Modelling the effects of chorus species composition and caller density on acoustic masking interference in multispecies choruses of crickets and katydids

Natural multispecies acoustic choruses such as the dusk chorus of a tropical rain forest consist of simultaneously signalling individuals of different species whose calls travel through a common shared medium before reaching their `intended' receivers. This causes masking interference between signals and impedes signal detection, recognition and localization. The levels of acoustic overlap depend on a number of factors, including call structure, intensity, habitat-dependent signal attenuation and receiver tuning. In addition, acoustic overlaps should also depend on caller density and the species composition of choruses, including relative and absolute abundance of the different calling species. In this study, we used simulations to examine the effects of chorus species relative abundance and caller density on the levels of effective heterospecific acoustic overlap in multispecies choruses composed of the calls of five species of crickets and katydids that share the understorey of a rain forest in southern India. We found that on average species-even choruses resulted in higher levels of effective heterospecific acoustic overlap than choruses with strong dominance structures. This effect was found consistently across dominance levels ranging from 0.4 to 0.8 for larger choruses of forty individuals. For smaller choruses of twenty individuals, the effect was seen consistently for dominance levels of 0.6 and 0.8 but not 0.4. Effective acoustic overlap (EAO) increased with caller density but the manner and extent of increase depended both on the species' call structure and the acoustic context provided by the composition scenario. The Phaloria sp. experienced very low levels of EAO and was highly buffered to changes in acoustic context whereas other species experienced high FAO across contexts or were poorly buffered. These differences were not simply predictable from call structures. These simulation-based findings may have important implications for acoustic biodiversity monitoring and for the study of acoustic masking interference in natural environments. (C) 2013 Elsevier B.V. All rights reserved.

Why do Chinese alligators (Alligator sinensis) form bellowing choruses: A playback approach

Crocodilians are quite vocal relative to other reptile groups, and the alligators are among the most vocal of the crocodilians. The Chinese alligator, Alligator sinensis, is usually solitary but engages in bellowing choruses in certain waters during the mating season. This paper reports the organization of Chinese alligator's bellowing choruses based upon field observations and playback experiments. Alligators of both genders engaged in the choruses, remaining immobile throughout and inclining toward bellowing synchronously (i.e., starting and finishing at about the same time). The choruses lasted about 10 min with abrupt onset and offset. Moreover, playback experiments revealed that both male and female alligators responded equally to bellowing stimuli from the same and opposite sexes and that none of the tested alligators approached the loudspeaker in spite of playback of male or female stimuli. These suggest that Chinese alligators. may not bellow to compete for or attract mates during the choruses. Instead, when their ecological behaviors, namely, dispersed inhabitation, multi-copulation, restricted mating season, etc., are considered, we hypothesize that they may synchronize bellows to enhance group detectability for assembling individuals into certain waters for subsequent copulations. (C) 2009 Acoustical Society of America. [DOI: 10.1121/1.3203667]

The songs, duetts, choruses, & c. in Fair Rosamond : a grand opera, in four acts ; performed, for the first time, at the Theatre Royal, Drury Lane, February 28th, 1837

the overture, and the whole of the music, by John Barnett

Masonick melodies : being a choice selection of the most approved masonick songs, duets, glees, catches, cannons, hymns, odes, dirges, and choruses, appropriate to all Masonick occasions: the whole set to musick ... /

Shoemaker

The Tyrolien lyre: a glee book, consisting of easy pieces arranged mostly for soprano, alto, tenor, and base [sic] voices, with and without piano-forte accompaniments; comprising a complete collection of solos, duetts, trios, quartetts, quintetts, choruses, &c. for the use of societies, schools, clubs, choirs, and the social circle,

Mode of access: Internet.

Taylor's Choral anthems : no. 1 : a new collection of choruses, anthems, quartetts, trios, duets and solos : original and selected, for singing societies, choirs and social musical circles /

Bound in blue, paper covered boards with cloth spine. Advertisements for "Choruses, anthems, quartetts, trios, duets and solos to appear in the following numbers of Taylor's choral anthems" p. p [4] of cover.

Songs of Uppingham School; a collection of part-songs and choruses ...

Mode of access: Internet.

The American minstrel; a choice collection of the most popular songs, glees, duets, choruses, &c., many of which are original.

Mode of access: Internet.

Songs, duets, choruses, etc. in the opera buffa entitled Betly. Performed for the first time in English at the Theatre Royal, English opera, on Tuesday, Mar. 9, 1841.

Original text by the composer after Scribe's Le chalet.

The chorus and choir : a superior collection of standard choruses, part-songs and anthems suitable for colleges, normals, choirs, choral societies, musical conventions, singing schools, etc., etc. /

Includes index.

The messenger of song. Contains a graded course for singing classes and day schools; also solos, duetts, quartetts, glees and choruses for musical conventions, musical institutes, etc., etc.

Mode of access: Internet.

The liber musicus : or, New York anthem book, and choirs' miscellany, comprising anthems, choruses, quartetts, trios, duets, songs, etc. /

Mode of access: Internet.

The David Bispham treasury of song : selected choruses for mixed voices for home, school and community singing and for choral societies /

Mode of access: Internet.

The Editor's introduction ; Reader's guide ; Index to the first lines of poems, songs & choruses, hymns & psalms ; General index ; Chronological index.

Series title on spine: Harvard classics : the five foot shelf of books.