Bottlenose dolphins are known to use signature whistles to identify conspecifics auditorily. However, the way in which they recognize individuals visually is less well known. We investigated their visual recognition of familiar human individuals under the spontaneous discrimination task. In each trial, the main trainer appeared from behind a panel. In test trials, two persons (one was the main ...

The evolutionary forces that drive fitness variation in species are of considerable interest. Despite this, the relative importance and interactions of genetic and social factors involved in the evolution of fitness traits in wild mammalian populations are largely unknown. To date, a few studies have demonstrated that fitness might be influenced by either social factors or genes in natural popu...

The present report describes the first study of continuous vigilance in dolphins. Two adult bottlenose dolphins (Tursiops truncatus), WEN (male) and SAY (female), maintained a very high detection rate of randomly presented, infrequent, 1.5-s target tones in a background of frequent 0.5-s equal-amplitude tones over five continuous 120-h sessions. The animals were able to maintain high levels (WE...

Echolocating animals adjust the transmit intensity and receive sensitivity of their sonar in order to regulate the sensation level of their echoes; this process is often termed automatic gain control. Gain control is considered not to be under the animal's cognitive control, but previous investigations studied animals ensonifying targets or hydrophone arrays at predictable distances. To test wh...

A complex lymphoepithelial gland is a constant feature in the larynx of Atlantic bottlenose dolphins, Tursiops truncatus, based on study of 56 animals. Larynges were removed from fresh, non-decomposed beach-stranded animals for gross examination and histological sampling. A large lymphoepithelial gland occurs in the rostro-ventral mucosa of the larynx, overlying the cricoid cartilage. It presen...

Silvio Berlusconi has dominated Italian political life since he was first elected prime minister in 1994. He has been the third longest-serving prime minister of Italy, after Benito Mussolini and Giovanni Giolitti, and, as of May 2011, he was the longest-serving current leader of a G8 country. This political longevity is often difficult to understand for foreign political analysts. The former I...

Schistosoma mattheei ova were collected from cattle in different localities in South Africa and after hatching, miracidia were used to infest Bulinus (Physopsis) globosus. Cercariae harvested from these snails were used to infest the definitive host Praomys (Mastomys) coucha and eggs from the resulting female S. mattheei were collected. These ova were compared with a Schistosoma haematobium X S...

Helisoma duryi is a planorbid snail, which has been suggested as biological control agent against the intermediate hosts of schistosomiasis. This snail species has been present in a sugar estate in northern Tanzania since 1972. In January 1981 a snail survey was done in this area in order to determine the distribution and abundance of H. duryi relative to other freshwater snail species. The dis...

Bottlenose dolphins have a global distribution throughout tropical and temperate waters, both inshore offshore. Many studies demonstrate the existence of at least two Tursiops species: truncatus, consisting offshore eco-types T. aduncus, coastal Indo-Pacific type known to extend south into waters down east coast Australia. To clarify taxonomic status populations (Port Phillip Bay Gippsland Lake...