Sri-Lanka(n)/Ceylon Lion, Ceylon (Bengal) Tiger & Ceylon (Asiatic) Cheetah

[Sanju]

(11-18-2018, 11:03 AM)GuateGojira Wrote: After all, there is also the possibility that large leopards or leopard-like big cats from the first "wave" from Africa that you described do colonize the island. This, of course, is just especulation but is a plausible scenario.

@GuateGojira I believe in researchers.

"We cannot be certain that the Batadomba phalanx (DASL 1982.01) and the Ratnapura M1 (NMSL F559) belong to the same species. While we are confident that the Ratnapura M1
belongs to a tiger, the Batadomba phalanx, while separating distinctly from the lion, is clearly distinct also from the tiger. At 45.3 mm dorsal length, this phalanx is less than 2% shorter than the longest of the 23 BMNH tiger phalanges (46.1 mm, from a female, BMNH 1884.1.22.6, from the “Deccan” [peninsular India]), which suggests that this tiger was comparable in size to the tiger. Pending the availability of further evidence, we choose to assign both the M1 and the phalanx to a single species, tentatively the tiger. While conceding that the large size of the Batadomba phalanx could be the result of taphonomic bias, the size of the Sri Lankan tiger appears to have been remarkable given that insular dwarfism like P. tigris populations (e.g. in the Sunda Islands) have generally been noted to be smaller than their mainland counterparts (Luo etal., 2004)."

However, the discovery of the Ratnapura tiger M1 in alluvium, together with hippopotamus and rhinoceros fossils, demonstrates that tigers did indeed occur in the island. Based on present-day submarine topography, a functional land bridge between Sri Lanka and India requires a sea-level lowering of only ~ 10 m. Sea levels were ~ 120 m below present-day levels at the last glacial maximum ca. 20,000 ybp (Siddall et al., 2003), thus facilitating a more than 80 km-wide terrestrial connection or land bridge. It appears likely that sea levels were sufficiently depressed during the final ~ 200,000 years of the Pleistocene to have supported a land connection between Sri Lanka and India for all or most of that time (Bossuyt et al., 2004), and probably until 5,000–10,000 ybp (S. Deraniyagala,1992; Anderson, 1998; Yokoyama et al., 2000).

Indeed, there is no known barrier to the dispersion of tigers into the Indian peninsula during the Pleistocene, though Kitchener & Dugmore (2000) speculated that the widespread presence of short grasslands may have resulted in the tiger being altogether absent, or present only in very small numbers, during this period, surviving successive glacial maxima in refugia such as the moist forests of the south-western Western Ghats mountains. The wet zone of Sri Lanka may have provided another such refugium.

It appears, however, that despite the existence of a land bridge, an ecological impediment to the dispersion of "moist-forest faunas" between the mainland and Sri Lanka did exist for much of the past 500,000 years (Bossuyt et al., 2004), though the nature of this barrier is not known. Although the climatic history of South Asia is not well documented, there is evidence that the climates of peninsular India and Sri Lanka experienced protracted desiccation during Pleistocene glacial maxima (S. Deraniyagala, 1992; Pant & Rupa Kumar, 1997), possibly resulting in desertification of the land bridge between India and Sri Lanka for much of that time.

Even during the present relatively pluvial period, southern India and northern Sri Lanka are remarkably dry, precipitation being seasonal and rarely exceeding 1,500 mm yr-1, with a vegetation of tropical dry shrub-land, a habitat not associated with tigers. In view of tigers having appeared in Sri Lanka, established a population sufficient to have justified hunting, and then become extinct at the end of the last glacial maximum, we suspect that their entry to Sri Lanka (and therefore peninsular India) may have coincided with a pluvial phase during or prior to the previous interglacial, ca. 70,000–2000,000 ybp, their apparent absence from Pleistocene India during this period being a sampling artefact.

*This image is copyright of its original author

*This image is copyright of its original author

There is fossil evidence, however, of the late Pleistocene presence in the island of the dhole (Cuon javanicus) (P. Deraniyagala, 1958), which has since been extirpated. The gaur (Bos gaurus),
also known from middens at Batadomba Cave (S. Deraniyagala, 1992), appears to have persisted longer, becoming extinct only in historical times (Knox, 1681: 78). In India and Southeast Asia, the range of the tiger completely overlaps that of the gaur (Corbet & Hill, 1992), the latter serving as a prey species for the former (Lekagul & McNeely, 1988).

While tigers occur in a diversity of ‘closed’ habitats ranging from tropical rainforests through mangrove swamps to tall grasslands, lions are associated mainly with ‘open’ habitats such as savannah, grassy plains and scrub (Nowak, 1999: 825, 832). The other fauna recorded from the same midden as the Batadomba phalanx include the land snails Acavus and
Paludomus, the carp Tor khudree, the jungle fowl Gallus lafayettii, gaur, and a variety of smaller mammals such as monkeys and porcupines (S. Deraniyagala, 1992: 314; pers. obs.). While many of these species occur in all Sri Lankan forest types, members of the endemic Sri Lankan mollusc genus Acavus are restricted to closed-canopy monsoon or ‘rain’ forest (Hausdorf & Perera, 2000). The late Pleistocene fauna of the Ratnapura area also included a now-extinct hippopotamus, Hexaprotodon sinhaleyus and rhinoceroses, Rhinoceros sinhaleyus and R. kagavena (see P. Deraniyagala,1963; S. Deraniyagala, 1992). Teeth of R. sinhaleyus (= R. sondaicus: see Laurie et al., 1983), from Adavatta, Lunugalaearliest direct evidence of modern humans in Sri Lanka dates to ca. 37,000 ybp (S. Deraniyagala, 2004).

Whether hunting pressure was sufficient to extirpate tigers from the island, however, is open to question: there is no direct evidence to support or refute the idea that modern humans impacted negatively on the fauna, resulting in ‘prehistoric overkill’ sensu Martin (1984)(Sri Lanka) have been thermoluminescence dated to 80,000 ± 20,000 ybp (S. Deraniyagala, 2004). Indeed, R. sondaicus, the Javan rhinoceros, is a rainforest species (whereas the Indian rhinoceros, R. unicornis, is typical of the floodplains ecosystem of the Terai). "These data suggest that the late Pleistocene habitat of Kuruwita comprised swampland and moist, closed-canopy rain forest that seems to have persisted" until large-scale clearing commenced ca. 150 ybp: elsewhere in the range of these species, such habitats are associated closely with tigers, but not with lions Further, rhinoceros, hippopotamus and lion remains are not represented in Sri Lankan cave middens: they seem to have disappeared before the occupation of these caves by early modern humans. (The records of lion remain in the Batadomba Cave middens—see S. Deraniyagala, 1992—are erroneous: the Batadomba phalanx, here attributed to a tiger, is the only specimen in sufficiently intact condition as to facilitate definitive identification). The lions, therefore, appear to have been victims of the advancing rainforests and dense monsoon forests that accompanied the pluvial phase that saw the advent of the tiger in Sri Lanka.

While the Kuruwita and Ratnapura fossils show that lions and tigers were sympatric in this area, however, there is no evidence to suggest they were syntopic. The Late Pleistocene is also significant because it was during this time that the initial dispersion of modern humans occurred. Although stone tools probably dating back to the Mid-Pleistocene have been found (S. Deraniyagala, 1992), the earliest direct evidence of modern humans in Sri Lanka dates to ca. 37,000 ybp (S. Deraniyagala, 2004). Extinctions on islands have generally been associated more with predation and prolonged attrition (“sitzkrieg”) than with environmental change (Barnosky et al., 2004; Guthrie, 2004). "While hunting may have impacted on the population of tigers in Sri Lanka, habitat loss too might have been an important determinant too".

Premathilake & Risberg (2003) show from a study of pollen that at Horton Plains, a present-day tropical montane rainforest (2,100 m a.s.l., ~ 40 km distant from Kuruwita), that a significantly cooler climate dominated 24,000 ybp, giving way to grasslands 18,000 ybp, semi-deciduous seasonal forest establishing itself about 14,000 ybp, with the final transformation into rainforest taking place only about 9,000 years ago.

"Ungulate prey of 5.3–63.8 animals km-2 are required to support typical tiger densities of 3.2–16.8 100 km-2" (Karanth et al., 2004; Karanth & Stith, 1999).

Both reduced prey density and shrinkage of dense forest (resulting from desiccation during the last glacial maximum) may significantly have reduced the range and population of the tiger in Sri Lanka, with human predation accelerating its demise.
"Opposing phases of climate-driven habitat flux appear to explain the disappearance of both the lion and the tiger from Sri Lanka, leaving this territory to the only truly generalist Asian big cat, the leopard". Even today, leopards are ubiquitous in Sri Lanka, persisting in all natural habitats and many anthropogenic ones, from sea level to montane cloud forest at up to 2,400 m a.s.l.

*This image is copyright of its original author

*This image is copyright of its original author

Yellow region in India indicates both the Asiatic and Primitive lion range map overlap but the latter is more ancient and with entire Indian peninsula occupation including Lanka before 1st millennium BC.

*This image is copyright of its original author

The probable Asiatic lion range...
https://www.researchgate.net/publication..._Sri_Lanka
Regarding #5, These are some of them which support they are at least two migratory waves colonized Asia by Lion in particular.
1. The Lion fossil evidences from West Bengal- "Occurrence of Fossil Lion and Spotted Hyena from Pleistocene Deposits of Susunia, Bankura District West Bengal"
The note records the occurrence of fossil lion, Panthera cf. leo, and spotted hyena, Crocuta cf. sivalensis, in the Pleistocene alluvial deposits near Susunia in Bankura district West Bengal. This is the first definite record of fossil lion from India, and that of C. cf. sivalensis from any Pleistocene deposit in Peninsular India. The fossils are described and their distribution is briefly discussed,
(http://www.geosocindia.org/index.php/jgs...view/63924) and similar grassland faunal herbivores and carnivores found extant in African soil are found in different parts of Indian peninsula dating back to Pleistocene indicating the habitat and environment similar to Africa in India which is a part of Gondwana separated and joined with Eurasia having similar type of mineral deposits in Indian peninsula favoured African fauna.
2. Fossil evidences from Deraniyagala who served as President of the Ceylon Branch of the Royal Asiatic Society from 1952 to 1955 and dicovered about Lion (Leo leo sinhaleyus 1939), Balangoda Man (Homo sapiens balangodensis 1930), Sri Lankan gaur (Bibos sinhaleyus 1962), Sri Lankan Hippopotamus (Hexaprotodon sinhaleyus 1937), Sri Lankan rhinoceros (Rhinoceros sinhaleyus 1936), Sri Lankan rhinoceros (Rhinoceros kagavena 1956).
3. Genetic studies say that they are multiple Lion expansion within and outside Africa to West Asia and Europe by Arabian and Iberian Peninsula similar to Human expansion-Out of Africa I and Out of Africa II as Man evolved almost similar period, habitat and as an apex predator with lion.
https://www.nature.com/articles/srep3080..._evolution
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2572142/
http://rspb.royalsocietypublishing.org/c...f-ref-27-1
https://web.archive.org/web/201305021011..._Lions.pdf Reply