This study investigated alarm calls given by Uinta ground squirrels (Spermophilus armatus) in the presence of a ground predator. I observed predator responses of 18 groups of three to four squirrels each for an average of three trials apiece. r~y objectives were: (1) to describe prey-predator interactions resulting in alarm calls, and (2) to test the following hypotheses: 1. Each Uinta ground squirrel (by sex and age) has an equal probability of giving an alarm call at any time of the season. 2. All Uinta ground squirrels are equally likely to call regardless of their distance to a burrow, closest conspecific, and the predator. 3. Alarm calls are as likely to occur in the search stage of predation as in the pursuit stage. 4. Callers and noncallers are equally vulnerable to predation. I found that: ( 1) each Uinta ground squirrel (by sex and age) in the experimental population had an equal probability of giving an alarm call in the presence of a predator through the season, (2) callers and noncallers were equally close to burrows at the time of the call, (3) the caller was typically located farther away from its closest conspecific than noncallers at the time of the cal l, (4) the caller was significantly closer to the predator than were noncallers at the time of the call, (5) alarm calls occurred significantly more often in the pursuit stage of predation than in the search stage, and (6) noncallers suffered significantly more predation than did callers. There appeared to be little risk and energetic cost associated with calling. Squirrels that called usually were being pursued by the predator and were very close to a burrow when they called. The callers had little to lose and could increase their inclusive fitness by warning relatives of the presence of danger. This study dealt only with responses to ground predators. Squirrels are likely to respond differently to avian predators. It is suggested that responses of animals to avian and terrestrial predators should vary with the potential threat that the predator poses. The apparent inhibition of secondary calls is discussed. Once animals are aware of the presence of danger, there is no need for another animal to repeat the message and reveal its location to the predator.

No description available.

Navigating the physical world may present only a small fraction of the challenges faced by social animals. Sociality brings with it numerous benefits, including access to important information that may have otherwise been harder to come by. However, almost every aspect of these apparent benefits may also entail additional cognitive challenges, including how to interpret signals from conspecifics, who to attend to, and how to incorporate knowledge about signallers when deciding how to respond. One approach to understanding the cognitive abilities associated with social function is to investigate social species that take part in potentially costly group behaviours, where individual decisions must be made in a social context. In this thesis I explore how jackdaws (Corvus monedula), a highly sociable corvid species, use acoustic information to coordinate collective anti-predator responses. In Chapter Two I showed using playback experiments that the magnitude of collective responses to anti-predator recruitment calls known as “scolding” calls depends on the identity of the caller, with larger responses to familiar colony members than unfamiliar individuals. In Chapter Three I then used habituation-dishabituation experiments to show that this vocal discrimination operates at the level of the individual, with jackdaws discriminating between the calls of different conspecifics, regardless of their level of familiarity. In Chapter Four, I examined whether aspects of call structure conveyed information about threat levels. Here, I found that high rates of scolding calls were associated with elevated threats, and playback experiments suggested that this information might result in larger group responses. The finding that jackdaws are capable of mediating their response to alarm calls based on the identity of the individual caller, and on structural variation in call production, raised the question of whether jackdaws employed similar forms discrimination between acoustic cues made by predators in their environment. I investigated this in Chapter Five, using playback experiments to show that jackdaws responded not only to the vocalisations of resident predators, but that this ability extended to novel predators, and that responsiveness was mediated by the phase of the breeding season in which predators were heard. Together, these findings provide insights in to how discrimination among acoustic cues can mediate group behaviour in species that respond collectively to threats.

LIPANSKÁ, B. 2011: Effect of alarm calls on tit's behavior on feeder. MSc Thesis. Faculty of Science, Charles University in Prague. Alarm calls of the Great tit (Parus major) used in the context of ground-predators or perching-raptors consist of high-frequency tonal syllables and of series of churring syllables with broad-frequency range. The function of some acoustical parametres of these complex calls was tested in playback experiment on feeder. As the most effective appeared to be alarm calling of two birds simultaneously. More important for warning function of the calls were broad-frequency range syllables. The length of series of these syllables had an opposite impact than in some north-American chickadees (genus Poecile). The Blue tit (Cyanistes caeruleus) responds to Great tit's alarm calls, but its reactions are weaker. This difference can be caused by its lower competition ability against the Great tit. Key words: antipredation behavior, alarm calls, tits, playback experiment

No description available.

Alarm calls are one of the essential components of antipredator behaviour in birds. In this study I recorded and analysed alarm responses of the barred warbler (Sylvia nisoria) to different mounts of avian predators and nonpredators. The information about danger is encoded through graded structure in its unspecific alarm call type.

Titi monkeys have long been known for their complex vocal behaviour with numerous high- and low-pitched calls, which can be uttered singly or combined in more complex structures. However, up to date very little is known concerning the function, meaning and context-specific use of these vocal utterances, and virtually nothing is known about their vocalisations in the predation context. This thesis presents a detailed description of the form and function of the anti-predator behaviour of one species of titi monkeys, the black-fronted titi monkey (Callicebus nigrifrons), with a specific focus on their alarm call behaviour. A second aim was to determine the exact mechanisms of alarm calling behaviour, with an emphasis on production and comprehension. Data were collected from several habituated groups in the Caraça Reserve, Minas Gerais, Brazil. Results showed that, when detecting predator species, C nigrifrons produce sequences that initially contain two types of brief, high-pitched calls with distinct frequency contours. Further evidence suggested that some of these sequences are meaningful to conspecific receivers, by indicating the general predator class and location of threat. There were also indications that, within the terrestrial threats, additional information may be encoded by acoustic and compositional differences. Analyses of call order and number of calls per sequence suggested that callers may be able to convey information on both predator type and location. The black-fronted titi monkeys’ vocal system thus provides a further example of zoo-syntax, in which acoustically fixed units of a vocal repertoire are combined into higher order sequences that are meaningful to recipients. According to current definitions, this type of calling behaviour qualifies as functionally referential, by indicating general predator class, terrestrial predator type and location. As such, this is the first empirical demonstration of a sequence-based alarm call system that conveys information on both predator category and location.

<p>Evolution is fuelled by independent reproduction events. Yet, the offspring of at least three percent of all bird species postpone dispersal and forego independent reproduction. The Siberian jay, <i>Perisoreus infaustus, </i>is such a species where some<i> </i>offspring are philopatric and remain in their natal territory for up to three years, forming family groups. The main finding of this thesis is that nepotistic anti-predator behaviour displayed by parents provided philopatric offspring benefits, which could be an incentive to stay and forego independent reproduction. Predation, (hawks - 80 % and owls - 15% of deaths observed) is the main cause of mortality. Parents increased their vigilance nepotistically; they were more vigilant against surprise predator attacks, and gave alarm calls when attacked when feeding together with offspring. However, the two parents differed in their behaviour. Mothers gave calls only when together with their offspring, while males also warned unrelated immigrants. Sitting predators were approached and mobbed more intensely by parents in the presence of philopatric offspring. The vocalisation of Siberian jays provides information about predation risk. Specific calls are given for hawks and owls, and calls also varied with hawk behaviour. The nepotistic anti-predator behaviour of parents is a benefit, which the offspring can gain only “at home”, and such behaviour appears to promote offspring to forego dispersal and independent reproduction. This was confirmed in an experimental manipulation; philopatric offspring dispersed when fathers were removed and replaced by a despotic, immigrant stepfather. From a life-history perspective, parents have an incentive to protect their reproductive investment. Nepotistic anti-predator behaviour create a safe haven in the natal territory for philopatric offspring and provides direct fitness benefits. Without such direct fitness benefits offspring may disperse and wait for a breeding opening elsewhere. </p>

Evolution is fuelled by independent reproduction events. Yet, the offspring of at least three percent of all bird species postpone dispersal and forego independent reproduction. The Siberian jay, Perisoreus infaustus, is such a species where some offspring are philopatric and remain in their natal territory for up to three years, forming family groups. The main finding of this thesis is that nepotistic anti-predator behaviour displayed by parents provided philopatric offspring benefits, which could be an incentive to stay and forego independent reproduction. Predation, (hawks - 80 % and owls - 15% of deaths observed) is the main cause of mortality. Parents increased their vigilance nepotistically; they were more vigilant against surprise predator attacks, and gave alarm calls when attacked when feeding together with offspring. However, the two parents differed in their behaviour. Mothers gave calls only when together with their offspring, while males also warned unrelated immigrants. Sitting predators were approached and mobbed more intensely by parents in the presence of philopatric offspring. The vocalisation of Siberian jays provides information about predation risk. Specific calls are given for hawks and owls, and calls also varied with hawk behaviour. The nepotistic anti-predator behaviour of parents is a benefit, which the offspring can gain only “at home”, and such behaviour appears to promote offspring to forego dispersal and independent reproduction. This was confirmed in an experimental manipulation; philopatric offspring dispersed when fathers were removed and replaced by a despotic, immigrant stepfather. From a life-history perspective, parents have an incentive to protect their reproductive investment. Nepotistic anti-predator behaviour create a safe haven in the natal territory for philopatric offspring and provides direct fitness benefits. Without such direct fitness benefits offspring may disperse and wait for a breeding opening elsewhere.

The ability to communicate referentially has been historically viewed as being uniquelly human. However, with the increasing amount of studies discussing the communicative faculty of animals in the context of the evolution of human language, there is now growing evidence that this ability is present in many animal species, too. Although we know a lot about mimetic abilities of domesticated African grey parrots' (Psittacus erithacus) and their competence to use human words in a referential way, we know very little about the elements of referentiality in their natural vocalization. Our goal in this work was to find, whether and in which context is functionally referential vocalization in this species of birds present. We were determining its presence by the experiment, in which we have exposed four captured African grey parrot, in the ownership of FHS UK Prague, to stimuli that in other animal species usually elicit functionally referential vocalization: predators and prefered type of food. We analysed the behaviour and vocalizations of the tested birds by analytic softwares Interact, respectively Soundforge 0.8. We find out, that despite the fact that birds reaponded to our experimental objects appropriatelly (i.e. "predators" caused more fear and the like), they give the major amout of...