A land-bridge island perspective on mammalian extinctions in western North American parks

  title={A land-bridge island perspective on mammalian extinctions in western North American parks},
  author={William D Newmark},
  • W. Newmark
  • Published 29 January 1987
  • Environmental Science
  • Nature
In recent years, a number of authors1–3 have suggested several geometric principles for the design of nature reserves based upon the hypothesis that nature reserves are analogous to land-bridge islands. Land-bridge islands are islands that were formerly connected to the mainland and were created by a rise in the level of the ocean. Land-bridge islands are considered supersaturated with species in that the ratio of island to mainland species numbers is higher than expected from the area of the… 

Insularization of Tanzanian Parks and the Local Extinction of Large Mammals

Island biogeography theory predicts that species will be lost on habitat “islands” created by the fragmentation of continental regions. Many Tanzanian parks are rapidly becoming habitat islands as a

Do forest plants conform to the theory of island biogeography: the case study of bog islands

It is hypothesized that the equilibrium pattern of forest herb layer in long-term fragmented landscape should comply with the theory of island biogeography, and the ‘small island effect’, i.e. greater overall species richness in small-area habitats, was observed, which was determined by the habitat preference of shade tolerant generalists.

Extinction Rates in Archipelagoes: Implications for Populations in Fragmented Habitats

To study the effect of habitat fragmentation on population viability, I used extinction rates on islands in archipelagoes and estimated the relative probability of extinction per species on single

Designing a Coherent Ecological Network for Large Mammals in Northwestern Europe

Abstract: In densely populated northwestern Europe, native large mammals are confronted with a very fragmented landscape, and most of the areas they inhabit are island‐like reserves threatened with

Reptile Extinctions on Land‐Bridge Islands: Life‐History Attributes and Vulnerability to Extinction

Only population abundance and habitat specialization explained a significant amount of the observed variation in species extinction rates and body mass itself did not explain variation in extinction rates, although it was strongly correlated with abundance.

Climate Change and Elevated Extinction Rates of Reptiles from Mediterranean Islands

This work calculated the population extinction rates of 35 reptile species from 87 Greek land‐bridge islands in the Mediterranean that occurred over the past 16,000 years to insight into the long‐term patterns of species responses to climate change.

Human demography and reserve size predict wildlife extinction in West Africa

This work shows that extinction rates for 41 species of large mammals in six nature reserves in West Africa are 14-307 times higher than those predicted by models based on reserve size alone, and indicates that, where the harvest of wildlife is common, conservation plans should focus on increasing the size of reserves and reducing the rate of hunting.

The Variances of Island Extinction Rates

  • T. Case
  • Environmental Science
    The American Naturalist
  • 1989
An indirect method that can be applied to Holocene land-bridge islands is the "relaxation method" (Diamond 1972), which makes use of the fact that insularity often results in species loss.

The Principle of Nested Subsets and Its Implications for Biological Conservation

: The nested subset hypothesis states that the species comprising a depauperate insular biota are a proper subset of those in richer biotas, and that an archipelago of such biotas, ranked by species

The Yellowstone to Yukon Initiative : A New Conservation Paradigm to Protect the Heart of North America

Recent research on animal movements and conservation biology theory indicates that our current protected areas are insufficient to sustain viable populations of large carnivores. A larger scale and



Biogeographic kinetics: estimation of relaxation times for avifaunas of southwest pacific islands.

  • J. Diamond
  • Environmental Science
    Proceedings of the National Academy of Sciences of the United States of America
  • 1972
Estimates of exponential relaxation times, t(r), for avifaunas of New Guinea satellite islands are calculated from analysis of four "experiments of nature": recolonization of exploded volcanoes, contraction in island area due to rising sea level, severing of land bridges, and disappearance of landbridge relict species.

Vegetation changes in Sequoia National Park, California

Twenty-one vegetation types occurring in Sequoia National Park are described and their changes under western man's influence are documented. Age-population structure of the trees, repeated old


The short mean intervals between fires suggest that pre-1875 mixed conifer forests did not usually have heavy accumulations of litter or dense thickets of under- story trees, and that the lack of frequent, low-intensity fires has resulted in a major increase in understory forest and fuels.

Faunal Equilibria and the Design of Wildlife Preserves

It is becoming increasingly apparent that the methods and the way of thinking that MacArthur and Wilson developed are extensible to a much larger range of situations, including the design of faunal preserves.

Movements by Birds and Small Mammals Between a Wood and Adjoining Farmland Habitats

(1) White-footed mice (Peromyscus leucopus) and chipmunks (Tamias striatus) moved between a beech-maple wood and connecting fencerows four times as often as they moved between traplines within the