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Anna Mcconville - One of the best experts on this subject based on the ideXlab platform.
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passive acoustics and sound recognition provide new insights on status and resilience of an iconic endangered marsupial koala phascolarctos cinereus to timber harvesting
PLOS ONE, 2018Co-Authors: Bradley Law, Traecey Brassil, Leroy Gonsalves, Paul Roe, Anthony Truskinger, Anna McconvilleAbstract:Retention forestry aims to mitigate impacts of native forestry on biodiversity, but data are limited on its effectiveness for threatened species. We used acoustics to investigate the resilience of a folivorous marsupial, the koala Phascolarctos cinereus, to timber harvesting where a key mitigation practice is landscape exclusion of harvesting. We deployed acoustic recorders at 171 sites to record male Bellows (~14,640 hours) for use in occupancy modelling and for comparisons of Bellow rate (Bellows night-1). Surveys targeted modelled medium-high quality habitat, with sites stratified by time since logging and logging intensity, including old growth as a reference. After scanning recordings with software to identify koala Bellows, we found a high probability of detection (~0.45 per night), but this varied with minimum temperature and recorder type. Naive occupancy was ~ 64% across a broad range of forests, which was at least five times more than expected based on previous surveys using alternative methods. After accounting for imperfect detection, probability of occupancy was influenced by elevation (-ve), cover of important browse trees (+ve), landscape NDVI (+ve) and extent of recent wildfire (-ve, but minor effect). Elevation was the most influential variable, though the relationship was non-linear and low occupancy was most common at tableland elevations (> 1000 m). Neither occupancy nor Bellow rate were influenced by timber harvesting intensity, time since harvesting or local landscape extent of harvesting or old growth. Extrapolation of occupancy across modelled habitat indicates that the hinterland forests of north-east NSW support a widespread, though likely low density koala population that is considerably larger than previously estimated. Retention forestry has a significant role to play in mitigating harvesting impacts on biodiversity, including for forest specialists, but localised studies are needed to optimise prescriptions for koalas.
Paul Roe - One of the best experts on this subject based on the ideXlab platform.
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passive acoustics and sound recognition provide new insights on status and resilience of an iconic endangered marsupial koala phascolarctos cinereus to timber harvesting
PLOS ONE, 2018Co-Authors: Bradley Law, Traecey Brassil, Leroy Gonsalves, Paul Roe, Anthony Truskinger, Anna McconvilleAbstract:Retention forestry aims to mitigate impacts of native forestry on biodiversity, but data are limited on its effectiveness for threatened species. We used acoustics to investigate the resilience of a folivorous marsupial, the koala Phascolarctos cinereus, to timber harvesting where a key mitigation practice is landscape exclusion of harvesting. We deployed acoustic recorders at 171 sites to record male Bellows (~14,640 hours) for use in occupancy modelling and for comparisons of Bellow rate (Bellows night-1). Surveys targeted modelled medium-high quality habitat, with sites stratified by time since logging and logging intensity, including old growth as a reference. After scanning recordings with software to identify koala Bellows, we found a high probability of detection (~0.45 per night), but this varied with minimum temperature and recorder type. Naive occupancy was ~ 64% across a broad range of forests, which was at least five times more than expected based on previous surveys using alternative methods. After accounting for imperfect detection, probability of occupancy was influenced by elevation (-ve), cover of important browse trees (+ve), landscape NDVI (+ve) and extent of recent wildfire (-ve, but minor effect). Elevation was the most influential variable, though the relationship was non-linear and low occupancy was most common at tableland elevations (> 1000 m). Neither occupancy nor Bellow rate were influenced by timber harvesting intensity, time since harvesting or local landscape extent of harvesting or old growth. Extrapolation of occupancy across modelled habitat indicates that the hinterland forests of north-east NSW support a widespread, though likely low density koala population that is considerably larger than previously estimated. Retention forestry has a significant role to play in mitigating harvesting impacts on biodiversity, including for forest specialists, but localised studies are needed to optimise prescriptions for koalas.
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koala Bellows and their association with the spatial dynamics of free ranging koalas
Behavioral Ecology, 2011Co-Authors: Paul Roe, W A Ellis, Sean Fitzgibbon, Fred B Bercovitch, Jason Wimmer, Alistair Melzer, Robbie S WilsonAbstract:Acoustic communication mediates sociality in a variety of animals. One of the more ubiquitous vocal signals to have evolved is the sexual advertisement call of males. Koala (Phascolarctos cinereus) males emit a sonorous Bellow call during the breeding season, but no detailed studies of the calling context appear to have been published. We used a novel remote sound detection network to monitor koala Bellowing while simultaneously collecting koala behavioral data using collar-mounted GPS units. Our approach enabled us to examine fine scale temporal variation in vocalization and spatial movements of free-ranging koalas without direct behavioral observations. Bellow occurrence was susceptible to weather conditions, with fewer calls occurring when wind speed and temperatures were high. The number of Bellow vocalizations recorded during an annual period mirrored breeding activity, with nearly all male Bellows recorded during peak mating season. The distance traveled by koalas and the occurrence of koala Bellows both peaked around midnight, but only female travel distance during the breeding season was temporally correlated with Bellow occurrence. We conclude that environmental factors might trigger male Bellowing to launch the breeding season and that these male vocal signals function more to attract females than to repel males. Female mate selection is probably an important component of male reproductive success in koalas, which is partly mediated by male Bellow characteristics.
W A Ellis - One of the best experts on this subject based on the ideXlab platform.
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perception of male caller identity in koalas phascolarctos cinereus acoustic analysis and playback experiments
PLOS ONE, 2011Co-Authors: Benjamin D Charlton, Allan J Mckinnon, Jacqui Brumm, Karen Nilsson, W A Ellis, Tecumseh W FitchAbstract:The ability to signal individual identity using vocal signals and distinguish between conspecifics based on vocal cues is important in several mammal species. Furthermore, it can be important for receivers to differentiate between callers in reproductive contexts. In this study, we used acoustic analyses to determine whether male koala Bellows are individually distinctive and to investigate the relative importance of different acoustic features for coding individuality. We then used a habituation-discrimination paradigm to investigate whether koalas discriminate between the Bellow vocalisations of different male callers. Our results show that male koala Bellows are highly individualized, and indicate that cues related to vocal tract filtering contribute the most to vocal identity. In addition, we found that male and female koalas habituated to the Bellows of a specific male showed a significant dishabituation when they were presented with Bellows from a novel male. The significant reduction in behavioural response to a final rehabituation playback shows this was not a chance rebound in response levels. Our findings indicate that male koala Bellows are highly individually distinctive and that the identity of male callers is functionally relevant to male and female koalas during the breeding season. We go on to discuss the biological relevance of signalling identity in this species' sexual communication and the potential practical implications of our findings for acoustic monitoring of male population levels.
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koala Bellows and their association with the spatial dynamics of free ranging koalas
Behavioral Ecology, 2011Co-Authors: Paul Roe, W A Ellis, Sean Fitzgibbon, Fred B Bercovitch, Jason Wimmer, Alistair Melzer, Robbie S WilsonAbstract:Acoustic communication mediates sociality in a variety of animals. One of the more ubiquitous vocal signals to have evolved is the sexual advertisement call of males. Koala (Phascolarctos cinereus) males emit a sonorous Bellow call during the breeding season, but no detailed studies of the calling context appear to have been published. We used a novel remote sound detection network to monitor koala Bellowing while simultaneously collecting koala behavioral data using collar-mounted GPS units. Our approach enabled us to examine fine scale temporal variation in vocalization and spatial movements of free-ranging koalas without direct behavioral observations. Bellow occurrence was susceptible to weather conditions, with fewer calls occurring when wind speed and temperatures were high. The number of Bellow vocalizations recorded during an annual period mirrored breeding activity, with nearly all male Bellows recorded during peak mating season. The distance traveled by koalas and the occurrence of koala Bellows both peaked around midnight, but only female travel distance during the breeding season was temporally correlated with Bellow occurrence. We conclude that environmental factors might trigger male Bellowing to launch the breeding season and that these male vocal signals function more to attract females than to repel males. Female mate selection is probably an important component of male reproductive success in koalas, which is partly mediated by male Bellow characteristics.
Bradley Law - One of the best experts on this subject based on the ideXlab platform.
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passive acoustics and sound recognition provide new insights on status and resilience of an iconic endangered marsupial koala phascolarctos cinereus to timber harvesting
PLOS ONE, 2018Co-Authors: Bradley Law, Traecey Brassil, Leroy Gonsalves, Paul Roe, Anthony Truskinger, Anna McconvilleAbstract:Retention forestry aims to mitigate impacts of native forestry on biodiversity, but data are limited on its effectiveness for threatened species. We used acoustics to investigate the resilience of a folivorous marsupial, the koala Phascolarctos cinereus, to timber harvesting where a key mitigation practice is landscape exclusion of harvesting. We deployed acoustic recorders at 171 sites to record male Bellows (~14,640 hours) for use in occupancy modelling and for comparisons of Bellow rate (Bellows night-1). Surveys targeted modelled medium-high quality habitat, with sites stratified by time since logging and logging intensity, including old growth as a reference. After scanning recordings with software to identify koala Bellows, we found a high probability of detection (~0.45 per night), but this varied with minimum temperature and recorder type. Naive occupancy was ~ 64% across a broad range of forests, which was at least five times more than expected based on previous surveys using alternative methods. After accounting for imperfect detection, probability of occupancy was influenced by elevation (-ve), cover of important browse trees (+ve), landscape NDVI (+ve) and extent of recent wildfire (-ve, but minor effect). Elevation was the most influential variable, though the relationship was non-linear and low occupancy was most common at tableland elevations (> 1000 m). Neither occupancy nor Bellow rate were influenced by timber harvesting intensity, time since harvesting or local landscape extent of harvesting or old growth. Extrapolation of occupancy across modelled habitat indicates that the hinterland forests of north-east NSW support a widespread, though likely low density koala population that is considerably larger than previously estimated. Retention forestry has a significant role to play in mitigating harvesting impacts on biodiversity, including for forest specialists, but localised studies are needed to optimise prescriptions for koalas.
James W Rajotte - One of the best experts on this subject based on the ideXlab platform.
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morphometric and metabolic indicators of metal stress in wild yellow perch perca flavescens from sudbury ontario a review
Journal of Environmental Monitoring, 2003Co-Authors: Patrice Couture, James W RajotteAbstract:Eighteen lakes studied near Sudbury and across Northeastern Ontario (Canada) over a five-year period provided a wide contamination gradient of cadmium (Cd), copper (Cu) and other metals such as nickel (Ni) and zinc (Zn). All were inhabited by yellow perch (Perca flavescens), which was sometimes the only species present. Liver Cd and Cu concentrations were monitored in these lakes, in some cases for several consecutive years and for multiple seasons. This data suggests that yellow perch from clean to mildly-contaminated environments loosely control their hepatic Cu concentrations between 7 and 50 µg g dry weight−1, and a threshold of 50 µg g dry weight−1 is suggested as the normal range of homeostatic control. Similar data collected by others support this value. Liver Cd concentrations appeared more variable among lake samples, but consistently remained below 10 µg g dry weight−1 in clean to mildly-contaminated lakes, also supported by data collected elsewhere. Condition factors allowed the discrimination between clean and polluted yellow perch, a conclusion consistent with data for the same species collected in the Rouyn-Noranda area (Quebec, Canada). Values of weight-to-length scaling coefficient lower than 3.0 also discriminated between clean and metal-polluted yellow perch. Finally, three studies indicated that chronic metal exposure can lead to an impairment of aerobic capacities in wild yellow perch, as indicated by lower muscle activity of citrate synthase (CS), aerobic swim performance and respiration rate. We propose that the combination of liver metal concentrations, scaling coefficient, condition factor and an indicator of physiological impairment such as muscle CS activity can provide a suitable range of parameters to adequately assess the effects of metal contamination on the health of yellow perch. Although yellow perch are ubiquitous in North America, this approach can potentially be applied to other small fish species more suitable to other study areas.