Behavior of an Adult Female Bottlenose Dolphin (Tursiops truncatus) Toward an Unrelated Dead Calf
Written by Quintana-Rizzo, Ester, and Wells, Randall S.
Abstract: We observed two unrelated, resident female common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida, one of which had a newborn calf that was alive for approximately 12 to 19 d. The behavior of the females was observed before and after the calf died. When the calf was alive, the two females spent most of their time in close proximity (93% of 46 time points collected over 3 d using the point sampling technique) with the calf generally surfacing between them. When the calf died, the females spent less time in close proximity but were within approximately 80 m of each other over 2 d. The unrelated female was near the dead calf most of the time (87% of 23 time points). In some cases, she surfaced next to the dead calf immediately after the calf appeared at the surface, suggesting that she brought it to the surface. The day after the calf was found dead, the females were still with the calf, and the unrelated female continued spending more time with the carcass than the mother. In fact, analysis of continuous data showed that the unrelated female spent 98% of the time points collected using the point sampling technique next to the dead calf, whereas the mother milled 10 to 80 m from them. The benefit that an unrelated female could gain from attending a dead calf is unclear, especially when there is evidence that she is more successful at raising her own calves than the mother of the dead calf.
Key Words: female, dead calf, assistance, bottlenose dolphins, Tursiops truncatus
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