Treesearch

Modeling ecosystems is an evolving science that is both practical and theoretical. The integration of modeling, landscape ecology, management, and rapidly changing technology offers an array of possible solutions to modern environmental quandaries. In order to address these concerns, a workshop was developed to discuss the role and management implications of modeling owl populations and their habitats. The purpose of the workshop was to reflect on the previous symposium's biological, environmental, and management research; as well as how modeling has affected our understanding of owl...

Ten years have elapsed since the first International Owl Symposium was held in Winnipeg. The number of topic species was expanded from 22 (1987) to 61 (1997) and the topic was broadened from owls of the northern forest to those of the northern hemisphere. The number of studies reported expanded from 38 studies (mean = 5.76 years for study period duration) to 101 studies (mean = 4.89 years per study). Fifteen species were reported on in 1987 and 17 species in 1997. The Northern Saw-whet Owl (Aegolius acadius) was the most reported species in 1997 and the Boreal or Tengmalm's Owl (Aegolius...

Monitoring of Burrowing Owl (Speotyto cunicularia) populations in Manitoba from 1987-1996 revealed a continuous population decline from 34 known nesting pairs to only one. Management activities are discussed including public awareness programs, reintroductions, habitat protection and provision of artificial nest burrows. Nest reuse in consecutive years ranged from 7 percent for 57 failed nests to 23 percent for 122 successful nests. Only 14 percent of unsuccessful territories were reused compared to 51 percent of successful sites. Higher nest reoccupancy rates were noted for artificial...

I compared the breeding-season diets of Northern Saw-whet Owls (Aegolius acadicus) and Western Screech-owls (Otus kennicottii). Prey items were obtained from regurgitated pellets collected from saw-whet owl and screech-owl nests found in nest boxes in the Snake River Birds of Prey National Conservation Area in southwestern Idaho.

In 1986, an "audiolure" was developed and tested at the Little Suamico Ornithological Station near Green Bay, Wisconsin. The audiolure consisted of broadcast amplified "solicitation" calls of Northern Saw-whet Owls (Aegolius acadicus) normally associated with courtship activities. From 1971 through 1985, using passive mist netting at Little Suamico, the mean number of owls captured each autumn was 57. Using an audiolure, from 1987 through 1995, the mean annual catch was 636 owls. During 1989, an audiolure was also tested at Finzel Swamp in western Maryland by comparing captures during...

The public knowledge of owls in Central America and Africa was compared based on 162 interviews in Costa Rica and 147 in Malawi. General knowledge of owls included: species, common names, habitats, food, and calls, and was quite similar in both study areas. In Malawi, more than 90 percent of the respondents connected owls with bad luck, witchcraft, and death. In Costa Rica, only 4 percent associated owls with bad omens and 3 percent listed them as frightening. Strong negative superstitions about owls are contributing to the unnecessary killing of owls in Africa, but they are also killed in...

A disjunct population of the Northern Saw-whet Owl (Aegolius acadicus) breeds in the montane spruce-fir forests of the southern Appalachian Mountains. These forests are listed as the second most endangered ecosystem in the United States, having suffered from logging and massive fir die-off from the exotic balsam woolly adelgid. We used audio playbacks to compare densities of saw-whets prior to fir die-off (1968-1969) with those now (1993-1994); numbers were almost identical, suggesting little if any impact from the adelgid. Extrapolation from our density estimates, however, show fewer than...

The Owl Foundation is a place where one can watch the development of intimate relationships between individuals of most of Canada's owl species. The by-product is that recycled genes go back to wild populations in released progeny (table 1).

In 1982, the Raptor Grid, a nation-wide program for monitoring birds of prey was started by the Finnish Ringing Centre. Voluntary banders were asked to select a 10 x 10 km study plot and find annually all active nests or at least occupied territories of birds of prey from their study plot (annual total averaged 120). Since 1986, additional information was collected with the Raptor Questionnaire. In 1996, more than 30,000 potential nest sites of owls were checked. The maximum annual number of nests were: e.g., Tengmalm's Owl 2,265, Ural Owl 901, Long-eared Owl 578, Tawny Owl 548, and Eagle...

It is my pleasure, as Executive Director of Bird Studies Canada (BSC), to take part in the opening ceremonies of the Second International Symposium: Biology and Conservation of Owls of the Northern Hemisphere. It is entirely appropriate that this symposium should take place in one of the colder cities in the Northern Hemisphere, in mid-winter, and it is fitting that temperatures have warmed substantially over the last few days to welcome international visitors. Even the owls are ready to cooperate, and Saturday?s field trip promises great camaraderie and great views of Northern Hawk Owls,...