Black Guillemot (Cepphus grylle) Science Article 5 abstract Colony attendance of Black Guillemots Cepphus grylle was studied at a colony on Skarveo in WestGreenland. Observations were conducted in the post hatching period by scan sampling birds in and near the colonyevery 30 minutes throughout five days. The rhythm of colony attendance varied diurnally, peaking in […]
An experimental assessment of the potential effects of human disturbance on Black Grouse Tetrao tetrix in the North Pennines, England
Black Grouse (Tetrao tetrix) Science Article 5 abstract In the United Kingdom, Black Grouse Tetrao tetrix have declined in range and abundance during the 20th century. In England at present, birds are largely found only on the margins of managed grouse moors in the north, where more than 80% of birds are confined to the […]
Combs and sexual selectionin black grouse (Tetrao tetrix).
Black Grouse (Tetrao tetrix) Science Article 6 abstract We studied supra-orbital combs in lekking black grouse (Tetrao tetrix) in relation to sexual selection at five leks in Finland 1991-1998 and four leks in Sweden 1992-1995. Comb size was estimated in two ways: by observing its natural size in the field at different behaviors (‘observed comb […]
Correlates of male mating success on black grouse (Tetrao tetrix L.)
Black Grouse (Tetrao tetrix) Science Article 2 abstract Sexual selection in black grouse was studied through multivariate analyses of possible correlates of mating success using data from an eight year study of 10 different leks. Body size was weakly correlated with mating status (0 or >= 1 mating) and tail length was significantly correlated with […]
Color Signals in the Black Grouse (Tetrao tetrix): SignalProperties and Their Condition Dependency
Black Grouse (Tetrao tetrix) Science Article 7 abstract Recent progress in techniques of quantifying betweenindividualdifferences of color-based ornaments has revealed undiscoveredpossibilities for research in sexual selection. We present howthe color spectra data can be comprehensively used for studying theimportance of sexual ornaments in the black grouse and how theseornaments are related to a male condition. […]
Inbreeding depression and male . tness in black grouse
Black Grouse (Tetrao tetrix) Science Article 1 abstract The male lifetime lekking performance was studied, and related to inbreeding
Increasing group size dilutes black fly attack rate in Black Grouse
Black Grouse (Tetrao tetrix) Science Article 3 abstract Black flies (Simuliid ) have been observed to harass Black Grouse (Tetrao tetrix) innorthern Finland during summer. We studied experimentally whether group size affectsthe attack rate of black flies on Black Grouse. The increase in flock size diluted the rate ofthe black fly attacks in the Black […]
Dispersal and migration of female Black Grouse Tetrao tetrix in boreal forests
Black Grouse (Tetrao tetrix) Science Article 4 abstract We studied the movement patterns of 209 female Black Grouse radio-marked during 1990-1993 in eastern central Finland. Females were captured for marking in late winter, and the transmitters had a life expectancy of 6-10months.Adults tended to initiate spring movement to breeding range earlier than yearlings. The median […]
RELATIVE USE OF SECONDARY FORESTS BY CRACIDS INCENTRAL AMAZONIA
Black Curassow (Crax alector) Science Article 1 abstract Curassows, guans, and chachalacas (familyCracidae) are large-bodied (400 g to 3500 g)galliform birds found exclusively in the Americas,with most species restricted to SouthAmerica (Delacour & Amadon 1973, delHoyo 1994). Despite their important role inforest dynamics as dispersers of seed plants,most cracid species remain poorly known(Strahl & Grajal […]
Conirostrum bicolor Parasitized by Molothrus bonariensis in Surinam
Bicolored Conebill (Conirostrum bicolor) Science Article 1 abstract Hellmayr (Field Mus. Nat. Hist. Publ. 347, Zoo1. Set. vol 13, 1935, p. 319) includes Surinam in the range of Conirostrum bicolor on evidence of the Penard brothers (Vogels van Guyana, 2, 1910, p. 475), though he mentions no specimens nor localities. In Surinam, as elsewhere in […]