Willow Warbler (Phylloscopus trochilus) Science Article 4 abstract Spring migration of Willow Warbler Phylloscopus trochilus over the western Mediterranean was studied using observations collected at a ringing station on the mainland of Spain (Aiguamolls de l’Emporda), and at an island station (Cabrera, one of the Balearics). During the years 1993-2001, birds were caught and measured […]
Intraspecific variation in sperm length in two passerine species, the Bluethroat Luscinia svecica and the Willow Warbler Phylloscopus trochilus.
Willow Warbler (Phylloscopus trochilus) Science Article 3 abstract Sperm cells are highly diversified in birds and considerable research effort has focused on variation in sperm morphology between species. However, surprisingly little is known about intraspecific variation in sperm morphology in birds. We analyzed between- and within-male variation in total sperm length in two passerine species, […]
Growth and size of Willow Tit Parus montanus under different environmental conditions
Willow Tit (Parus montanus) Science Article 1 abstract This six years study focuses on the effect of environmental factors on Willow Tit (Parus montanus) nestling growth . For each brood, nestling growth during the growth period (day 1-12) was related to the amount of food and temperature du ring this peri od as well as […]
Factors influencing Willow Tit Poecile montanus site occupancy: a comparison of abandoned and occupied woods
Willow Tit (Parus montanus) Science Article 4 abstract The British Willow Tit Poecile montanus kleinschmidti underwent a decline of 85% between 1970 and 2003. The cause of this decline is unknown. However, several hypotheses have been put forward to account for it: competition from other tit species, predation by Great Spotted Woodpeckers Dendrocopos major and […]
Hunger-dependency of hiding behaviour after a predator attack in dominant and subordinate Willow Tits.
Willow Tit (Parus montanus) Science Article 3 abstract We studied rank-specificity of predation risk taking in captive Willow Tits Parus montanus. Level of risk taking was expressed by duration of hiding after a simulated predator attack. By manipulating available food, we separated the effects of hunger and other rank associated factors on accepted predation risk. […]
The breeding biology of the Willow Tit in Northeastern Siberia
Willow Tit (Parus montanus) Science Article 2 abstract The Magadan region of northeastern Siberia. Clutch size and number of fledglings averaged 7.5 and 6.5, respectively, and both were correlated negatively with the date of the first egg. Nestling growth rate was correlated positively with the date of the first egg, but was not related to […]
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 […]
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 […]
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 […]
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 […]