Joseph J. Luczkovich

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We present a graph theoretic model of analysing food web structure called regular equivalence. Regular equivalence is a method for partitioning the species in a food web into "isotrophic classes" that play the same structural roles, even if they are not directly consuming the same prey or if they do not share the same predators. We contrast regular(More)
In the last fifteen years, ecosystem ecologists have developed a theoretical approach and a set of computational methods called " ecological network analysis " (Ulanowicz, 1986; Kay et al. 1996). Ecological network analysis is based on input/output models of energy or material flows (e.g., carbon compound flows) through a trophic network (e.g., a food web(More)
Simultaneous audio and video were recorded of a silver perch Bairdiella chrysoura producing its characteristic drumming sound in the field. The background noise contribution to the total sound pressure level is estimated using sounds that occurred between the pulses of the silver perch sound. This background contribution is subtracted from the total sound(More)
Cownose rays are implicated in the consumption of commercially important shellfish on the U.S. East Coast. We tested this assumption by developing a molecular technique for species identification from cownose ray gut contents. Digestive tracts sampled from 33 rays in Pamlico Sound, NC and Chesapeake Bay, VA contained pieces of partially-digested tissue,(More)
Fishes in the drum family (Sciaenidae) makes sounds to communicate, but they do not make the same sounds. They make species-specific calls with different dominant frequencies. Sounds are produced in spawning aggregations at different times of the day, night and season, and there is spatial segregation among the spawning fish populations. This results in a(More)
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