Dynamic soaring harvests energy from a spatiotemporal wind gradient, allowing albatrosses to glide over vast distances. However, its use is challenging to demonstrate empirically and has yet to be confirmed in other seabirds. Here, we investigate how flap-gliding Manx shearwaters optimize their flight for dynamic soaring. We do so by deriving a new metric, the horizontal wind effectiveness, that quantifies how effectively flight harvests energy from a shear layer. We evaluate this metric empirically for fine-scale trajectories reconstructed from bird-borne video data using a simplified flight dynamics model. We find that the birds’ undulations are phased with their horizontal turning to optimize energy harvesting. We also assess the opportunity for energy harvesting in long-range, GPS-logged foraging trajectories and find that Manx shearwaters optimize their flight to increase the opportunity for dynamic soaring during favorable wind conditions. Our results show how small-scale dynamic soaring affects large-scale Manx shearwater distribution at sea.
We describe and illustrate a new species of pselaphine beetles, Paramaurops zagoricussp. n., from the Zagori region of Epirus, Greece. A list summarising the distribution of Amauropini known from Greece is also provided.
14 June 2023 in Journal of The Royal Society Interface
The aerial interception behaviour of falcons is well modelled by a guidance law called proportional navigation, which commands steering at a rate proportional to the angular rate of the line-of-sight from predator to prey. Because the line-of-sight rate is defined in an inertial frame of reference, proportional navigation must be implemented using visual-inertial sensor fusion. By contrast, the aerial pursuit behaviour of hawks chasing terrestrial targets is better modelled by a mixed guidance law combining information on the line-of-sight rate with information on the deviation angle between the attacker’s velocity and the line-of-sight. Here we ask whether this behaviour may be controlled using visual information alone. We use high-speed motion capture to record n = 228 flights from N = 4 Harris’ hawks Parabuteo unicinctus , and show that proportional navigation and mixed guidance both model their trajectories well. The mixed guidance law also models the data closely when visual-inertial information on the line-of-sight rate is replaced by visual information on the motion of the target relative to its background. Although the visual-inertial form of the mixed guidance law provides the closest fit, all three guidance laws provide an adequate phenomenological model of the behavioural data, whilst making different predictions on the physiological pathways involved.
We confirm the ‘rediscovery’ of Attenborough’s long-beaked echidna (Zaglossus attenboroughi), one of only five modern egg-laying mammals and, until now, one of the planet’s most enigmatic ‘lost species’. Unrecorded for 62 years, we present the first scientific evidence of its survival to the present day. We highlight the importance of combining local Indigenous knowledge with camera-trapping to making the rediscovery, and we also discuss follow-up conservation actions to safeguard this Critically Endangered species.
New Guinea, the world’s largest tropical island, supports the planet’s richest insular avifauna. Large areas of New Guinea remain poorly surveyed, however, in part due to the island’s challenging terrain. In hard-to-access areas, like many mountainous parts of New Guinea, automated surveying tools, like camera traps, may be especially helpful to address the survey deficit. Here we present the results of a camera-trap survey of the avifauna of the Cyclops Mountains, a range in New Guinea’s western, Indonesian provinces (Indonesian Papua). To our knowledge, our results represent only the second published camera-trap survey of birds from Indonesian Papua. We deployed 73 camera traps along an elevation gradient (143–1963 m) of the Cyclops Mountains for 11,869 camera-trap nights, recording 22 bird species from 1696 independent detections. Our species list is, to our knowledge, the first to include observations from the upper northern slopes of the Cyclops Mountains. It documents the first record of Masked Bowerbird (Sericulus aureus) in the range and provides photographic rediscoveries of two ‘lost’ species: Mayr’s Honeyeater (Ptiloprora mayri) and Mayr’s Forest Rail (Rallicula mayri). We also report substantial elevation range extensions for several species, including numerous records of Northern Cassowary (Casuarius unappendiculatus) over 1000 m above its historically known elevation ceiling. These findings provide new insights into species distributions and ecological flexibility in New Guinea’s montane systems, highlighting the potential for previously undocumented biodiversity in under-surveyed regions. Although camera traps detected fewer species than traditional ornithological methods, they were effective in documenting several elusive, ground-dwelling bird species, highlighting their value as a complementary tool for ornithological research in challenging terrain like New Guinea. Finally, we use our data to publish an updated bird species checklist for the Cyclops Mountains.
Carayonia papuana sp. nov. (Hemiptera: Heteroptera: Reduviidae: Emesinae: Visayanocorini is described from New Guinea, representing the first record of the genus and the tribe from New Guinea.