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losing time?2009) and avian (Boyer and Jetz 2010) body sizeon islands also found robust scaling relationshipsbetween maximum size and island area. Theseeffects imply that to persist large species requirelarge areas to sustain viable population sizes, andimportant concept in reserve design andconservation of large-bodied mammals (Kelt andVan Vuren 2001). However, Jetz et al. (2004)found a high degree of home range overlap inlarge mammal species, suggesting that populationdensity rather than home range size is the bettermeasure to use in quantifying individual areaneeds for conservation purposes. Since manyislands experienced extinctions during the latePleistocene (Alcover et al. 1998), and theseextinctions may have affected the local body-sizedistribution (Lyons et al. 2004, Boyer and Jetz2010), we re-examined the scaling of maximumsize with land area before the influence of humanmediatedextinctions.We gathered data on the largest mammalspecies found today and in the late Pleistocene on30 islands and landmasses around the world.Mammal data were limited to herbivorous andomnivorous species, owing to differences in thescaling of population density and space usebetween carnivores and herbivores (Peters 1983,Jetz et al. 2004). Island area was based on present-day measurements. Because island mammalswould have experienced a dynamic land area dueto eustatic sea-level changes during the late-Pleistocene, and because the extinct taxa in ourdataset also differ in their dates of lastappearance, we found it difficult to assign a singlelate-Pleistocene value for land area to each island.However, because sea levels in most areas wereover 100m lower than present levels during thelast glacial maximum (Fleming et al. 1998), theland area of many islands would have beensubstantially larger during the late-Pleistoceneand some islands were connected to nearbycontinents by exposed land bridges. To control forthese issues, we excluded all land-bridge islandsand islands where extinction occurred when sealevels were substantially lower than current levels(ca. 7000 years before present, Fleming et al.1998). For comparison to the island data, we alsoincluded late-Pleistocene and modern body massFigure 2. Relationship between maximum body size and area of landmass for extant (open circles, N = 28) and latePleistocene (closed circles, N = 30) mammals. Modern data are missing for two islands, Barbuda and East Falkland,due to the extinction of all terrestrial, non-carnivorous, mammals. Both body size and area were log 10 -transformedprior to analysis. Slopes were indistinguishable between the two time periods, but the intercept for late-Pleistocenemammals was significantly larger (ANOVA; p < 0.01) than for extant species, suggesting that islands supported largeranimals in the past.30 © 2012 the authors; journal compilation © 2012 The International Biogeography Society — frontiers of biogeography 4.1, 2012