| cutaneous hemangiosarcoma in a pacific parrotlet (forpus coelestis). | a 2-month-old pacific parrotlet (forpus coelestis) was presented for assessment following a traumatic injury to the right wing that resulted in persistent swelling and inflammation. six weeks postinjury the bird underwent surgical resection of a large hemorrhagic cavitated mass that had formed at the site of the original injury and a second, smaller mass on the body in direct contact with the wing mass. histopathology of the wing mass confirmed a diagnosis of hemangiosarcoma. while commonly diag ... | 2016 | 27315383 |
| lift calculations based on accepted wake models for animal flight are inconsistent and sensitive to vortex dynamics. | there are three common methods for calculating the lift generated by a flying animal based on the measured airflow in the wake. however, these methods might not be accurate according to computational and robot-based studies of flapping wings. here we test this hypothesis for the first time for a slowly flying pacific parrotlet in still air using stereo particle image velocimetry recorded at 1000 hz. the bird was trained to fly between two perches through a laser sheet wearing laser safety goggle ... | 2016 | 27921999 |
| a depressed, ataxic, and regurgitating pacific parrotlet. diagnosis: acute lead poisoning. | | 2002 | 12040380 |
| birds repurpose the role of drag and lift to take off and land. | the lift that animal wings generate to fly is typically considered a vertical force that supports weight, while drag is considered a horizontal force that opposes thrust. to determine how birds use lift and drag, here we report aerodynamic forces and kinematics of pacific parrotlets (forpus coelestis) during short, foraging flights. at takeoff they incline their wing stroke plane, which orients lift forward to accelerate and drag upward to support nearly half of their bodyweight. upon landing, l ... | 2019 | 31767856 |
| birds land reliably on complex surfaces by adapting their foot-surface interactions upon contact. | birds land on a wide range of complex surfaces, yet it is unclear how they grasp a perch reliably. here, we show how pacific parrotlets exhibit stereotyped leg and wing dynamics regardless of perch diameter and texture, but foot, toe, and claw kinematics become surface-specific upon touchdown. a new dynamic grasping model, which integrates our detailed measurements, reveals how birds stabilize their grasp. they combine predictable toe pad friction with probabilistic friction from their claws, wh ... | 2019 | 31385573 |
| how birds direct impulse to minimize the energetic cost of foraging flight. | birds frequently hop and fly between tree branches to forage. to determine the mechanical energy trade-offs of their bimodal locomotion, we rewarded four pacific parrotlets with a seed for flying voluntarily between instrumented perches inside a new aerodynamic force platform. by integrating direct measurements of both leg and wing forces with kinematics in a bimodal long jump and flight model, we discovered that parrotlets direct their leg impulse to minimize the mechanical energy needed to for ... | 2017 | 28560342 |