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Full-Text Articles in Physical Sciences and Mathematics

Fences Impede Long-Distance Mongolian Gazelle (Procapra Gutturosa) Movements In Drought-Stricken Landscapes, Kirk A. Olson, Thomas Mueller, Peter Leimgruber, Craig Nicolson, Todd K. Fuller, S. Bolortsetseg, Amanda E. Fine, B. Lhagvasuren, William F. Fagan Jan 2009

Fences Impede Long-Distance Mongolian Gazelle (Procapra Gutturosa) Movements In Drought-Stricken Landscapes, Kirk A. Olson, Thomas Mueller, Peter Leimgruber, Craig Nicolson, Todd K. Fuller, S. Bolortsetseg, Amanda E. Fine, B. Lhagvasuren, William F. Fagan

Craig Nicolson

Human-generated landscape barriers are especially problematic for species whose life histories entail long-distance movements. In May 2008, hundreds of Mongolian gazelles (Procapra gutturosa) became entangled in border fences as thousands attempted to move from Mongolia into Russia. Typically, the root cause of such (non-migratory) mass animal movements can only be superfi cially described. Here we draw upon satellite imagery and a fortuitously timed fi eld study to investigate a likely hypothesis. At the same time that gazelles were attempting to cross from Mongolia into Russia, gazelles equipped with satellite-linked collars repeatedly attempted to emigrate from Mongolia into China. Satellite-derived estimates …


Seasonal Source-Sink Dynamics At The Edge Of A Species’ Range, Todd K. Fuller, L. L. Kanda, P. R. Sievert, R. L. Kellogg Jan 2009

Seasonal Source-Sink Dynamics At The Edge Of A Species’ Range, Todd K. Fuller, L. L. Kanda, P. R. Sievert, R. L. Kellogg

Todd K. Fuller

The roles of dispersal and population dynamics in determining species' range boundaries recently have received theoretical attention but little empirical work. Here we provide data on survival, reproduction, and movement for a Virginia opossum (Didelphis virginiana) population at a local distributional edge in central Massachusetts (USA). Most juvenile females that apparently exploited anthropogenic resources survived their first winter, whereas those using adjacent natural resources died of starvation. In spring, adult females recolonized natural areas. A life-table model suggests that a population exploiting anthropogenic resources may grow, acting as source to a geographically interlaced sink of opossums using only natural resources, …


Remnants Of Medieval Field Patterns In The Czech Republic: Analysis Of Driving Forces Behind Their Disappearance With Special Attention To The Role Of Hedgerows, Petr Sklenicka, Kristina Molnarova, Elizabeth Brabec, Peter Kumble, Blanka Pittnerova, Katerina Pixova, Miroslav Salek Jan 2009

Remnants Of Medieval Field Patterns In The Czech Republic: Analysis Of Driving Forces Behind Their Disappearance With Special Attention To The Role Of Hedgerows, Petr Sklenicka, Kristina Molnarova, Elizabeth Brabec, Peter Kumble, Blanka Pittnerova, Katerina Pixova, Miroslav Salek

Elizabeth Brabec

Remnants of medieval field patterns, called “pluzina” in the Czech Republic, are valuable historical landscapes, similar in character to the bocage landscapes typical for some countries in Western Europe. The original historical pattern of fields and meadows has persisted due to the stabilizing network of hedgerows. As in other countries, the development of these medieval fields in recent decades for intensive agriculture or residential purposes has led to their dramatic decline. This study evaluates the dynamics of the development of medieval pluzina hedgerows during the second half of the 20th century in the Plzen Region of the Czech Republic, using …