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United States Department of Agriculture

Agricultural Research Service

Title: Can manipulating water color deter piscivorous bird activity within an artificial environment?

item Radomski, Andrew
item Ludwig, Gerald
item Hobbs, Melissa
item Thomson, Steven
item Perschbacher, Peter

Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/4/2006
Publication Date: 8/6/2006
Citation: Radomski, A.A., Ludwig, G.M., Hobbs, M.S., Thomson, S.J., Perschbacher, P. 2006. Can manipulating water color deter piscivorous bird activity within an artificial environment? Ecological Society of America Abstracts. Available:

Interpretive Summary:

Technical Abstract: Recent advancements in studies within the fields of avian acuity and remote sensing have allowed ecologists a unique opportunity to conduct field experiments within the birds' perceived environment. This study was an attempt to test and predict piscivorous bird use and avoidance within an artificial habitat (fish ponds). We measured (1) physical (size, length, width, depth, surface condition, secchi depth) (2) biological (fish size and stocking density, algal species composition and enumeration), and physiochemical (pH, temperature, salinity, dissolve oxygen, total phosphorus, TAN, nitrite, nitrate, hardness, and chlorophyll a) variables within catfish ponds every 10 days to determine pond dynamics. In conjunction, piscivorous bird use was quantified over the duration of the study. Preassessment of ponds were classified as 'preferred' or 'avoided' by piscivorous birds (namely, double-crested cormorants, great blue herons, and great egrets). Assessment of pond reflectance was conducted using digital values from pond images obtained by low-altitude aerial digital video during these 10 day intervals. Digital numbers were classified using ArcView and Panavue software. The treatment groups received AquashadeTM, a U.S. Environmental Protection Agency approved dye for use in aquaculture. The treatment was applied to 4 ponds (2 preferred, 2 avoided) at 2 geospatially isolated catfish farms and replicated over 2 years. Results from this study indicate that no single variable was able to predict >60% of bird use of the pond. However, some pond attributes were slightly better at predicting those fish ponds with greater bird use. Ecological significance of these findings within an artificial environment should be tested within these avian's natural habitats and potentially could be used to predict probability of piscivorous bird use.

Last Modified: 06/23/2017
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