Abstract This study analyzed the contexts of three types of agonistic calls (Growl, Threat rattle, Vibrato growl) in Formosan macaques and their responses to predators and alarm calls at Mt. Longevity. Under natural condition, 112 five-minute scan samplings and 100 twenty-minute behavior samplings were collected to record agonistic behaviors and agonistic calls of macaques. In addition, 11 dog-presence tests and 102 playback experiments were successfully conducted from January 2003 to April 2004. Of 385 agonistic events, 61.8% comprise of vocal bouts contained units belonging to single type of agonistic calls, and 31.8% bouts were mixed units contained more than one type of agonistic calls. Among these three single types of agonistic calls, Vibrato growl was used most frequently during conspecific interactions (44.3%); Threat rattle was used toward human (51.7%) and dogs (94.4%). During intraspecies conflicts of macaques, the vocal rates of three single type agonistic calls decreased from adult males, adult females and juveniles to infants. The average units per bout of Growl was higher than that of Threat rattle and Vibrato growl (p<0.0002). However, the agonistic interactions explain the different functions of the three types of agonistic calls. Growl was frequently accomplished with chase of callers (45.6%), while flee was usually expressed by receivers (57.9%). When monkeys uttered Threat rattle or Vibrato growl, open mouth threat was the most frequent behavior expressed by callers (80.5% and 73.1%), while evade was most frequent behavior expressed by receivers (43.9% and 31.9%). Growl conveyed messages about intense callers and contexts, and receivers avoided damage through fleeing. These results support Smith (1981) hypothesis referential signal carry information about external objects, contexts or a caller internal state as reflected in the probability of its subsequent behavior pattern. Receivers are able to attribute a certain meaning and express appropriate responses by the combination of signal structure and the context in which they are exposed the call. Six different acoustic features of alarm calls existed between adult males and juvenile males. Alarm calls from Juveniles have higher Maximal, Median and Modulation Fundamental Frequencies than from adult males (p<0.0001). But alarm calls from juveniles have lower Highest Frequency, Total Range of Frequency and Duration of each Unit than from adult males (p<0.005). The results support current theory that the duration and fundamental frequency reflect body size. In the playback experiments, macaques responded stronger to alarm calls from adult males than from juvenile males (p<0.0001). The average response score of macaques toward alarm calls from playback experiments was highest from infants, followed by juveniles, adult females and adult males. Adult macaques often responded to playbacks by looking in the direction of the loudspeaker. Juveniles and infants most often responded to playback calls by escape and startle. In playback experiments of alarm calls from adult males, F troop had significant different responses in three different places, strongest in the unfamiliar place (p<0.0001). The presents of dog elicited macaques with stronger responses than playback of dog barks (p<0.0001).

Predation is a major source of mortality, resulting in strong selection on strategies to avoid being captured. Individuals have access to multiple sources of information on predation risk: they can detect danger directly themselves, and they can attend to behavioural cues or warning signals produced by others. Rapid responses are vital when hunted by aerial predators in particular, as split-second decisions can mean the difference between life and death. I studied New Holland honeyeaters, Phylidonyris novaehollandiae, as a model system to examine how alarm calls encode information about danger and to understand how this information is used by receivers. In Chapter 2, observational data showed that these honeyeaters produce multi-element, aerial alarm calls in response to flying threats. Male honeyeaters had more opportunities to detect threats than did females and showed a greater propensity to alarm call when presented with gliding model predators. In Chapter 3, a combination of observational data and model presentations demonstrated that aerial alarm calls encode urgency in both the number of elements, with more dangerous threats receiving more elements, and the acoustic structure of the first element. Playback presentations of alarm calls and video recordings to measure responses revealed that honeyeaters made extremely fast decisions about fleeing to cover based on the acoustic structure of the first alarm element, while the number of elements determined for how long they hid. These two chapters demonstrate that receivers have rapid access to detailed information about the type and degree of danger from conspecific alarm calls. In Chapter 4, I investigated how birds integrate personal information about danger with social information from alarm calls. Perched birds were faster to detect model predators than feeding birds, suggesting that they have greater access to personal information. Consistent with this, perched birds were less likely to flee to cover in response to alarm playbacks than foraging birds. Birds also fled less in response to less urgent social information, such as playbacks of more distant alarm calls, and less relevant social information, in the form of calls from another species with overlapping but not identical threats. In Chapter 5, I tested how honeyeaters value social information about danger derived from single versus multiple sources, both within and across species. Birds paid attention to the number of independent signallers when assessing information from both conspecifics and heterospecifics, responding more strongly to playbacks of alarm calls from two sources than a single source, but they also moderated their responses according to signal relevance. Together, these results show that birds make flexible decisions about danger by integrating information from multiple sources and assessing its quality, allowing them to mitigate the costs of fleeing to false, or irrelevant, alarms while taking advantage of the multitude of information provided by the prey community's neighbourhood watch.

This study describes chick-a-dee calling behavior of Carolina chickadees (Poecile carolinensis) in the presence of “flying” predator models. Previous experimental research with black-capped chickadees (Poecile atricapilla) as well as Mexican chickadees (Poecile sclateri) suggested a relationship between the presence of predator stimuli and the note composition of chick-a-dee calls. Carolina chickadees were presented with two types of stimuli in field settings. These models were painted to resemble either a predatory sharp-shinned hawk (Accipiter striatus) or a blue jay (Cyanocitta cristata). Models consisted of pairs of five varying shapes, making ten models in all. A randomly chosen model was covered with a cloth and attached to a zip-line fastened to a tree about five meters high. During the procedure the cloth was removed and the model was released, causing it to “fly” to the opposite end of the zip line, which was attached at ground level. These trials were audio recorded at 20 field sites in eastern Tennessee from January - March 2010 and January - February 2011. Chickadees produced more C notes in response to hawk models than to blue jay models. Additionally, chickadees produced more A and C notes as well as more total notes during the post-exposure period than during the pre-exposure period for both the hawk and the blue jay conditions. The chickadees’ increased production of C notes in response to the hawk stimuli is consistent with previous research conducted on Mexican chickadees, potentially suggesting that the call structure of Carolina chickadees in threatening predator contexts is more similar to that of Mexican, rather than black-capped chickadees. Finally, chickadees increased production of A notes and C notes to the presence of both model types, providing support for the “Better Safe Than Sorry” strategy.

I examined the effect of the conspecific mobbing call of the Red-backed Shrike (Lanius collurio) on nest defence against arial predator (kestrel). I used a playback experiment in the presence of a dummy of kestrel (Falco tinnunculus) in two variants either with nature look or with adjusted key features (pigeon beak, claws and eyes), and pigeon (Columba palumbus) as a control. Shrikes were attracted by the mobbing call and arrived to their nests faster. Only the modified kestrel was attacked more likely in the presence of the playback, that suggests possible function of the mobbing call as a cue for social learning of predator recognition.

The thesis deals with vocalizations produced by Eurasian ground squirrels of the genus Spermophilus. It is mainly focused on inter-species and intra-species variability in acoustic structure of alarm calls which are emitted in presence of predators.The major part of the thesis deals with intra-species variability in acoustic structure of the alarm calls in five Eurasian ground squirrels, Spermophilus citellus, S. taurensis, S. xanthoprymnus, S. suslicus and S. fulvus. It has been confirmed that the alarm calls of these ground squirrels show a high level of species specificity. The thesis further describes another vocalizations produced by three Eurasian ground squirrel species, Spermophilus suslicus, S. citellus and S. fulvus, and shows that with the exception of the alarm calls, vocal repertoires of these three ground squirrels are remarkably similar. The last part of the thesis deals with individual distinctiveness of the alarm calls of three Eurasian ground squirrels, Spermophilus citellus, S. taurensis and S. xanthoprymnus. It has been shown that the alarm calls of these species have a significant potential to encode information about caller identity.

No description available.

This thesis presents several nonlinear mathematical models applied to ecoepidemiology and evolution. A detailed study involving predator-prey type models considering an alternative resource for the predator was carried out, investigating the situation of infection in the prey and in the predator on separate models. Such study served as a theoretical contribution to the investigation of problems such as bovine tuberculosis in wild animal species presented in a specific model. We also developed models to explain the evolution of alarm calls in species of birds and mammals. The theoretical framework adopted for those evolution models is that of Population Ecology. The models were developed using Ordinary Diferential Equations (ODEs) to describe the population dynamics. The biological assumptions of the systems that we wanted to analyse were enumerated and explained / Esta tese apresenta vários modelos matemáticos não-lineares aplicados à ecopidemiologia e à evolução. Foi realizado um estudo detalhado envolvendo modelos do tipo predador-presa considerando um recurso alternativo para o predador, investigando situações de infecção na presa e no predador em modelos separados. Tal estudo, serviu de aporte teórico para a investigação de problemas como a tuberculose bovina em espécies de animais selvagens apresentado em um modelo específico. Também desenvolvemos modelos para explicar a evolução dos chamados de alarme em espécies de aves e mamíferos. O quadro teórico adotado para esses modelos de evolução é o da Ecologia de População. Nos modelos desenvolvidos usamos as Equações Diferenciais Ordinárias (EDOs) para descrever a dinâmica populacional. Consideramos pressupostos biológicos dos sistemas biológicos analisados

Black-and-white colobus monkeys are renowned for their impressive vocal behaviour, but up to date there have been only very few systematic efforts to study this. These monkeys are able to produce loud and low-pitched roars that transmit over long distances, which has lead to the assumption that these calls function in inter-group spacing and male-male competition. The fact that the monkeys sometimes produce the same calls to predators as well, has not received much attention so far. This thesis presents a detailed description of the form and function of the anti-predator behaviour of one species of black-and-white colobus monkeys, the Guereza (Colobus guereza), with a specific focus on their alarm calling behaviour. A second aim was to determine the effects of predator experience on their anti-predator behaviour, with a specific focus on call comprehension and production. Data were collected from two populations of Guereza monkeys in the Budongo Forest Reserve, Uganda, that differ in predation pressures experienced by their main predators: leopards, eagles and chimpanzees. Results showed that Guerezas use a basic form of zoo-syntax in order to compose predator-specific call sequences that vary in the number of roaring phrases and snorts. These sequences are meaningful to recipients, at least at the level of the predator class, but there were also indications for additional levels of encoded information: Guerezas appear to have evolved a second system, based on acoustic variants of individual phrases, which allows them to narrow down the information content of call sequences, generating the potential to communicate highly specific information by using a mix of syntactic and semantic cues. The monkeys’ vocal behaviour was influenced by predator experience, but not strongly so. Monkeys without prior experience with leopards lacked some of the behavioural nuances seen in leopard-experienced monkeys, but they nevertheless responded appropriately to visual and acoustic leopard models, suggesting they had retained the basic capacities to recognise this predator type as relevant and dangerous. Results are discussed in light of the comparative approach to the study of human language evolution. Although human language is unique in a number of ways, for example through its use of complex syntax and intentional semantics, some animal communication systems have revealed similar features, and Guerezas, the first member of the colobine family to be studied in this respect, are no exception. The Guerezas’ alarm calling behaviour is complex and flexible, and these monkeys have provided another piece of empirical evidence that is directly relevant for the comparative approach to human language evolution.