Category: North America

Can parasites synchronise the population fluctuations of sympatrictetraonids? / examining some minimum conditions

Willow Ptarmigan (Lagopus lagopus) Science Article 12 abstract Sympatric populations of tetraonid birds tend to fluctuate in synchrony, at least onlocal scales. If shared parasites among sympatric populations of different tetraonidspecies are to operate as a local, synchronizing factor for population fluctuations atleast two conditions should be met Per R. Holmstad, Peter J. Hudson, Vigdis […]

The shape of red grouse cycles

Willow Ptarmigan (Lagopus lagopus) Science Article 7 abstract We examined 223 time-series of red grouse (Lagopus lagopus scoticus) numbers compiled from shooting bag-records from grouse moors located across England, Scotland and Wales for evidence of non-time-reversibility, asymmetry in cycle shape and non-linearity. We found 44% of time-series to be non-time-reversible. Over 80% of time-series spent […]

Local genetic structure in red grouse (Lagopus lagopus scoticus): evidence from microsatellite DNA markers

Willow Ptarmigan (Lagopus lagopus) Science Article 11 abstract Allelic variation at seven hypervariable tri- and tetranucleotide microsatellite loci was used to determine levels of population differentiation between 14 populations of red grouse (Lagopus lagopus scoticus) in northeast Scotland, UK. Despite the potential for long-distance dispersal in grouse, and a semicontinuous habitat, significant population divergence was […]

Vegetation analysis of the territorial boundary between red grouse (lagopus scoticus) and ptarmigan (Lagopus mutus)

Willow Ptarmigan (Lagopus lagopus) Science Article 2 abstract The location of the boundary between the territories of red grouse (Lagopus lagopus scoticus) and ptarmigan (Lagopus mutus) is related to the vegetation of the hills where both these species occur. If the he vegetation is dominated by tall, vigorous Calluna vulgaris, grouse occur. At greater altitudes […]

Breeding losses of red grouse in Glen Esk (NE Scotland): comparative studies, 30 years on

Willow Ptarmigan (Lagopus lagopus) Science Article 3 abstract Hatching success, brood survival and predation rates of red grouse chicks were examined at four sites in north-east Scotland over two years (1994-1995). Two of these sites have previously been the focus of a large-scale population study on grouse during the late 1950s enabling a comparison to […]

Identifying disease reservoirs in complex systems: mountain hares as reservoirs of ticks and louping-ill virus, pathogens of red grouse

Willow Ptarmigan (Lagopus lagopus) Science Article 8 abstract We examined the role of mountain hares in the louping-ill virus/Ixodes ricinus tick system to determine whether hares were reservoirs of these pathogens for red grouse. A field experiment, which involved reducing mountain hare densities was undertaken and changes in tick abundance, louping-ill virus seroprevalence and red […]

Seasonal infection patterns inWillow Grouse(Lagopus lagopus L.) do not supportthe presence of parasite-induced winter losses

Willow Ptarmigan (Lagopus lagopus) Science Article 4 abstract We examined the hypothesis that endoparasites ofWillow Grouse (Lagopus lagopus L.)affect host winter losses, by examining two samples ofWillow Grouse collected in earlyautumn and late winter. Body condition of juvenile birds improved from September toFebruary, but parasite-induced hostmortalities among hosts in poor conditionwere probablynot the cause. If […]

Breeding Flight Display in the Female White-rumped Sandpiper

White-rumped Sandpiper (Calidris fuscicollis) Science Article 1 abstract Independent female aerial display or female participation in the aerial display of the male is virtually unreported. I present here my observations of an incident of female participation in the aerial flight display of the White-rumped Sandpiper (Calidris fuscicollis) at Barrow, Alaska. Brian J. McCaffery, Auk, volume […]