Access to abstract restricted until December 2014. / Acess to thesis restricted until December 2014. / Department of Biology

The marine birds comprising the order Procellariiformes are an ancient and diverse assemblage. A large proportion are both nocturnal and burrow-nesting at their breeding colonies, where in sharp contrast to their behaviour at sea, they are highly vociferous. Virtually nothing is known regarding the adaptive features of this process. Various aspects of vocal behaviour have therefore been investigated from 1981 to 1983 for seven species at breeding stations in both the boreal and sub-tropical North Atlantic Ocean. In addition, the problem of how these birds return to their correct burrows at night has been considered. A detailed study was conducted on the Manx Shearwater Puffinus puffinus. Various approaches showed that immatures contribute most to the calling heard. Males establish and defend burrows, but both sexes partake in aerial calling. Calling at ground level serves both sexual and territorial functions, whereas aerial calling is probably mainly concerned with sexual advertisement. Some males are more silent in flight than others. These probably represent birds as yet without burrows, perhaps the youngest age classes. Flighting activity probably expedites the acquisition of burrows and mates in these birds which are awkward on land, and aerial calling probably improves signalling efficiency in attracting mates. Six other species (Bulweria bulwerii, Calonectris diomedea, Puffinus assimilis, Hydrobates pelagicus, Oceanodroma castro, Pelagodroma marina) were studied. As with Puffinus puffinus, sexual differences in voice exist for all except Bulweria and Pelagodroma, which also lack aerial calls. Thus a functional link exists between flight calls and their sexual divergence. Selection probably favours such divergence in species where males leave burrows to display in flight; the sexual identity of those species whose males do not is unambiguous as they remain in burrows and call. The calls of Puffinus puffinus and Hydrobates pelagicus were compared at local and regional levels. Divergence exists between but not within islands. Vocal drift in Puffinus puffinus is also apparent after several years. The calls of the nocturnal Procellariiformes are reviewed and discussed in relation to their systematics. The potential use of calls in petrel systematics is also evaluated and shown to be useful. Observations on Puffinus puffinus showed that olfactory and auditory cues are not used for burrow homing. Experiments also confirmed this, and point to sufficient visual development in this species, although other senses may be emphasised in different ecological situations.

Chipmunk antipredator calls were examined during the summers of 1990 and 1991. The structural characteristics of the three calls, chipping, chucking and the trill, were obtained through taped recordings and sonagraphic analysis. Behavioural observations indicated that chucking by choruses of individuals occurs in the presence of aerial predators, chipping by choruses of individuals occurs in the presence of terrestrial predators and the trill is given by single individuals when fleeing from predators. / Experiments were carried out to determine the function of the trill and chipping. Demographic and contextual effects indicate that the trill is in part a call which functions to warn kin but may also indicate to conspecifics that the caller has escaped into a refuge. An experiment with a tethered cat concluded that chipping is likely to function to deter predators from hunting in the area. This is done through vocal mobbing by several individuals whose home ranges overlap.

Variation in advertisement call structure of whistling frogs, Litoria ewingi, was studied among breeding sites in the vicinity of Christchurch on the East coast and Harihari on the West coast of the South Island. Males vocalized in breeding choruses throughout the year and females moved toward and appeared to evaluate calls of territorial males before initiating amplexus. Acoustic interactions between neighbours led to modification of call structure and timing, and wrestling matches between males were frequent. I quantified call structure for 1623 calls of 168 individuals using 24 call parameters. Most temporal characteristics were significantly correlated with the caller's body temperature and dominant frequency was negatively correlated with body size. These results are consistent with the prediction of temperature-dependent metabolic rates in a poikilotherm's nervous system. I compared call structure among the study populations using both multivariate and univariate analyses. Advertisement call structure showed highly significant variation among populations for most call variables. The greatest difference occurred between the West and East coast populations, and a clinal trend occurred in the East coast populations on a microgeographic scale. Variation among East coast populations in some variables was comparable to the scale of variation between coasts. These results suggest that whistling frogs exhibit natal philopatry. I obtained repeated recordings for 21 individuals and examined variation in call structure within and among individuals using nested multivariate analyses of variance. Highly significant variation occurred both within and among individuals for most call characters, but certain call characters were more variable among individuals. This suggests that whistling frog advertisement calls are individually distinctive.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 121-136).

Thesis (MSc)--Oxford Brookes University, 2005. / "Date of submission: 31st October 2005"--title page. Title from initial PDF page image (viewed October 5, 2006). Includes bibliographical references (p. 45-49).

Thesis (MSc)--Oxford Brookes University, 2005. / "2005"--title page. Title from initial PDF page image (viewed October 5, 2006). Includes bibliographical references (p. 68-79).

Diploma thesis--Anthropological Institute and Museum, University of Zürich, 2004. / "2004"--title page. Title from initial PDF page image (viewed October 5, 2006). Includes bibliographical references (p. 59-63).

Recent studies on the social life and vocal production, usage and comprehension of nonhuman primates have brought new insights into the evolutionary mechanisms of cognition and communication as well as the emergence of language. A key point in the current literature concerns the flexibility of vocal production. In contrast to humans, some birds and some cetaceans, vocal flexibility is thought to be very restricted in nonhuman primates, which creates a startling phylogenetic gap. At the same time, research has shown that a number of African forest guenons' alarm calls appear to have language-like properties. With the hypothesis that looking at the vocal repertoire more broadly, especially the social calls, was likely to reveal other complex communicative abilities, I studied in detail the social life and vocal behaviour of a guenon species, Diana monkeys. First, the comparison of its social system with the system of another closely related species, Campbell's monkeys, stressed in both species the reduced number of physical interactions, although females maintained preferential relationships that were not biased towards kin. Second, the study of Diana females' vocal repertoire is restricted but flexible. Females emit social calls with a combinatorial structure, the use of which is affected by external events. Third, focusing on a highly frequent and highly social call revealed flexibility in the identity advertisement (divergence – convergence) which accommodates to the context. Fourth, to explore the nature of nonhuman primates' comprehension skills, I performed playback experiments of De Brazza monkey social calls to three species of Old World monkeys; Campbell's monkeys, black-and-white colobus monkeys and red-capped mangabeys. Altogether, the three species were able to discriminate hetero-specific voices of individuals they knew from individuals they had never met. Overall, my results have revealed a considerable degree of flexibility in the vocal communication of nonhuman primates, a finding that is consistent with the hypothesis of a continuous evolutionary transition from animal vocal behaviour to human language.

The aim of the study was to map the repertoire of vocalization of four wild-caught grey parrots (Psittacus erithacus), two males and two females. Data were collected during nine days from June to November 2008 by recording of vocalization in standardized conditions. Recorded sounds (3 052) were categorized according to their characteristics using both visual inspection of spectrograms and listening. We found 70 different call types, which were combined into 18 bigger groups. We found no subject to use the whole repertoire. Important differences were found both between individuals and between males and females. almost all call types were used throuthout the whole period of recording. Model spectrograms of all call types are shown. Key words: grey parrot, Psittacus erithacus, repertoire, vocalization