40 research outputs found
Balance: a neglected factor when attaching external devices to penguins
We observed that external attachments on penguins reduced their balance, which may be of as great concern to the individuals as the effect of increased drag. Little penguin Eudyptula minor swimming activity was observed in captivity at the Penguin Parade (r), Phillip Island, Australia. Initially, time-depth recorders (TDRs) were attached centrally to the lower back of the penguins, the point for attachment widely suggested in the literature. In the water, the penguins showed strong signs of imbalance. They tilted from side to side trying to maintain stability, avoided diving and did not move around the pool. When the TDRs were moved forward, closer to the penguins\u27 centre of gravity, the penguins started diving, swimming and preening as they had before having the TDRs attached. These observations suggest that the lower back area may not be the best attachment position for little penguins and that balance could be an important factor to consider when using back-mounted devices
Finding the balance: the effect of the position of external devices on little penguins
Many studies on the foraging behaviour of penguins rely on data collected with back-mounted data recorders, which can greatly affect the drag of swimming birds. In recent years, the size of devices has been minimised to reduce drag. In addition, devices have been positioned on the lower back of penguins to reduce the effect of the flow separation caused by the device on the penguinユs body. Nevertheless, a device placed on the lower back of penguins is further away from the centre of gravity which may make balancing and swimming difficult. In this study, we used accelerometers to measure and test quantitatively whether the heaving and surging acceleration (as a measure of imbalance) of penguins swimming through a winding channel was different when an external accelerometer was positioned on the lower back compared to the middle of the back (closer to the centre of gravity).Heaving acceleration was different only for two of the seven penguins when a device was placed on the lower back rather than the middle of the back. While the difference was statistically significant, it was too small (less than 1 m/s2) to indicate a difference in the swimming behaviour. Although surging acceleration was consistently different in all seven penguins, we suspect this measurement indicated differences in acceleration between two parts of the body (tail and middle back) rather than an effect in balance. Overall, it seems that the balance of little penguins is not greatly affect by positioning of a device. Nevertheless, further experiments with free-ranging penguins are needed to evaluate fully whether the positioning of a device can affect balance of a penguin swimming on the water surface or its buoyancy when diving in the water
Happy Feet in a Hostile World? The Future of Penguins Depends on Proactive Management of Current and Expected Threats
Penguins face a wide range of threats. Most observed population changes have
been negative and have happened over the last 60 years. Today, populations of 11
penguin species are decreasing. Here we present a review that synthesizes details
of threats faced by the world’s 18 species of penguins. We discuss alterations to
their environment at both breeding sites on land and at sea where they forage. The
major drivers of change appear to be climate, and food web alterations by marine
fisheries. In addition, we also consider other critical and/or emerging threats, namely
human disturbance near nesting sites, pollution due to oil, plastics and chemicals such
as mercury and persistent organic compounds. Finally, we assess the importance of
emerging pathogens and diseases on the health of penguins. We suggest that in the
context of climate change, habitat degradation, introduced exotic species and resource
competition with fisheries, successful conservation outcomes will require new
and unprecedented levels of science and advocacy. Successful conservation stories
of penguin species across their geographical range have occurred where there has
been concerted effort across local, national and international boundaries to implement
effective conservation planning
Translating Marine Animal Tracking Data into Conservation Policy and Management
There have been efforts around the globe to track individuals of many marine species and assess their movements and distribution with the putative goal of supporting their conservation and management. Determining whether, and how, tracking data have been successfully applied to address real-world conservation issues is however difficult. Here, we compile a broad range of case studies from diverse marine taxa to show how tracking data have helped inform conservation policy and management, including reductions in fisheries bycatch and vessel strikes, and the design and administration of marine protected areas and important habitats. Using these examples, we highlight pathways through which the past and future investment in collecting animal tracking data might be better used to achieve tangible conservation benefits
Moving in the anthropocene: global reductions in terrestrial mammalian movements
Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission
Happy feet in a hostile world? The future of penguins depends on proactive management of current and expected threats
Penguins face a wide range of threats. Most observed population changes have been negative and have happened over the last 60 years. Today, populations of 11 of the 18 penguin species are decreasing. Here we present a review that synthesizes details of threats faced by the world’s 18 species of penguins. We discuss alterations to their environment at both breeding sites on land and at sea where they forage. The major drivers of change appear to be climate, and food web alterations by marine fisheries. In addition, we also consider other critical and/or emerging threats, namely human disturbance near nesting sites, pollution due to oil, plastics and chemicals such as mercury and persistent organic compounds. Finally, we assess the importance of emerging pathogens and diseases on the health of penguins. We suggest that in the context of climate change, habitat degradation, introduced exotic species and resource competition with fisheries, successful conservation outcomes will require new and unprecedented levels of science and advocacy. Successful conservation stories of penguin species across their geographical range have occurred where there has been concerted effort across local, national and international boundaries to implement effective conservation planning
Exploring subcolony differences in foraging and reproductive success: the influence of environmental conditions on a central place foraging seabird
While differences in foraging and reproductive success are well studied between seabird colonies, they are less understood at a smaller subcolony scale. Working with little penguins (Eudyptula minor) at Phillip Island, Australia, we used an automated penguin monitoring system and performed regular nest checks at two subcolonies situated 2 km apart during the 2015/2016 breeding seasons. We examined whether foraging and reproductive success differed between subcolonies. We used satellite data to examine how sea surface temperature, as environmental pressure, in the foraging regions from each subcolony influenced their foraging performance. In the pre-laying and incubation breeding stages, the birds from one subcolony had a lower foraging success than birds from the other. However, this pattern was reversed between the subcolonies in the guard and post-guard stages. Breeding success data from the two subcolonies from 2004–2018 showed that reproductive success and mean egg-laying had a negative relationship with sea surface temperature. We highlighted that variation in foraging and reproductive success can arise in subcolonies, likely due to different responses to environmental conditions and prey availability. Differences at the subcolony level can help refine, develop and improve appropriate species management plans for conserving a range of colonial central place seabirds
Does Foraging Performance Change with Age in Female Little Penguins (Eudyptula minor)?
Age-related changes in breeding performance are likely to be mediated through changes in parental foraging performance. We investigated the relationship of foraging performance with age in female little penguins at Phillip Island, Australia, during the guard phase of the 2005 breeding season. Foraging parameters were recorded with accelerometers for birds grouped into three age-classes: (1) young, (2) middle age and (3) old females. We found the diving behaviour of middleaged birds differed from young and old birds. The dive duration of middle age females was shorter than that of young and old birds while their dive effort (measure for dive and post-dive duration relation) was lower than that of young ones, suggesting middle-aged birds were in better physical condition than other ones. There was no difference in prey pursuit frequency or duration between age classes, but in the hunting tactic. Females pursued more prey around and after reaching the maximum depth of dives the more experienced they were (old. middle age. young), an energy saving hunting tactic by probably taking advantage of up-thrust momentum. We suggest middle age penguins forage better than young or ol