The presence of ultrasonic harmonics in the calls of the rifleman (Acanthisitta chloris)

Ultrasonic vocalisations (frequencies > 20 kHz) have been extensively studied in the context of echolocation by bats and other mammals (Sales & Pye 1974; Wilson & Hare 2004). Ultrasonic calls have also been recorded from birds, including the blue-throated hummingbird ( Lampornis clemenciae ) (Pytte et al. 2004), where it was first thought that individuals made use of high pitch calls to avoid masking by background noise in a visually obscured environment. Similarly, city-dwelling great tits ( Parus major ) use song with a higher minimum frequency (although not ultrasonic) compared to woodland birds to communicate with conspecifics to avoid the predominantly low-frequency background noise in the city (Slabbekorn & Peet 2003). The theory that birds use ultrasound to avoid noise masking was discarded when it was discovered that there was no corresponding auditory brainstem response (i.e. sensory perception) to the ultrasonic calls in the hummingbirds producing those calls.

Random shots from a rifleman.

Mode of access: Internet.

Four new avian mitochondrial genomes help get to basic evolutionary questions in the late cretaceous

Good phylogenetic trees are required to test hypotheses about evolutionary processes. We report four new avian mitochondrial genomes, which together with an improved method of phylogenetic analysis for vertebrate mt genomes give results for three questions in avian evolution. The new mt genomes are: magpie goose (Anseranas semipalmata), an owl (morepork, Ninox novaeseelandiae); a basal passerine (rifleman, or New Zealand wren, Acanthisitta chloris); and a parrot (kakapo or owl-parrot, Strigops habroptilus). The magpie goose provides an important new calibration point for avian evolution because the well-studied Presbyornis fossils are on the lineage to ducks and geese, after the separation of the magpie goose. We find, as with other animal mitochondrial genomes, that RY-coding is helpful in adjusting for biases between pyrimidines and between purines. When RY-coding is used at third positions of the codon, the root occurs between paleognath and neognath birds (as expected from morphological and nuclear data). In addition, passerines form a relatively old group in Neoaves, and many modern avian lineages diverged during the Cretaceous. Although many aspects of the avian tree are stable, additional taxon sampling is required.

Arms and the man.

Official organ of the National Rifle Association of America.

The new British novelist; comprising works by the most popular and fashionable writers of the present day.

The young queen. v. 1-3.--E��carte�� [by John Richardson] v. 4-6.--Sentiment not principle [by Mrs. C. DeHavilland] v. 7.--The sea-king in England [by Edwin Atherstone] v. 8-9.--The exiles of Palestine [by John Carne] v. 10-12.--Walter Colyton [by Horatio Smith] v. 13-15.--The adventures of a king's page [by Charles White] v. 16-18.--Stratton Hill [by John Carne] v. 19-21.--Richmond [by Thomas Gaspey] v. 22-24.--English fashionables abroad [by Mrs. C.D. Burdett] v. 25-27.--Confessions of and old maid [by E. Carrington] v. 28-30.--Florence [by Mrs. Robertson] v. 31-33.--The incognito. v. 34-36.--Exile of Erin [by W.F. Deacon] The magic of love. v. 37.--Truckleborough hall [by W.P. Scargill] v. 40-42.--No enthusiasm. v. 43-44--The man of two lives [by James Boaden] v. 45-46.--The military bijou [by John Shipp] v. 47-48.--The rifleman's comrade. v. 49.--The Boyne water [by John Banim] v. 50.