampling areas covering sections of forest
fragments where the species had been previously detected.
These five areas included two lowland dry forest (Central Bekaraoka and Andasibe), a semievergreen forest
fragment (Andrainginala), and two premontane evergreen forests (Binara and Antsahabe; Fig. 1). To determine number of groups per site, a minimum of four
replicate counts were carried out for two consecutive
days in each sampling area (i.e. two counts from 8:00 to
12:00 h and two counts from 15:00 to 17:30 h). These
repeated counts allowed us to ensure that our group
measures were consistent. Densities at each sampling
area were estimated as number of groups sighted divided by the total visible area from such points. Total
observed area was calculated from a 1:100,000 topographic map that included altitude lines. Comparisons
between the different forest types allowed us to obtain
minimum and maximum number of groups per unit of
area (km2).
In order to classify P. tattersalli into the IUCN Red
List Categories we used the latest criteria established by
the IUCN Species Survival Commission, version 3.1,
approved in February 2000 (IUCN, 2001). Input data
included all updated information on golden-crowned
sifaka’s geographic distribution (including actual extent
of occurrence and area of occupancy), estimated abundance, effective population size, number of subpopulations, threats to the species, fragmentation patterns,
population trends, and estimates of potential declines
(Table 1).
3. Results and discussion
3.1. Geographic distribution
Throughout the 6 weeks of fieldwork, a total of 948
man-hours were invested in searching for P. tattersalli.
Table 1
Criteria met by Propitheus tattersalli based upon IUCN’s Red List Categories and Criteria: version 3.1
Critically endangered
A. Population reduction
Past decline
Future decline
Endangered
Vulnerable
No decline in the past 10 years
Criterion A2ca
> 80% In three generations
B. Geographic range
Extent of occurrence
Area of occupancy
880 km2
360 km2
Criterion B1.ab
Criterion B2.ab
C. Population size
6 6,100 to 10,000
D. Number ofmature individuals
6 6,100 to 10,000 (Ne 6 2500 to 4000)
b
Criteria D2b
N/A
E. Quantitative analyses
a
Comments
IUCN, 2001.
This study.
We carried out a total of 83 interviews, with an average
of four interviews per group of neighboring forest
patches. In general, if P. tattersalli existed within the
vicinity of an area, local villagers were able to identify it
from poster drawings. Information provided by local
villagers regarding the presence or absence of sifakas in
nearby forests was found to be accurate, and only on
three occasions we found sifakas in small fragments that
local villagers had regarded as negative. Goldencrowned sifakas are highly conspicuous and widespread
throughout their distribution range. While searching for
the species, we were frequently able to establish their
presence in a fragment before even settling in a specific
observation point. In general, sightings occurred within
the first 15 min of observation and, if there were sifakas
in the targeted forest fragment they could be usually
located within the first hour of observation (authors,
unpublished data).
Ground surveys resulted in sightings of 108 sifaka
groups, including a total of 334 observed individuals. Of
the 74 surveyed fragments, 66 were located within the
limits established by the Loky and the Manambato
Rivers, while eight fragments were selected north and
south of both river margins, respectively. Actual presence or absence of sifakas was confirmed in 65 of the
74 surveyed fragments, of which 44 (59.5%) were positive and the remaining 21 were negative (Fig. 1). Nine
fragments where we could not find sifakas were classified as undetermined, since they did not meet the criteria
to be classified as negative (Fig. 1). Data analyses show
that the area, where we confirmed sifaka presence,
comprises approximately 44,125 ha of forest fragments
that vary in size and degree of encroachment. A minimum convex polygon that included all known sites of
species presence resulted in an overall extent of occurrence of 88,240 ha (Table 1).
During surveys, we found presence of golden-crowned
sifakas outside the geographic limits that were previously suggested for the species (Meyers and Ratsirarson, 1989; Mittermeier et al., 1994). Presence of
sifakas outside the western edge of the Loky River—in
the three-patch cluster centered around Antanimarazoko (3o 10 S–49o 270 E, Fig. 1), was first suggested by
local villagers during interviews and afterwards it was
corroborated by onsite surveys. Since these patches are
isolated from other forests to the west they represent the
westernmost distribution of P. tattersalli. The north and
south distribution of P. tattersalli is marked by the
Loky (12o 500 S) and the Manambato (13o 190 S) Rivers,
respectively, while the furthest East where we verified
presence of sifakas was within patches of the Amporaha
mountain (13o 40 S–49o 490 E). These geographic boundaries represent one of the most restricted distributions
of any lemur species (Fig. 1).
3.2. Species abundance
Density estimates were obtained from five sites that
represented different forest types. Repeated counts on
Binara and Antsahabe, the two highest forests in the
region, yielded no positive observations of sifakas on
the high areas of both forests, and only two sightings
on the lowest foothills of Antsahabe. Also, out of the
334 sifakas sighted during our study, only two groups
(n=6 individuals) were spotted at altitudes between 600
and 700 m, with no animals being detected above 700
m.a.s.l. Binara and Antsahabe are the only fragments in
Daraina that have forested areas above 700 m, and a
recent biodiversity survey of Binara also resulted in no
sifaka sightings above 700 m.a.s.l. (A.V., personal
observation). Pending further research, our data implies
that sifakas show a negative selection towards high
altitude forests. Therefore, to obtain estimates of species’ abundance, we only considered data obtained at
three representative sites of deciduous and semievergreen forests of altitudes below 700 m.a.s.l. Repeated counts yielded consistent results regarding the
number of groups present in a given area, allowing us to
determine that golden-crowned sifakas occurred at densities that varied between 0.18 and 0.29 km2/group.
Considering an average of five individuals per group
(Meyers, 1993; Jimenez and Vargas, 2000), minimum
and maximum density estimates ranged between 17 and
28 ind/km2, respectively. These density estimates are
higher than those reported for P. diadema edwardsi
(Glander et al., 1992; Wright, 1995) and P. verreauxi
verreauxi (Richard, 1978). Taking into account that,
throughout the region, there are approximately 440 km2
of forests available to the species (i.e. forests where we
confirmed the species’ presence), of which approximately 80 km2 are above 700 m.a.s.l., we estimated that
the potential area of occupancy for the golden-crowned
sifaka is 360 km2 (Table 1). Minimum and maximum
density estimates multiplied by total area of occupancy
resulted in total population estimates of 6120–10,080
individuals, respectively. Given that only one male and
one female reproduce per year in each group (Meyers,
1993), effective population size for the species falls
between 2520 and 3960 individuals. Our estimates of
overall abundance are consistent with those presented
by Meyers (1996), who reported a total estimated
population of 8000 golden-crowned sifakas.
3.3. Threats to the species
Interviews and direct observations indicated that
major threats to the golden-crowned sifaka included
slash-and-burn agriculture, uncontrolled grass fires,
wood extraction for housing and firewood production,
logging of precious woods, gold mining, and hunting.
This is consistent with previously listed threats to this
species (Meyers and Ratsirarson, 1989; Mittermeier et
al. 1992, 1994; Randrianarisoa et al., 1999). Slash-andburn agriculture (tavy), or shifting cultivation, is a
common practice throughout the Daraina region. Plots
for farming generally yield crops for 2 or 3 years, and
need approximately 10–15 years of fallow in order to
replenish nutrients and become productive again. Tavy
in primary forests is more productive than in secondary
forests, and new rice plots need to be progressively created to meet people’s needs, thus encroaching steadily
on remaining habitat.
Uncontrolled grass fires, presumably aimed to clear
pasture and provide forage for cattle, are widespread in
Madagascar (Phillipson, 1994). In Daraina, ‘‘fire season’’ takes place primarily in November, and frequently
occurs under uncontrolled conditions. Since there is no
regulation on distance to forest fragments, fires set to
clear vegetation and promote the growth of pasture can
also destroy natural flora and forest edges, therefore
reducing the size of remaining forests overtime. We
observed significant damage due to tavy and grass fires.
Ground proofing of forest fragments that appeared in
the 1994 LANDSAT image revealed that at least 5.5%
(n=4) of the forest fragments selected for surveys had
disappeared within the last 6 years. In addition, a significant portion of surveyed forests fragments presented
various degrees of damage due to tavy and grass fires,
indicating that these activities pose a significant threat
to habitat availability for P. tattersalli.
Wood extraction is mostly carried out to build house
frames, pirogues, and for fencing rice fields. Coal and
kitay (firewood for cooking) are traditionally produced
from live and dead wood, respectively, gathered from
the forest. Throughout the region, the use of kitay is
more commonplace than that of coal, although the latter is preferred when family income permits its acquisition. Information provided by villagers indicated that in
many forest fragments, naturally occurring dead wood
is gradually being depleted and the extraction of young
trees to produce kitay is becoming more common.
Freshly cut tree stumps were observed in the majority of
surveyed fragments, although patches that were close to
established villages seemed to be subject to greater
impact. The degree to which exploitation of precious
woods affects the Daraina region is not well established,
but illegal logging of large trees has been occurring in
the forests of Bekaraoka and Binara (authors, personal
observation). Presently, there are no reforestation
efforts to counter resource exploitation. A thorough
evaluation of current levels of wood extraction within
the region, including viable alternatives to ameliorate
present pressures, should be conducted as part of the
ultimate objective of establishing a protected area
within the region of Daraina.
Gold mining is an activity that mostly takes place
outside forested areas, although it may also occur along
riverbeds within forested areas. Throughout the region,
gold mining occurs as small-scale operations, and within
forests it involves digging out large pits near and under
the roots of large trees, an activity that ultimately
destroys the tree. This has already caused notable
damage to certain riparian forests. During the past decades, most migrants that arrived into the Daraina
region were itinerant gold miners, though apparently
such migrations have decreased in the past few years
(Rajaobelina, personal communication). But previous
attempts to establish a protected area in the region were
denied, partially because they were perceived as a
potential obstacle to uncontrolled mining in the region
(Meyers, 1996). At current levels of exploitation, gold
mining ‘per se’ does not seem to pose a significant threat
to P. tattersalli’s survival (Meyers, 1996; this study).
Yet, we believe that gold mining actually remains a
significant potential threat to the region, since it is not
possible to ascertain if new hordes of miners will arrive
in the area or if a large commercial company will decide
to set up an industrial endeavor in the region.
Hunting of P. tattersalli appears to be of limited
extent. Regional beliefs dictate that it is fady (taboo) to
eat this species and, although respect for this fady is
generally honored, immigrant miners do not always
respect local traditions (Meyers, 1996). In general,
targeted lemur species for hunting are Eulemur fulvus
sanfordi, Eulemur coronatus, and Lepilemur spp. (Randrianarisoa et al., 1999), and we found lemur traps in
some of the surveyed fragments. Interviews revealed
that the species is rarely hunted. In addition, most
sifaka groups encountered during our study seemed
unwary of human presence, indicating that respect for
the fady against eating them appears to predominate.
Through a multivariate analysis, Jimenez and Vargas
(2000) determined that P. tattersalli was more likely to
be found in large forest fragments ( > 1000 ha) and that
proximity to large, positive fragments and connectivity
between patches were important predictors of species
presence. These results follow classic predictions from
island biogeography theory regarding the effects of
habitat fragmentation on wildlife distribution (MacArthur and Wilson, 1967; Schafer, 1990). However, a few
details indicate that the golden-crowned sifaka might be
especially well adapted to survive in a fragmented
landscape. For instance, four groups were observed in
riparian corridors comprised of single lines of trees at
each side of a creek, and three other groups were
observed feeding or resting in small clusters of trees
( < 1 ha) unconnected to nearby forests. One of these
groups jumped to the ground and crossed more than
200 m of savanna to reach the closest forest after
noticing our presence. This, together with similar
accounts reported by local people, suggested that P.
tattersalli might be able to cross long distances through
unforested habitat. In addition, the golden-crowned
sifaka is not restricted to undisturbed forests, being
also found around gold-mining villages, inside degraded forests and showing, in some cases, a tamed
behavior towards humans. All this information indicates that, although P. tattersalli is sensitive to forest
degradation and fragmentation, it is fairly resilient to
human presence and associated activities, allowing for
conservation strategies in a landscape where both,
humans and sifakas, can exist together.
Illegal logging, tavy, gold mining, and grass fires have
led to habitat destruction and, consequently, to severe
fragmentation between the Loky and the Manambato
Rivers. A recent evaluation of deforestation patterns in
the Daraina region shows that shapes and sizes of most
forest fragments have remained stable during the past
50 years (Jimenez and Vargas, 2002). Yet, approximately 5% of small to medium-sized forests have
disappeared during the past 6 years (Jimenez and Vargas, 2000), indicating a growing increase in human
encroachment. Upon such scenario, P. tattersalli’s present status quo could rapidly change and, if no efficient
protection action is rapidly taken, the species could
easily slip into an extinction vortex.
3.4. IUCN Red List status
During the past decade, the golden-crowned sifaka
has been classified as a critically endangered species
(Mittermeier et al., 1992; IUCN, 1994, 2001). Under the
new IUCN criteria, the species continues to be classified
as critically endangered based on a potential population
reduction (IUCN criteria A2c), as well as on its limited
geographic range (criteria B1+2bcd; Hilton-Taylor,
2000). Our data show that the species’ present extent of
occurrence is 880 km2 and, thus, greater than the 100
km2 established by the new criteria. Area of occupancy
is 360 km2—also significantly greater than the 10 km2
established to meet the critically endangered status
(Table 1). In addition, population numbers are well
beyond the established maximum of 250 animals. Even
though the golden-crowned sifaka has a very restricted
geographic distribution in a severely fragmented habitat, our data indicate that the species’ classification as
critically endangered under the IUCN ‘‘B’’ criterion is
not warranted (Table 1).
Classification as critically endangered under criteria
A2c entails that the species could suffer a ‘‘population
reduction of at least 80%, suspected to be met within
the next three generations (approximately 27 years for
P. tattersalli, P. Wright, personal communication),
based on a decline in area of occupancy, extent of
occurrence and/or quality of habitat’’ (IUCN, 2001;
CBSG, 2001). Although fragmentation patterns in the
Daraina region have remained stable during the past 50
years (Jimenez and Vargas, 2002), the existence of gold
and precious stones in the region makes Daraina a
potentially dangerous target for mining operations. In
addition, logging pressures have been continuously
increasing since 2001 (authors, personal observation).
Recently, the Malagasy NGO Fanamby began to
implement a ‘‘Conservation and Natural Resource
Management Program for the Daraina Region’’, a program ultimately conceived to grant protection to the
golden-crowned sifaka and the habitat upon which it
depends, while improving the quality of life of the people that inhabits the area. At present, however, no forests in the area enjoy a legal protection status and, given
Madagascar’s political unrest, the region’s future protection remains uncertain. Considering all available
information, we support the IUCN classification of the
golden-crowned sifaka as a critically endangered species
until effective protection measures are in place to ensure
its conservation. Yet, we recommend a revision of
current IUCN categorization of this species in order to
re-catalogue it under criterion A2c only.
4. Management recommendations
1. To ensure conservation and long-term survival
of P. tattersalli in such fragmented and complex
landscape, it is important to establish—in the
near future—a Network of Protected Areas.
Three forest complexes stand out as the most
relevant for golden-crowned sifaka conservation:
(A). Bekaraoka and neighboring connected fragments to the west (Ambilondamba) constitute
the species’ central reservoir (Fig. 1). These forests probably harbor the largest and most continuous extension of optimal dry-lowland habitat
for the golden-crowned sifaka, and are currently
experiencing the highest impact from human
populations living around the village of Daraina.
(B). The large forest tracts of Binara-AntsahabeAmbohitsitondroina, along with the network of
connected forests north of the Manambato River
constitute P. tattersalli’s southern reservoir
(Fig. 1). This complex includes the largest tracts
of undisturbed forests within the region, but
much of this area seems to hold suboptimal
habitat for P. tattersalli due to its high elevation.
The southwest fragments of Bobankora, Ampoetany, and Ankaramy constitute a smaller network of forests that harbor excellent low- to
mid-altitude semievergreen forest, which constitute prime habitat for the species. In addition,
these forests are transitional between dry and
humid domains, and harbor a unique vegetation
assemblage with no analog in Madagascar. (C)
The northern forest complexes of Antsaharaingy,
Ampondrabe, Antanifotsy, and Benanofy constitute the species’ northern reservoir (Fig. 1).
Their vegetation communities are also distinct
and they should be included as part of the network of protected areas.
2. The existence of a highly fragmented landscape,
lacking large forest tracts and surrounded by
significant human presence, precludes the design
of a single large reserve. Thus, any regional
strategy directed to conserve local forests and
golden-crowned sifakas should include what we
define as ‘‘Conservation Gradients’’. Such concept implies the design and enforcement of different degrees of protection throughout various
forests fragments present in the region. Accordingly, some areas of the earlier mentioned forests
complexes should be included within a National
Park or Nature Reserve, while other forests
should be designated as Forêt classé or Regional
Reserve, where sifakas can share their habitat
with some human activities. Conservation of
small riparian forests (corridors) could rely on
community agreements and incentives, while
some forests that have low potential for conservation could be used for extraction purposes.
3. We recommend the implementation of a Flagship
Species Program utilizing the golden-crowned
sifaka as a catalyst for regional biodiversity conservation. This program should be implemented
as support to the ongoing ‘‘Initiative for Conservation and Natural Resource Management in
the Daraina Region’’, a program established by
the Malagasy Association FANAMBY since
June 2001. The Flagship Species Program should
include management, education/outreach, and
research actions, with management actions
focusing primarily on the design and implementation of a Protected Areas Program and the
use of incentives for conservation. Education and
outreach activities should promote the goldencrowned sifaka’s endemic condition as a source
for local pride and the species’ ecotourism potential as a reason for local involvement in its conservation. Finally, research activities should focus
on metapopulation studies. Priority questions
that need to be addressed in order to implement
appropriate management actions include: metapopulation dynamics, demography, potential
genetic effects due to geographic isolation
between populations, and the importance of
large, undisturbed forest tracts on the species
survival.
5. Summary and conclusions
1. Propithecus tattersalli’s distribution is restricted
to the region comprised between the Loky and
Manambato Rivers, with the exception of a few
groups residing in a small forest cluster on the
other side of the Loky River. Golden-crowned
sifakas dwell in forest types that vary from drydeciduous to semi-evergreen and pre-montane
evergreen forests, and they have never been
reported at elevations above the 700 m.a.s.l.
2. Throughout the 360 km2 of forests available to
the species, the golden-crowned sifaka is abundant and found in fragments of variable sizes.
Total population estimates range from 6100 to
10,000 individuals, with an effective population
size of 6 2500 to 4000 sifakas.
3. The species appears to be distributed as a complex metapopulation, with three large populations that contain smaller subpopulations within
them (Fig. 1).
4. P. tattersalli seems to be fairly resilient to human
disturbance. This adaptable behavior is likely to
allow the species to survive in a fragmented
landscape as long as human disturbance does not
increase significantly and that large forests tracts
(i.e. larger than 1000 ha) are not destroyed.
5. The golden-crowned sifaka can be classified as a
critically endangered species under criterion A2c
of the IUCN’s new Red List Categories and
Criteria. Its long-term survival depends on a
precarious status quo, and major potential
changes in local land use (e.g. beginning of
industrial gold-mining) could lead the entire
population into an extinction vortex.
6. The golden-crowned sifaka is both a reason and
a resource to start a regional process for biodiversity conservation in the Loky-Manambato
region. It is a reason because it is endangered
and endemic to a small area in northeast Madagascar. And it is a potential conservation
resource because it is charismatic and can easily
attract ecotourism attention.
Acknowledgements
This project would not have been possible without the
support and enthusiasm of Serge Rajaobelina and
the FANAMBY crew, who laid the ground to allow us
to conduct research in Madagascar. We thank the project’s field assistants Rindra Andriambola, Emilienne
Rasoazanabary, Romule Rakotondravony, Abel Razonajaona, Margarida Fernandes, and Luka Clarke for
their dedication while searching for golden-crowned
sifakas. Financial support for this project was provided
by Conservation International, through a grant from
the Margot Marsh Biodiversity Foundation. Additional
funding was granted by the Society for the Conservation and Study of Endangered Species and Populations
(Germany), Conservation des Especes et des Populations Animales (France), Idea Wild (USA), and the
Oregon Zoo Conservation Foundation (USA). The
‘‘Project D’Appui de Gestion de L’Environnement’’
supported the costs of two Malagasy students, Tafita
Andriamanantena and Setra Andriamanaitra. We want
to express our gratitude to Bill Konstant, who believed
in this project from the beginning and supported our
efforts every step of the way.
References
ANGAP, 2000. Plan de Gestion du Reseau National des Aires Protegees de Madagascar, 2000–2005. Ministere de L’Environnement,
Association Nationales pour la Gestion des Aires Protegees, Madagascar.
BIODEV-FANAMBY, 1998. Inventaire Ecologique dans la Region
de Daraina (Unpublished Report, decembre). Association
Fanamby, Antananarive, Madagascar.
CBSG, 2001. Evaluation et Plans de Gestion pour la Conservation de
la Faune de Madagascar: Lemuriens, Autres Mammiferes, Reptiles
et Amphibiens, Poissons d’eau douce. 10–25 mai 2001, Mantasoa,
Madagascar.
Ganzhorn, J.U., Rakotosamimanana, B., Hannah, L., Hough, J., Iyer,
J., Olivieri, S., Rajaobelina, S., Rodstrom, C., Tilkin, G., 1997.
Priorities for Biodiversity Conservation in Madagascar. Primate
Report 48 (1).
Glander, K.E., Wright, P.C., Daniels, P.S., Merenlender, A.M., 1992.
Morphometrics and Testicle Size of Rainforest Lemur Species from
Southeastern Madagascar. J. Human Evolution 57, 1–17.
Hilton-Taylor, C., 2000. 2000 IUCN Red List of Threatened Species.
IUCN, Gland, Switzerland and Cambridge, UK.
IUCN, 1994. IUCN Red List Categories. Version 2.3. December,
1994. IUCN Species Survival and Commission, IUCN, Gland,
Switzerland.
IUCN, 1997. The World’s Top 25 most Endangered Primates. IUCN/
SSC Primate Specialist Group, Gland, Switzerland.
IUCN, 2001. IUCN Red List Categories and Criteria: Version 3.1.
IUCN Species Survival and Commission, IUCN, Gland, Switzerland and Cambridge, UK.
Jimenez, I.J., Vargas, A.V., 2000. A Report on the Conservation Status of the Golden-crowned Sifaka (Propithecus tattersalli) (Unpublished Report, October). Association Fanamby, Antananarive,
Madagascar.
Jimenez, I.J., Vargas, A.V., 2002. Patterns of Forest Cover Change in
the Daraina Region (Unpublished Report, February). Association
Fanamby, Antananarive, Madagascar.
MacArthur, R.H., Wilson, E.O., 1967. The Theory of Island Biogeography. Princeton University Press, Princeton, New Jersey.
Meyers, D., 1993. The Effects of Resource Seasonality on the Behavior
and Reproduction of the Golden-crowned Sifaka (Propithecus tattersalli, Simons, 1988) in three Malagasy forests. PhD Dissertation,
Duke University, University microfilms, Ann Arbor, Michigan,
USA.
Meyers, D., 1996. Update on the endangered sifaka of the north.
Lemur News 2, 13–14.
Meyers, D., Ratsirarson, J., 1989. Distribution and conservation of
two endangered sifaka in northern Madagascar: Propithecus diadema perrieri, Lavauden, 1931 and Propithecus tattersalli, Simons,
1988. Primate Conservation 10, 81–86.
Mittermeier, R.A., Konstant, W.R., Nicoll, M.E., Lagrand, O., 1992.
Lemurs of Madagascar: An Action Plan for their Conservation 1933–
1999. IUCN/SSC Primate Specialist Group, Gland, Switzerland.
Mittermeier, R.A., Tattersall, I., Konstant, W.R., Meyers, D.M.,
Mast, R.B., 1994. Lemurs of Madagascar. Conservation International, Washington DC, USA.
Mittermeier, R., Goettsch, C., 1999. Megadiversity: Earth’s Biologically
Wealthiest Nations. Conservation International, Washington DC.
Phillipson, P.B., 1994. Madagascar. In: Davis, S.D., Heywood, V.H.,
Hamilton, A.C. (Eds.), Centers of Plant Diversity: A Guide and
Strategy for their Conservation. The World Wildlife Fund for Nature and the International Union for the Conservation of Nature,
Cambridge, UK, pp. 271–281.
Randrianarisoa, P.M., Rasamison, A.A., Rakotozafy, L., 1999. Les
Lemuriens de la region de Daraina: Foret d’Analamazabaza, foret
de Bekaraoka et foret de Sahaka. Lemur News 4, 19–21.
Richard, A.F., 1978. Behavioral Variation: Case Study of a Malagasy
Lemur. Bucknell University Press, Lewisburg, Pennsylvania.
Safford, R.J., 2000. Etude Environnementale et ecologique du Lac
Sahaka, Madagascar. Royal Holloway Institute for Environmental
Research, University of London, Royaume-Uni, London.
Schafer, C.L., 1990. Nature Reserves: Island Theory and Conservation
Practice. Smithsonian Institution Press, Washington DC.
Simons, E.L., 1988. A new species of Propithecus (Primates) from
northeast Madagascar. Folia Primatologica 50, 143–151.
Tattersall, I., 1982. The Primates of Madagascar. Columbia University
Press, New York.
Wright, P.C., 1995. Demography and life history of free-ranging Propithecus diadema edwardsi in Ranomafana National Park, Madagascar. International Journal of Primatology 16 (5), 835–848.
ZICOMA, 1999. Les Zones D’Importance pour la Conservation
des Oiseaux a Madagascar. Project ZICOMA, Antananarivo,
Madagascar.