George S. wise Faculty of Life Sciences
Department of Zoology
STUDIES ON THE BIOLOGY
OF THE INDIAN CRESTED PORCUPINE (Hystrix indica)
IN THE COASTAL PLAIN OF ISRAEL
Thesis submitted towards M. Sc. degree of the
The research for this thesis has been carried out
at the Department of Zoology of the Tel—Aviv
University under the direction of
Prof. H. Mendelssohn
Ternporal and spatial patterns of activity, as well as social and feeding
behaviour were monitored in free ranging Indian Crested porcupines (Hystrix
indica) in the coastal plain of Israel, using radio telemetry.
Fourteen porcupines (youngsters, subadults and adults) equipped with
collar transmitters were radio tracked on 138 full nights and 3% partial
nights and were also directly observed once a week by starlight scopa,
during April 1983 — December 1984.
HOME RANGE AND SPZJXTIAL ACTIVITY
Differences in spatial activity were found between pairs and single
males. There were no single female in the raearch area. The activity of the
pairs was restricted to definite home ranges. Two pairs fedmainly in
orchards; their home ranges were smaller and the utilisation was more evenly
distributed as compared to a pair that fed mainly in a natural habitat
((5.335 km2,0.487 kmz vs. 1.215 kmz). Single males had a very wide temporary
home range until they found a female with which to form apairbond.
Considerable overlaps of home ranges between single males and pairs as
well as among the single males, indicate that a single male is not
territorial. Pairs displayed a characteristic movement pattern. A pair leaves
its den for a specific area, where it spends most of the night. It usually
returns to that-same den at the end of the night. Single males act alone. On
some nights they may have the same movement pattern as described for pairs,
but on others they wander for long distances (up to 8 km per night), sometimes
ending up in a different den or even hiding in dense thickets. The average
walking distance per pair per night is shorter than that of a single male
(1684 i 789 vs. 23m : 1784 m. ).
‘Ihe pattern of habitat utilisation is different for pairs and for single
male porcupines; _15airs utilise specific areas on different nights. Single
males utilise certain areas (sub-home ranges) for certain periods.
Part of the research population was active in the sub—urban regiors. The
problems posed by the railway and the highways that cross these areas, were
solved by the porcupines‘ use of the large drainage-pipes passing under the
tra nsportation 1i nes.
TEMPORAL ACTIVITY PATTERNS
Porcupines leave their dens in the evening after waiting for some time
(ﬂ—45 min. ) at the entrance. The porcupines forage every night and their
activity above ground is continuous. In spring and summer 7.8% of the exits
were before complete darkness (sun 129 under the horizon), in summer and
autumn 61.5% of the observed returns to the den occured beyond the darkness
hours and with the beginning of dawn.
There is a connection between the type of habitat used by the porcupines
and their emergence time. Those living in natural habitat start their
activity two hours earlier than porcupines living on agricultural crops, but
they all end their activity at the same time. During winter the activity ended
at about $2.15 A. M., while in summer it was terminated between 04.(2H2l to $5.69
A. M.. A single male might finish its activity very late even during the
Duration of activity increased from winter to late summer. Adult animals
(14.5 1 2.1 kg. ) are active per night, in winter and spring, for 6.3 i 1.6
hrs. in natural habitat and 4.3 i 1.0 hrs. in agricultural habitat. This
average activity reprsents 50% or less of the darkness hours. In summer and
autumn activity increased up to 7.4 1 0.9 hrs. and 5.2 1 1.3 hrs.
respectively to the habitats and represents 98% and 66% of the darkness
Rain inhibits above ground activity. There was no correlation of activity
parameters with temperatures and humidity but it appears that a combination of
high humidity and low temperature is the signal to enter the den in winter
nights. I 7
During winter porcupines reduce their aboveground activity for minimal
exposure to moonlight, but the lunar response wanes thereafter and disappears
completely by summer. Moon avoidance may be a defence behaviour pattern
against predators, that can be expressed during winter, but disappears during
short summer nights, when there are not enough darkness hours to meet foraging
requirements. Results suggat that porcupin$ accumulate foraging deficit for
about 19 consecutive nights per winter lunar cycle, and compensate for it
during moonlas nights.
During the day the porcupines usually hide underground, but sometimes in
above ground shelters. Single males often use dense thickets as shelters
during the day, while pairs usually hide in underground shelters. ‘Ihe burrows
are used by the porcupines as places for spending inactive time and for
reproductive purposes. As underground shelters porcupines use "artificial
dens" (drainage—pipes along and under highways and under a cemetery, 450 to
-690 meters long and 76 cm. in diameter) as well as self-dug dens. A natural
den usually has an hemieliptic entrance (39 :6 cm. wide and 24 :4 cm. high),
the den is long (8.7 i 5 m. ) and its diameter is in accordance with the
porcupine's size. The den ends with a nest, providing a place for two adult
porcupines (80x90x5(J cm. ). Food and faeces were not found inside the dens. In
the sub—urban region porcupines prefer to use the drainage-pipe: as dens.
Ten species of geophytes were identified from the
digging activity. The density of the porcupines‘ diggings can be as high as
one digging for every square meter of soil. ‘Ihe average size of a digging is
Porcupines do not usually eat the above ground parts of thegeophyte.
During autumn, winter and spring porcupines were observed eating buds and
green grass on the ground. In agricultural areas porcupines fed on vegetables
and fruit, including fruits growing on low branches, that could be reached by.
REPRODUCTION AND DEVELOPMENT
Data in this section includes information from the museum of Tel-
Aviv University and from porcupines captured in the Judean mountains.
Births occur throughout the year, but mostly during spring and autumn.
The litter range is 1-3 and the average is 1.77 1 6.56 (N=3l). The average
weight of neonates is 327 j-_ 27 gr (N=5). This represents 2.6% of the mean
body weight of an adult female.
Until the age of 4.5 months the body weight of the young increases with
increasing age. From this age on the increase in body weight slows down and
becomes very slow from the age of 11 months. From recapture of adult
porcupines it was found that porcupines continue to gain weight throughout
‘Ihe birth of a neonate, born to a 12 months old female and a 16 months
old male indicata that porcupines are able to copulate at the age of 9 and 7