First Observation of the Parturition and Peripartum Events in a Harbor Porpoise (<I>Phocoena phocoena</I>)

Abstract

Parturition events in cetaceans are difficult to observe in nature and scarcely described in detail. Observations from animals in captivity offer the possibility to follow complete gestations and to obtain a precise description of the series of events pertaining to pregnancy and parturition. After a gestation period of 11 mo, the parturition of a harbor porpoise (Phocoena phocoena) was observed for the first time at the Danish research facility Fjord & Boelt on 8 August 2007. Five prepartum signs useful to predict the onset of parturition were identified: (1) decrease in appetite (from 5,064 Kcal/d to 907 Kcal/d at 2 d before birth [B-2]), (2) unusual behavior (disinterest in training sessions, seeking of physical contact with the trainers, restlessness), (3) decrease in body temperature of 1.6º C at B-1, (4) swollenness in the genital area, and (5) increase in the inter-mammary distance (from 5 to 8 cm at B-1).During labor, three stages described for other mammals in literature were observed and each stage's duration recorded: Stage 1 was characterized by uterine contractions and dilation of the cervix (between 2 h 19 min and 7 h 39 min), Stage 2 started with the rupture of fetal membranes (1 h 42 min at least), and Stage 3 comprised the expulsion of the fetus and its membranes (7 h). The total duration of the parturition was at least 16 h 21 min as there is an uncertainty in regards to the exact beginning of the labor.The sequence of visible events occurring during parturition was as follows: apparition of the amniotic sac, apparition of the calf's flukes, apparition of the peduncle, delivery of the calf, and expulsion of the left horn of the placenta followed by the right horn. As described for other cetaceans, the delivery was caudal.Contractions seemed to be longer and more frequent during the first stage and during the beginning of the second stage of labor. The contractions then shortened and became more regular during the expulsion of the calf. We observed that the expulsion of the calf was not provoked only by contractions but helped at the end by a violent rotational movement of the mother that broke the umbilical cord. The female's breathing rate increased dramatically towards the end of the expulsion of the calf.

Observations of parturition in humpback whales (Megaptera novaeangliae) and occurrence of escorting and competitive behavior around birthing females

“…Additionally, similar to many captive odontocetes (Asper et al, 1988;Blanchet et al, 2009;Deng et al, 2019;Essapian, 1963;McBride & Kritzler, 1951), humpback whales may not always immediately pass the placenta (a placenta was seen immediately after the birth only in Events 2 and 8). During Event 1 in Hawaii, the placenta was observed only after 15 min of the neonate's first sighting (Silvers et al, 1997).…”

Case of Cephalic Presentation of Foetus in a Harbour Porpoise Phocoena Phocoena (Cetacea, Phocoenidae), with Notes on Other Aquatic Mammals

“…It is known that a cetacean foetus can change its position in the uterus during pregnancy but it usually moves into a tail-first position by the last months (Slijper, 1966;Reidenberg, Laitman, 2009). The harbour porpoise is not an exception; its parturition in captivity was recently described in details by Blanchet et al (2009): the expulsion of the newborn (stage 2 of the parturition) lasted 1 hour 42 minutes, tail first. This study provides an evidence for the opposite case, the cephalic presentation in porpoises.…”

Composition Analysis of the Colostrum and Attempted Hand-rearing of a Neglected Harbor Porpoise (<i>Phocoena phocoena</i>)

“…After observing this, the mother seemed to lose interest in the calf; she did not swim alongside it or assume a suckling position. The first nursing attempt in captive harbor porpoises is usually made within 2 hr after birth, and successful nursing tends to occur within 4 hr after birth, although these behaviors often vary markedly among individuals [9]. However, in this case, the keepers decided to separate the mother and calf at 2 hr after birth, before the aquarium opened to the public, because the mother had lost interest in the calf and the staff would be occupied during opening hours.…”

“…They have a short lactation period (8-12 months) compared to other delphinids (typically 12-20 months) [7,8]. There are a few examples of breeding harbor porpoises in captivity [9,10]. The Otaru Aquarium in Japan provides the only example of rearing and breeding small herds [11].…”