Intrinsic and climatic factors in North-American animal population dynamics

• Main Authors: Nicolas Loeuille, Michael Ghil
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: population dynamics; climatic effects; principal component analysis; spectral analysis; multi-annual periodicities. Short title; Intrinsic and climatic factors in population dynamics; North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.7.1628; http://www.atmos.ucla.edu/tcd/PREPRINTS/PRS-B_Text.pdf

In the present article, we combine two data analysis methods --principal component analysis and spectral analysis-- to analyze the dynamics of eleven North-American species. This combination allows us to determine the importance of different factors that affect this dynamics, such as hunting pressure, climate change, and biological interactions. Our datasets include fur counts and climatic indices that represent the North Atlantic Oscillation, the El Nio-Southern Oscillation, and Northern Hemisphere temperatures. Our results show that all three climatic indices influence the animal-population dynamics, first because they explain a substantial part of the variance in the fur counts and second because they share characteristic periods with the fur-count dataset. In addition to these climate-related periods, the fur-count time series also contain a significant 3-year period that is, in all likelihood, caused by biological interactions.