Zoogeography of felids

Chapter 3

Zoogeography of felids Chapter Outline 3.1 The zoogeographical regions South-Eastern Asia: a biodiversity hot spot for safeguarding some rare species of felids The Felids of the Indochinese Subregion and Sundaic Subregion New species in the Sunda Archipelago

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The great eruption of the Toba volcano in Sumatra 3.2 The origins of the current distribution of felids around the world 3.2.1 The most Ancient migratory wave 3.2.2 The subsequent migratory waves and extinction of the megafauna

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The subject of zoogeography or biogeography attempts to give an answer to the current distribution of the animal species, studying their diffusion and displacements of the past with the help of the following parameters:

G

G

Today, genetics also helps in the study of zoogeography: both by studying the DNA of current species and that of fossils it is possible to understand that the presence of a species in a particular place on Earth is the result of genetic, ecological, and historical causes (phylogeography).

G

The location of fossiliferous sites and records studied by paleontology; The study of paleoclimatic variations (alternations of glacial and warm periods) that influenced migrations or caused extinctions of whole taxa;

The reconstruction of the ancient disposition of the emerged lands that continually varied with the sea level that increased or decreased as a result of climatic variations and caused the formation of intercontinental bridges.

These two species of lion, now extinct, lived in Eurasia and the Americas, where there are no longer any lions. Both had woolly fur to protect themselves from the cold climate of the period in which they lived. Their manes were not as abundant as those of current lions, and their fur was probably spotted. https://upload.wikimedia.org/wikipedia/commons/c/cb/Panthera_leo_atrox_Sergiodlarosa.jpg.

Felines of the World. DOI: https://doi.org/10.1016/B978-0-12-816503-4.00003-9 © 2020 Elsevier Inc. All rights reserved.

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Distribution area of the current lion and two species of extinct lion, according to the fossil record. Mitogenomics of the extinct cave lion, Panthera spelaea (Goldfuss, 1810), resolve its position within the Panthera cats Barnett, R., Zepeda Mendoza, M.L., Rodrigues Soares, A.E., Ho, S.Y.W., Zazula, G., Yamaguchi, N., et al., 2016. Open Quat. 2, 4. https://upload. wikimedia.org/wikipedia/commons/8/81/Cave_lion_range.png.

The distribution area of lions in late the Pleistocene is indicated by both fossil finds and the cave paintings left by our ancestors, which tell us that up to about 10,000 15,000 years ago some species of lion were distributed around almost the entire world, while their predecessors (Panthera fossilis and Panthera shawi) were already extinct. About 1.8 Mya the separation between current lions and the cave lions occurred; the latter are therefore to be considered as a separate species, not a subspecies of the current lion. From Eurasia, the cave lion and the Beringian cave lion (Panthera spelaea and Panthera vereshchagini) reached the northern part of North America through the Bering bridge. However, P. fossilis had previously arrived in North America where it originated the American lion (Panthera atrox). This species, known through many fossils, had first colonized North America and then crossed the isthmus of Panama, according to the latest findings of fossil remains, and reached Chilean and Argentine Patagonia (Chimento and Agnolin, 2017).

The current lion is now divided into just two subspecies, a northern one (Panthera leo leo) that once lived in North Africa, the Middle East, and which today is also found in India (Gir forest where, however, perhaps it was first imported?), and another (Panthera leo melanochaita) from East Africa to southern Africa (at one time it reached the Cape of Good Hope but today it is extinct in almost all of South Africa). Evolved from the lions of Laetoli in Tanzania (perhaps P. shawi, 3.6 Mya) they had spread throughout Africa, Turkey, the Middle East, India, and perhaps southern Europe. Clashes with the first Mediterranean civilizations and then the massive anthropization of Africa greatly reduced their original range. https://www.shutterstock.com/it/image-photo/lion-4-half-years-pantheraleo-21140812?src 5 TXN1T681JqV2gpFmVcmL4Q-1-29.

Zoogeography of felids Chapter | 3

3.1 The zoogeographical regions The various terrestrial continents have been divided into zoogeographic regions and subregions, based on the species (especially of vertebrates) that inhabit them. Not all experts agree on the number of regions and their exact boundaries, many considering some areas of faunal transition between one region and another, while others consider these transition zones as true zoogeographic subregions. Each region is characterized and defined by a number of orders, families, genera, or species that are exclusive and typical and which are called “endemisms” (from the Greek: indigenous, native). The Felidae family has colonized almost all zoogeographic regions: 1. Palearctic region (Eurasia, including most of China, North Africa, Middle East). The central part of this region is considered the area of origin of the Felidae, and certainly of the Panterinae, whose oldest fossil so far was found in Tibet; today it is frequented by a greater number of species (16) than any other region. 2. Nearctic region (North America and part of Central America). The Palearctic and Nearctic regions, for many valid ecological and wildlife reasons, are often brought together in the Holarctic super region. In North America there are only three species of felidae: the puma, the bobcat, and the Canadian lynx; however, further south toward Central America, the number increases with the addition of some South American or Neotropical species (ocelot, etc.). 3. Ethiopic or Afrotropical region (Africa south of the Sahara and part of the southwestern Arabian peninsula). The large island of Madagascar, which the felids have never colonized, is sometimes associated with this region and sometimes separated into the Malagasy region. 4. Indo-Malaysian region (India, south of the Himalayas, Indochina, the Sunda Islands up to Bali, the Philippines). In the tropical forests and the big islands of the Sunda live a large number of species of felids of which eight are endemic; therefore this region has a higher number of endemic species than any other region. Bali island and Lombok are separated by a sea passage, not wide but very deep, which has never allowed the two islands to unite. Here passes the border line that separates the Indo-Malaysian region from a wildlife province that also includes the island of Sulawesi (formerly Celebes), which reaches up to New Guinea— this is called Wallacea—in these islands and in the Australasian region, there have never been felids. 5. Neotropical region (South America and parts of Central America, Cuba, and Caribbean islands). This region presents a large number of endemic species of the genus Leopardus, which is exclusive to the region except for the ocelot which extends to the north encroaching into the Nearctic region with the jaguar.

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As regards the mammals that characterize these zoogeographic regions, the longer the isolation of a region has been, the more numerous its endemisms are; as an example, the Australian region, being an island and having almost never had any wildlife exchanges with other continents, has evolved a group of mammals, the marsupials, which are almost all endemic. The Afrotropical or Ethiopian region has some endemic mammals such as the Giraffidae, the Hippopotamidae, and some prosimians: the Galagonidae family, the monkeys of the genera Cercopithecus, Cercocebus, Mandrillus, the Colobidae and many others, and among the great apes (Antropoidea) the gorillas and chimpanzees. Typically of Afrotropical origin (although some doubts have recently arisen about the exact origin of some Families, not exclusively African) is the Supraordinal mammalian Clade Afrotheria which includes the Families: Tubulidentata (Orycteropus afer), Tenrecidae (Tenreks), Chrysochloridae (Golden moles), Macroscelidae (Sengis or elephantshrews), Hyracoidea (hyraxes), Proboscidea (elephants), Sirenia (dugongs and Manatees). The Neotropical region has many endemisms such as the Xenarthra (sloths, anteaters, and armadillos) and the monkeys Platyrrhini (Cebidae, Atelidae, etc.), and the only marsupials that live outside the Australasian region, the opossum (Didelphidae), of which one species is the North American or Virginia opossum (Didelphis virginiana), which has colonized part of the Nearctic region. The Palearctic and Nearctic regions have very few endemisms because for a long time, in the past, during the great Pleistocene glaciations, they were very often united by a bridge of emerged lands, where today there is a sea passage, called the Bering Strait, between Alaska and Eastern Siberia. Therefore previously, horses, lions, jaguars, saber-toothed cats, mammoths, and mastodons were widespread in both continents. Some disappeared during the period of the great extinction of the Pleistocene megafauna, which hit the boreal areas bringing about climatic and ecological upheavals which many species were unable to adapt to or escape from. It is almost certain, however, that the low temperatures due to glaciations, however rigid, took place gradually and certainly over long timescales, so they were not the cause of great extinctions. In reality, in the late Pleistocene, a series of very severe climatic episodes were recorded with sudden temperature falls of more than 15 C, which have been confirmed as the cause of the extinction of many large mammals (Megafauna) in many regions, since such wide and sudden variations did not leave time either to adapt or to migrate. Climate change could affect the ecology of entire regions; for example, the disappearance of a certain type of vegetation could mean the extinction of some populations of herbivores, and consequently of the carnivores which usually preyed on them.

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(Top) Map by Serban Proches and Syd Ramdhani (2012) https://www.researchgate.net/figure/Vertebrate-zoogeographical-regions-and-subregions-asderived-from-the-four-analyses_fig1_234563430.

These were the main causes of the extinction of many felids that were once present in Eurasia and today are no longer there; among the great predators of the past, a saber-toothed cat (Homotherium) disappeared 28,000 years before the present (BP), the cave lion (and the North American lion) 11,000 12,000 years BP, and even the current leopard lived in Europe up to 27,000 years BP.

These maps show two different proposals for the subdivision of terrestrial continents, in zoogeographic regions and subregions. Not all authors accept the Andean and Arctic regions; others such as the Caribbean, the Wallacean, the New Guinean, and the Madagascar regions are often considered to be subregions or transitional zones between a region and the neighboring region, such as the

Zoogeography of felids Chapter | 3

Saharo-Arabian subregion, often considered a transition faunistic zone between Africa and Eurasia. The Super Oloarctic region with boreal distribution is composed of three regions with many zoological and ecological-environmental affinities, including: 1. The Arctic region, containing Alaska, northern Canada, Greenland, and northern Siberia, which not accepted by all experts; it has only one terrestrial habitat, the Arctic tundra and the circumpolar glaciers; probably the only species of felines whose distribution areas touch the merional limits in this area are the Eurasian lynx and the Canadian lynx in North America. 2. The Nearctic region of North America. 3. The Palearctic region of continental Eurasia, to which must be added the Sino-Himalayan subregion

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(China), also known as the Chinese transition zone, and the Saharo-Arabian subregion, also known as the Saharo-Sindic transition zone, North Africa, the northern Sahara, and the Middle East. Here live some species or subspecies of very interesting felids, in populations that are isolated and separated from their sub-Saharan Africa congeners. The famous lions of the Atlas or Barbary lion were hunted almost to extinction at the start of the 20th century. The caracal and the serval they survive in Algeria and Tunisia and in some small areas of the Moroccan mountains, maybe with the leopard. In some particularly favorable small areas, there is a population of very rare Sahara cheetahs (Acinonyx jubatus heckii?) which some genetically identify more closely with Asian cheetahs.

(A) The canadian lynx (Lynx canadensis) lives in the Tundra and in the forests of the Taiga, in the Nearctic zoogeographic region. (B) The siberian tiger (Panthera tigris tigris ex altaica) lives in the mixed birch and coniferous threes forests of eastern Siberia in the Palearctic zoogeographical region. https://www.shutterstock.com/it/image-photo/running-tiger-snowy-furr-wild-winter-625445456?src 5 9J7BV8gnkuCHGAUM03IYVw5-78; https://www.shutterstock.com/it/image-photo/canadian-lynx-canadensis-walks-right-through-630052376?src 5 pynzE6piBhns4VpHscLTTQ-3-94.

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The Holarctic super region with boreal distribution is composed of three regions with many zoological and ecological-environmental affinities, including: 1. The Arctic region, containing Alaska, northern Canada, Greenland, and northern Siberia, which not accepted by all experts; it has only one terrestrial habitat, the Arctic tundra and the circumpolar glaciers; probably the only species of felines whose distribution areas touch the merional limits in this area are the Eurasian lynx and the Canadian lynx in North America. 2. The Nearctic region of North America. 3. The Palearctic region of continental Eurasia, to which must be added the Sino-Himalayan subregion (China), also known as the Chinese transition zone, and the Saharo-Arabian subregion, also known as the SaharoSindic transition zone, North Africa, the northern Sahara, and the Middle East. Here live some species or subspecies of very interesting felids, in populations that are isolated and separated from their sub-Saharan Africa congeners. The famous lions of the Atlas or Berbers were hunted almost to extinction at the start of the 20th century. They survive in some small areas of the Moroccan mountains, along with the leopard, and in Algeria and Tunisia, the caracal and the serval. In some particularly favorable small areas, there is a population of very rare Sahara cheetahs (Acinonyx jubatus heckii?) which some genetically identify more closely with Asian

cheetahs. In North Africa the Libyan desert cat (Felis lybica lybica) and the sand cat (Felis margarita) can also be found, while in the delta of the Nile in Egypt the only African population of the jungle cat lives (Felis chaus). In North America and Eurasia, the same latitudinal bands are matched by the same climatic-vegetation characteristics. From north to south in succession there are: the tundra, the coniferous taiga, the mixed coniferous and deciduous forests, and broad-leaved forests, grassy areas (the North American prairies and the Eurasian steppes), and the xerophilous scrub vegetation (the Mediterranean maquis on the coasts of the Mediterranean in Europe and North Africa), the chaparral in North America and, finally, further South, a dry predesert and desert belt. Eurasia and North America, especially in the northern areas, still share many species, genera, or entire families that in the Pleistocene were able to cross the Bering bridge between the two continents. For example, among the Bovidae they have in common: the bison (American and European), the musk ox, the wild sheep (Ovis); among the Cervidae the deer wapiti, the moose, the reindeer, and the caribou; and among the carnivores the brown and polar bear, the gray wolf, the red fox, many mustelids (wolverine, martens, stoat, weasels), and the Lynx genus. Even among the rodents there are many shared species: marmots, squirrels, flying squirrels, ground squirrels (Citellus, etc.), and chipmunks (Tamias, etc.)

The current distribution of the terrestrial ecoregions (ecosystems) in the various continents is influenced by the characteristics of the climate (especially by temperature, rainfall, and seasonality) that vary with latitude and altitude. With the climate the characteristics of the vegetation change, which in turn affects the type of fauna. This map shows the layout of the various habitats and highlights that in the northern hemisphere, from the north the same succession of ecosystems is present in both North America and Eurasia. In the intertropical zone (between the two tropics) we notice the presence of savannas and large tropical and equatorial forests. https://upload.wikimedia.org/wikipedia/commons/e/e4/Vegetation.png.

The distribution of terrestrial ecosystems has changed many times in the past, both under the influence of land provision, which changed based on continental drift and ocean level, and on slow but continuous climate changes. One of the causes that influenced the current distribution of animals was the succession of four glaciations (cold periods), alternating with four interglacial periods (warmer periods), which occurred in the Pleistocene period. The map shows the distribution of the terrestrial ecoregions, during the last great glaciation of the Pleistocene or Last Glacial Maximum (LGM, called Wu¨rm in Eurasia and Winsconsin in North America) that occurred about 20,000 year BP. Under the influence of the lowest temperatures, polar ice had invaded the most northern parts of the continents and the transformation of large masses of water into ice had decreased sea levels by as much as 120 m. This meant that Eurasia and North America were united by the Bering bridge, the platform of the Sunda had completely emerged, India and Ceylon were united, and Japan was in contact with Siberia. The cooling of the climate had upset the arrangement and extension of many terrestrial ecoregions, increasing the spread of the cold-climate ecosystems (tundra, taiga, etc.) that pushed more and more southward, and decreased the temperate-warm climate woods and the equatorial forests, which were replaced by grasslands and tropical savannahs.

African leopard Photo by V. Martegani

Snow leopard (Continued )

(Continued) Among the felids there are species that have anatomical, physiological, and behavioral characteristics which enable them to live in different natural environments. These are euribionte species (from the Greek euri 5 large, great, and bionte 5 that can live) that have a great potential for adaptation to both different temperatures and types of prey. Euribionte species among the felines include the leopard, the tiger, and the Asian leopard cat. These species do not have extreme specializations and live in warm humid tropical habitats and in the cool temperate forests of Manchuria, feeding on a wide range of prey. The leopard especially has a vast distribution area that includes the Afrotropical, Palearctic, and Indo-Malaysian regions. The puma also has this ability and lives in many habitats of the Nearctic and Neotropical regions; among the felids, the puma is the species with the widest north south distribution area: from the Yukon (north Canada) to southern Chilean Patagonia.

In contrast, other species (stenobionte species from the Greek steno 5 narrow, limited, and bionte 5 that can live) have less adaptability, are very specialized, and live only in certain habitats, as they need particular climatic-ecological conditions. Among the felid stenobionte species is the snow leopard which, with its thick fur, lives only in high mountainous environments or in cold climates; this big cat has specialized in hunting mountain animals such as goats and marmots. Even the Iberian lynx, due to its specialized diet based on European wild rabbits (Oryctolagus cuniculus), lives only in the Iberian peninsula (Spain and Portugal) in Mediterranean scrublands.

Zoogeographic distribution of the species and the main subspecies of Felidae. Regions

Endemic species

Species/subspecies

Six endemic species European wildcat (Felis silvestris) Chinese desert cat (Felis bieti) Iberian Lynx (Lynx pardinus) Eurasian lynx (Lynx lynx) Snow leopard (Panthera uncia) Manul or Pallas cat (Otocolobus manul)

16 total species

Amur leopard (Panthera pardus orientalis) Persian leopard (P. pardus tulliana ex saxicolor) Arabian leopard (P. pardus nimr) North African Lion (Panthera leo leo) Siberian and Caspian tiger (Panthera tigris tigris) Asian African wildcat (Felis libyca libyca and Felis libyca ornata) Sand cat (Felis margarita) Caracal (Caracal caracal) Asian cheetah (Acinonyx jubatus venaticus) Saharan cheetah (A. jubatus hecki) Jungle cat (Felis chaus) Asian leopard cat (Prionailurus bengalensis euptilurus) Temminck’s or Asiatic golden cat (Catopuma temminckii moormensis)

One endemic species Canadian lynx (Lynx canadensis)

Bobcat (Lynx rufus) Ocelot (Leopardus pardalis) Northern puma (Puma concolor cougar) Jaguarundi (Puma (Herpailurus) yagouaroundi) Jaguar (Panthera onca)

6 total species Three endemic species Black-footed cat (Felis nigripes) African golden cat (Caracal aurata) Serval (Leptailurus serval)

Leopard (P. pardus parduss) Cheetah (A. jubatus) West and Central African Lion (P. leo leo) East and South African Lion (P. leo melanochaitus) Jungle cat (F. chaus) Caracal (C. caracal) African wildcat (F. libyca cafra) Sand cat (F. margarita)

10 total species Eight endemic species

14 total species

Indochinese clouded leopard (Neofelis nebulosa) Sunda clouded leopard (Neofelis diardii) Sunda leopard cat (Prionailurus javanensis) Rusty spotted cat (Prionailurus rubiginosus) Marbled cat (Pardofelis marmorata) Bornean bay cat (Catopuma badia) Flat-headed cat (Prionailurus planiceps) Fishing cat (Prionailurus viverrinus)

Asiatic lion (P. leo leo ex persica) Leopard (P. pardus) Tiger (P. tigris) Leopard cat (P. bengalensis) Temminck’s or Asiatic golden cat (C. temminckii) Jungle cat (F. chaus)

(Continued )

(Continued) Zoogeographic distribution of the species and the main subspecies of Felidae. Regions

Endemic species

Species/subspecies

Seven endemic species Pampas cat (Leopardus colocola) Geoffroy’s cat (Leopardus geoffroyi) Guigna or Kod kod (Leopardus guigna) Andean cat (Leopardus jacobita) Northern oncilla (Leopardus tigrinus) Southern oncilla (Leopardus guttulus) Margay (Leopardus wiedii)

Southern puma (Puma concolor) Bobcat (L. rufus) Ocelot (L. pardalis) Jaguarundi (P. (Herpailurus) yagouaroundi) Jaguar (Panthera onca)

12 total species

The Borneo bay cat (Pardofelis badia) and the Iberian lynx (Lynx pardinus) are two of the rarest feline species with the smallest distribution areas. The first is an endemism of the Island of Borneo. The second is an endemism of the Iberian peninsula (Spain and Portugal). https://www.lynxexsitu.es/.

The current felids are distributed in all the zoogeographic regions except the Australian or Australasian region and the Antarctic continent. Many species of felids live in more than one region; for example, the lion lives in the Ethiopic region and, in historical times, lived in southern Europe, while in north Africa it was present until about 1920 (or possibly as late as 1940). Today it also survives in some small reserves in western India, with the best known being the semiarid forest of Gir in Gujarat; the caracal lives in Africa, the Middle East, and India; the cheetah lives in Africa and in the Middle East (now only in Iran); and the Libyan wildcat, with three subspecies, and the leopard with eight or nine subspecies, have wide distributions in Africa, Eurasia, and the Indo-Malaysian region. The Asian leopard cat (Prionailurus bengalensis) and the tiger are found in the Indo-Malaysian region, in the south to the island of Bali, while in the north they are

found as far as the Manchuria area in the Palearctic region. The Puma lives in North, Central, and South America, while the jaguar and ocelot are found in Central and South America and also in some restricted areas of North America (Texas). Some species, like many felines of the genus Leopardus (L. colocolo, L. geoffroyi) are endemic to the Neotropic region (South and Central America), some are endemic to the Andean region or subregion, such as the Andean cat (L. jacobita) and guigna (L. guigna). In the Indo-Malaysian region there are many endemisms such as the clouded leopard (Neofelis), the marbled cat (Pardofelis marmorata), and Temminck’s cat (Pardofelis temminckii), whereas the Borneo bay cat (Pardofelis badia), the Sunda leopard cat (Prionailurus javanensis), and the flat-headed cat, are endemic to the Sunda island and Sundaic subregion.

Zoogeography of felids Chapter | 3

The European wildcat, the Chinese desert cat, the snow leopard, the Eurasian lynx, and the Iberian lynx are endemic to the Palearctic region. The Canadian lynx lives only in North America, while the red lynx or bobcat goes further south and reaches Mexico and Central America.

South-Eastern Asia: a biodiversity hot spot for safeguarding some rare species of felids The Eastern or Indo-Malaysian zoological region includes India, the countries of Southeast Asia, and the archipelagos of the Philippines and the Sunda Islands. The various types of forest habitats of Southeast Asia (tropical evergreen forests, plains, mountains, mangroves, deciduous forests, monsoon forests, bamboo, Dipterocarpacee, etc.) are a complex mosaic of ecosystems that are ideal for hosting a great biodiversity including a large number (14) of Felid species. The complex geological vicissitudes of the Malacca peninsula and the Sundaic Archipelago between the end of the Pliocene and throughout the Pleistocene, have favored phenomena of species expansion and subsequent isolation, due to the continuous variations in sea level and

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climate changes that have caused repeated transformations of the various ecosystems. This complex of phenomena has favored speciation phenomena and the present and past presence of many forest environments rich in ecological niches has allowed many species of felids to evolve and adapt by cohabiting without significant competition; today we have arboreal (marbled cat and the two species of clouded leopards), moderately arboreal species and terrestrial (leopard, Temmink’s cat), terricolous (tiger and Borneo bay cat), and aquatic species (flat-headed cat, fishing cat), etc. Unfortunately, today most of the forests of Southeast Asia and the Sunda Islands have been destroyed to obtain timber or to make way for huge oil palm plantations that have made the ecological landscape more uniform and monotonous, while anthropization has continued to restrict the original natural areas (original wildlife). For this reason many species and subspecies or insular populations of Felidi have become extinct, such as those of the tigers of the islands of Bali and Java; many others have become very rare or are on the verge of extinction, given the small island areas to which they had adapted. Today, the Sundaic or Sumatran tiger and Malay and Java leopards and the various species of small cats (fishing cat, marbled cat, Borneo bay cat, flat-headed cat, Sunda leopard cat) all risk becoming extinct.

https://www.shutterstock.com/it/image-vector/tiger-681343525?src 5 mWFVeMaycln1rZoNCWvl4g-1-22.

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The Felids of the Indochinese Subregion and Sundaic Subregion Southeast Asia is divided into subregions, two of which are: G

G

The Indochinese subregion which includes parts of south China, Vietnam, Laos, Myanmar, and Thailand; The Sundaic subregion or Sundaland, with Malaysia and the large and small Sunda islands (Sumatra, Borneo, Java, Bali, etc.). It is probable that long periods of geographic isolation on the various islands have

The Indo-Malaysian zoogeographic region

favored the diversification of various species of small and medium-sized felids; one of these, the Borneo bay cat is endemic to Borneo, while the Sunda leopard cat (P. javanensis) is endemic to the Sunda and some small islands of the Philippines. In addition to the tiger and leopard and the two species of clouded leopards (lineage Panthera), many small cats live in these regions. The small cats of Indochina and the Sunda archipelago belong to the ancient lineage of the Borneo bay cat and to the more recent lineage of the Asian leopard cat. In Southeast Asia, more species and subspecies of Felids live than in any other part of the world.

Southeast Asia is divided into four subregions; the Indochina or Indochinese subregion and the Sundaic (or Sundaland) subregion have as a point of passage from one to the other, both today and in the past, the Isthmus of Kra. Instead, in the south, between the islands of Bali and Lombok it crosses the border with the subregion Wallacea (Sulawesi Timor and other islands of New Guinea). In the northeast there is the subregion of the Philippines, often united in the Sundaica

https://en.wikipedia.org/wiki/Indomalayan_realm#/media/File:Ecozone_Indomalaya.svg, Map by David S. Woodruff, D.S., 2010. Biogeography and conservation in Southeast Asia: how 2.7 million years of repeated environmental fluctuations affect today’s patterns and the future of the remaining refugialphase biodiversity. Biodivers. Conserv. 19, 919 941.

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Starting from the late Pliocene and during the Pleistocene sea levels have risen and lowered several times under the influence of episodes of sudden variations in temperature that have occurred, especially in the late Pliocene. 10 rapid level increases of more than 80 m and 48 increases of 40 80 m have been documented in the last 5 million years (Woodruff and Turner, 2009). This has caused continual expansions and decreases of land in the Sundaic region, with the Isthmus of Kra being a geographical barrier to the expansion of the Sundaic species in Indochina. The lowering of the sea level allowed the emergence of land bridges between the continent and the Sunda Islands. (A) In the Pleistocene period of the Great Glaciations, during the LGM which occurred about 20,000 year BP, the sea level lowered to a level never seen before, 120 m, so that the Sunda platform emerged and the archipelago became a single block of land, a continuation of the Indochinese peninsula. Because of these phenomena, many species, including the Felids, were able to colonize lands that they could not reach previously. (B) (C) When the sea levels increased, the various species remained isolated on the various islands of the archipelago and had no further contact with the Indochinese species. Map by Woodruff, D.S., 2010 Biogeography and conservation in Southeast Asia: how 2.7 million years of repeated environmental fluctuations affect today’s patterns and the future of the remaining refugial-phase biodiversity. Biodivers. Conserv. 19, 919 941.

New species in the Sunda Archipelago Three species of small felidae are endemic to the Sundaic subregion: the Borneo bay cat (Bay cat lineage), the flatheaded cat, and the Sunda leopard cat (leopard cat lineage), in addition to the Sunda clouded leopard (lineage Panthera). Separate species live in the Indochinese subregion and in the islands of the archipelagos: the fishing cat, Asiatic leopard cat, marbled cat, Temminck’s golden cat, and the tiger and leopard. These species took advantage of the repeated lowering and rising of the sea level, which united and divided the islands of the Sundaic subregion with the Malacca peninsula. By crossing bridges of emerged lands (like the Isthmus of Kra), they became distributed throughout almost the whole territory. With the definitive increase in the level of the seas, islands were formed where the cats remained “isolated” and over time diversified into a number of subspecies distinct from those of the Indochinese peninsula. By studying the insular subspecies from a genetic point of view,

researchers (Shu-Jin Luo et al.) published a scientific article in 2014 where they analyzed many biological samples. They proved that, what were considered the subspecies of the leopard cat of the Sundaic islands and the Philippines (P. bengalensis borneoensis, P. bengalensis javenensis, P. bengalensis sumatranus, P. bengalensis heaneyi, P. bengalensis rabori) and of the marbled cat (P. marmorata marmorata), have been isolated for an extremely long time (up to 2 million years) and have no had no further genetic exchanges and so are phylogenetically distinct from those living in the rest of Indochina and the Indo-Malayan region. These researchers thus proposed to group the insular subspecies of the leopard cat by separating them into a new species called the Sunda leopard cat (P. javanensis) splitting the leopard cat of India from that of China and Indochina (P. bengalensis). The family Felidae has therefore been enriched by a new species, while studies on the marbled cat will soon give results for or against separation into a further new species.

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Map courtesy by Peter Gerngross (2012) www.biogeomaps.eu. Modified by Bellani.

Observing this map with the distribution of felids in the Sundaic or Sundaland subregion, we can see some peculiarities in the distribution of some species: G

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The fishing cat today does not reach Bali, where it seems to have never lived; The leopard is not present in Sumatra and currently we have no evidence that it lived there in the past; It is established that although there are no longer tigers in Borneo, a large island that could sustain a good population of this big cat, they were present on the island until the beginning of the Holocene, as reported by Piper et al. (2007); moreover, tiger fossils dating back to less than 20,000 years ago have also been found in Sri Lanka and Palawan where it no longer lives, probably due to the eruption of the Toba volcano; Tigers were present until the end of the 20th century in Bali and Java, the islands of the sub-Sundaic region more distant from Indochina and where they were extinguished by excessive anthropic pressure (hunting and destruction of forests); The clouded leopard (Neofelis nebulosa) and the Asian leopard cat (Prionailurus bengalensis) in the Sunda Islands have diversified into species other than

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the corresponding species in Indochina: the Sunda clouded leopard (Neofelis diardi) and the Sunda leopard cat (Prionailurus javanensis). It is possible that a different species of marbled cat (from Sumatra and Borneo) will soon be found; Temmink’s cat from the Malay Peninsula reached Sumatra but not Borneo; The flat-headed cat has only populated Sumatra, Borneo, and the Malacca peninsula but has gone no further north of the Strait of Kra; The position of the Toba volcano in Sumatra (today a volcanic lake) is also indicated, the eruption of which caused climate changes that greatly influenced the distribution of the species of many mammals in Southeast Asia and particularly in the Sundaic region.

The great eruption of the Toba volcano in Sumatra The current distribution of felids (and probably other species of mammals) in the Sunda archipelago has also been greatly influenced by the large volcanic eruption of Mount Toba, north of Sumatra Island. This is a

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phenomenon that has only been studied in depth recently, and has given truly surprising results from the point of view of climate change at the time. About 73,000 years ago the volcano exploded emitting 2800 km3 of ash and lava, perhaps the largest known volcanic explosion; it is very probable that the fumes emitted obscured the sky for a vast area, causing temperatures to fall by almost 3 C 5 C for several years after the event. It seems that in the first year the temperatures may have decreased by as much as 10 C, having a tremendous influence on the ecology of the entire planet; this icy wave seems to have also caused the extinction of many species of mammals and much of the human population at the time. This phenomenon could be due to the singular absence of the leopard from Sumatra Island, as it is certain that about 73,000 years ago a large part of the population of tigers from Southeast Asia was almost wiped out and that the current population shows a low genetic variability of the species which indicates that it has undergone a genetic bottleneck, and which has repopulated today’s areas starting from a small contingent of survivors after some environmental catastrophe.

3.2 The origins of the current distribution of felids around the world The current distribution of all the species of Felidae in the various continents of the world and in the related zoogeographic regions is the result of migratory waves (at least two) that took place over a few million years, and which were caused by climatic-ecological changes that alternated in the last geological periods, from the Miocene to today. Some of these changes, such as the great glacial and interglacial periods of the Pleistocene, up to the LGM, have influenced sea levels and alternately created and destroyed land bridges between continents, such as the Bering bridge which united Asia and North America, the isthmus of Panama between the Americas, and the lowering of some inland seas such as the Mediterranean and the Red Sea. These appearing and disappearing land bridges also occurred between continents and islands, such as the isthmus of Kra between Indochina and the Sunda Islands, which for a limited period of time were all united by the emergence of the Sondaic Platform of which they represent the highest lands. During the LGM sea levels fell by approximately 120 meters, and the entire Sunda Shelf was exposed. Some groups of felids adapted to climate change, others became extinct, but many started migrations from one continent to another, perhaps following their prey that often had migratory habits; behavioral instinct would also encourage many species to expand their distribution area as new generations were able to move away from the places they were born to conquer new territories.

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Consequently, with passing time and growth of the population, the territory occupied by a group of felines becomes ever wider. Felines are also very skilled predators, and they are able to quickly explore and conquer new areas as soon as the opportunity arises, and so it is not surprising that they have successfully colonized unexplored regions. These migratory movements and territorial dispersions were favored by the emergence of land bridges created by lowering sea levels, and which allowed the colonization of continents that had never previously been reachable. This also favored many species of felids that, moving easily from one region to another and moving away from their original populations, often evolved into new species.

3.2.1 The most Ancient migratory wave From the Early-Middle Miocene at the beginning of the Pliocene, from about 15 12 to 5 4 Mya We do not know exactly how many millions of years ago the first specimen of carnivore appeared that would later become the progenitor of all modern felids. Various hypotheses have been formulated ranging from about 9 to about 15 Mya, in the period between the Early and Middle Miocene. That the place of origin of the current felids was Central Asia has been hypothesized and also calculated through genetic analysis based on molecular biochemistry, but this has never really been proven. The discovery of the fossil Panthera blyteae, on the Tibetan plateau, dating back to 4 6 Mya, gives us almost irrefutable proof. It is therefore Central Asia that has been identified as the place where the first ancestors of the Felids in the Miocene began and evolved and then spread, first across the continent and then, thanks to their success as predators in the various natural environments, they began to diversify into various species and, under the influence of climateecological changes, to migrate from their place of origin, which may have become too cold, to Africa (as precursors of the caracal lineage) and North America (as precursors of the lynx, puma/jaguarundi, and ocelot lineages) and, only much later, also to South America (ocelot lineage). During this period, migrations were facilitated by particularly low sea levels, as the glaciation of many water resources caused levels to decrease by about 60 m. For this reason they formed bridges of emerged lands such as the isthmus of Bering, a Panama bridge even larger than the current one in Central America, a well-traveled route between the Middle East and Africa (through the Red Sea), and between the Indochina peninsula and Sunda Islands. By means of these bridges the felids began to conquer new territories.

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From about 15 to 12 Mya, Asia was also inhabited by the precursors of the Pantherinae and about 6 Mya the genus Neofelis began its separation from the precursors of the genus Panthera, and migrated to Southeast Asia and the Sundaic Islands. The ancestors that gave rise to the caracal, the serval, and the African golden cat (caracal lineage), reached Africa about 12 8 Mya. Many felines crossed the Bering bridge and arrived in North America in different eras: 10 Mya the ancestors of the ocelot lineage began. This was followed about 6 Mya by lynxes and, almost 5 Mya, by the precursors that gave rise to the genera of Puma and Jaguarundi (while their relatives, the cheetahs, remained in Eurasia and later headed to Africa and the Middle East as the current species). In the same period, about 6 Mya, an ancestor of the golden cat of Borneo was separated by dividing from the lynx and began a migration to the south that led it to Indochina and the Sunda Islands; and here, at the beginning of the Pliocene (5 Mya) it gave rise to the present species, first the marbled cat and then the two species of golden cat. Afterwards (about 3.8 Mya), probably due to climate cooling, the ocelot lineage moved toward the south looking for more favorable climaticecological conditions and reached South America. Here, the most favorable climate, a tropical environment and with very diverse geographical conditions (from wetlands and forests to semiarid plains up to the Andes) favored the diversification of the current species of the genus Leopardus (ocelot, kod kod, margay, Geoffroy’s cat, Pampas, and Andean cats, etc.).

After this wave of migration the climate changed and sea levels increased, again separating the continents, so that many groups of felids remained isolated and continued their evolution separately from their predecessors.

(A) Ocelot (Leopardus pardalis). The ancestors of the ocelot lineage crossed the Bering bridge to North America about 10 Mya; 3.8 Mya they arrived in South America and differentiated into various species, including the ocelot. (B) Serval (Leptailurus serval). The ancestors of the lineage caracal, which also includes the serval, reached Africa very early between 12 and 8 Mya. Only the caracal then reached the Middle East and western India.

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3.2.2 The subsequent migratory waves and extinction of the megafauna

A beautiful image of the Spanish paleontologist-artist Mauricio Anton. Megafauna is represented in the north of Spain during the Pleistocene: woolly mammoths (Mammuthus primigenius), woolly rhinoceros (Coelodonta antiquitatis), a herd of Equidae and European cave lions (Panthera leo spelaea) with a reindeer carcass. https://upload.wikimedia.org/wikipedia/commons/e/e6/Ice_age_fauna_of_northern_Spain_-_Mauricio_Ant%C3%B3n.jpg

From the Pliocene to the Pleistocene: 5 4 Mya to up to 8000 10,000 years BP In a period ranging from four million up to a few thousand years BP, many other migrations occurred, always in correspondence with the lowering of sea levels and the consequent emergence of new lands; these served as passages or areas to expand the territories to be colonized. The last migration of the felids was that of the puma which occurred between 8000 and 10,000 years ago. This species returned from South America to repopulate North America where it had become extinct during the LGM which had caused a great extinction of the megafauna in the Northern Hemisphere. Species and climatic-ecological changes Between the Pliocene and the Pleistocene there was a continuous succession of different climatic phases, up to the four great glaciations of the Pleistocene (Gunz, Mindel, Riss, and Wurm) that, with the continuous alternations between cold and interglacial periods with more

or less warm periods, drastically changed the ecological landscapes of the continents and their geography, continually connecting them with each other and then dividing them again, due to changing sea levels. Under the influence of these recurring climatic changes and with the possibility of migrating from one continent to another, the felids diversified into new species that were increasingly adapted to the new conditions. In fact, between the Pliocene and the Pleistocene the diversification and birth of the largest number of new species occurred. These are the same species that still populate almost all the continents of the Earth today. Naturally, as fossil finds show us, many other species were unable to adapt and survive; for example, during the Pleistocene the so-called “great extinction of the megafauna” took place which destroyed more than half (perhaps as much as 70%) of the large species of herbivores and carnivores that had represented the typical fauna of the Quaternary. Especially in North America the phenomenon was very drastic because with the melting of the last glaciation ice (Wurm, about 15,000 12,000 years ago)

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the vegetation did not recover as in the past, and the herbivores (horses, camels, mastodons, woolly rhinos, giant ground sloths, etc.) became extinct, and their predators

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disappeared with them. These included many species of saber-toothed cats (Machairodontinae), American pumas, and the puma-cheetah-like Miracinonyx.

About 7 Mya two related lineages, the ancestors of the domestic cat lineage (Felis), and the Asian leopard cat lineage, separated and began to colonize Asia and Africa (the former) and Southeast Asia (the latter). The lineage of the domestic cat (genus Felis) expanded and first reached Africa as the black-footed cat (Felis nigripes), an ancient species that dates back to almost 3 Mya and reached South Africa where it is still widespread today. The sand cat and Felis libyca followed. Meanwhile the Manul or Pallas cat, an ancient species attributed (with some doubt) to the lineage of the Asian leopard cat, dates back to 6 Mya and has not undergone large variations to the present. Less than 2 Mya some lynxes returned to Eurasia, while others stayed in North America, where they remain today. The cheetahs populated Eurasia (Acinonyx pardinensis, etc.), while the current species expanded to reach Africa and the Middle East. About 300,000 400,000 years ago, the cave lion (Panthera spelaea) and perhaps other species populated Eurasia, while others reached the Americas and became Panthera atrox. These cold-climate lions died out around 10,000 11,000 years BP. The current lions survived from Asia and migrated to Africa and the Middle East at the same time as the leopard. The jaguar, with a Eurasian origin (such as Panthera gombazgoegensis 5 toscana), migrated to North America 3 Mya and then reached South America. The puma and the jaguar colonized South America. Only recently did the Puma migrate to South America from North America and then return to recolonize almost all of North America. About 2.5 Mya the tiger began its evolution and colonized southern Asia, pushing toward the Sunda islands. About 73,000 years BP the terrific eruption of the Toba volcano in Sumatra destroyed almost the entire population that was also once widespread in Borneo, Sri Lanka, and Palawan.