The Status of the World's Land and Marine Mammals: Diversity, Threat, and Knowledge

Abstract

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action.

Buffer zone use by mammals in a Cerrado protected area

“…The replacement of native vegetation by agriculture, pastures and urban areas is a top concern in the Neotropics, where deforestation rates are high (Schipper et al 2008). In Brazil, notwithstanding its conservation importance, the Cerrado has already lost between 48% and 55% of its original area (Klink & Machado 2005;IBGE 2010).…”

“…Among mammals, one in each four species is already threatened, mainly due to habitat loss and degradation. Furthermore, the effect of hunting or gathering species for food, medicines or fuel in natural areas of the Neotropics affect 64% of the large-bodied mammals, which have large home ranges and depend on a large amount of area to maintain viable populations (Schipper et al 2008). However, the maintenance of large natural areas depends primarily on public policies that regulate land use and protection, together with community commitment (Watson et al 2014).…”

Evolution of mammalian migrations for refuge, breeding, and food

“…The over 5,400 extant mammals are a tractable clade for studying migration as they are historically well‐studied despite relatively few, highly visible species (e.g., wildebeest) having been examined with respect to migration per se (Harris, Thirgood, Hopcraft, Cromsigt, & Berger, 2009). The diversity of mammalian locomotion types (walking, swimming, flying), habitats (terrestrial, freshwater, marine; Schipper et al., 2008), and diets (carnivore, omnivore, herbivore) permits examination of the importance of biophysical constraints on the evolution of migration. Evidence suggests that mammal migrations are declining (Bolger et al., 2008).…”

Trends in tagging of marine mammals: a review of marine mammal biologging studies

“…fisheries interactions, etc.) are concentrated at the equator and mid-latitudes (Schipper et al 2008). This indicates a substantial spatial mismatch, with the exception of the Australian coastline, between the general use of biologging technologies on marine mammals and the spatial areas where such information is most likely to inform conservation and/or management actions.…”

“…Marine mammals are a comparatively poorly known group, facing high threat levels (Schipper et al 2008), and biologging studies have the potential to inform numerous conservation and management actions. The potential benefits of using biologging instruments in animal conservation research are many (see review by Cooke 2008).…”