Contents
Convergent Characteristics in Sympatric Species: a Possible Relation to Interspecific Competition and Aggression
Martin L. Cody
Birds and the Ant X Acacia Interaction in Central America, with Notes on Birds and Other Myrmecophytes
Daniel H. Janzen
Seasonal Cycle of Reproductive Physiology in the Black-billed Magpie
Michael J. Erpino
Food Habits of Canvasbacks, Redheads, and Lesser Scaup in Manitoba
James C. Bartonek and Joseph J. Hickey
Respiratory Metabolism of the Red-winged Blackbird in Relation to Ambient Temperature
R. W. Lewies and M. I. Dyer
The Song of the Chingolo, Zonotrichia Capensis, in Argentina: Description and Evaluation of a System of Dialects
Fernando Nottebohm
News and Notes
The Condor
Publications Received
The Condor
Cooper Ornithological Society Statement of Assets and Fund Balances Resulting from Cash Transactions
The Condor
The Bulletin Board
The Condor
Covers
Back Matter (PDF)
The Condor
Front Matter (PDF)
The Condor
Communications
Calculation and Miscalculation of the Equations Relating Avian Standard Metabolism to Body Weight
Robert C. Lasiewski and William R. Dawson