New and interesting records of birds in Wallacea

During ten years (1981-1990) of birdwatching throughout the islands of Wallacea, I have accumulated a number of records which supplement and compliment information presented in White & Bruce's (1986) annotated checklist of the birds of this region and in subsequent publications. With the impending publication of a handguide to the birds of the region (Bishop & Coates in prep), it was considered important to document these observations prior to their inclusion in such a publication

Little known Tyto owls of Wallacea

During the preparation of The Guide to the Birds of Wallacea, and a review of the conservation and status of Wallacea's endemic birds, it became clear that reviews of little know species or species groups would perhaps aid those species' conservation by drawing attention to them. Secondly such accounts would also provide a useful resource to the growing number of field workers in this, until recently, sadly neglected region. This first account deals with three virtually unknown Tyto Owls endemic to Wallacea

A CCIR aeronautical mobile satellite report

Propagation effects in the aeronautical mobile-satellite service differ from those in the fixed-satellite service and other mobile-satellite services because: small antennas are used on aircraft, and the aircraft body may affect the performance of the antenna; high aircraft speeds cause large Doppler spreads; aircraft terminals must accommodate a large dynamic range in transmission and reception; and due to their high speeds, banking maneuvers, and three-dimensional operation, aircraft routinely require exceptionally high integrity of communications, making even short-term propagation effects very important. Data and models specifically required to characterize the path impairments are discussed, which include: tropospheric effects, including gaseous attenuation, cloud and rain attenuation, fog attenuation, refraction and scintillation; surface reflection (multipath) effects; ionospheric effects such as scintillation; and environmental effects (aircraft motion, sea state, land surface type). Aeronautical mobile-satellite systems may operate on a worldwide basis, including propagation paths at low elevation angles. Several measurements of multipath parameters over land and sea were conducted. In some cases, laboratory simulations are used to compare measured data and verify model parameters. The received signals is considered in terms of its possible components: a direct wave subject to atmospheric effects, and a reflected wave, which generally contains mostly a diffuse component

An annotated checklist of the birds of the Tanimbar Islands

Wallacea, after years of seeming ornithological neglect, has recently come to the fore (see White & Bruce 1986, Coates & Bishop 1997). Since about 1981 there has been an increasing number of bird watchers and expeditions to the region resulting in the rediscovery of a number of 'feared extinct' and little known species. Most of the islands or island groups have by now received at least a cursory visit during the last 17 years. As a result many species previously known only from collections have been rediscovered, and others thought to be threatened have, thankfully, been shown not to be (see Coates & Bishop 1997). One of, the few exceptions to this coverage is the Tanimbar Islands

Rediscovery of Heinrich's Nightjar Eurostopodus diabolicus

Sulawesi, the largest island of Wallacea, Indonesia, supports a rich and distinctive avifauna that includes 10 endemic genera and 41 species (White & Bruce 1986, Coates & Bishop in press). Among the least known of these endemics is Heinrich's Nightjar Eurostopodus diabolicus (Caprimulgidae) (or Diabolical and/or Satanic Nightjar in some recent literature), known previously only from the unique type (Stresemann 1931, 1940). We now report its rediscovery and field observations

The Black-headed Gull Larus ridibundus in Irian Jaya

Gulls (Laridae) are a familiar group of birds at temperate and subtropical latitudes in both northern and southern hemispheres. However, they are rarely encountered in the tropics, particularly those of Asia and the Pacific. It is therefore interesting to note a group of 20 Black-headed Gulls Larus ridibundus apparently over-wintering in Sorong harbour at the extreme western tip of Irian Jaya (New Guinea) in January and February 1986