Tag: all of Lagopus

Territorial behaviour and population dynamics in red grouse Lagopus lagopus scoticus. II. Population models

Willow Ptarmigan (Lagopus lagopus) Science Article 1 abstract 1) Recent experiments on cyclic red grouse populations discovered that aggressiveness, induced by testosterone implants, depressed population density for more than a year after the implants were exhausted. 2) This confirms the observation, also made in previous studies of this territorial species, that aggressiveness can determine population […]

Willow ptarmigan chicks consume moss sporophyte capsules

Willow Ptarmigan (Lagopus lagopus) Science Article 5 abstract Willow Ptarmigan( Lagopus lagopus) chicks consumes sporophyt capsules, a moss, istichiumin clinatuma, at La Perouse Bay, near Churchill, Manitoba, Canada.S ix chicks(6 -16 days old) were examined over 3 yr, and crops of all chicks containemd moss capsules.In two chicks, capsules represented a substantial portion of the […]

Evidence of re-nesting after brood loss in Red Grouse Lagopus lagopus scoticus

Willow Ptarmigan (Lagopus lagopus) Science Article 9 abstract The Red Grouse Lagopus lagopus scoticus is a single-brooded species that can re-lay if a clutch is lost during the nesting period (Cramp & Simmons 1980). However, there is no reported evidence regarding second clutches being attempted after a brood of young chicks is lost. Indeed, there […]

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 […]

OFFSHORE MARINE OBSERVATION OF WILLOW PTARMIGAN,INCLUDING WATER LANDINGS, KUSKOKWIM BAY, ALASKA

Willow Ptarmigan (Lagopus lagopus) Science Article 10 abstract We report an observation of Willow Ptarmigan (Lagopus lagopus) encountered 8 to 17 kmfrom the nearest shoreline on Kuskokwim Bay, Alaska, on 30 August 2003. The ptarmigan were observed flying,landing on our research vessel, and landing and taking off from the water surface CHRISTIAN E. ZIMMERMAN et […]

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 […]