Publication Details

Category Text Publication
Reference Category Journals
DOI 10.3161/00016454AO2017.52.2.005
Title (Primary) Is the seasonal variation of abundance and species richness in birds explained by energy availability?
Author Pfeifer, R.; Stadler, J.; Brandl, R.
Source Titel Acta Ornithologica
Year 2017
Department BZF
Volume 52
Issue 2
Page From 167
Page To 178
Language englisch
Keywords seasonal patterns; species richness; niche breadth; energy-availability hypothesis
UFZ wide themes RU1;
Abstract Energy availability explains the spatial variation of species richness. However, in arctic to temperate regions
species richness in birds shows also a seasonal pattern with high species numbers in summer and low numbers in winter. Is it possible to explain this pattern by high energy availability in summer and low availability in winter? The ‘energy availability hypothesis’ rests on a positive correlation between abundance and species richness. Using weekly counts along a transect in Northern Bavaria (S Germany), we found the expected seasonal annual as well as biannual cycles in species richness (108 species observed in total). In contrast, the number of individuals showed no clear seasonal cycle, but erratic fluctuations particularly in winter. Weather conditions had only small effects on the number of individuals and on species richness. Adding weather variables to analyses increased explained variance only by 1.5% to 10%. The energy availability hypothesis is not able to explain the seasonal variation of species richness in temperate regions.
However, bird assemblages during winter consist of species able to feed on various resource types, in particular seeds produced during summer. These left-overs provide the resources for diet generalists to survive the winter.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=19902
Pfeifer, R., Stadler, J., Brandl, R. (2017):
Is the seasonal variation of abundance and species richness in birds explained by energy availability?
Acta Ornithol. 52 (2), 167 - 178 10.3161/00016454AO2017.52.2.005