place ihc harness on the baby. The 

 danger from the mother was made 

 clear when a crewman began working 

 within a few meters of one. The female 

 whale lifted her tail, bent it back and 

 thrashed the flukes around in a semi- 

 circle, horizontal to the water surface. 

 She missed the man by quite a dis- 

 tance but the force of the blow was 

 enough to send a sheet of water over 

 everyone nearby. 



The baby remained rather quiet 

 during the harnessing process. The 

 harness was usually slipped on under 

 the snout and v/orked posteriorly to 

 the pectorals which were then inserted 

 through the harness. The harness was 

 then tightened in place until snug over 

 the baby's body. At this point, timing 

 for harness release began as a corrosi- 

 ble magnesium bolt which held the 

 release mechanism began to corrode 

 away in salt water. 



Three or four men pushed the baby 

 back into deep water over the shelf 

 taking care to avoid the mother. In all 

 but one case she was nearby and 

 quickls took up station with her off- 

 spring. In one case the mother left 

 before the baby was launched and 

 was a kilometer or so down the bay 

 shore when the baby began to swim 

 in deep water. This baby cruised 

 quietly for a short time and then, when 

 about 300 m from the mother, turned 

 as if on a signal and raced toward her. 

 The mother did the same, turning 

 toward the baby and beginning to 

 swim rapidly. Once they were near 

 the mother circled the baby, thrashing 

 the water with her flukes. It was prob- 

 able that an acoustic recognition sig- 

 nal was involved. This young animal 

 had been emitting short low frequency 

 signals while stranded. Even if the 

 young did become separated from the 

 mother by some distance, chances for 

 reunion remained excellent because 

 of the restricted channels available 

 for swimming. 



In all cases the presence of the har- 

 ness had no visible effect on the be- 

 havior of the mother-young pair. 



HARNESS DESIGN 



The harness was constructed of 

 four lasers of one-way stretch Lino 

 241,' commonly used in fabricating 

 girdles and corsets, that permitted 

 expansion and contraction around the 

 whale's circumference. The two legs 

 of each harness half (Figure 3) were 

 attached together ventrally by "D" 

 rings to a timed-release mechanism. 

 Dorsally they were bolted to a curved 

 metal plate holding the radio trans- 

 mitter. Horizontal rows of grommets 

 5 cm apart in the heavy plasiic- 

 impregnated nylon reinforcing band 

 at the dorsal ends of the harness legs 

 allowed adjustments to animals of 

 different circumferences and allowed 

 the harness to be secured under differ- 

 ent degrees of tension. We pulled 

 the harnesses snug on our animals, 

 which prevented flutter from water 

 passing around the swimming animal 

 and kept the harness in place during 

 dives (the harness was 40 cm wide 

 and 1 12 cm long). 



The strength feature of the harness 

 was a 2,5 cm wide by 0.6 cm thick 

 woven nylon strap in the leading and 

 trailing edge of each harness half. 

 These straps, held in sewn folds of the 

 harness, were sewn to the harness only 

 near the ventral "D" rings, thus per- 

 mitting harness and straps to be ad- 

 justed independently to the whale's 

 circumference. The grommeted ends 

 of both the harness itself and the 

 strengthening straps were attached to 

 bolts on the dorsal plate by means of 

 knurled nuts. 



A plastic cup on each side by mid- 

 body simulated an instrument housing, 

 and a poK vinyl chloride rod sewn 

 across the harness above the pectorals 

 acted as a batten, preventing bunching 

 of the harness in the anterior-posterior 

 direction. 



The timed-release mechanism con- 

 sisted to two aluminum plates held 

 together by a central spring-loaded 



' Reference to Irade names does not imply en- 

 dorsement by the National Marine Fishieries 

 Service, NCAA 



magnesium bolt. One plate had four 

 tapered corner posts that tit into four 

 receptacles on the other plate. The 

 "D" rings of the harness legs slipped 

 over the posts and over four strong 

 springs that assisted in forcing the 

 plates apart during jettisoning. All 

 tensions of the harness and nylon 

 straps were e.xerted against these posts. 

 The magnesium bolt bore only the 

 vertical strain of a spring between the 

 two plates. 



The wall thickness of the magnes- 

 ium bolt determined the interval be- 

 tween submergence in seawater and 

 the time of breakage. When the bolt 

 broke the springs forced the two plates 

 apart and released the "D" rings from 

 their posts. Corrosion of the bolts was 

 insured by a central copper sleeve that 

 promoted rapid electrolysis. 



The dorsal plate to which the har- 

 ness attached was constructed of ? mm 

 curved aluminum, designed to fit over 

 the body contour of a baby whale. 

 An Ocean Applied Research Model 

 PT-202 radio transmitter was secured 

 to the center of this plate, and a paint- 

 ed yellow cap moulded of high density 

 polyurethan foam was fitted over the 

 transmitter for flotation. Foam neo- 

 prene sheeting was glued to the ventral 

 surface of this plate to prevent chafing 

 the whale's skin. 



To fasten the harness around the 

 animal, the two halves, connected 

 ventrally to the timed-release mechan- 

 ism, were slid under the animal and 

 the pectoral flippers inserted through 

 the harness. The radio, float, and plate 

 were placed on the dorsal midline, 

 and each harness half was pulled tight; 

 the appropriate rows of grommets 

 in the harness were fitted over bolts in 

 the dorsal plate and the nuts tightened 

 down. Then the excess rows of grom- 

 mets were cut off with a knife and the 

 heavy nylon straps secured in place 

 and similarly trimmed. Finally straps 

 from the float were attached, and the 

 calf was ready to be launched to its 

 mother. Figure 4 shows the harness 

 and radio in place as the released calf 

 joins its mother. 



61 



