Search results for "Tetrao"
showing 10 items of 135 documents
Behavioural evidence for ultraviolet vision in a tetraonid species - foraging experiment with black grouse Tetrao tetrix
2002
In addition to wavelengths visible to humans (400-700 nm), many birds are able to detect near ultraviolet light (320-400 nm). Most studies of ultraviolet (UV) vision in birds have concentrated on the importance of UV vision in intraspecific signalling, especially in passerine birds. However, birds may also use UV vision for other purposes, e.g. foraging. We performed a laboratory experiment to test whether a tetraonid species, black grouse Tetrao tetrix, could detect the difference between UV-reflecting and non-UV-reflecting food items (two colour morphs of bilberry Vaccinium myrtillus). Black grouse preferred UV-reflecting berries when UV light was used for illumination, but showed no pref…
Neuroglobins from the Zebrafish Danio rerio and the Pufferfish Tetraodon nigroviridis
2001
Neuroglobin is a recently discovered respiratory, porphyrin-containing protein that is expressed in the brain of mouse and man. Here we show that neuroglobin is also present in the teleost fish. Complete cDNA sequences are reported from the pufferfish Tetraodon nigroviridis and the zebrafish Danio rerio. In addition, the neuroglobin gene of T. nigroviridis was sequenced, demonstrating the conservation of the B12.2, E11.0 and G7.0 introns plus the presence of an additional intron in the 5' noncoding region. The fish neuroglobins each comprise 159 amino acids and are 84.3% identical. Phylogenetic analyses show a basal position of the neuroglobins within the metazoan globin tree. An enhanced a…
CCDC 104283: Experimental Crystal Structure Determination
1997
Related Article: J.Ratilainen, K.Airola, M.Nieger, M.Bohme, J.Huuskonen, K.Rissanen|1997|Chem.-Eur.J.|3|749|doi:10.1002/chem.19970030515
Black Grouse leks on ice: Female mate sampling by incitation of male competition?
1995
Male-male competition is assumed to limit female choice of mates, but it may also help females to choose the most vigorous males. We studied the mate sampling behaviour of female black grouse (Tetrao tetrix) at spatially unstable leks on ice-covered lakes. In the absence of territories and site-dependence in outcomes of fights, the male dominance hierarchy is very evident on ice. When being courted by dominant males, females frequently tried to approach other males. This was frequently prevented because (1) the courting male and the approached male were involved in physical fight, or (2) the dominant male followed the female and the approached male escaped and avoided contact with him. Thes…
Individual and Environmental Determinants of Daily Black Grouse Nest Survival Rates at Variable Predator Densities
2010
Nest predation in ground nesting black grouse (Tetrao tetrix) inhabiting managed boreal forests is arguably the single most important cause of nesting failure. Little is known, however, about indirect effects of other factors, such as maternal or environmental properties, and to what extent maternal and habitat qualities interact with varying levels of predator densities. Using an information-theoretical approach, we studied maternal and environmental determinants of daily nest survival rates under variable predator densities of 210 individual black grouse hens in central Finland. Environmental determinants were far more important than maternal ones, and the effects were more apparent at hi…
Paternity, copulation disturbance and female choice in lekking black grouse
1996
Female copulation behaviour in the black grouse, Tetrao tetrix, was studied by detailed observations of individually marked birds together with DNA fingerprinting analyses for paternity assessment. For each breeding occasion females typically mated only once with one male, and did not mate outside the lek arena. They re-mated with the same or another male usually only if the initial copulation was disturbed and was probably unsuccessful in sperm transfer. The willingness of females to copulate only once with one male suggests that multiple mating with several males incurs a cost that more than outweighs any possible fertility or sperm competition benefits. Attempts by neighbouring males to …
Testosterone and male mating success on the black grouse leks
1996
On black grouse (Tetrao tetrix) leks females prefer dominant, viable males that have managed to acquire relatively central territories. The immunocompetence hypothesis predicts that, because high levels of testosterone are costly to the immune system, male sexual traits that are controlled by testosterone are likely to serve as reliable indicators of male health. Indeed, testosterone concentrations of black grouse males were highly variable, and strongly correlated with male mating success. This is related to the fact that males with high testosterone levels had most central territories. However, the association of testostestorone level with male mating success was not solely related to cen…
Unusual genomic structure: melanocortin receptors in Fugu.
2005
The melanocortin (MC) receptors are found in five subtypes in mammals and chicken, while recent studies have shown that the Fugu (Takifugu rubripes) genome has only four MC receptors and the zebrafish genome has six subtypes. The MC3 receptor seems to be missing from the two closely related pufferfishes, Fugu and Tetraodon (Tetraodon nigroviridis). The MC2 and MC5 receptors in the pufferfish have introns. Moreover, these two receptors are found in a tandem that is remarkably conserved in several vertebrate species. Here, we speculate about the genomic origin of the MC receptors.
Short- and long-term population dynamical consequences of asymmetric climate change in black grouse
2006
Temporal asymmetry in patterns of regional climate change may jeopardize the match between the proximate and ultimate cues of the timing of breeding. The consequences on short- and long-term population dynamics and trends as well as the underlying mechanisms are, however, often unknown. Using long-term data from Finland, we demonstrate that black grouse ( Tetrao tetrix ) have responded to spring warming by advancing both egg-laying and hatching. However, early summer (the time of hatching) has not advanced, and chicks have to face colder post-hatching conditions. Demonstrating that these conditions are critical to post-hatching survival, we show that chicks are increasingly suffering highe…
Short communication: Landscape and season effects on the diet of the Goshawk
2009
There are two general effects of habitat loss and frag-mentation of mature boreal forests (Schmiegelow &Monkkonen 2002). First, fragmentation by farmlandcreates stable structures such as permanent edge zoneswith enrichment of species diversity and density(Andren 1992, Berg & Part 1994). Secondly, modernforestry with clear-cuts creates sharp, unstable bound-aries between forest and open areas, usually with lesspronounced edge effects (Helle 1983, Schmiegelow &Monkkonen 2002). Considering the vast array of stud-ies on the effects of habitat loss and fragmentation onbird populations, relatively little attention has beenpaid to the role of predators, other than nest preda-tors, across different…