Historical and current distribution ranges and loss of mega-herbivores and carnivores of Asia

Abstract

Ecosystem functioning is dependent a lot on large mammals, which are, however, vulnerable and facing extinction risks due to human impacts mainly. Megafauna of Asia has been declining for a long, not only in numbers but also in their distribution ranges. In the current study, we collected information on past and current occurrence and distribution records of Asia’s megafauna species. We reconstructed the historical distribution ranges of the six herbivores and four carnivores for comparison with their present ranges, to quantify spatially explicit levels of mega-defaunation. Results revealed that historically the selected megafauna species were more widely distributed than at current. Severe range contraction was observed for the Asiatic lion, three rhino species, Asian elephant, tigers, and tapirs. Defaunation maps generated have revealed the vanishing of megafauna from parts of the East, Southeast, and Southwest Asia, even some protected Areas losing up to eight out of ten megafaunal species. These defaunation maps can help develop future conservation policies, to save the remaining distribution ranges of large mammals.

Megafauna extinctions produce idiosyncratic Anthropocene assemblages

“…Average adult body masses for all species was determined by the PanTHERIA database ( 55 ) and by Francis and Barrett ( 56 ) for species not included in the database (e.g., gaur). We limited our analysis to megafauna species currently recognized by the IUCN as extant in at least one of our 10 landscapes; thus, we did not include species historically distributed across our 10 landscapes [e.g., Javan rhino ( Rhinoceros sondaicus ) ( 57 ) or spotted hyena ( Crocuta crocuta ) ( 35 )]. For species weights, IUCN status, and detection histories, see Table 2 .…”

“…Holocene ranges were defined as the most likely distribution across our 10 study landscapes ~11,700 years ago, at the beginning of the Holocene epoch ( 8 , 9 ). Holocene ranges were extracted and fact-checked in the published literature, primarily using two main references ( 35 , 57 ). We also used “snowball sampling,” where we examined the reference lists from the two main references ( 37 , 53 ), and IUCN Red List reports for each species (table S3).…”

Lost mutualisms: Seed dispersal by Sumatran rhinos, the world’s most threatened megafauna

“…Sumatran rhinos have undergone a dramatic range reduction in the past 100 years (Figure 1). They once roamed from the foothills of the Eastern Himalayas, through Myanmar, Thailand, China, and Vietnam, to the Malay Peninsula, Sumatra, and Borneo (Mahmood et al, 2021;Wilson & Mittermeier, 2011). The latter two islands are the only places Sumatran rhinos are still known to occur, and they do so in tiny and fragmented populations with a global wild population estimated to be of less than 80 individuals (e.g., Gokkon, 2020).…”

Sundaic elephants prefer habitats on the periphery of protected areas

“…Most terrestrial megafauna have faced dramatic range contraction in historical times (Mahmood et al, 2021), with around 60% of the world's largest carnivores and herbivores classified as threatened with extinction based on the IUCN Red List (Ripple et al, 2014(Ripple et al, , 2015(Ripple et al, , 2016. This situation is particularly critical in the Sundaic region, a global hotspot for biodiversity (Myers et al, 2000) and threatened terrestrial megafauna (Ripple et al, 2016).…”