Like other regions of the northern hemisphere, the northeastern United States has experienced a general increase in regional temperatures over the past 20 years. Quantifying the ecological implications of these changing temperatures has been severely constrained by a lack of multispecies distributional data by which to compare long-term changes. We used the New York State Breeding Bird Atlas, a statewide survey of 5332 25 km 2 blocks surveyed in 1980-1985 and 2000-2005, to test several predictions that the birds of New York State are responding to climate change. Our objective was to use an information-theoretic approach to analyze changes in three geographic range characteristics, the center of occurrence, range boundaries, and states of occurrence to address several predictions that the birds of New York State are moving polewards and up in elevation. As expected, we found all bird species (n 5 129) included in this analysis showed an average northward range shift in their mean latitude of 3.58 km [Prob(H a |-data) 5 0.87)]. Past studies have found that northern range boundaries are more likely to be influenced by climatic factors than southern range boundaries. Consequently, we predicted that northward shifts would be more evident in northern as opposed to southern range boundaries. We found, however, that the southern range boundaries of northerly birds moved northward by 11.4 km [n 5 43, Prob(H a |data) 5 0.92], but this pattern was less evident in northern range boundaries of southerly birds. In addition, we found that bird species demonstrated a general shift downhill in their mean elevation, but demonstrated little change in their elevational boundaries. The repeated pattern of a predicted northward shift in bird ranges in various geographic regions of the world provides compelling evidence that climate change is driving range shifts.
/ Populations of white-tailed deer (Odocoileus virginianus) inhabiting many state and national parks and suburban areas have grown to the point that they conflict with human activities. Conflicts range from destruction of vegetation through browsing to public perception that diseases carried by deer pose threats to human health. Traditional modes of hunting to control populations are inappropriate in many of these areas because of intense human development and activity. This article explores an alternative approach for population reduction based on deer social organization. Female white-tailed deer are highly philopatric and female offspring remain near their dams for life. This suggests that a population expands slowly as a series of overlapping home ranges in a form analogous to the petals on a rose. Incorporating the rose petal concept into a model of population growth shows that removal of deer by family unit can potentially alleviate conflicts in localized areas for as many as 10-15 yr.
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