Spatial scale and the conservation of threatened species

"The spatial scale of conservation necessary to avoid species extinctions is one
of the most vigorous debates in conservation biology. One approach holds that
protecting sites should be the primary level for action on the ground, the other
that conservation action targeting broader seascapes and landscapes is more
important. We address this debate systematically by assessing the appropriate
spatial scales of conservation for all 4,239 threatened mammals, birds, tortoises
and turtles, and amphibians. We find that, in the short- to medium term, 20%
of these species are dependent on conservation at single sites, 62% on multiple
sites, 18% on both sites and sea- or landscape-scale efforts, and <1% on broadscale
actions alone (where sites are variably sized units that are actually or
could potentially be managed for conservation, and “broad scale” refers to seaor
landscape-scale and is determined by the needs of the species in question).", In Conservation Letters, vol.1,no.1 (2008)