Search results for "Parus"

The design of artificial nestboxes for the study of secondary hole-nesting birds: A review of methodological inconsistencies and potential biases

2010

The widespread use of artificial nestboxes has led to significant advances in our knowledge of the ecology, behaviour and physiology of cavity nesting birds, especially small passerines. Nestboxes have made it easier to perform routine monitoring and experimental manipulation of eggs or nestlings, and also repeatedly to capture, identify and manipulate the parents. However, when comparing results across study sites the use of nestboxes may also introduce a potentially significant confounding variable in the form of differences in nestbox design amongst studies, such as their physical dimensions, placement height, and the way in which they are constructed and maintained. However, the use of …

Paraphyly of the Blue Tit (Parus caeruleus) suggested from cytochrome b sequences

2002

The phylogenetic relationships of the Blue Tit-Azure Tit assemblage (genus Parus; Aves: Passeriformes) were studied using mitochondrial DNA sequences of 24 specimens representing seven subspecies from Eurasia and North Africa. Previous work based on comparative morphological and acoustic data suggested a division of the Blue Tit (Parus caeruleus) into two species. Our analyses clearly indicate that the Blue Tit represents a paraphyletic assemblage, including a European/Middle Asian clade that is the sister group to the Azure Tit (Parus cyanus) and a North African clade. The North African clade (teneriffae subspecies group) is a sister group to the European Blue Tit/Azure Tit clade. We sugge…

Mallerenga blava = Herrerillo común

Altres noms vulgars: Blue Tit (Anglès), Mésange bleue (Francès), Blaumeise (Alemany) Gabinet de Vertebrats (Departament de Zoologia), Facultat de Ciències Biològiques (Campus de Burjassot), C/ Doctor Moliner, s/n, Bloque B. 5é plant, Burjassot (Valencia). Armari: 31-4 Macho

Age-dependent responses to alarm calls depend on foraging activity in Willow TitsPoecile montanus

2011

Survivorship in animals depends on both foraging activities and avoidance of predation, and thus behavioural decisions often reflect a trade-off between predation risk and foraging efficiency. In this experimental study, we compared behavioural responses of free-living adult and juvenile Willow Tits Poecile montanus to a conspecific alarm call in two treatments. The alarm call was played back when a focal bird was either not feeding, or feeding on a sunflower seed on the middle part of a spruce branch. When feeding at the time of the alarm call, juveniles more often stayed motionless or moved shorter distances than adults. Our results suggest that in hierarchical groups, juveniles are force…

Geographical variation in egg size of the Great Tit Parus major: a new perspective

2002

A recent study on geographical variation in egg size of Great Tits Parus major concluded that: (1) mean egg size tended to increase with increasing latitude; and (2) mean egg size was positively correlated with mean clutch size. Including new data on both egg and clutch size, we reanalysed the relationships between egg size, clutch size and latitude, and investigated the possible effects of habitat type, female body size and egg shape on these relationships. We found that (1) egg volume showed minimum values around 51 ° N, increasing both north and southwards; (2) female body size increased linearly with increasing latitude; (3) female body size was positively correlated with egg breadth, b…

Clutch size and egg volume in great tits (Parus major) increase under low intensity electromagnetic fields: a long-term field study.

2012

Exposure to electromagnetic fields (EMFs) can affect a wide range of biological processes, including reproduction, growth and development. Experiments aimed at investigating the biological effects of EMFs, focused on potential harmful effects on humans, have been mostly carried out in vitro or with animal models in laboratory conditions. By contrast, studies performed on wild animals are scarce. The effects of EMFs created by an electric power line on reproductive traits of a wild great tit (Parus major) population were explored by analysing data gathered during nine breeding seasons. EMF exposure significantly increased clutch size (7%) and egg volume (3%), implying a 10% increase in clutc…

Effects of novelty and gregariousness in survival of aposematic prey

1997

We examined the reactions of captive wild great tits to novel unpalatable prey with (1) a traditional aposematic signal (black and yellow) (2) a novel signal (light pink), and (3) a control signal (brown). Prey were offered either singly or in groups to see whether novel signals with fewer possibilities for synergistic benefits are more dependent on grouping than are the traditional signals. Indeed, responses of birds toward unpalatable prey depended significantly on spatial distribution of prey (grouping versus solitary) and die type of die signal. Birds avoided more the traditional black and yellow signals than novel pink signals in both experimental set ups, but both of diese prey items …

Distribution and habitat selection of wintering birds in urban environments

1998

Habitat selection of wintering land-birds was studied in 31 human settlements in Finland. A total of 26 wintering bird species representing 5155 individuals were observed. Between-year variation (CVB%) and short-term fluctuation within one winter (CVW%) in species richness (CVB=10% CVW=15%) were low, as were total numbers of birds (CVB=22% CVW=24%) and populations of the most common bird species (CVB=20–40% CVW=15–47%). The most abundant bird species (e.g., Passer domesticus, Parus major and Pica pica) occurred in most of the study sites. The total densities of omnivorous birds, sedentary birds and bird species that commonly use feeding tables were higher in a heavily urbanized areas than i…

Predator experience on cryptic prey affects the survival of conspicuous aposematic prey.

2001

Initially, aposematism, which is an unprofitable trait, e.g. noxiousness conspicuously advertised to predators, appears to be a paradox since conspicuousness should increase predation by naive predators. However, reluctance of predators for eating novel prey (e.g. neophobia) might balance the initial predation caused by inexperienced predators. We tested the novelty effects on initial predation and avoidance learning in two separate conspicuousness levels of aposematic prey by using a 'novel world' method. Half of the wild great tits (Parus major) were trained to eat cryptic prey prior to the introduction of an aposematic prey, which potentially creates a bias against the aposematic morph. …

Evolution of foraging ecology in Fennoscandian tits ( Parus spp.)

1994

Species belonging to the same genus exploit similar resources in a similar manner. Despite their general similarities in behaviour, they differ in morphology, and these differences are often interpreted as adaptations for use of different resources. Here we report on the relation between morphology, habitat selection and feeding ecology in seven tit species (Parus spp.) in Fennoscandia. A problem previously disregarded in most ecomorphological studies is that members of a guild with closely related species share their common ancestry. This historical legacy causes similarity in ecology and morphology. We have used phylogenetic information with proper comparative methods to reveal the evolut…