6 research outputs found

    Alarm calls of a cooperative bird are referential and elicit context-specific antipredator behavior

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    Although functionally referential signals have been extensively studied, largely in mammals (e.g., nonhuman primates, see Cheney and Seyfarth (1988); mongooses, see Manser et al. (2002); and other ground-dwelling species, see Blumstein and Armitage (1997), other social taxa such as birds would similarly benefit from the use of referential signals. We therefore investigated alarm calling in the cooperative noisy miner (Manorina melanocephala), a species that has been anecdotally recorded producing aerial alarms to flying predators and empirically recorded generating terrestrial alarms to ground-based threats. For these signals to be truly referential however, they must meet 3 criteria. First, calls must be structurally distinct, a requirement that these 2 call types meet. Second, calls must be stimulus-specific and reliably associated with a given stimulus. We tested this on free-living birds by exposing them to a simulated aerial predator that was either in flight or subsequently perched and thus presented one of the first studies on functionally referential alarm systems where both aerial and terrestrial alarm calls have been tested. Miners only produced aerial alarms while the stimulus was in flight, switching to terrestrial alarms once it landed. Third, referential signals must elicit different escape responses that are "appropriate" to the associated threat. Under field conditions, aerial alarm playback alone provoked an almost instantaneous response of fleeing to vegetation cover, whereas terrestrial alarm playback elicited significantly slower responses by receivers and an increase in scanning behavior. During laboratory experiments, aerial alarms stimulated birds to spend more time looking upwards, whereas terrestrial alarm calls stimulated individuals to scan perpendicularly, as expected if these stimuli provided information on likely predator location. Although other avian taxa have been shown to use referential alarm signals, this system provides novel evidence of referential calls based on the behavior rather than the type of predator, providing a highly adaptive means of communicating risk to other members of the social group in this cooperative species

    Using referential alarm signals to remotely quantify 'landscapes of fear' in fragmented woodland

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    Land-use changes have greatly impacted biodiversity and led to new conservation challenges, including greater predation pressure, although this can be difficult to quantify. Here we directly monitor predator encounters in fragmented woodlands by using passive acoustic monitoring (PAM) and a semiautomated assessment protocol to detect functionally referential alarm vocalisations of the noisy miner Manorina melanocephala. We demonstrate that measuring changes in perceived predation pressure, the so-called 'landscape of fear', in a prey species across temporal (dawn, midday, dusk across multiple seasons) and spatial scales (small/large fragments and edge/ centre locations within fragments) is achievable. Vocalisations linked with ground predator presence were rarer during midday recordings, but more commonly detected from the edge rather than centre of smaller fragments. While the probability of detecting aerial alarm calls directed at flying raptors also increased in edge habitat, aerial alarm detections declined from a dawn peak to a minimum during dusk recordings. These patterns did not simply reflect noisy miner occupancy or different sections of monitored patches, but highlighted higher perceived predation risk along edges, particularly for small patches, demonstrating the nuanced insights that PAM can offer when quantifying animal behaviou

    Experiment One: Are the type of alarm signals produced stimulus-specific?

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    Presentation of a stimulus similar to a gliding raptor established a direct association between aerial stimuli and aerial alarm call production by noisy miners

    Experiment Two: Does receiver flight response alter between alarm call types?

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    In the second field test, noisy miners demonstrated the ability to alter their behavior according to changes in the alarm call type broadcast

    Experiment Three: Does receiver observational response differ between alarm call types?

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    Birds were then tested in standardized conditions and demonstrated the ability to alter their behavior in the 20 seconds post-playback as expected under a referential signaling communication system

    Intercultural capacity deficits : contested geographies of coexistence in natural resource management

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    Focusing on the coexistence of competing and contested interests in intercultural natural resource management (NRM) systems in Australia and Malaysia, this paper explores the ways in which ontological pluralism and the interplay of socio-cultural, political-economic and biophysical influences shape NRM systems. We aim to foster a discursive space in which to reframe the challenges of capacity building in the rapidly changing spaces of intercultural NRM systems. The paper synthesizes the conceptual arguments of field research to conclude that capacity deficits of dominant institutions, processes and knowledge systems drive many systemic failures in land and sea management affecting Indigenous peoples. We advocate urgent action to build intercultural competence and new capacities and competencies in those institutions. The paper reframes intercultural NRM in terms of coexistence and invites wider debate about these 'new geographies of coexistence' in intercultural NRM systems.15 page(s
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