1002 SHORT COMMUNICATIONS The Condor 99:1002-1004 0 The Cooper Omlthological Society 1997 MAXIMUM DIVE DEPTHS OF THE PERUVIAN DIVING-PETREL’ CARLOS B. ZAVALAGA Av. Guardia Chalaca 1333, Callao, Peru, e-mail:
[email protected] JAIME JAHNCKE~ Institute de1 Mar de1 Peru ’ (IMARPE), Apartado 22, Callao, Peru, e-mail:
[email protected] Abstract. The mean maximum dive depth attained METHODS for 22 adult Peruvian Diving-petrels (Pelecanoides The field work was carried out on La Vieja Island, garnotii) was 31.6 + 3.6 m. The deepestdive was 83.1 Peru (14”16’S, 76”ll’W) from August 1995 to May m. This maximum dive depth was 81% deeper than 1996. The island lies at the entranceof Independencia that predicted by its body size (46 m) and the deepest Bay, about 50 km south of the ParacasPeninsula. reported for a seabird weighing less than 210 g. Depth gauges were deployed on 66 adult birds at Key words: Peruvian Diving-petrels, diving different stagesof the breeding cycle (incubation and depths, foraging behavior, Pelecanoidesgamotii. chick rearing). Adults were capturedin their burrows, weighed, measured,and ringed. Gaugeswere attached to feathersin the center of the bird’s back using quick- The maximum dive depth of several taxa of free-living set epoxy glue (Devcon 5-minute epoxy). The devices seabirdshas been successfullydetermined using cap- were retrieved after l-3 days. illary-tube gauges. Although these devices provide Capillary-tube depth gauges, similar to those de- only the record of the deepest dives, which normally scribed by Burger and Wilson (1988), consistedof a 6 represent less frequent exploratory dives beyond the cm length of flexible, clear PVC tubing (internal di- animal’s normal foraging depths (Lishman and Croxall ameter of 0.8 mm), coated internally with a thin layer 1983.