Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 August 2020 | 12(11): 16424–16433
ISSN 0974-7907 (Online) | ISSN
0974-7893 (Print)
doi: https://doi.org/10.11609/jott.5839.12.11.16424-16433
#5839 | Received 05 March 2020 |
Final received 31 July 2020 | Finally accepted 10 August 2020
Habitat preference and current distribution of Chinese
Pangolin (Manis pentadactyla L. 1758) in
Dorokha Dungkhag, Samtse,
southern Bhutan
Dago Dorji 1, Jambay
2, Ju Lian Chong 3 & Tshering Dorji 4
1 Sarpang Forest Division, Department of Forest and Park Services, 31101 Sarpang, Bhutan.
2 Faculty of Forest Sciences,
College of Natural Resources, Royal University of Bhutan, Lobesa,
13001 Punakha, Bhutan.
3 Faculty of Science and Marine
Environment & Institute of Tropical Biodiversity and Sustainable
Development, University Malaysia, Terengganu, 21030 Kuala Nerus,
Terengganu, Malaysia.
4 Thimphu Forest Division, Department of Forest and Park Services, 11001 Thimphu, Bhutan.
1 ddorjee@moaf.gov.bt
(corresponding author), 2 jambay89@cnr.edu.bt, 3 julian@umt.edu.my,
4 tdorji1@moaf.gov.bt
Editor: Anwaruddin Choudhury, Rhino Foundation for nature in North East India, Guhawati, India. Date of publication: 26 August
2020 (online & print)
Citation: Dorji,
D., Jambay, J.L. Chong & T. Dorji
(2020). Habitat preference
and current distribution of Chinese Pangolin (Manis pentadactyla
L. 1758) in Dorokha Dungkhag, Samtse,
southern Bhutan. Journal of Threatened Taxa 12(11): 16424–16433. https://doi.org/10.11609/jott.5839.12.11.16424-16433
Copyright: © Dorji et al. 2020. Creative Commons Attribution 4.0 International License. JoTT allows
unrestricted use, reproduction, and distribution of this article in any medium
by providing adequate credit to the author(s) and the source of publication.
Funding: The Rufford Foundation, UK (Project ID: 20287-1).
Competing interests: The authors declare no competing interests..
Author
details: Dago Dorji graduated with a
Bachelor of Science (Forestry and wildlife) from College of Natural Resources
(CNR), Royal University of Bhutan. Currently he is working as Sr. Forest Ranger
in Sarpang Forest Division under Department of Forest
and Park Services. His research
interests are in the, field of wildlife management, Remote Sensing & GIS.
He is also interested in wildlife photography. Jambay is an Associate Lecturer
in the department of Forest Sciences at the College of Natural Resources (CNR),
Royal University of Bhutan. He graduated with a MSc in forestry from Forest
Research Institute, Dehradun India and BSc in Life Science from Sherubtse college, Bhutan. His research interests are in
the field of wildlife management, watershed, and statistical analysis of research
data. He is currently researching forest-water cycling and land-management
impacts on wildlife and their habitats in Bhutan. Ju Lian Chong graduated with a BSc
in Zoology with first class degree (Honours) and
PhD (Genetics) from Universiti Kebangsaan
Malaysia. Currently she is based at as a senior lecturer at the Faculty of
Science and Marine Environment and Institute of Tropical Biodiversity and
Sustainable Development in Universiti Malaysia
Terengganu, where she studies various species of fauna including pangolins,
moths, bats, birds and civets, on aspects of their ecology, biology and
populations in order to better understand the intricate interactions between
organisms and their ecosystem to ensure their existence as heritage for the
future generations. Tshering Dorji works
under Thimphu Forest Division under Department of
Forest and Park Services. He is currently the Head of Social Forestry and
Extension Section and manages Samazingha Agroforestry
Project. His main job responsibilities include developing community forest
management plans, monitor plantation programs, etc.
Author
contribution: Dago Dorji and Jambay designed and conducted the study. Data compilation:
Dago Dorji and Jambay.
Manuscript writing: Dago Dorji and Jambay. Improved manuscript writing and editing:
Chong Ju Lian and Tshering Dorji.
Acknowledgements:
We are truly grateful to the Rufford
Foundation for the generous funding support for this study. Our sincere thanks to the Department of
Forests and Park Services Bhutan for kindly permitting us to undertake this
study. We also extend our sincere thanks
to former chief forestry officer, Divisional Forest Office, Samtse
for providing valuable support during field data collection. Mr. Dawa Tshering, range officer of Dorokha
Range and his dedicated field staff are acknowledged for their hardship and
sacrificing their time during the entire data collection period. Likewise, Mr. Ram Bdr
Subba,sr. forester, Dorokha
Range for helping in identification of plant species. Lastly, we are indebted to the anonymous
reviewers and subject editor for their rigorous reviews and edits.
Abstract: The
Chinese Pangolin (CP), Manis pentadactyla L.
is one of the two pangolin species recorded in Bhutan. Not many studies, however, were carried out
on the species in Bhutan. The present
study was carried out to assess the habitat preference and current distribution
of CP, Manis pentadactyla in Dorokha Dungkhag, Samtse from
January to March 2017. Belt transect
method consisting of 100 x 100 m each was used to assess the habitat preference
and estimate burrow density, coupled with an extensive search of indirect signs
of pangolin presence (burrows, scat, footprint, scales, scratches) was utilized
to determine the current distribution of the CP. Modelling of habitat was carried out using
QGIS and Maxent. A total of 181 burrows
were recorded from 48 plots with burrow density of 0.104 per hectare. These were mostly distributed in the habitat
dominated by needlework trees (Schima wallichii), evergreen broadleaf (Castanopsis hytrix)
and shrubs (Viburnum species).
The preferred habitat of the CP was recorded to range from an altitude
of 1,300–1,700 m, with highest feeding activities recorded within the periphery
of cardamom plantation and adjacent forested area. A higher burrow density was recorded in humid
soils, with high termite presence, and in the vicinity of human
settlements. Habitat modelling revealed
that 23.57km2 of the study area was highly suitable and 37.88km2
was a suitable habitat for the species.
Similar studies are suggested to be carried out in other parts of Bhutan
in different seasons to better understand the species and its distribution in
the country.
Keywords:
Burrow, Manis pentadactyla, density,
distribution, modelling, threatened species
INTRODUCTION
The Chinese Pangolin (CP) Manis pentadactyla
L. is one of the eight species belonging to the order Pholidota, family Manidae, and
genus Manis (IUCN Pangolin Specialist Group 2020). The word “Manis” is from ‘manes’ which is
Latin for spirit of the dead (Gotch 1979), while
“pangolin” is derived from the Malay phrase ‘Pen Gulling’ meaning “rolling
ball” (Pearsall 2002). In Bhutan the
pangolin is known as ‘Saghu’ (in Dzongkha, the
national Language) and ‘Salak’ (in Lhotshamkha, the southern Bhutan dialect), due to its scaly
armored body (Wangchuk 2013).
Pangolins are nocturnal, elusive, non-aggressive, solitary,
insectivorous, and are known to utilize burrows (Gaubert
2011). Of the four species found in
Asia, the CP is found in eastern Asia, northern southeastern
Asia and parts of southern Asia (Katuwal et al. 2015;
Wu et al. 2020). It is found in Bhutan,
Bangladesh, China, Hong Kong, Taiwan, India, Laos, Myanmar, Nepal, Thailand,
and Vietnam (Challender et al. 2019). In neighboring
India, the CP is reported to occur in northern Bihar, south of the Nepalese
border (Muarya et al. 2018), while in the north-east
which borders Bhutan, the species has been recorded in Arunachal Pradesh,
Assam, Meghalaya, Nagaland, Manipur, Tripura, and Mizoram (Zoological Society
of India 2002; Srinivasulu & Srinivasulu
2012). The species occupies a number of
different habitats including primary and secondary forest, tropical forests,
bamboo forest, grassland and agriculture fields (Katuwal
et al. 2015). In Bhutan, the CP is
mostly found in southern districts such as Samtse, Samdrup Jongkhar, Sarpang, Pemagatshel, and Chukha (Wangchuk et al. 2004).
In recent decades, there has been a notable decline in the population of
CP across its range. Its numbers and
population are decreasing, primarily due to hunting, poaching, and habitat
destruction (Challender et al. 2019). Unsustainable
hunting and poaching for international and local use are currently the main
threats to the CP (Wu et al. 2020), as pangolins are poached mainly for their
scales that are used in traditional medicine and for their meat (Newton et al.
2008). Due to its rampant population
decline, it was listed as Critically Endangered (IUCN 2014) and in Appendix I
of the Convention on International Trade in Endangered Species of Wild Fauna
and Flora (CITES 2016).
In Bhutan, habitat destruction and illegal poaching had become rampant
issues (Wangchuck 2013) which might lead to localized
extinction of the CP. As such, a clear
understanding of the species habitat ecology, habitat preferences and local
distribution pattern is immensely important for any species-specific conservation
plan. Most information on the ecology of
the CPs, however, is from Taiwan and southern China studies (Wu et al. 2020)
and there is no reliable information on CP in Bhutan, despite their paramount
ecological roles (Fairhead et al. 2003; Challender et al. 2014) in the ecosystems. This could have severe implications on the
conservation of the Critically Endangered CP.
Therefore, the results of this study will contribute to the scientific
information about the habitat preferences and also the current distribution of
CP in the southwestern part of Bhutan for better conservation measures in the
near future.
METHODS
Study area
The study was conducted in Dorokha Dungkhag
block (27.07–26.95˚N & 89.09–89.30˚E) which spans an area of 256.4km² under
the Samtse District in southwestern Bhutan (Figure
1). The Dungkhag consists of three
blocks (geog), namely, Dophuchen,
Dumtoed, and Denchukha,
with the altitude ranging from 1,000–2,500 m, with daily temperature between
12–15°C in winter to 26–32°C in summer.
The climatic condition is hot and wet in summer, and cold and dry in
winter with mean annual rainfall ranging from 1,200 to 3,000 mm. The study area is mostly covered by Himalayan
subtropical broad-leaf forest and few shrub species. The broadleaved forests are mostly dominated
by needlework trees (Schima wallichii), evergreen broadleaf (Castanopsis
hytrix), Beischmiedia roxburghian, and shrubs like Viburnum
sp., while the agricultural landscape consists of cardamon
(Amomum subulatum) plantations. For this study, the vegetation was classified
as cool broadleaved forest (CBL), which is found on moist exposed slopes, and
along the foothills, and warm broadleaved forest (WBL) which is found higher
up, extending to 2,000m.
Field data collection
A preliminary survey was carried out to assess the current status of CP
in the study area and to identify the potential sites where the CP could
occur. The survey was conducted after
discussion with the Dorokha Forest Range staff, local
community and community forest members from the three geogs
to ascertain and validate the presence of CP.
Based on the information obtained, an extensive survey of 90 days was
carried out from 01 January 2017 to 30 March 2017 in the identified areas to
determine the presence/absence of the species and to know the general
distribution of the CP in the study area.
Field
sightings and records of indirect signs were used to investigate the current
distribution of CP in the study area (Mahmood & Hussain 2014). The whole Dorokha
Dungkhag area was searched for direct sighting and indirect signs (burrow,
footprint, scales, scat) of CP, and coordinates using the global positioning
system (GPS) was recorded wherever the indirect and direct sightings of the
species were observed. The QGIS software
(version 2.18.20) was then used to generate a map illustrating the current
distribution pattern of the CP in Dorokha Dungkhag.
We adopted
the belt transect method for investigating CP habitat preference and burrow
density (Rogor 1991).
This method is usually used for low density, rare and elusive
animals. A total of eight transects with
a plot of 100m x 100m size was laid out at every 100m with a total of six plots
per transect (Figure 2). Habitat
parameters such as altitude, ground and canopy cover, dominant species, soil
type, nearest distance from water body, road, settlements were recorded (Chalise & Bhandari 2014). Indirect signs like burrows, scats,
footprints, scales and scratches in each plot were also recorded to assess the
habitat preference and burrow density.
The
burrows were classified into two different types, namely living burrows which
are much deeper in depth than feeding burrows and feeding burrow (less than 1m
depth with presence of ants and termite colonies). A living burrow is categorized as active if
any indirect signs of the species such as footprints, scale prints or presence
of faecal samples are recorded around that particular burrow (Mahmood et al.
2014). Feeding burrows were further
classified into new burrows (recently active) and old burrows (more than one
year old) (Chalise & Bhandari 2014). The burrow density was estimated by counting
the number of active living burrows in all the plots in a transect according to
Irshad et al. (2015).
The
habitat preference in different habitat parameters namely canopy and ground
cover, elevation, slope, aspect, soil type, distance from water bodies and
settlements were assessed using the Statistical Package for Social Science
(SPSS) version 23 and Microsoft Excel. A
non-parametric Kruskal-wallis test was performed to
compare the relationship between the habitat parameters and numbers of CP
evidences. Spearman rho correlation was
conducted between number of CP burrow with slope, elevation, crown, and ground
cover to evaluate their association. The
burrow density (D) was estimated at eight selected sampling sites by counting
active living burrows following Begon (1979).
We used MaxEnt (version 3.3.3k) for estimating the probability
distribution of the CP in the area and for predicting potential suitable
habitat for the species (Jennings & Vern 2011; Wilting et al. 2010). Indirect active signs and direct sightings of
the CP were used as presence points and we took eight related environmental
variables (elevation, aspect, slope, settlement, drainage, landuse,
temperature, precipitation) to estimate the probability distribution for its
occurrence. Maxent models help to assess
the importance of each environmental variable on a species distribution and the
mean value generated by the model is used for the whole targeted area ( Elith et al. 2011; Phillips et al. 2006).
All the
spatial layers were processed using QGIS software (version 2.18.20). We converted all the layers (raster format)
into ASCII format with a standard cell size of 30 m based on the resolution of
the Digital Elevation Model (DEM) and occurrence record in comma separated
value (.csv) format which was then imported to the Maxent software.
Model
performance was assessed by using the training and test data for the area under
the curve (AUC) of the receiver-operating characteristic (ROC) plot. The data were jackknifed
by the inbuilt model’s feature for evaluating each environmental variable’s
influence on the predicted suitable habitat distribution of CP. The percent contribution of each variable was
calculated on the basis of how much the variable contributed to an increase in
the regularized model gain as averaged over each model run. The habitat suitability for wildlife then was
classified based on the logistic threshold value of maximum of test sensitivity
and specificity (Jiménez & Lobo 2007) with area above the logistic
threshold of maximum test sensitivity and specificity classified as being
suitable habitat.
RESULTS AND DISCUSSION
General
information on burrow characteristics
A total of 181 burrows and two direct
sightings of the CP was reported during the sampling period of three months
(Table 1).
Habitat
preference of the CP
Among 181
burrows and two direct sightings observed from three different habitat
types—agricultural land (AL), WBL, and CBL.
The highest number of burrows (n = 87) was observed from AL. One-way ANOVA showed significant difference
in the numbers of CP evidence recorded in different habitats (Kruskal-Wallis
chi-squared H (3) 6.537, p .038).
The presence of more burrows in the AL could be due to the availability
of prey (ants and termites inside burrow) which was comparatively higher in AL
(cardamom cultivation area) as compared to other habitat types during the field
survey. Similarly, Wangchuk (2013)
observed more pangolin evidence in cardamom area in Tendruk
and Norgaygang block in Samtse.
Generally,
pangolins are found in a wide range of habitats including primary and secondary
tropical forests, limestone forests, bamboo forests, broadleaf and coniferous
forests, grasslands and agricultural fields (Gurung et al. 1996; Azhar et al. 2013; Katuwal et al.
2015). In China, Wu et al. (2003)
reported that CP preferred broad-leaved forest dominated by Schima
superba, Machilus chinensis and undergrowth with good shelter mainly
comprised of Woodwardia japónica, Blechnum orientale, Dicranopteris dichotoma while
in Nepal, pangolins are found in forest patches and agricultural land near
human dominated landscapes (CITES 2016), with mixed forest containing various
tree species dominated by Shorea robusta, Schima wallichii, Castanopsis
indica, and Alnus
nepalensis as the main habitat type which
recorded majority of the pangolin burrows (74%) (Suwal
et al. 2020).
In this
study, relationship between canopy cover and burrow counts were analyzed to determine the influence of canopy cover over
the number of burrows in an area.
Results revealed that in WBL within canopy cover ranging from 26–50 %,
burrows were high (n = 50), and only one burrow recorded within the
within canopy cover of 51–75 %. While in
CBL, 44 burrows were within canopy cover of 26–50%, and only one burrow within
canopy cover of 51–75 %. As such,
burrows were high (n = 94) within the canopy cover ranging from 26–50 %;
and low (n = 2 burrow) within the canopy cover of 51–75 %. A negative correlation between the canopy
cover and the number of pangolin burrow was shown, (r (48) = -.310, p
= 0.016), indicating that burrows increase when crown cover decreases and
vice-versa (R2 = 0.33). The
reason could be because more tree stumps and some dead trees were found in the
open canopy cover that provides a good nesting area for termites during field
survey. Similar results were reported by
Bhandari & Chalise (2014) which could be due to
the presence of their prey i.e. termites in open spaces. A study conducted by Hemachandra
et al. (2014) also revealed that termites’ occurrence was highest in dry than
wet areas.
As for
ground cover, the number of burrow count were high (n = 100) within the
ground cover of 76–100 % and low (n = 8) within the ground cover
0–25%. Spearman’s correlation shows
positive relationship of burrow counts to ground cover r (48) = .241, p
= .050, indicating that the increase in burrows with increase in ground
cover and vice-versa. This suggests that
the CP tend to avoid open ground and preferred dense ground cover layer for
locomotion and feeding in order to avoid.
Wu et al. (2003) also reported that CP used dense ground cover for protection
of their burrow entrance while Suwal et al. (2020)
inferred that pangolins prefer areas with medium canopy cover (50-75%).
For
elevation, evidence of CP was recorded between 1,026–2,100 m. The highest record of CP occurrence in the
entire study area was recorded at elevation of 2100m. Within this elevation range, results showed
that CP preferred elevation of μ = 1533m and SD = 267m. The number of CP burrow to elevation showed a
negative relationship, (r (48) -.585, p 0.001), indicating that
the species prefers lower altitude but are mostly in mid elevation during
winter. Similar results were also
reported in Nepal by Bhandari & Chalise
(2014). This could be due to the
decrease in the diversity of termites with increase in the elevation as reported
by Hemachandra et al. (2014).
Slope
utilization by CP were observed between 5-–65 % (with μ = 34.56%, SD = 12.87%)
slope with preference for gentle slopes.
The Spearman’s rho correlation showed strong negative association
between slope and the number of occurrences of CP burrows (r = -.551, p
= 0.001). In WBL, slope range of 25–45
% were the most preferred with 61 burrows recorded. Similarly, with CBL and AL, slope gradient of
25–45 % recorded highest number of burrows (n = 45, n = 27) respectively. In China, Wu et al. (2004) reported that the
CP burrows were mostly recorded at slope between 30–60 % while Suwal et al. (2020) reported that pangolins were more
observed between 30–50 % slope in Nepal.
In the study area, it should be noted that soft clayey loam soil was
dominant in the slope gradient from 24–45 % which may facilitate digging of
burrows.
Additionally,
a higher number of burrows were observed in the northeast aspect (n = 64)
followed by northwest (n = 63) while minimum burrows were encountered in
southwest (n = 4). There were,
however, no burrows encountered in south and west aspect in both the forest
types (Figure 3). Kruskal-Wallis test
showed that a significant difference between the mean numbers of burrow and the
aspect, (H (7) = 15.64, p = .016) with a mean rank score highest
in northwest with 30.62 and minimum mean rank score of 6 in the west. Most pangolin burrows encountered in the
present study site were from the northeast and northwest. Similarly, this finding is in agreement with
Bhandari & Chalise (2014), who reported that
pangolin burrows were mostly found in northwest aspect in the Nagarjun Forest, Shivapuri Nagarjun National Park in Nepal. Also, according to Wu et al. (2004), the
pangolin burrow entrance often faces the sun, probably to maintain the burrow
temperature in winter.
For soil
type, the highest number of burrows were in the clay loam soil (n = 78),
followed by sandy loam (n = 53) and the least in the silty loam (n = 7). No burrows were recorded in sandy and loamy
soils. This could be due to the presence
of more termites in clay loam and sandy loam soil in the study area. The clay loam and sandy loam soils form soft
layers, which may be generally preferred by the Chinese Pangolin due to the
ease of burrowing in the soil as Wu et al. (2004) noted that the species mainly prefer soil that is moist, rich and of
a certain soft layer thickness to dig burrows.
As for
vegetation, a total of 24 families and 42 tree species were recorded from 48
plots. Trees were classified into three
major forms namely evergreen (22 species), deciduous (13 species),
semi-deciduous tree (one species) and unidentified (five species). Vegetation in the potential sites of CP
consisted of 60% evergreen, 30.1% deciduous, 1.4% semi-deciduous and 6.4%
unidentified tree species (Figure 4).
Overall, the most dominant tree species recorded with maximum Importance
Value Index (IVI) was Schima wallichii (IVI = 68.16) followed by Castanopsis
hytrix (IVI = 54.94) and Viburnum species
(IVI = 29.05), while least for Cinnamomum bejolghota (IVI= 13.99) (Table 2).
(Note: IVI
determined Species dominance encountered in the study area. Higher the IVI,
more dominant tree species in the area)
A total of
18 species from 14 families of shrubs were recorded and categorized into three
forms namely deciduous shrub (nine species), evergreen (12 species) and
unidentified shrubs (six species). Two
dominant species (Maesa chisia
and Edgeworthia gardneri)
were recorded from WBL and Daphne bholua and Daphne
sureli from CBL.
Maesa chisia
was the common dominant species in both forests. Furthermore, both forests were dominated by evergreen
shrub species (Figure 5). Shanon-Wiener diversity index (H’) for the CBL, where
burrows were recorded showed the highest tree diversity (H’= 2.36) as compared
to WBL (H’= 2.14). Similarly, shrub
diversity was high (H’= 2.23) in CBL as compared to WBL (H’= 1.80). Species richness (SR = 7) for trees species
and (SR = 31) for shrub species were observed comparatively lesser in
broad-leaved forest, (SR = 8 for species in and SR = 29 for shrub species) than
warm-tree cool broad-leaved forest.
Burrow
Density of CP
Eight
sampling sites were utilized to estimate burrow density of CP where only active
living/sleeping burrows were considered (Begon
1979). Permanent plots in the belt
transect were recorded repetitively after 30 days for three months from January
2017 to March 2017. A total area of
48,000 m2 from a 48 sample plots were surveyed and recorded only
five active living burrows. As such,
overall burrow density of the study area was found to be 0.104 signs per
hectare which is lower than Bhandari & Chalise
(2014) with 0.833 signs per hectare in the Nagarjun
Forest, Shivapuri Nagarjun
National Park in Nepal. This could be as
only active living burrows were recorded in this study.
Current
distribution of the CP
Extensive
search of indirect signs and direct sightings of CP along the eight transects
was then used to assess the distribution of the species in the three blocks
under Dorokha Sub-District. All blocks recorded the presence of CP. In the Dophuchen
block, CP signs were recorded from Dagap, Manidara, Basentey, Satakha, Laptsegaon, Sengdhen, Wangchuk, Jigme, Mithin,
and Mithun Top villages, while in the Dumtoed block, the species’ signs were sparse, being only
in a few localities in Daragaon, Gairegaon,
Khalinggaon, and Kuchey
villages. The presence of CP, however,
were observed only from Relukha village in the Denchukha block.
Among
these villages, CP presence was found comparatively more in Dogap,
Manidara and Basentry
villages under Dophuchen block, Daragaon
village under Dumtoed block as indicated by the red
dots (Figure 6). This could be due to
the existence of more cardamom cultivation and soft soil. The species presence was more moderate in Laptsekha under Dophuchen and Relukha under Denchukha block as
indicated by green dots (Figure 6). The
presence of CP (indicated by the orange dots) in Sengdhen,
Satakha, Mithun under Dophuchen and Gairegaon and Khalingtar villages under Dumtoed
block, however, was very low which might be due to the high elevation in these
areas.
The Maxent
program predicted few patches of the study area as high probability of CP
occurrence. The high probability areas
are located in close proximity to human settlements and correspond to
broad-leaved forest (performed with 0.883 for training data and 0.886 for test
data (Figure 7). The Maxent result
showed that currently 23.57km2 of the study area is classified as
highly suitable habitats (as indicated by red), 37.88km2 of the
study area as suitable habitat (yellow color) with
the remaining study area of 194.98km2 not suitable habitat for the
CP (Figure 8). In this study, modelling
was influenced by the variable “elevation” which contribute to 34.3% of the
model gain followed by “settlement” with 23.4% contribution. This is due to more evidence of the presence
of the species to settlements and mid elevation between 1,250–1,500 m. The least contributed variable was “mean
precipitation” (0.6%) indicating that mean precipitation is not an important
factor for the species distribution. Likewise, the variable “slope” contributed
4.3% (Table 3) as the presence of CP was recorded in almost all the slopes
(5–65 %) in the study area although it prefers gentle slope (25–45 %).
Conclusion and Recommendation
This study
provides more in-depth information on the CP distribution and habitat
preference in a mountainous country like Bhutan and should serve as a baseline
for future monitoring. The information
obtained from the research will also prove to be significant to the Chinese
Pangolin conservation in Bhutan, such as habitat recovery and management,
population management, population assessment and others. Although, CP population is declining
globally, Bhutan holds potential as a conservation stronghold for pangolins due
to its strict conservation laws namely Forest and Nature Conservation Rules
2017 and management practices.
CP was
encountered in very low density in the study area and distributed in few
villages of Dorokha Dungkhag with burrow density of
0.104/ha. Burrow distribution was highly
influenced by the elevation, aspect and soil type while the highest elevation
record of CP occurrence in the current study area was 2100 m. We also observed CP presence near human
settlements, in Agriculture land and adjacent forest. Results of this study shows that 56.95% of
the potential area of CP in the study areas is close to human settlement
(Agricultural land), as CP prefer to choose termites nest for its greater
biomass that is mostly found in Cardamom cultivation area especially in winter. As a result, population of the species may be
decreasing as they make easy targets for hunters. As such, detailed studies need to be
conducted to envisage its ecological or social implications with an in-depth
study focusing on distribution of pangolins in Bhutan to ensure that appropriate
conservation measures are in place. At
the same time, relevant authorities such as the Samtse
Forest Division could implement programs targeted to the farmers residing in
the potential habitat of CP on the legislation protecting pangolins, their
ecological roles and benefits of CP conservation in order to change the
attitude of local people towards pangolins.
Table 1.
Number of burrow types and size recorded.
Types of
burrow |
Burrow
condition |
No. of
burrow recorded |
Burrow
size |
|
Circumference
(cm) |
Depth
(cm) |
|||
FD |
Old |
66 |
69.3 ± 5.7 |
62.8 ± 28.4 |
FD |
New |
95 |
69.8 ± 7.1 |
66.1 ± 30.1 |
LB |
Active |
05 |
73.8 ± 4.6 |
|
LB |
inactive |
15 |
69.2 ± 8.7 |
252.6 ± 23.8 |
FD—Feeding
burrow | LB—Living burrow (The depth of active living burrow was not measured).
Table 2. Dominant and co-dominant tree
species in the study area.
Species |
Relative density |
Relative dominance |
Relative frequency |
IVI |
Schima
wallichii |
26.04 |
11.03 |
31.09 |
68.16 |
Castanopsis
hytrix |
17.08 |
16.14 |
21.72 |
54.94 |
Viburnum
sp. (Asaray) |
10.42 |
3.65 |
14.98 |
29.05 |
Beischmiedia
roxburghiana |
5.63 |
13.62 |
7.49 |
26.73 |
Nyssa javanica |
5.21 |
12.43 |
7.49 |
25.13 |
Engelhardtia
spicata |
11.46 |
6.66 |
3.00 |
21.11 |
Acer thomsonii |
6.04 |
5.21 |
8.24 |
19.49 |
Macaranga
denticulata |
9.17 |
7.04 |
1.50 |
17.70 |
Cinnamomum
bejolghota |
2.92 |
10.69 |
0.37 |
13.99 |
Euaria
aquaminita |
3.54 |
8.87 |
1.50 |
13.91 |
Caeserea
glomerita |
2.50 |
4.96 |
2.62 |
10.09 |
Mean |
9.09
± 6.79 |
9.12
± 3.80 |
9.09
± 9.31 |
27.3
± 17.28 |
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