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Biodiversity is being eroded worldwide. Many human pressures are most forcefully exerted or have greatest effect during a particular period of the day. Therefore when species are physically active (their diel niche) may influence their risk of population decline. We grouped 5032 terrestrial extant mammals by their dominant activity pattern (nocturnal, crepuscular, cathemeral and diurnal), and determine variation in population decline across diel niches. We find an increased risk of population decline in diurnal (52.1% of species), compared to nocturnal (40.1% of species), crepuscular (39.1% of species) and cathemeral (43.0% of species) species, associated with the larger proportion of diurnal mammals that are primates. Those species with declining populations whose activity predominantly coincides with that of humans (cathemeral, diurnal) face an increased number of anthropogenic threats than those principally active at night, with diurnal species more likely to be declining from harvesting. Across much of the land surface habitat loss is the predominant driver of population decline, however, harvesting is a greater threat to day-active species in sub-Saharan Africa and mainland tropical Asia, associated with declines in megafauna and arboreal foragers. Deepening understanding of diel variation in anthropogenic pressures and resulting population declines will help target conservation actions. [ABSTRACT FROM AUTHOR]

Strandings provide opportunities to collect data on interactions between megafauna and marine litter which help address the limited information available on the impacts of litter in developing countries, such as the Philippines. However, the perception that single‐individual strandings yield minimal data restricts the scope of publication, resulting in the limited dissemination of potentially valuable information. Here we present a case of plastic ingestion by a Bryde’s whale in the Philippines and discuss the importance of consistent long‐term collection of strandings data and the value of publishing these results. [ABSTRACT FROM AUTHOR]

Aim: For tens of millions of years, herbivorous megafauna were abundant across the globe, fulfilling important ecological roles including seed dispersal. Megafruits are very large fruits that are dispersed most effectively by megafauna. However, megafruits also occur in ecosystems where megafauna are extinct or were never present, emphasizing our incomplete understanding of megafauna–megafruit relationships. Here we use the complex biogeography of tropical Asia to investigate how megafruit diversity and traits are associated with the diversity of megafauna, smaller animals, and abiotic factors. Location: Tropical Asia, from the Indian subcontinent in the west to tropical China in the north to the Maluku archipelago (Indonesia) in the east. Time period: Late Pleistocene to the present day. Major taxa studied: Megafauna (body weight > 500 kg) that consume fruits, including stegodons, elephants, rhinoceroses, giant tapirs, and large bovids. Fleshy‐fruited plant species across the region with a fruit width > 40 mm (i.e., megafruits). Methods: We compiled a list of all megafruits along with selected plant, fruit, and seed traits in 16 subregions across tropical Asia. We explored biogeographical patterns in megafruit diversity and traits in relation to the diversities of past and present megafauna, large‐ and medium‐sized animals and abiotic factors (mean temperature, mean precipitation, precipitation seasonality, insularity). Results: We identified 496 megafruits in tropical Asia. Megafruit diversity was highest in subregions with high megafaunal diversity, particularly extant species. Megafruit traits were influenced most strongly by abiotic factors (mainly temperature and land area), and weakly by megafauna and smaller dispersers. Main conclusions: Our results are consistent with megafauna maintaining or responding to megafruit diversity, but variation in megafruit traits is primarily associated with abiotic factors. Given the massive megafaunal losses in tropical Asia since the Late Pleistocene, it is important to identify fruit traits that can increase megafauna‐dependence and thus vulnerability to these losses. [ABSTRACT FROM AUTHOR]

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Asian elephants (Elephas maximus) have inhabited almost all forests in tropical Asia until recently, yet little is known about their role in ecological processes, particularly in the Sundaic forests of South‐East Asia. These forests are peculiar in their phenology, with supra‐annual and highly irregular episodes of mast fruiting. Here, we present a long‐term (6‐year) monitoring of the seeds dispersed by elephants in dipterocarp forests of northern Peninsular Malaysia. We conducted monthly dung surveys at two mineral licks (11.3 km apart) frequently visited by elephants. Additionally, we recorded haphazard observations of seeds and seedlings in elephant dung at other locations. We recorded a minimum of 48 morphospecies from at least 25 plant families dispersed by elephants. Elephant seed dispersal was very heterogenous in space, with only 30.3% of the morphospecies dispersed at both sites (Jaccard dissimilarity index = 0.48). Temporally, elephants dispersed seeds in sporadic pulses of abundance and diversity, without any apparent seasonality (seeds appeared in 19.1% of 1,284 dung piles and 57.1% of the 63 months in which we found dung) and with long periods without any seed being dispersed. Nearly half (48%) of the plants dispersed by elephants belong to a megafaunal dispersal syndrome. Our long‐term approach allowed us to unravel an important aspect of Asian elephants' role and effectiveness in the seed dispersal cycle. Sundaland's forests are undergoing a rapid loss of their previously common megaherbivores (rhinos and elephants), with profound and long‐term consequences for ecosystem functioning. Abstract in Malay is available with online material. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The agricultural revolution is a significant turning point in human history. Its effects are still deeply felt on many aspects of humankind's social, political, and economic development. For the first time, this study empirically examines the birth of agriculture and identifies the global extinction of megafauna (large mammals) in the past 100,000 years as a paramount related event. During the ice ages, humans and plants heavily depended on megafauna for survival. Megafauna's decreased abundance shifted human subsistence strategies toward more control over vital common resources. These strategies, in turn, underpinned the type of coevolutionary interactions between humans, animals, and plants that eventually resulted in domestication. The severity of extinction varied considerably in regions occupied by hominins (different species of humans) at different times over the past seven million years. Extinctions were negligible in Africa, moderate in Asia, and severe in the New World. Regression analyses of these exogenous differences reveal a non-monotonic effect of extinction on agriculture. Agriculture was most likely to emerge independently in the lower latitudes of Asia. All other regions experienced suboptimal extinction events, which had varying effects on the birth of agriculture. [ABSTRACT FROM AUTHOR]

The megafaunal seed dispersal hypothesis posits that mega-fruits co-evolved for seed dispersal by extremely large mammals, such as elephant-like gomphotheres, which became extinct during the Pleistocene. Nevertheless, various plants in subtropical Asia still produce oversized fruits as a seed dispersal syndrome anachronism. Here, we investigated how a mega-fruited perennial woody liana, Akebia trifoliata achieves the consumption of its large, sweet, edible fruits to disperse its seeds in a subtropical region on China where the mega frugivores are absent nowadays. We hypothesized that some other surrogate species may be fulfilling this dispersal function. From 2926 fecal samples from 13 species of mammal and various unidentified birds, collected over two years, we identified A. trifoliata seeds in only 13 feces from the masked palm civet (Paguma larvata). Our systematic sampling allowed us to eliminate any role being played by all other plausible dispersal mutualists; not least, these fruits rarely fall to the ground and deteriorate quickly, and so must be picked from the vine by species able to reach 2–5m above the ground. Of 338 masked palm civet feces examined during the August to September fruiting season only 3.85% (frequency of occurrence) contained A. trifoliata seeds, although when seeds were present, they were abundant (c. 600/feces). All seeds passing through the gut of masked palm civets were intact. Moreover, masked palm civets mainly dispersed A. trifoliata seeds in degraded habitats (i.e., the logged, and selectively logged forests). These results showed that although masked palm civets dispersed A. trifoliata seeds in low proportion, they could play a surrogate seed dispersal role for this mega-fruit vine species, especially in degraded forests. Our findings highlight that, in subtopical Asia, small frugivorous carnivores can act as surrogate seed dispersers for oversized fruit plants, advancing knowledge on how past species interactions and defaunation underlie modern plant distributions. • Several plants bear oversized fruits, suggesting a megafaunal seed dispersal syndrome. • Megafrugivores are absent in its current distribution and are considered anachronism. • Civets act as surrogate dispersers for a megafaunal-fruited vine in subtropical Asia. • Surrogate role of carnivores as seed dispersers of megafruit plants may be pervasive. [ABSTRACT FROM AUTHOR]

Large mammalian terrestrial herbivores, such as elephants, have dramatic effects on the ecosystems they inhabit and at high population densities their environmental impacts can be devastating. Pleistocene terrestrial ecosystems included a much greater diversity of megaherbivores (e.g., mammoths, mastodons, giant ground sloths) and thus a greater potential for widespread habitat degradation if population sizes were not limited. Nevertheless, based on modern observations, it is generally believed that populations of megaherbivores (>800 kg) are largely immune to the effects of predation and this perception has been extended into the Pleistocene. However, as shown here, the species richness of big carnivores was greater in the Pleistocene and many of them were significantly larger than their modern counterparts. Fossil evidence suggests that interspecific competition among carnivores was relatively intense and reveals that some individuals specialized in consuming megaherbivores. To estimate the potential impact of Pleistocene large carnivores, we use both historic and modern data on predator-prey body mass relationships to predict size ranges of their typical and maximum prey when hunting as individuals and in groups. These prey size ranges are then compared with estimates of juvenile and subadult proboscidean body sizes derived from extant elephant growth data. Young proboscideans at their most vulnerable age fall within the predicted prey size ranges of many of the Pleistocene carnivores. Predation on juveniles can have a greater impact on megaherbivores because of their long interbirth intervals, and consequently, we argue that Pleistocene carnivores had the capacity to, and likely did, limit megaherbivore population sizes.