Ein Blick in die Kinderstube von Tursiops truncatus (Montagu, 1821) im Zoo Duisburg mit Hilfe von Videoaufnahmen aus der Routineüberwachung

Abstract

From videorecordings of a bottlenose dolphin (Tursiops truncatus) during calving and subsequent rearing taken by commercial surveillance cameras, which cover a period of two months, we selected three days (I = day of birth, II = 7^th day after birth; III = 14^th day after birth) to qualitatively and especially quantitatively describe exemplarily the locomotion calculated as covered distance, respiratory rate, resting periods of the mother (Daisy) as well as respiratory rate and amount and duration of suckles of her calf (Darwin). For quantitative analysis we used the freeware-program tracker. The observed calving process followed the pattern well-known from literature.

Comparing the collected data we show a considerable decrease of Daisy's distance swimming before birth, an increase after birth, followed again by a significant decrease until day III. Distances travelled by Daisy per day were exceptionally large (ca. 100 km). Before birth her respiratory rate was significantly lower than after birth, and then it was relatively constant over time. Periods of inactivity were frequent before birth, not observed after birth, and began to increase from day II. The respiratory rate of Darwin increased over time (day I to day III) exceeding that of Daisy (day II, III). Frequency and number of suckling bouts decreased over time. Some of the behavioral changes of Daisy shown during the observation period can be associated with Daisy's care of the calf and its increasing independence. Altogether our approach allowed quantifying behavioural elements of mother and calf very detailed even in recordings not necessarily suitable for such studies. The fine-scale analysis revealed reproducible and reliable data, which show in the present case again the considerable changes in the behaviour of mother and calf even within a period of only two weeks.