Natural range extension, sampling artifact, or human
mediated translocations? Range limits of Northern type Semnopithecus entellus (Dufresne, 1797) (Primates:
Cercopithecidae: Colobinae) in peninsular India
Krishnaswamy
Sudarshan Chetan Nag 1, Pramod Padmanabhan 2 & Kota
Praveen Karanth 3
1,3 Centre for
Ecological Sciences, Indian Institute of Science, Bengaluru, Karnataka 560012,
India
1,2 Salim Ali
Centre for Ornithology and Natural History, Anaikatty Post, Coimbatore,Tamil Nadu 641108, India
Email: 1 chetan@ces.iisc.ernet.in, 2 pramodpalakkad@gmail.com, 3 karanth@ces.iisc.ernet.in(corresponding author)
Date of
publication (online): 26 August 2011
Date of
publication (print): 26 August 2011
ISSN
0974-7907 (online) | 0974-7893 (print)
Editor: Mewa Singh
Manuscript details:
Ms # o2740
Received 29 March 2011
Final received 15 June 2011
Finally accepted 18 July 2011
Citation: Nag, K.S.C.,P. Padmanabhan & K.P. Karanth (2011). Natural
range extension, sampling artifact, or human mediated translocations? Range
limits of Northern type Semnopithecus entellus (Dufresne,
1797) (Primates: Cercopithecidae: Colobinae) in peninsular India. Journal
of Threatened Taxa 3(8): 2028–2032.
Copyright: ©
Krishnaswamy Sudarshan Chetan Nag, Pramod Padmanabhan & Kota Praveen
Karanth 2011. Creative Commons Attribution 3.0 Unported
License. JoTT allows unrestricted use of this article in any medium for
non-profit purposes, reproduction and distribution by providing adequate credit
to the authors and the source of publication.
Acknowledgements:The study was financially supported by the
Department of Biotechnology, Government of India (BT/PR-7127/BCE/08/445/2006)
and Ministry of Environment and Forest. We are
grateful to the forest departments of Maharashtra, Karnataka, and Andhra
Pradesh forest for permissions and cooperation. Special thanks to Chaitra,
Achyuthan, Anjana Shenoy, Rishikesh Bahadur Desai, Rishi Kumar, Santosh
Shanbhag, Sridhar Gadiyar, Kushal Kamble, Harish Bhat, Laurens Verwijs, Martin
Zaruba, Hanka Svobodova, affiliates of Karanth laboratory for their generous
support during the study. We like
to thank K.V. Gururaja who helped us with drawing the maps. We also like to
thank the reviewers for their constructive comments on the manuscript.
Abstract: The Semnopithecus
entellus can be broadly classified into two morphotypes based
on tail carriage, namely the northern and the southern types (NT &
ST). The borderline between these
morphotypes runs along the Tapti-Godavari rivers in
peninsular India. However there have been anecdotal reports of range extension
of NT in peninsular India. To
investigate this scenario we undertook an intensive survey of S.
entellus morphotypes along the borderline districts in the
states of Gujarat, Maharashtra, Karnataka and Andhra Pradesh. The GPS coordinates of the two
morphotypes were mapped using MapInfo professional software and the resulting
map was compared with the map generated by Roonwal. Results indicate that NT S.
entellus range limit fall further south of Roonwal’s
borderline. This incongruence in
NTs distribution between the present study and Roonwal’s might be due to
natural range extension of NTs in some areas or a product of sampling
artifact. Furthermore in parts of
Andhra Pradesh and Karnataka human mediated translocations might have also
contributed to this range extension.
Keywords:Anthropogenic activity, hybrid zone, peninsular India, range limit, river, tail
carriage, under sampling.
For figure, table -- click here
Faunal
range expansions are dynamic and are of great relevance as they often indicate
important changes in habitats due to the profound influence of human
intervention, climate change or other environmental variables (Ehrlich et al.
1988; Ohmart 1994; Wehtje 2003; Oden et al. 2004). Variations in species distributions can alter important
ecological interactions. Therefore
range contractions or expansions may also have economic, management, and safety
implications in wildlife management (Darimont et al. 2005). Here we report the range limits of one
of the morphotypes of Hanuman Langur Semnopithecus entellus, one of the most widely
distributed common species of primate in India.
The
Hanuman Langur is a well-known, revered, and extensively studied non-human
primate of India. These langurs
are known for their habituation to humans and show varied adaptations to
urbanization (Pirta et al. 1997; Chauhan & Pirta 2010; Sharma et al. 2011).
They are dispersed throughout most of India and Sri Lanka (Ellerman & Morrison-Scott
1966; Oates et al. 1994) and are also found in parts of Pakistan, Nepal
(Roonwal 1984; Oates et al. 1994; Minhas et al. 2010), Bhutan and Bangladesh
(Choudhury 2007). Hanuman langurs
are well adapted to a wide range of habitats: from arid regions of Rajasthan to
the rainforests of the Western Ghats and in altitudes ranging from the sea
level (Nag et al. 2011) to 4270m in the Himalaya (Hrdy 1977; Bishop 1978).
Based
on tail carriage, Roonwal (1979, 1984) identified two distinct morphotypes among
Hanuman Langur, namely Northern type (NT) and Southern type (ST). The NT has a tail that loops forward
towards the head and is distributed north of the Tapti-Godavari rivers. The ST has a tail that loops backward away from the
head and is distributed south of these rivers in peninsular India and Sri Lanka
(Roonwal, 1979; 1984) (Fig. 1). These tail loop variations have been reported earlier by Hill
(1938) and Rowell (1972). Nevertheless, Roonwal (1984), for the first time gave the exact
borderline (here after referred to as Roonwal’s line) between the NT and ST which according to him runs along the Tapti-Godavari
rivers (see Fig. 1).
There
have been several anecdotal evidences suggesting that the range of NT has
extended beyond the Roonwal’s line but no systematic study has been undertaken
to confirm this scenario. Thus to
fill this gap we attempted to map the southern limits of the distribution of
NTs in peninsular India. Here we
report new information that suggests the range limits of NTs in peninsular India and discuss the possible
reasons and implications of these range extensional limits.
Methods
We
conducted our survey in peninsular India in the states of Gujarat, Andhra
Pradesh, Maharashtra and Karnataka such that the states on either side of the
borderline given by Roonwal (1984) were included. Every district along the borderline in each of the states
mentioned above was intensively surveyed on foot along roads and trails betweenJune to December 2009 for approximately six
months. Surveys were also carried
out in jeep and a two wheeler along major roads. All the surveys were carried out by the
first author of this paper along with local field assistants provided by the
respective state forest departments. In these districts langur troops were located based on information from
past surveys (Roonwal 1979, 1984; Kurup 1981, 1984; Srinivasulu & Nagulu
2001) and also by conversing with the local people. On locating a troop the tail carriage information along with
GPS location of the troop were recorded. Tail carriage characters were recorded
when the animal was walking casually and not when it was standing or running
(as per Roonwal 1984). Troops were
typed as NT or ST when all adult members of the troop exhibited either northern
or southern type tail carriage respectively. Whereas when both morphotypes were observed in the same
troop (mixed troops) they were entered as mostly NT (mNT) or mostly ST (mST)
depending on the predominant tail carriage observed. For example a troop was typed as mNT when >50% of its
adult members had NT tail carriage. Additionally tail carriage information for troops from
adjoining state were also collated from published material (Srinivasulu &
Nagulu 2001; Kumara & Singh 2004; Kumar et al. 2010; Nag et al. 2011) and
information and photographs provided by other researchers in the field. The approximate distributions of these
morphotypes were determined by plotting the sampling locations of each
morphotype on a map using MapInfo Professional and DIVA-GIS software (Hijmans
et al. 2004). On this map Roonwal’s line was traced using MapInfo Professional
software.
Results
Results
from our survey are shown in Fig. 1, wherein the locations of
all NT and ST troops are given by black circles and rectanglesrespectively. Mixed troops are represented by open circles for mNT and open
triangles for mST. The GPS locations of troops up to 200km on either side of
Roonwal’s line are given in Table 1. As is apparent from Fig. 1, there are up to ten troops to the south of
Roonwal’s line that consist of langurs with NT tail carriage. Among them two troops in the eastern
parts of the range, south of the Krishna River were NTs. Five troops were mNTs and three troops
were mSTs. These results suggest
that the southern limit of the NT morphotype is further south of Roonwal’s
line. Furthermore this “range
extension” is more pronounced in the south-central and southeastern parts of
the NT’s distribution. For example
according to Roonwal (1979; 1984) the southern most limit of NTs along the east
coast was Godavari delta north of Krishna River, whereas our observations
indicate that they are distributed south of Krishna River in Guntur District of
Andhra Pradesh (Fig. 1).
However,
up to six troops to the north of Roonwal’s line consisted of langurs with ST
tail carriage, but these were predominantly mNT. Interestingly these troops were largely restricted to the
western end of Roonwal’s line near the mouth of Tapti and Narmada rivers (See
inset in Fig. 1). In this part of
Gujarat, Roonwal (1984) reported the northernmost populations of STs near Surat
(bank of Tapti River) and southernmost populations of NT at Bharuch (bank of
Narmada River).
Our
field observations indicate that northernmost population of ST occurs 85km
north of Surat, in and around Bharuch. Thus Narmada River in the northwest and Krishna River in the southeast
form the borderline between the southern and northern types in peninsular
India.
Discussion
Interestingly,
there were twice as many troops (n=10) south of Roonwal’s line with at least
one NT individual than there were troops (n=6) north of this line with at least
one ST individual. Moreover this
change in the range of these morphotypes is more extensive in the case of NT,
whereas in the STs it is largely confined to western end of Roonwal’s
line. Additionally in most of the
mixed troops (n=14) the predominant tail type is NT (mNT=10, mST=4). Preliminary observations also suggest
that these mixed troops represent a hybrid zone between NT and ST (Nag et al.
2011). Taken together these
patterns are indicative of introgression of NTs into the range of ST.
There
are three possible explanations for the incongruence between our observations
and those of Roonwal (1984). The
first possible scenario is that NTs were always distributed south of Roonwal’s
line but these areas were poorly /under sampled by Roonwal (1984). Thus our results might reflect the
natural range of NTs. Alternately
the results reported here might be indicative of range extension of NTs, in
some parts, into areas where formerly STs were distributed. This scenario is
supported by the largely unidirectional introgression discussed above. Thirdly in parts of Andhra Pradesh and
Karnataka the range extension of NTs might be due to human mediated
translocations. Translocations
of “problem langurs” were reported by forest department and local people
around places like Guntur, Nalgonda, Warangal and Medak districts of Andhra
Pradesh, and Bidar and Gulbarga districts of Karnataka (see underlined location
in Fig. 1). We have also observed
two instances of translocations wherein NTs were caught around Guntur and later
released into Srisailam forests.
Interestingly,
the range of NT Hanuman Langur overlaps with that of Rhesus Macaque Macaca mulatta in India and among
Rhesus Macaques too there have been reports of range extension. Here again, the range extension of Rhesus
Macaques is mostly into the northern parts of the state of Andhra Pradesh in
and around Srisailam (Kumar et al. 2011). These observations hint at a common underlying mechanism driving range
extensions in these two sympatric primate species. Interestingly, Kumar et al. (2011) also invoke natural
process as well as human introductions for range extension in Rhesus
Macaques. We believe that a
detailed behavioral, ecological and genetic study of the hybrid zone between
the two morphotypes of Hanuman Langurs might help us better understand this
pattern.
References
Bishop,
N.H. (1978). Langurs living at high
altitudes. Journal of the Bombay Natural History Society74: 518–520.
Chauhan, A. & R.S. Pirta (2010). Socio-ecology of two species of non-human primates, Rhesus Monkey (Macaca mulatta)
and Hanuman Langur (Semnopithecus
entellus), in Shimla, Himachal Pradesh. Journal of Human Ecology30(3): 171–177.
Choudhury,
A.U. (2007). The eastern limit of distribution of the
Hanuman Langur Semnopithecus entellus Dufresene. Journal of the Bombay Natural History Society 104: 199–200.
Darimont, C.T.,
P.C. Paquet,
T.E. Reimchen, V. Crichton (2005). Range expansion by moose into coastal
temperate rainforests of British Columbia, Canada. Diversity
& Distribution 11: 235–239.
Ellerman, J.R. & T.C.S. Morrison-Scott
(1966). Checklist of Palaearctic and Indian Mammals, pp. 1758-1946, 2ndEdition. Trustees of the British
Museum (Natural History), London, 810pp.
Elrcih, P.R., D.S. Dobkin & D. Wheye (1988). Range Expansion. University
of Stanford. (Essay available at
http://www.stanford.edu/group/stanfordbirds/text/essays/Range_Expansion.html).
Hrdy, S.B. (1977). The Langurs of
Abu-Female and Male Strategies of Reproduction. Harvard
University Press, Cambridge, 361pp.
Hill,
W.C. (1938). The mode of carrying
the tail in leaf-monkeys. Ceylon Journal of Science (B) 21:
66–67.
Hijmans,
R.J., L. Guarino, C. Bussink, P. Mathur, M. Cruz, I. Barrentes & E. Rojas
(2004). DIVA-GIS. Vsn. 5.0. A
geographic information system for the analysis of species distribution data.(manual available at: http://www.diva-gis.org).
Kumar,
R., S. Radhakrishna & A. Sinha (2011). Of Least Concern? Range Extension by Rhesus Macaques (Macaca mulatta) Threatens Long-Term Survival of Bonnet
Macaques (M. radiata)
in Peninsular India. International Journal of Primatology 32:
945–959.
Kumara,
H.N. & M. Singh (2004). Distribution
and abundance of primates in rain forests of the Western Ghats, Karnataka,
India and the conservation of Macaca silenus. International Journal of Primatology 25(5):
1001–1018.
Kumara,
H.N., S. Kumar & M. Singh (2010). Of
how much concern are the ‘least concern’ species? Distribution
and conservation status of Bonnet Macaques, Rhesus Macaques and Hanuman Langurs
in Karnataka, India. Primates 51: 37-42.
Kurup,
G.U. (1981). Report on the census surveys of rural and
urban populations of Non-Human Primates of south India, Zoological Survey of
India, Calicut.
Kurup, G.U.
(1984). Census survey and
population ecology of Hanuman Langur, Presbytis entellus (Dufresne, 1797) in
south India. Proceedings of Indian National Science Academy 50:
245–256.
Minhas,
R.A., K.B. Ahmed., M.S. Awan & N.I. Dar (2010). Social organization and reproductive biology of Himalayan Grey
Langur (Semnopithecus
entellus ajax) in Machiara National Park, Azad Kashmir (Pakistan). Pakistan Journal of Zoology 42(2):
143–156.
Nag,
K.S.C., P. Pramod & K.P. Karanth (2011). Taxonomic implications of a field study of morphotypes of Hanuman
Langurs (Semnopithecus
entellus) in peninsular India. International Journal of Primatology 32:
830–848.
Oates,
J.F., A.G. Davies & E. Delson (1994). The
diversity of living colobines, pp. 45–73 In: Davies, A.G. & J.F.
Oates (eds.). Colobine Monkeys: Their Ecology, Behaviour
and Evolution. Cambridge University
Press, Cambridge, 415pp.
Oden,
J.D., N.L. Poff, M.R. Douglas, M.E. Douglas & K.D. Fausch (2004). Ecological and evolutionary consequences of biotic homogenizations. Trends in Ecology and Evolution 19:
18–24.
Ohmart,
R.D. (1994). The effects of
human-induced changes on the avifauna of western riparian habitats. Studies in Avian Biology15: 273–185.
Pirta,
R.S., M. Gadgil & A.V. Kharshikar (1997). Management of the Rhesus Monkey Macaca mulatta and Hanuman Langur Presbytis entellus in
Himachal Pradesh, India. Biological Conservation 79: 97–106.
Roonwal,
M.L. (1979). Field study of geographical, sub specific
and clinal variations in tail carriage in the Hanuman Langur, Presbytis entellus (primates) in South Asia. Zoologischer Anzeiger, Jena 202: 235–255.
Roonwal,
M.L. (1984). Tail form and carriage in Asian and other
primates, and their behavioral and evolutionary significance, pp. 93–151.
In: Roonwal, M.L., S.M. Mohnot & N.S. Rathore (eds.). Current Primate Research. Jodhpur University
Press, India, 627pp.
Rowell, T. E. (1972). Social Behaviour of Monkeys. Cox and Wyman, London, 203pp.
Srinivasulu, C. & V. Nagulu (2001). Status of Primates in Andhra Pradesh. Envis Bulletin: Wildlife and Protected Areas 1(1):
109–112.
Sharma,
G., C. Ram, Devilal & L.S. Rajpurohit (2011). Study of man-monkey conflict and its
management in Jodhpur, Rajasthan (India). Journal of Evolutionary Biology Research3(1): 1–3.
Wehtje,
W. (2003). Range expansion of the Great-tailed
Grackle. Journal of Biogeography30: 1593–1607.