Note on breeding and parental care behavioursof albino Hoary-bellied Squirrel Callosciurus pygerythrus (Rodentia: Sciuridae) in Sibsagar District
of Assam, India
Girindra Kalita
Sr. Lecturer and Head, Department of Zoology, Guwahati College, Guwahati, Assam
781021, India
Email: girin_05@yahoo.co.in
Date of online
publication 26 June 2009
ISSN 0974-7907 (online) |
0974-7893 (print)
Editor: C. Srinivasulu
Manuscript details:
Ms # o1770
Received 03 May 2007
Final received 08 May 2009
Finally accepted 30 May 2009
Citation: Kalita, G. (2009). Note on breeding and parental care behaviours of albino Hoary-bellied Squirrel Callosciurus pygerythrus(Rodentia: Sciuridae) in Sibsagar District of Assam, India. Journal of ThreatenedTaxa 1(6): 358-360.
Copyright: © Girindra Kalita 2009. 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: Author is
thankful to the Oil and Natural Gas Corporation Ltd. India, Assam State
Department of Forest and Social forestry division, Sibsagardistrict of Assam, Society for Zoology and Nature, GuwahatiCollege and Principal, Guwahati College for their
help in various ways and cooperation during the study. Author is also thankful
to Dr. M.M. Goswami, Professor, Department of
Zoology, Gauhati University
due to his encouragement in revising the scientific paper.
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Twelve genera belonging to the
Family Sciuridae are known from the Indian
subcontinent (Srinivasulu et al. 2004). Some of the species occurring in the
north-eastern states of India including Assam are Belomys pearsonii, Petaurista petaurista, P. philippensis,P. caniceps, Hylopetes alboniger, Ratufabicolor, Dremomys lokriah,D. pernyi, D. rufigenis,Callosciurus pygerythrus,C. erythraeus and Tamiops macclellandii (Choudhury1997).
During a field survey conducted
by the team of Society for Zoology and Nature, Guwahati,
between October,1997 to June, 1998, a few individuals of albino squirrel (Image
1) belonging to the species Callosciurus pygerythrus were recorded from Sibsagardistrict of Assam, India (Kalita 1998). Albinism in this species is rare and has not
been widely reported in India (Bhattacharyya & Murmu2004; Sharma 2004, Mahabal et al. 2005).
The present paper deals with some
of the habitats, ecology and feeding habits of the albino Callosciurus pygerythrus. One female albino individual of Callosciurus pygerythruscollected from its natural habitat along with a normal male of the same species
were observed in captive conditions for five years (from 2000 to 2005) and
their breeding biology and subsequent parental care behaviourrecorded.
Methods
The approach to locate the albino
squirrels of the species Callosciurus pygerythrus was through questionnaire surveys to
ascertain the presence of albino squirrels, and thorough surveys of the entire Sibsagar District. Communities in direct contact with the forest as tribalsand the Muga keepers were interviewed for
vital information on the sightings of this species.
One individual albino squirrel
out of two encountered was captured with the help of the villagers of that area
for observation on its breeding and parental care behaviour. The squirrel was housed in a 6x4.5x3.6 m cage
of iron net constructed in a private place, in a well ventilated condition, and
a normal male individual of the same species was introduced into the cage. The roof of the cage was covered with
thatch. Shade was also arranged to
protect the cage from high temperatures. The inside of the cage was decorated with potted shrubs and dry pieces
of bamboo with holes at internodes. The
cage was also provided with a small tray for drinking water. The water was renewed and the cage was
cleaned every day. Fresh fruits and nuts
like bananas, oranges, pineapples, coconuts, betel nut and seeds or fruits of Ficus spp., Azadirachta indica, Nerium indicum (ripe fruit) and Bombax ceiba, were provided as normal diet. Fruits, nuts and seeds were selected from
observations in its natural habitat. Some times orthopteran insects like
grasshoppers and crickets were also included in the diet. Curd was the favouredfood of the albino variety and was a convenient medium for administering oral
drugs and vitamins.
No
special treatment was provided for their breeding in captivity, except giving a
drop of vitamin E from a freshly punctured IP 200mg liquid vitamin E capsule
along with 20ml curd every morning during September 2002 to October 2004.
Observations
Morphologically, the albino
squirrel is completely white, the tail faded white, eyes red and ears untufted; fore limbs with 4 toes and hind limbs with 5
toes. Total length is 30cm, body 12cm
and tail 18cm.
Information regarding the existence
of albino squirrels in the study areas is quite localized. The squirrels were observed to prefer a rich
and varied habitat consisting predominantly of Bamboo, Ficusspp., Azadirachta indica,Bombax ceiba,
and various other fruit plants and wild shrubs and trees. This is owing to the proximity to the two
major rivers, the Disang and the Dikho cutting through the SibsagarDistrict. Observed habitat of albino
squirrel is plain villages near two main rivers of Sibsagardistrict namely, Disang and Dikho. The
population of this albino variety in its habitat is observed to be very
low. Maximum 3 individuals were recorded
in 1995 in a village of that area. A
detailed list of its occurrence in the studied areas has been incorporated in
Table 1.
Albino squirrels in their natural
habitat are quite lethargic. They never
go up to the tip of their supporting trees. In most cases they are observed up to a maximum height of 20feet. During the day they mostly remain sitting on
the low branches of bushy trees. However, they become active at dawn and at dusk.
In their natural habitat they
were observed consuming fruits, nuts, bark born fungus and insects infesting Ficus spp., Olea europaea, Bombax ceiba, Bambusaspp. and Dendrocalamus spp.
Breeding
and parental care habit of albino squirrel in captivity
The male Callosciurus pygerythrus in captivity exhibited hostile behaviour towards the albino female. In the first two years of captivity (2000
& 2001) breeding was not observed. However, after adding vitamin E to the
diet in the third year (2002) the pair exhibited courtship behaviourfrom the last week of September (2002) and were observed occupying the same
hole during that period. From first
fortnight of October, the female was observed collecting dry leaves and thatch
as nest building material. In the last
week of April 2003, the female gave birth to a single male pup. The new born baby was black in colour and about 13cm in length (Image 2). Its eyes remained closed for 22 days (Image
5). The individual was born in a
hairless condition. However, normal
hairs developed and grew thicker and longer to resemble the normal male
individual except for a morphological dissimilarity of a slightly tufted ear
(Image 6). During that period the mother
squirrel was observed to be aggressive towards the male driving him away from
the hole/drey. She suckled the pup at intervals of 40 to 70 minutes. She exhibited parental care behaviour by transferring the pup as and when there was a
disturbance by carrying it in her mouth to a safer place in the cage. Even after every handling of the pup for
photography she transferred it to a new drey (Images
3 & 4). The first baby survived in
captivity till August, 2003.
Breeding was observed in the
second consecutive year too, and a male offspring was born on the 4th of May
2004 and attained its full grown stage. During the study, the albino squirrel did not exhibit pairing tendency
with her male baby. The adult male was not aggressive towards the male baby and
play between them was often observed. However, he was aggressive towards the baby during the time of feeding.
The mother albino squirrel
survived till 18th February, 2005. During her survival no courtship behaviour with her baby was observed.
Discussion
Albinism in wild animals is not
very common. However, there are previous
reports on albinism in some species of mammals including squirrel in India and
abroad (Gee 1959; Walker 1968; Tehsin & Chawra 1994; Kalita 1998;
Bhattacharyya & Murmu 2004; Sharma 2004; Mahabal et al. 2005). The occurrence of the present albino variety of Callosciurus pygerythrus in the studied areas in Sibsagar district of Assam was discovered as early as
1995. The emergence of this albino
species to such a new territory might be due to its migration from other
territories of forest cover, which is yet to be ascertained. It is known that variations in coat colour may develop among squirrels living in the same place
(Prater 1980). However, it is very difficult to ascertain the species status of
albinos unless one goes through a genetic study. The present albino variety is found together
with the colony of gray C. pygerythrus. Individuals of albinos differ from the gray C.pygerythrus in only the following points.
- The coat colour of the albino variety is snow white; but, the gray
squirrel bears gray hair on its dorsal surface and smoke white to the ventral.
- Eyes of the
albino variety are red, but it is black in gray species.
- Tail fur in
albino variety is thicker and longer than the gray species.
- Gray squirrels
are not friendly to the albino variety.
- Albinos are
lethargic in comparison to the gray species.
All these differences may be due
to their body physiology and has the scope for further study. Although there appears no significant
difference between the albino and the gray variety of the studied species apart
from the above, the breeding performance in captivity brings forth to an idea
for considering it under the same species category of C. pygerythrus.
Accurate observation on the life
history of most of the rodents in the wild is very difficult as they are
evasive and fleet in nature (Lang 1925). Vitamin E is a long investigated drug in reproductive physiology in
different animals particularly in rodents (Hafez 1970) which has been tried
here. Earlier it was investigated in
laboratory reproduction of squirrel like, Citellus tridecemlineatus pallidus Allen
by George & Wade (1931). However, in
rodents, the requirement of vitamin E in reproduction is species related (Hafez
1970). Though administration of vitamin
E as oral dose in ground squirrel like, C. tridecemlineatus pallidus Allen does not affect in reproduction
(George & Wade 1931), present observation signifies its requirement as oral
dose in the reproduction of Callosciurus pygerythrus.
The parental care behaviour of carrying its offspring by the squirrel and
other rodents is unlike that of cat species (Lang 1925). However, they also use the mouth to carry
their young during danger (Lang 1925). Lang (1925) has confirmed the babies cooperation in maintaining balance
during its shifting from one place to an other by the mother, as studied in a
Central American squirrel, Sciurus hoffmanni which the present study contradicts that in
early stages the babies are too weak to provide support by holding their mother
with the help of tail or legs (Images 3 & 4). The baby supports its mother only by bending
its head and tail parts in an inward direction (Images 3 & 4).
It is known that normally the
litter size in most of the species is 2-4 pups and they breed 2-3 times in a
year (Walker 1968; Prater 1980). However, the development of single fetus during April-May in the present
observations is significant and may be a reason for its lower population in the
study area. The lethargic nature of the
albino variety in day time may be related to their biological inability to cope
with strong daylight. The present study
may be regarded as base-line information for breeding experiments in albino squirrel
in the region. Further study is required
for more information regarding breeding and parental care behaviourof the animal. However, albinos are at a
distinct disadvantage in nature as they are easy prey and subject to killing
out of curiosity. The urgent need of
conservation measures on this rare animal is emphasized.
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