BREEDING BEHAVIOUR OF TIGER
As an organized Field Study tour has been introduced as a compulsory in the Courses of Zoology Practical subject in the +3 Degree Course as per the new U.G.C. guide line. We, the U. G. Fifth Semester students of Zoology Honours, xxxx College, Baliapal, Balasore, were advised to go on a field study. An organized field Study on study of animal behaviour was undertaken at “Nandankanan”, Bhubaneswar, by the Department of Zoology, xxx. College, Baliapal on 14th February 2021. It was conducted under the guidance of Dr. L. K. Jena, Reader and Head, Dept. of Zoology assisted by the other staff members.
BREEDING BEHAVIOUR OF TIGER (Panthera tigris)
“The tiger is the spirit of the Indian jungle”. After a disastrous decline in it’s population during fifties and sixties, the importance of the tiger as one of the most endangered fauna of India has been realized and the need to ensure its conservation has engaged the attention of not only the biologists and conservationists, but also the politicians. In early nineties when the tiger is, at best, sure of its conservation, it demands that behaviour should be studied thoroughly. Tigers are not animals characterized for being sociable. The only links are those of a mother with her offspring. Males and females are polygamous and only encounter in the estrus period, and after mating, both take different paths. In this context a study was undertaken to provide information – (i) on the reproductive behaviour of the tiger, (ii) breeding season, (iii) oestrus period, (iv) inter – oestrus interval, (v) gestation period, (vi) litter size, (vii) sex ratio , as well as (viii) agonistic behaviour of Panthera tigris.
MATERIAL AND METHODS
Nandankanan Biological Park has a very good record of breeding tiger in captivity. Tiger reach sexual maturity between three and five years; Female mature at 3 or 4 year of age, but males do it a little later, at 4-5 years. Female usually enter estrus every 3-9 weeks but are receptive only a few days, which are usually 3 to 6. During the time before the heat, females mark their territory with the urine that leaves a very particular smell, different from the smell that they always emit. Once a tigress enters heat, it tries to communicate it to the males emitting frequent and repetitive vocalizations that consist of roars, moans, and other odorous excretions
The first of tiger cubs (normal coloured) was recorded in December, 1966. Since 1966, many tiger cub were born in the park. A landmark was achieved in the field of tiger – breeding, with the birth of three white of three white tiger cubs from two coloured parents on 8th January 1980, the first ever in the world, while in captivity. As on 6th April 1933 Nandankanan Biological Park is home to 27 white tigers, the highest number in captivity, in the world.
The tigers in the park are kept in spacious enclosure, each of which has two retiring cells. Usually tigers are kept in Paris and separated about a fortnight before the excepted date of parturition till the cubs are 9month old. Tigers at Nanadankanan Biological Park are fed six days in a week with beef, no food being given Mondays. On an average each adult tiger is given 15 kg of fresh raw beef (bone to flesh ratio 1:2). The amount of beef given to tigers ranges from 4kg to 15kg depending upon the age, size, sex and general conditions of animal.
BREEDING BEHAVIOUR OF TIGER OBSERVATIONS
Mating of the tigers occurs at the time of year, although in regions with tropical climates happens more frequently during the period between November and April when temperatures are colder. Those tiger living in temperature zones mate only during the winter months.
Duration of oestrus:-
The tigress in oestrus becomes restless and moves frequently, marking in the structures of the enclosure, i.e., the wall, the fence (Chain – link mesh), the plants with her marking fluid. The tiger sniffs the places of marking followed by grimacing, with nose wrinkled and tongue protruding out.
The duration of oestrus was calculated on the basis of the total number of days for which the above mentioned behaviour of the tigress was recorded and when she permitted mounting and copulation by the male. The duration of three oestrus periods were 5 days each.
Tigers usually remain in pairs. Same pairs of tigers were allowed to mate repeatedly. As they remained together, mutual confidence was soon established. But no physical contact was noticed till actual mating took place.
The mating behaviour consisting of courtship interactions involved mainly olfactory, auditory, and visual inputs. Initiative for mating was taken by the tigress in oestrus. She displayed a variety of mating behaviours to lure the male. She came to the resting male and rubbed her face with that of the male (Cheek rubbing) and then rubbed her body with the body of male (flank rubbing). This stimulated the male and he stood up. The female turned her back and with raised tail moved forward, followed by the male for some distance. Then both moved in two different directions and again closed to a spot, where female sat in a low crouching position (lordosis posture) in front of the male. In this position she presented herself by sitting with fore – legs fully extended and hind – legs more than half bent with hind quarters kept in somewhat raised position. The male, then approached from the font, mounted the female first by the left hind limb and positioned himself over her by arching his back, bringing his copulatory organ in contact with genital region of the female. The tiger mounted her in half – knees -bent position without putting any pressure on her body. The female than began to trend by pushing against the ground with her hind-limbs and to facilitate proper vaginal contact, she turned her tail sharply to one side exposing her genital region. During this time, the tail of the male remained in usual position. Then mating took place by a series of vigorous pelvic thrusts by the male. In this condition the tigress produced a low deep growing sound—-” OaarOaa”. At the climax the male tiger extended his neck and grasped a fold of skin on the tigress’s head and produced a peculiar metallic high -pitched squeal — “Aee Ooaa” trailing off into “AeeAee”.
With the production of this sound by the male, the female growled and gave a sudden jerk to dislodge the male. She then turned upside down, angrily raised her fore paw towards the male, and attempted to attack just as in a mock buttle. The male jumped off from the female hurriedly and moved for a certain distance with the tail raised. It was noticed that the tiger jumped 5 ft -6 ft distance. During this condition the copulatory organ of male remained out of few seconds.
Vocalizations are very important during mating. Usually a tigress in oestrus produces a long low sound expelling air through the parted lips and nostrils called ‘prusten’. When the female approaches the male in the pre mating condition this sound is produced as a greeting signal and is immediately reciprocated by the male and he become ready for mating. The sound is produced by both prior to check rubbing, flank rubbing and when the male follows the female for mating. In several instances, it was also marked that when the male was inside the water moat, the female produced this ‘prusten’ to attract him. The male then came out from the water, and without check rubbing and flank rubbing mating took place.
The mating call made by the courting couple “Aungooooaongh”. The call of male was comparatively more deep throated, louder, and shorter.
The actual mating time varied from 7 – 35 seconds.
The inter-mating period varied from 2-70 minutes.
Mating took place both during the day as well as the night. Under this study mating could be observed only during day time. Frequency of mating was more in morning hours. As it was very hot in Nandankanan towards the end of February, tigers remained indoors all along the hot hours of the day after feeding, without any occurrence of mating. Mating is more frequent during the mid 2-3 days of oestrus period and the duration was longer during the last of the period.
Unsuccessful matings are not uncommon. In such cases, the male did not hold the fold of skin in the neck, and the peculiar high pitched squeal as well as growling sound was not produced by the male and female respectively. In some cases the male produced the characteristics ‘prusten’ only.
Post –mating behaviour:-
After each copulation, the male moved away from the female and walked about in the enclosure, or usually lay on the ground. The tigress, after successful copulation lay motionless for 3-5 minutes and then she rolled on her back. After mating, in most instances, the male tiger sprayed scent on the wall, wire – mesh, the bushes and the trees. In between two consecutive mating, the present workers have observed, maximum of 6numbers of scent spraying by male. No scent spraying (MF) by the female in the post mating stage was observed. The male also moved rubbing its cheek and body against the tree trunk or wire – mesh. In between mating the male was found scratching small patches of parallel ground with his hind legs, and either rested there, or else urinated or defected there. In the post – mating session, both male and female tigers were found to be drinking and cooling inside the water moat.
After a short interval (average of 24.35” 6.35”), the female approach the male, and again, the whole process of courtship and copulation took place.
Inter – oestrus interval:-
When the female tiger not become pregnant with the first mating, and again she came into oestrus after an inter-oestrus interval of 30 days and again mate with male tiger.
Gastration means the pregnancy period of the tigress. It may take 93 – 112 days.
The tigress gave birth mainly 2 to 3 cubs. The colour of the cubs is normal coloured just like their parents.
1:2, 0:2 and 1:2, male and female cubs were born to aforesaid parents respectively.
When two tigers cause their mating, another lone male tiger watch them closely, from the adjacent enclosure. It was noticed that the lone male was coming very close to the said enclosure and producing a small mating call, tolure the mating female. Very often, it was found to be gazing eagerly at the female. The enraged the mating tiger, who chased the other opponent many times, in order to drive him out from the scene by showing aggressiveness through growling and jumping against the middle wire -mesh. The same reflex is shown by lone tiger, in retaliation. The attitude continued up to 2 to 3 days. This might have caused fatal consequences to the male, if not prevent by other. Once they were old habitat mating started as usual.
The tiger in India breeds all the year round and the cubs are born in any month of the year. In having the oestrus cycle of captive tigresses and observed the following indices of heat , such as the lordosis posture (presenting herself), rolling on her back, flank rubbing, cheek rubbing, and puffing sound called ‘prusten’ and calling or moaning.
The mating period of tiger ranges from 3-23 days. The average length of receptivity of 14 oestrus period was reported to be 7 days. Further, the average of 48 oestrus period of 7 tigers is shown in Calcutta Zoo .The inter- oestrus interval in tiger is about 3 weeks. The interval between mid-points of consecutive oestrus periods in one tigress varied from 45 – 55 days.
It is evident from the present study, that, no mating takes place immediately after feeding, probably due to heavy stomach. In the cold winter season, mating occur throughout the day, where as in the summer months, it is restricted to the morning. Perhaps, the atmospheric temperature regulates the mating process. Unsuccessful mating occurs due to continuous and repeated mating. As a result in few cases, perhaps, ejaculation fails to occur.
Mating time varies a little in different investigations. It is reported to be 15-20 seconds, 15-30 seconds and 8-35 seconds in comparison to present study of 7-35 second. The gestation period of tiger given as 99 to 112 days. The size of litter varies from 1 to as many 4, 5, 6 or even 7, the usual size being 2 or 3 cubs. The ratio of male to female in 11 litters is 13 to 19.
There is no such published report of agnostic behaviour between two male during mating in captivity. Another important finding is that the sudden changes of habitat and outside interference affected mating.
The tiger’s wider ecological tolerance, adaptability in diverse habitats, high reproductive capacity with short gestation period, suggests that if better conditions are maintained they can reproduce well in captivity.