Exploring Nature/Exploration Camp/Scion of Lion. Asiatic Lion The Natural History. Asiatic Lion (Part I) Draft Report Prepared by Dwaipayan Ghosh

Transcription

1 Asiatic Lion (Part I) Draft Report Prepared by Dwaipayan Ghosh

2 Content Sl. No Particulars Page No. A Chapter 1 1 Taxonomy 2 2 General Description 3 3 Evolution of Lion 4 4 Differences between Sub-Saharan African Subspecies and Asiatic Subspecies 7 5 Social Structure and Reproduction of Asiatic Lion 8 6 Predation and Feeding 10 B Chapter 2 1 Former range 11 2 Present days distribution and Population 11 3 Home Range and Habitat Use 13 C Reference 15 Page 1

3 Chapter 1 Taxonomy The Asiatic Lion Kingdom : Animalia Phylum Class Order : Chordata : Mammalia : Carnivora Family : Felidae Subfamily : Patherinae Genus : Panthera Species Subspecies Biological Name : leo : persica : Panthera leo persica Figure 1: Asiatic Lion Male in Gir Sanctuary (Source: Photographed by Arnab Basu) Page 2

4 General Description Head and Body Length : cm (male) cm (female) Height at Shoulder Tail Length Weight : cm : cm : kg (male) kg (female) Colour Other Salient Features : Tawny un-patterned body (cubs have darker spots in early days those disappear with the maturity) : Long naked tail with tuft at the tip. Males have mane Figure 2: Asiatic Lion Female in Gir Sanctuary (Source: Photographed by Dwaipayan Ghosh) Page 3

5 Evolution of Lion Figure 3: The Cat Family Tree (Source: Evolution of Cats in Scientific American) Lion is one of the 37 species of the Family Falidae or what we call the cat family. It belongs to the Sub-Family Pantherinae i.e. big cats and Genus Panthera that symbolises the Roaring Cats. An initial radiation by the felid occurred during the Oligocene (ca. 34 MYA), giving rise to the sabre-toothed cats. This was followed in the Miocene (ca. 23 MYA) by an evolutionary line from which arouse modern genera (Klemian and Eisenberg 1973). Since then it was an amazing journey to Lions, the king of the beast. As illustrated in Figure 3, it is assumed on the basis of genome sequencing that a panther like predator, considered as the ancestor of all 8 lineages of modern cats was living somewhere in Asia. Approximately 10.8 MYA ancestors of modern big cats separated from other felids. These ancestors of modern big cats were roaming around in Asia. Approximately ca. 6.4 MYA ancestors of non-roaring big cats like Clouded Leopards and Bornean Clouded Leopards got separated from ancestors of modern roaring cats. Then approximately 3.7 MYA, a significant bifurcation took place among Panthera ancestors. Ancestors of Asian Big cats, Tiger and Snow Leopard separated from ancestors of Lion, Leopard and Jaguars. Then ca. 3 MYA Jaguars separated from ancestors of Leopard and lion and approximately 2.7 MYA Lions and Leopards speciation took place. Page 4

6 Ancestors of Lions migrated to Eastern Africa in late Pliocene and evolved further to adopt in African Savanna (described in Figure 4 as the 8 th Feline Migration in the 2 nd wave). Figure 4: Feline migration waves (Source: Evolution of Cats in Scientific American) Page 5

7 Lion fossils trace to the Late Pliocene in Eastern Africa and the Early Pleistocene in Eastern and Southern Africa coincident with the flourishing of grasslands approximately MYA. By Mid Pleistocene ( 500,000 years ago), lions occupied Europe and by the Late Pleistocene ( 130,000 10,000 years ago) lions had the greatest intercontinental distribution for a large land mammal (excluding man), ranging from Africa into Eurasia (Migration to Eurasia illustrated in Figure 4) and the Americas (Migration to the Americas illustrated in Figure 4 as 9 th Feline Migration in the 2 nd wave.). Lions in Americas couldn t survive the competition with Jaguars that migrated to Americas earlier. Lions were extirpated from Europe 2,000 years ago and within the last 150 years from the Middle East and North Africa. Today, there are less than 50,000 free-ranging lions that occur only in sub-saharan Africa and the Gir Forest, India (Figure 5). Based on patterns of genetic diversity and phylogenetic analysis of lion, a scenario of a period of refugia/isolation in the Late Pleistocene followed by two major lion expansions across Africa and Asia in proposed. Figure 5: Migration of Lion in Eurasia and Africa (Source: The Evolutionary Dynamics of the Lion Panthera leo Revealed by Host and Viral Population Genomics) Page 6

8 Differences between Sub-Saharan African Subspecies and Asiatic Subspecies The Asiatic lion was long considered to differ from its African cousin, in being smaller and less powerful and with paler coloration. But after detailed study, it is found that though there are some physical differences between the African (P. l. leo) and Asiatic (P. l. persica) Subspecies but those differences are even smaller than the genetic distance between human racial groups. Physical differences between Asiatic and African Lions: Male Asiatic Lions have only moderate mane growth at the top of the head and around cheek and chin leaving their ears visible, whereas, in African Lions, mane is fully developed around its head and neck completely obscuring the ears. Unlike African lions, both sexes of Asiatic lions have a distinct fold of skin along the bally. Asiatic lion skulls have a large percentage of bifurcated infra-orbital foramina while African lions have only one foramen on either sides of the skull. Behavioural differences between Asiatic and African Lions: Lion is the only feline that lives socially. Both African and Asiatic lions live in fissionfusion social group called Pride. African lions generally live in large harem structured pride of male, female and young ranging up to 20 individuals with a mean of 3.3. There are also some all-male coalition ranging from 1 to 4 with a mean of 1.6. All female groups with numerical range of 1-11 with a mean of 2.1 are also there in Africa. Whereas, Asiatic lions live in smaller prides constituted by 2 5 related females and their cubs while a single male or an all-male coalition ranging up to 5 individuals hold tenures of one or more than one prides. Association between male (single or coalition) and female prides are temporary in of Asiatic Lions. Male (single or coalition) joins pride only when there is a large kill or when there female in oestrus. Male cubs are disowned by the pride on maturity to avoid inbreeding in both the cases. Page 7

9 Social Structure and Reproduction of Asiatic Lion Exploring Nature/Exploration Camp/Scion of Lion Sociality in lions could be traced to coordinated group hunts, which are more successful. However, what would seem to be most obvious explanation increased hunting success yields more food become less so on examination. In fact, the highest rate of food intake per hunt appears to be gained by solitary females. Based on the theory of Kin Selection, Packer (1986) argued that lions become social because it is evolutionarily more advantageous to share kill with scavenging relatives than to yield to strange lions or other large predators. Other benefits of sociality are defence of young, long term maintenance of territories and insurance against individual injury or incapacity. Asiatic Lions like its African cousins are very social. The core unit of Asiatic Lions matrilocal society is called Pride that consists of a group of related females (none dominant) and their cubs. The Prides of Asiatic lions are much smaller than their African counterpart. A Pride consists of as fewer as 2 5 females and their cubs in case of Asiatic lions. Pride hunts or scavenges in cooperation. Mature females in a Pride even synchronises oestrus to give birth cubs synchronously. That always increases survival rates of cubs and ensures maximum maternal care as all the females in the pride take care of all the cubs and cubs suckling freely from any lactating female. Though some males live alone, but males are also very social and often live in Coalition of up to 5 related/unrelated males. These Coalitions hunts or scavenge cooperatively like female Prides. Unlike their African cousins, single male or a Coalition joins Pride only either if there be a large kill or females of the Pride are in oestrus. This can be explained by the average weight (ca. 40kg) of the most common prey (spotted deer) by Asiatic Lion, which will not provide enough meat to a Pride accompanied by males. Kin Selection will not allow males to rob the foods from their own cubs. The time span, for which a single male or a Coalition holds over a Pride or more, is called Tenure. Competition among males for Pride Tenure is intense and average Tenure is only of Two to Three years. However, larger Coalitions of 4 5 males can hold longer Tenure for even more than 47 months. Males in a Coalition consisting of 2 3 members may be unrelated but for a Coalition of 4 or more, all members are always related males. Page 8

10 When a single male or a Coalition wins over Tenure of a Pride most females with dependent offspring from old male or Coalition, lose their cubs within a month of take over despite of maternal defence. Pregnant females also lose their cubs immediately after giving birth. In this ways males ensure their paternity during the short reproductive life and reduces competition for their own gene. In the response, females of the Pride show a heightened sexual activity for about three months attracting other males and encouraging competition to ensure that the fittest is able to gain the Tenure. Females remain infertile during this Testing Period. Whenever a Coalition of more than 4 males takes over a Pride, it has been always observed that at least one member of the Coalition fails to breed successfully. Through the Kin Selection, the non-breeding helpers, by being related, still ensures that some portions of their genes are passed on. While onset of spermatogenesis begin at 30 months in males and females may begin mating at 24 months, in case of Asiatic Lions, males establish their first Tenure for reproduction at the age of 5 to 8 years and females first give birth at the age of 4 years. In female, oestrus period lasts for 4 days with an inter-oestrus period of 16 days, and a gestation of days. Mating has been observed in most months in Gir, but more mating were recorded at the end of September and in October. Nearly 86% of births occurs in the first half of the year with an average litter size of 3. Page 9

11 Predation and Feeding Asiatic lions require 5-6kg of meat per day but they can eat 20kg a day. Asiatic Lion is at the top of the food chain in Gir. It is the top predator. Asiatic lions prey on peacock to camel. But, in 1973, Dr. Paul Joslin found from scat analysis of Asiatic lion, domestic stock contributes about 75% in Asiatic lions diet in Gir Forest. During his sample survey, there were estimated 44,000 domestic stock (including buffalo, cattle, horses and cows) and 5,600 wild angulates (including Spotted deer, Nilgai, Sambar, Wild boar, Four Horned Antelope and Indian Gazelle) roaming in Gir forest. In a study by Dr. Ravi Chellam and Dr. A.J.T Jhonsingh later in 1993, some very interesting facts have been found. Nearly 65% of the lion kill were wild angulates at that time. It might be due to increase in number of wild angulates after initiation of Gir Sanctuary Project. But this statistics also may have been underestimated as carcass of domestic stock is easier to be found than that of a wild angulate. Moreover, villagers reported whenever their domestic stocks were killed by lions. On analysing preying patterns of Asiatic lions in Gir, Dr. Chellam and Dr. Jhonsingh found that the male : female ratio of spotted dear kills were 179:100 whereas the sex ratio of the population was 45:100. The same study on Sambar, the largest deer in Indian woods, revealed that sex ration in lion kills was 150:100 whereas the same in total population was 49:100. It establishes that lions prefer to kill larger animals to make the both ends meet for the whole pride. Studying domestic stock kills, it was found that male lions were on 56 kills whereas female prides were on 15 and mixed groups were on 7. These preying patterns establishes that to meet the requirement of food Asiatic lions in Gir, especially males, prefers to prey on domestic stocks as they are easier to hunt and provide more meat than wild ungulates and also available even inside the forest due to various tribal settlements (Maldhari, Rabari etc.) inside the Gis forest. Page 10

12 Chapter 2 Former range Lion spread into north-western Asia from Europe and then westward into Africa, where it established its dominion practically over the whole of the continent. During Biblical times lions were abundant in Asia Minor and Palestine. From these parts, their territory extended to Iraq through Iran, to Baluchistan into India. The lion came to India by way of our north western passes and it once inhabited practically the whole northern and central India from Sindh to Bengal, from the Ganges and Indus to the northern banks of Narmada. Its limited distribution in India suggest that the lion is comparatively recent immigrant into India. The Asiatic/Persian lion (P. l. persica) once was found in Europe and Asia (eastward up to India s Gangetic plain). In Asia, this subspecies was historically stretched from Syria, across the Middle East to Eastern India. In early 19 th century even around 1850, the lions distribution was quite extensive across Indian subcontinent. Large number were found in present day states of Rajasthan, Gujarat, Punjab, Haryana, Uttar Pradesh and Madhya Pradesh with reports of strugglers from Bihar and Odisha. A lion never reported from south of Narmada river. The last lions in India outside Gir forest had been shot by 1888 (Lydekker 1895). The last reports of Asiatic lions outside India (Heaney 1944, Champion-Jones 1945) were in Iran. Present days distribution and Population The once widely distributed Asiatic lion is now confined in the Gir Forest and surrounding areas, in the state of Gujarat in north-western India. In 2007, lions were restricted into 1621 sq.km distributed in five (5) Protected Areas (Gir National Park, Gir Sanctuary, Pania Sanctuary, Mitiyala Sanctuary and Girnar Sanctuary). Among these five (5) Protected Areas, Gir National Park, Gir Sanctuary and Pania Sanctuary cover an area of 1452 sq.km of a compact block forest in Junagadh, Gir-Somnath and Amreli districts of the state of Gujarat. Mitiyala Sanctuary near Gir East and Girnar near Gir West are the first two satellite sanctuaries for the lion, where animals move freely from the Gir forest through both forests and non-forest areas. With strengthening conservation measures and habitat recovery, the number of lions has increased and they have dispersed into the satellite areas Girnar, Mitiyala, Page 11

13 Babara vidi, coastal areas, Amardi, Liliya Krankach, Jesor, Shatrunjay hills and Hippavadli areas (Figure 6). Page 12 Figure 6: Asiatic Lion Distribution range in 2015 More than the area of PAs covering satellite areas and their corridors has been proposed for notification as an Ecological Sensitive Zone (ESZ), which is pending with the Government of India for final declaration (source: Gujarat Forest Department). With five PAs (1649 km2), and a substantial area (more than five PAs) under the proposed ESZ, the total area under the conservation regime would be quite high. However, the visiting area of lions may be three times the above, spreading in over 1475 villages of the four districts (Junagadh, Gir Somnath, Amreli and Bhavnagar). The number of Asiatic lion was lowest during the first and second decade of the 20th century, when only a few dozen of them survived in and around the Gir. The restriction on hunting and protection measures initiated during the second and third decades in the 20th century paid dividends and helped in the conservation of lions. The Asiatic lion again faced problems on transition of political power after independence, when the animal was on the verge of extinction in the late 1950s and early 1960s. After the establishment of the Gir Wildlife Sanctuary in 1965 and resettlement of 588 maldhari (a cattlerearing community) families among 845 families outside Gir, the situation improved. Analysis of census data shows that the

14 impact of intensive conservation during the last five decades since implementation of the Gir Sanctuary Project is reflected in the population growth of prey and predator (Tables 1). Table 1 : Population trend and lion dispersion Area Year Core Population Gir Forest including Pania and Babara vidi Satellite I : Girnar * Satellite II : Mitiyala * * 7 8 Satellite III : Coastal Junagadh Satellite IV : Coastal Amreli Satellite V : Amardi Lilia Krankach Savarkundala in Amreli district -- * Satellite VI : Satrunji Jesor Hippavadli, coastal area in Bhavnagar district Total * A few lions frequented from the Gir forest and were counted with the core population. In 14th Asiatic Lion census done in 2015, 523 individual wild Asiatic Lions comprising of 109 adult males, 201 adult females and 213 cubs were present in Gir Forest and its surrounding areas. Home Range and Habitat Usue Dr. Joslin Paul (in 1973) found that the home ranges of 2 coalitions of 2 males to be 74 and 188 sq km, respectively, whereas ranges of two female groups were 74 and 81 sq km. On an average females moved 2.5km per day and 95% of their movements were less than 5.3km. Males moved daily an average of 5.3km and 95% of their movements did not exceed 13.4km. In 1993 Dr. Chellam and Dr. Johnsingh found by analysing radio tracking data that males had annual home range of ca 100 sq km and females had 50 sq km. Even resident males were regularly observed using the area outside the limits of the protected area even in Crop fields and human settlements. Page 13

15 Figure 7: Asiatic Lion Distribution Range 1. Category A Village : High rate of livestock killing 2. Category B Village : Moderate rate of livestock killing 3. Category C Village : rare or occasional livestock killing Page 14

16 Reference 1. Mammals of South Asia Ajt Johnsingh & Nima Manjrekar 2. Indian Mammals S. H. Prater 3. A Handbook of The Mammals in India T. C. Jerdon 4. Indian Mammals a Field Guide Vivek Menon 5. Evolution of Cats by Stephen J. O Brien & Warren E. Johnson in Scientific American 6. The Evolutionary Dynamics of the Lion Panthera leo Revealed by Host and Viral Population Genomics 7. Dispersion of the Asiatic lion Panthera leo persica and its survival in humandominated landscape outside the Gir forest, Gujarat, India H. S. Singh th Lion Population and Estimation Report, 2015 Gujarat Forest Depertment 9. The Asiatic Lion: A Study of Ecology and behaviour by Dr. Paul Joslin (1973). PhD Thesis, Department of Forestry and Natural Resources, University of Edinburgh. 10. Ecology of Asiatic lion (P. l. persca) by Dr. Ravi Chellam, PhD Thesis, Saurashtra University, Rajkot. Page 15