Great Grey Owl (Strix nebulosa) Science Article 4 abstract I observed a Great Gray Owl (Scotiaptex nebulosa nebulosa) in the Bridger Mountains,about 20 miles northeast of Bozeman, Montana. The locality was in the upper Canadian Zone, at 7,000 feet elevation. The day was cloudy and dark, with occasional spatters of rain. C. A. TRYON, JR., […]
NESTING CHRONOLOGY OF THE GREAT GRAY OWL AT AN ARTIFICIAL NEST SITE IN THE SIERRA NEVADA
Great Grey Owl (Strix nebulosa) Science Article 5 abstract The California Great Gray Owl (Strix nebulosa) population is centered in the Yosemite region of the Sierra Nevada (Winter 1980). Efforts were initiated in 1980 to enhance breeding habitat at Ackerson Meadow in the Stanislaus National Forest by providing artificial nests at 1400 m elevation, the […]
Sex and Age Composition of Great Gray Owls
Great Grey Owl (Strix nebulosa) Science Article 2 abstract In the winter 1995/1996, a nearly continent-wide movementof Great Gray Owls (Strix nebulosa) occurred. A sample of 126 owlsexamined during this period, mainly from northeast of Winnipeg,included a large number from the 1994 hatch-year. Robert W. Nero and Herbert W.R. Copland, 2nd Owl Symposium Download article […]
Nest Site Habitat and Prey Use of aBreeding Pair of Great Gray Owls in theUpper Peninsula of Michigan
Great Grey Owl (Strix nebulosa) Science Article 3 abstract We describe nest site habitat characteristics at two spatial scales and prey use forthe first confirmed successful nesting pair of Great Gray Owls (Strix nebulosa) inMichigan. Habitats around the nest site were considerably heterogeneous out to 2km, but relatively homogeneous at over 50 m. R. Gregory […]
Plumage and sexual maturation in the Great Frigatebird Fregata minor in the Galapagos Islands
Great Frigatebird (Fregata minor) Science Article 1 abstract The adaptive significance of distinctive immature plumages and protracted sexual and plumage maturation in birds remains controversial. This study aimed to establish the pattern of plumage maturation and the age at first breeding in the Great Frigatebird Fregata minor in the Galapagos Islands. We found that Great […]
Food intake of Great Crested Grebes Podiceps cristatus wintering on cold water as a function of various cost factors
Great Crested Grebe (Podiceps cristatus) Science Article 4 abstract Food intake rate during the nonbreeding season of Great Crested Grebes Podiceps cristatus was estimated by reconstructing the stomach content of drowned birds from recognizable remains of the fish prey. Food intake by individual birds since the ejection of the last pellet (the accumulated prey mass) […]
Phenology habitat choice and reproduction of the Great Crested Grebe Podiceps cristatus on a fish-farm.
Great Crested Grebe (Podiceps cristatus) Science Article 2 abstract On a fish-farm in The Netherlands Great Crested Grebe breeding pairs arrived in two distinct periods. We suggest this pattern reflects differences in migratory behaviour, whereby late birds are migrants. In early arriving grebes clutch size decreased with an increasing pre-laying period, whereas in late grebes […]
Ringing recoveries and the increase in numbers of European Great Crested Grebes Podiceps cristatus.
Great Crested Grebe (Podiceps cristatus) Science Article 3 abstract 221 recovery data of European Great Crested Grebes were analysed. Great Crested Grebes migrate SE to winter mainly in southern parts of the (former) Soviet Union or Turkey (Fennoscandian birds), or in the central European lakes (individuals from northwestern Europe). A second wintering area is found […]
Breeding success of Great Crested Grebe Podiceps cristatus on fishponds
Great Crested Grebe (Podiceps cristatus) Science Article 1 abstract Between 1993 and 2000, breeding success of Great Crested Grebe Podiceps cristatus was monitored at two fishpond localities, Vrbje in central and Race in north-eastern Slovenia. During the study 50 and 23 nests with eggs were found, respectively. On average, 1.3 chicks per territorial pair survived […]
The Great Bustard Otis tarda in Andalusia, southern Spain: status, distribution and trends
Great Bustard (Otis tarda) Science Article 4 abstract Between 2001 and 2004 the first comprehensive census of Great Bustards Otis tarda was carried out in Andalusia, southern Spain. This region holds one of the most endangered populations of the Iberian Peninsula. The aims were to establish the locations of current leks and the numbers of […]