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| In this study, we investigate patterns in the prevalence of dynamic range–abundance
relationships of the Danish avifauna, using breeding bird atlases from 1971 to 1974
and from 1993 to 1996. We focus on differences between common and rare species
by dividing the assemblage into range-size quartiles. The trend in total population
size was determined using an index. Range was determined as grid cell occupancy and
standardized to facilitate comparisons between common and rare species. While
narrow-ranging species showed strong and consistent range–abundance relationships,
the relationships for widespread species were weak and exhibited considerable
variation. This may be due to differences in patterns of resource use, since widespread
species generally have wider niches, and so may be less affected by resource-based
factors linking range and abundance. Since a tight and dynamic relationship is upheld
for rare species, monitoring strategies based on range size surveys seem viable. | |
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