576 



Fishery Bulletin 92(3), 1994 



Neilson, 1985; Recchia and Read, 1989) and squid 

 beaks are less easily passed through the digestive 

 tract than are otoliths (Hawes, 1983; Bigg and 

 Fawcett, 1985). This potential bias tends to 

 strengthen the principal finding of this study: an- 

 choveta was by far the most important prey species 

 of all reproductive classes of Peruvian dusky dolphins 

 in the summers and winters of 1985-86. 



Acknowledgments 



I was supported throughout this study by a scholar- 

 ship from the Natural Sciences and Engineering 

 Research Council (NSERC) of Canada. The research 

 was funded by grants to David Gaskin (University 

 of Guelph, Canada) from the United Nations Envi- 

 ronmental Program and the International Union for 

 the Conservation of Nature, and NSERC. 



Andy Read, Julio C. Reyes, Koen Van Waerebeek, 

 Linda Lehman, Maria Valle-Riestra, Steve 

 Farnworth, and Mark Chandler assisted with field 

 work. Without Julio Reyes, in particular, the project 

 would have been much less successful. Patricia 

 Majluf, Tony Luscombe, Leonardo Mendizabal 

 Manrique, and the Farnworth, Malasquez, Reyes- 

 Robles, Valle-Riestra, and Yonge families were hos- 

 pitable and helpful in many ways. Jorge Zuzunaga, 

 Marco Espino, and especially Juan Velez (all of 

 IMARPE) provided much useful assistance and in- 

 formation. I thank the Capitania, Empresa Peruana 

 de Servicios Pesqueros, and Ministerio de Pesqueria 

 for allowing us to work in the fish markets. 



Sue Candela identified many squid beaks, and 

 Franz Cardoso was also instrumental in these iden- 

 tifications. Dan Ryan and O.B. Brian helped with 

 statistics. Kenny Richard assisted with data input 

 and checking. David Gaskin, Ronald Hardy, Linda 

 Jones, Andy Read, and two anonymous reviewers 

 provided many helpful comments on the manuscript. 



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