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Center for Nonlinear Studies |
The critically endangered Ivory-billed Woodpecker is one of the iconic species of North America. Due to a 'perfect storm' combination of factors related to habitat and behavior, this ultra-elusive bird has repeatedly been feared extinct only to be rediscovered during the past 100 years. The most recent rediscovery, which took place in Arkansas, was announced in an article that was featured on the cover of Science in 2005. It was the first report of the Ivory-billed Woodpecker by ornithologists in several decades. Although another group of ornithologists reported sightings in Florida the following year, the persistence of the species became controversial when neither group managed to obtain a clear photo. This talk will discuss video footage obtained in Louisiana and Florida during encounters with birds that were identified in the field as Ivory-billed Woodpeckers. All three of the videos show field marks, body proportions, flights, and other behaviors consistent with that species but no other species of the region. According to historical accounts, the Ivory-billed Woodpecker has spectacular flights, but no flights appear in the only existing historical film (obtained in 1935). The videos reveal secrets about the flights and other behaviors of this fascinating species that were thought to have been lost forever when it was feared to be extinct. Most woodpeckers signal by drumming, but the Campephilus woodpeckers signal with double knocks. One of the discoveries that came out of this work is that drumming and double knocks may both be modeled in terms of a harmonic oscillator, with periodic forcing in one case and impulsive forcing in the other. In particular, a double knock is driven by a single thrust of the body.
Michael Collins' Bio
Michael Collins was born in Greenville, Pennsylvania, in 1958. After getting an education at MIT (B.S.) and Northwestern (Ph.D.) in mathematics, he began a career in 1985 at the Naval Research Laboratory, where he has divided his time between the offices in Washington (D.C.) and at Stennis Space Center (Mississippi). One of his research interests has been non-separable wave propagation problems in ocean acoustics, seismology, Arctic acoustics, and other areas and the development of techniques based on the parabolic equation method for solving such problems accurately and efficiently. His other interests include source localization, signal processing, inverse problems, and experiments (at sea and in the lab). Outside of his day job, he has has an interest in the Ivory-billed Woodpecker and its conservation. After the rediscovery of this ultra-elusive bird was announced in an article that was featured on the cover of Science in 2005, he decided to launch a search effort in the Pearl River swamp in Louisiana, which borders the Stennis Space Center.