Aggressive distance in juvenile coho salmon (Oncorhynchus kisutch)

DILL, L. M. 1978. Aggress~ve distance in juvenile coho salmon (Oncorhynchus kisutch). Can. J . Zool. 56: 14411446. The distances from which resident coho salmon approached, charged, or gave lateral displays to inhuders were recorded, as were rhe npproach and charge velocities. Ench of five residents was terted while under rhree Feeding t e ~ i m e ~ . and In response to three sizes of intnzder COmm ~maller, 10mm bmaller. and of the siime size a5 the res~denr), Larger intruders were ;ipproached and displayed to from greater distances. and charge distance also tended to increase with intruder size. Feeding regime had no erfects on aggressive distance. Neither approach nor charge veloc~ty was influenced ky intruder size. hut charge velocity was highest In the least well fed fish. These results are discussed with reference to theeconomic defendirhility theory of territorial~tv.