An exploratory analysis of liver element relationships in a case series of common loons (Gavia immer)

Daniel J. O'Brien, Robert H Poppenga, Carl W. Ramm

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

To examine the relationships among liver element concentrations, principal component analysis (PCA) was performed on data from a case series of 54 common loons collected in Michigan during the period from July 1988 to February 1993. Data available for each bird included season and district of collection, age, sex, necropsy findings, and liver concentrations of twelve elements as determined by spectrophotometry. The first three principal components (PC) accounted for 86% of the total variability of the data, which made possible a substantial reduction in dimensionality. Within PC1-PC3, calcium, iron, mercury and lead were the most influential elements in accounting for variation. The possibility of a competitive interaction between mercury and lead for selenium is suggested, with consideration given to possible alterations in bioavailability due to environmental acidification. PCA can generate hypotheses that subsequently can be investigated under conditions which allow causal inference and better control of confounding factors. Consequently, sparse field data can be used efficiently to generate information on risk factors for environmental diseases, and to provide bases for intervention strategies.

Original languageEnglish (US)
Pages (from-to)37-49
Number of pages13
JournalPreventive Veterinary Medicine
Volume25
Issue number1
DOIs
StatePublished - 1995
Externally publishedYes

Fingerprint

Gavia
Principal Component Analysis
Mercury
mercury
principal component analysis
liver
Spectrophotometry
Liver
Selenium
Biological Availability
acidification
selenium
Birds
bioavailability
spectroscopy
necropsy
risk factors
Iron
iron
Calcium

Keywords

  • Exploratory data analysis
  • Lead
  • Loons
  • Mercury
  • Principal component analysis (PCA)
  • Selenium

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Food Animals

Cite this

An exploratory analysis of liver element relationships in a case series of common loons (Gavia immer). / O'Brien, Daniel J.; Poppenga, Robert H; Ramm, Carl W.

In: Preventive Veterinary Medicine, Vol. 25, No. 1, 1995, p. 37-49.

Research output: Contribution to journalArticle

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