Biology 2013, 2(2), 742-754; doi:10.3390/biology2020742
Article

A Deeper Statistical Examination of Arrival Dates of Migratory Breeding Birds in Relation to Global Climate Change

Jr.email
Received: 22 November 2012; in revised form: 9 April 2013 / Accepted: 10 April 2013 / Published: 26 April 2013
(This article belongs to the Special Issue Biological Implications of Climate Change)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Using an 18-year dataset of arrival dates of 65 species of Maine migratory breeding birds, I take a deeper view of the data to ask questions about the shapes of the distribution. For each year, most species show a consistent right-skewed pattern of distribution, suggesting that selection is stronger against individuals that arrive too early compared to those that arrive later. Distributions are consistently leptokurtic, indicating a narrow window of optimal arrival dates. Species that arrive earlier in the spring show higher skewness and kurtosis values. Nectarivorous species showed more pronounced skewness. Wintering area did not explain patterns of skewness or kurtosis. Deviations from average temperatures and the North Atlantic Oscillation index explained little variation in skewness and kurtosis. When arrival date distributions are broken down into different medians (e.g., 5% median and 75% median), stronger correlations emerge for portions of the distribution that are adjacent, suggesting species fine-tune the progress of their migration. Interspecific correlations for birds arriving around the same time are stronger for earliest migrants (the 25% median) compared to the true median and the 75% median.
Keywords: birds; migration; skewness; kurtosis; arrival dates; weather; climate change; phenology
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MDPI and ACS Style

Wilson, W.H., Jr. A Deeper Statistical Examination of Arrival Dates of Migratory Breeding Birds in Relation to Global Climate Change. Biology 2013, 2, 742-754.

AMA Style

Wilson WH, Jr. A Deeper Statistical Examination of Arrival Dates of Migratory Breeding Birds in Relation to Global Climate Change. Biology. 2013; 2(2):742-754.

Chicago/Turabian Style

Wilson, W. H., Jr. 2013. "A Deeper Statistical Examination of Arrival Dates of Migratory Breeding Birds in Relation to Global Climate Change." Biology 2, no. 2: 742-754.

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