Collared Flycatcher Research Articles

The effect of body condition on the cost of reproduction in female Collared Flycatchers Ficedula albicollis

Survival of females in relation to their body condition was investigated in the Collared Flycatcher Ficedula albicollis on Gotland, Sweden. The brood size was manipulated by enlarging or reducing the number of nestlings by one or two chicks. We found a positive relationship between experimental treatment and the condition of the female in the year of the experiment. Among females which disappeared (had apparently died) between years, the relationship was negative but not significant. When the effect of brood manipulation on the probability of survival was analysed separately for females in poor and good body condition, a negative relationship between experimental treatment and probability of survival among females in poor condition was found. This result indicates the existence of a cost of reproduction in terms of survival in low quality females. There was no effect of brood manipulation on the survival of females in good body condition. Our analyses suggest that individuals have different costs of reproduction, depending on their conditional state.

Expression of Genetic Variation in Body Size of the Collared Flycatcher Under Different Environmental Conditions

Expression of Genetic Variation in Body Size of the Collared Flycatcher Under Different Environmental Conditions

Problems with Testing Inbreeding Avoidance: The Case of the Collared Flycatcher

Problems with Testing Inbreeding Avoidance: The Case of the Collared Flycatcher

Interspecific Competition for Nest Holes Causes Adult Mortality in the Collared Flycatcher

Interspecific competition for nest sites between tits (Parus spp.) and Collared Flycatchers (Ficedula albicollis) was responsible for the death of 23 flycatchers during one breeding season. Eighteen (78%) of the killed flycatchers were males, and nineteen (83%) of the kills took place in nest boxes occupied by Great Tits (Parus major), and two (9%) in boxes occupied by Blue Tits (P. caeruleus). The number of casualties in different plots increased with increasing proportion of nest boxes occupied by tits (r = 0.76), and decreased with increasing density of nest boxes (r = -0.43). The number of casualties equalled up to 17% of all flycatcher individuals breeding in a given plot, indicating that interspecific competition for nest sites may constitute a significant source of adult mortality in the Collared Flycatcher population studied.

Sexual Dimorphism and Breeding Success in Tree Swallows and Collared Flycatchers

The common pattern of small differences in body size between the sexes of many bird species has been related to a number of ecological factors, including functional differences in niche utilization (Selander 1966, Wallace 1974, Hogstad 1978), sexual differences in nest defense requirements (e.g., Wiklund and Stigh 1983, Safina 1984), and to differential migration strategies (Ketterson and Nolan 1983). While a number of these studies assume that a small degree of sexual dimorphism in body size leads to differential flight performance (see Andersson and Norberg 1981), the possible consequences of such differences have rarely been investigated empirically. Gosler (1987a, 1987b) suggested that sexual differences in the bill length of Great Tits (Parus major) may enhance the ability of pair members to aquire food, through decreased intrapair competition. This same argument has been made for the evolution of reversed sexual size dimorphism in raptors (Newton 1979), typically in reference to differences in wing size/shape and flight performance. This argument rests on the premise that pair members that differ in body size/shape are able to exploit a wider range of prey items. Gosler's (1987a, 1987b) studies of Great Tits provided such evidence and also drew a direct link between the degree of within-pair sexual dimorphism and breeding success. However, more recent work by Matthysen et al. (1991) found no such link among Blue (P. caeruleus) and Great Tits in Belgium. Previous studies have demonstrated significant effects of small differences in wing length and shape on the foraging behavior of several species of birds (e.g., Andersson and Norberg 1981, Lifjeld and Slagsvold 1988). In this paper, we assess the relationship between reproductive success and intra-pair differences in wing length. This study differs from previous efforts by focusing on an aerial insectivore, the Tree Swallow (Tachycineta bicolor), and on a species that feeds by gleaning and flycatching, the Collared Flycatcher (Ficedula albicollis).

BACK FROM AFRICA: WHO'S RUNNING AHEAD? ASPECTS OF DIFFERENTIAL MIGRATION OF SEX AND AGE CLASSES IN PALEARCTIC-AFRICAN SPRING MIGRANTS

Summary Spina F., Massi A., Montemaggiori A. 1994. Back from Africa: who's running ahead? Differential migration of sex and age classes in Palearctic-African spring migrants. Ostrich 65:139-150. The differential migration of sex and age classes in 16 species of Palearctic-African migrants during their northward spring journey through the Central Mediterranean has been investigated from a large data set collected on 4 Italian islands during the “Progetto Piccole Isole”. Species investigated were: Euro Nightjar Caprimulgus europaeus, Barn Swallow Hirundo rustica, Yellow Wagtail Motacill flava. Common Redstart Phoenicurus phoenicurus, Whinchat Saxicola rubetra, Northern Wheatear Oenanthe oenanthe, Black-eared Wheatear O. hispanica, Subalpine Warbler Sylvia cantillans, Whitethroat S. communis, Blackcap S. atricapilla, Collared Flycatcher Ficedula albicollis, Pied Flycatcher F. hypoleuca. Golden Oriole Oriolus oriolus, Red-backed Shrike Lanius collurio, Woodchat Shrike L. senator, Ortolan Bunting Emberiza hort...

Correlates of Clutch Desertion by Female Collared Flycatchers Ficedula albicollis

Correlates of Clutch Desertion by Female Collared Flycatchers Ficedula albicollis

Maternal Inheritance of Condition and Clutch Size in the Collared Flycatcher

Maternal Inheritance of Condition and Clutch Size in the Collared Flycatcher

"Terminal Investment" and a Sexual Conflict in the Collared Flycatcher (Ficedula albicollis)

When the expectation of future reproduction is reduced by senescence, life-history theory predicts that reproductive effort will increase with increasing age. This idea was examined in the collared flycatcher by estimating whether reproductive costs increase with female age, comparing feeding rates and weight losses of old, "senescent" females (i.e., >=5 yr old) and middle-aged females (2-3 yr old) with the same breeding phenology and the same brood size, and testing whether feeding rate was correlated with daily energy expenditure and with weight loss of females during the nestling period. There was a negative relationship between fledgling production and subsequent survival among old females (>=5 yr old), but not among younger age classes, which suggests that reproductive effort increases with age. Also, old females fed their nestlings more often and lost more weight during the nestling period than did middle-aged females Observed feeding rates were positively correlated with daily energy expenditure and weight loss. Since there was no evidence that individuals that survived to old ages were better at all ages, the results strongly suggest that old collared flycatcher females increase their reproductive effort at the cost of a decreased probability of surviving to the next year. However, the payoff of the increased reproductive effort of old females seemed to be small. We suggest that this is a consequence of a conflict between the sexes over the division of work, because old females generally are mated to younger males that probably have better future prospects. Data on male feeding rates in relation to female feeding rates support this idea.

Selection on Fledging Mass in the Collared Flycatcher and the Great Tit

The selection on residual mass (relative to body size) at fledging was investigated in the Collared Flycatcher Ficedula albicollis and the Great Tit Parus major. Directional selection for high fledging mass was evident in 6 of 7 yr in Collared Flycatchers but only in 1 of 5 yr in Great Tits. Three different methods of demonstrating and testing stabiilizing selection are compared. Stabilizing selection on relative mass occurred in both species, but the frequency with which this was established depended on which method was used. None of the methods seemed to be universally reliable, and the problem of defining and testing stabilizing selection is discussed. In Collared Flycatchers mass seemed to be most important for juvenile survival. Also in Great Tits mass was important, but in addition other traits (e.g., hatching date) strongly influenced juvenile survival in this species. This possible difference between the two species is suggested to relate to differences in their territory establishment.

Evidence from hatching success and DNA fingerprinting for the fertility of hybrid Pied × Collared Flycatchers Ficedula hypoleuca × albicollis

The Pied and Collared Flycatchers Ficedula hypoleuca and F. albicollis hybridize on the Baltic islands of Öland and Gotland. Field studies of hatching success in clutches from 36 breeding hybrid males indicate that male hybrids reproduce successfully. In comparison, 25 hybrid females had normal clutch sizes but failed to hatch nestlings, suggesting female hybrid sterility. The paternity of seven hybrid males was investigated by DNA fingerprinting using two hypervariable minisatellite probes. Of these hybrid males, six were assessed as fertile. Three of the hybrid male families (43%) contained nestlings with extra‐pair paternity and the frequency of extra‐pair fertilization among 37 nestlings was 22%. One nestling originated from intraspeciflc female nest parasitism. The sterility pattern in hybrids between these two flycatchers with sterile female and fertile male hybrids is in agreement with Haldane's rule.

Philopatry Pays: A Comparison between Collared Flycatcher Sisters

Philopatry Pays: A Comparison between Collared Flycatcher Sisters

The cost of incubation in relation to clutch‐size in the Collared Flycatcher Ficedula albicollis

This study examines the importance of avian incubation costs as determinants of clutch‐size variation by performing clutch‐size and brood‐size manipulations in the same population of Collared Flycatchers Ficedula albicollis during the same breeding season. In 2 5 cases when three or more clutches of the same size were completed on the same day, we moved two eggs on the day after the last egg had been laid from one randomly selected clutch (C) to another (C) and moved two other eggs from this to a third clutch (C+). In 20 other cases of simultaneously completed clutches of the same size, we moved two randomly selected young from one brood to a second and from that moved two other young to a third (B, B and B+groups). Most females were weighed the day after completion of the clutch and 1–4 days before hatching of the young, and some of them also 10–14 days after hatching of the young. We measured the daily energy expenditure of females incubating manipulated clutches of 4, 6 and 8 eggs by means of the doubly‐labelled water (D218O) technique and also recorded their nest attendance. Hatching success of fertilized eggs was reduced in the enlarged clutches compared with control and reduced clutches. Females expired on average 3142.6 ml CO2 and expended 78.6 kJ per day while incubating, which corresponds to a metabolic intensity of 3.3 times BMR. Daily energy expenditure increased with clutch‐size due to higher costs while incubating, and not because of changed activity patterns. There were no significant differences in length of incubation, female mass or mass changes between phases for the C, C and C+groups. In both the C and B groups, enlarged broods produced significantly more fledged young than control broods, and those significantly more than reduced broods. Fledgling tarsus‐length and mass did not differ significantly between treatments in either the C or B groups. There was no significant difference in breeding success between clutch and brood manipulations. In this season, incubation costs did not entail significant fitness losses, expressed either as fledgling production or female condition. Also, control females could have raised more young to fledging age than they did with no apparent costs.

Hybridization between Pied and Collared Flycatchers—sexual selection and speciation theory

AbstractThe Pied Flycatcher Ficedula hypoleuca and the Collared Flycatcher F. albicollis hybridize frequently on the islands of Gotland and Öland in the Baltic. Hybrids have highly reduced fertility, but introgression is likely to occur. Mating is incompletely species‐assortative and mixed pairs are common. In Central Europe, Pied Flycatcher males are brown in areas of sympatry, and thus have less resemblance to the black Collared Flycatcher males. It has been suggested that females could use male colour to increase the probability of assortative mating, and hence that a speciation process by reinforcement might be taking place. However, we found no indications that the colour of male Pied Flycatchers had an influence on their risk of disassortative mating, and therefore reinforcement probably cannot explain the geographical pattern of colour variation in Pied Flycatcher males. The song and the white collar of Collared Flycatcher males are features more likely to serve in species recognition. The songs of the two species differ greatly, but in areas of sympatry, “mixed” singing by Pied Flycatcher males was common, and this is likely to increase the risk of hybridization. It seems that interactions between the two species are far more complex than predicted by the theory of speciation by reinforcement.

Natal Dispersal in the Collared Flycatcher: Possible Causes and Reproductive Consequences

Possible causes and reproductive consequences of natal dispersal in both sexes of the Collared Flycatcher Ficedula albicollis were investigated using data from a longterm population study on the island of Gotland in the Baltic. Females moved further than males. Of several factors related to natal conditions, only natal brood size was significantly related to dispersal distance, females from small broods moving further than those from large broods. No association between population density and natal dispersal was found. Increased natal dispersal distance was associated with low reproductive success among females and low survival rate among males. For both females and males this association was only significant among birds hatched late in the season. Natal dispersal distance of resident species has been found to show positive, negative, or no correlation with population density and time of birth. I suggest that the use of simple correlations, which fail to detect other relationships than monotonically increasing or decreasing ones, may be one explanation for this inconsistency. It is suggested that prior knowledge of a breeding area may tend to raise the quality of sites chosen and that short-dispersers therefore are more successful than long-dispersers. This may be an important advantage of philopatry.

Breeding Dispersal in the Collared Flycatcher (Ficedula albicollis): Possible Causes and Reproductive Consequences

SUMMARY (1) Correlates of breeding dispersal (between years) in the collared flycatcher were analysed using data from a population on the Swedish island of Gotland in the Baltic. (2) Females on average moved further than males. Only 8% of the males and 2% of the females reoccupied their previous nest box. Individual size or body condition were not related to breeding dispersal. (3) Among females both total failures and reduced number of fledged young were associated with long subsequent movements in yearlings, whereas dispersal of older individuals was not related to previous breeding success. The pattern of breeding dispersal was similar in males but the difference was not significant. (4) Males that remained unpaired throughout the breeding season moved further in the next year than did mated males. There were no differences in breeding dispersal patterns between polygynous and monogamous males, nor between monogamous and secondary females. (5) Occupation of previous nest boxes by breeding tits were significantly correlated with dispersal distances in 2-year-old males, but not in older males. Female breeding dispersal was not related to this factor. (6) Males breeding for the first time in their natal area subsequently moved shorter distances than males breeding in another area. Females showed no significant differences in dispersal with respect to their birth place. (7) Breeding dispersal distance was not correlated with age when breeding success, occupation of previous nest boxes by breeding tits and distance from natal area were controlled for. (8) The reproductive correlates of movements were different for different categories of individuals. There was a negative correlation between distance moved and subsequent fitness (measured as survival and number of recruits produced) among previously successful females, whereas the trend was the opposite among previously unsuccessful females. These relationships were most prominent among young females. There were no significant correlations of dispersal and subsequent reproductive performance in males. (9) The hypothesis is advanced that breeding dispersal distances (to some extent) reflect individual choices among available territories, in that individuals with little and/or bad local experience disperse more because they benefit from exploring more sites before

Inter-Specific Aggression between the Collared Flycatcher and the Pied Flycatcher: The Selective Agent for the Evolution of Light-Coloured Male Pied Flycatcher Populations?

The average plumage colour of the head and back of male Pied Flycatchers varies geographically. Light-coloured males live in sympatry, dark-coloured males in allopatry with the Collared Flycatcher. Because the two species of flycatcher compete for nesting holes, inter-specific aggression may have been a selective agent behind the evolution of light-coloured male Pied Flycatchers. Experiments with stuffed dummies of male Pied Flycatchers showed that male Collared Flycatchers were more aggressive towards a black dummy than towards a light-coloured one. Light-coloured male Pied Flycatchers may avoid attacks by male Collared Flycatchers either because they appear less threatening to the Collared Flycatcher in the competition for nest-holes (i.e. inter-specific status signalling) or because they closely resemble female Collared Flycatchers (i.e. inter-specific female mimicry).

Density Dependence in Reproduction of the Collared Flycatcher (Ficedula albicollis) at High Population Levels

Density Dependence in Reproduction of the Collared Flycatcher (Ficedula albicollis) at High Population Levels

Inter‐ and intraspecific competition for nest holes in a population of the Collared Flycatcher Ficedula albicollis

Field experiments with nest boxes show that nest holes are a limiting factor on the local population size of the Collared Flycatcher Ficedula albicollis. When this limiting resource occurs with different types that are quality related there is intraspecific competition among males for the best nest boxes, with bigger males being the better competitors. Population dynamics of Great Tit Parus major and Blue Tit P. caeruleus when compared with Collared Flycatchers suggests that there is strong interspecific Competition for available nest holes. This is also shown by removal experiments.

Divergent character displacement in the song of two allospecies: the Pied Flycatcher Ficedula hypoleuca, and the Collared Flycatcher Ficedula albicollis

Songs of the three flycatcher forms, Ficedula hypoleuca hypoleuca, Ficedula albicollis albicollis and Ficedula albicollis semitorquata, were distinguishable from one another using a multivariate analysis. F. albicollis semitorquata, which has an intermediate song character, is considered to be a primary allopatric form while the nominate subspecies of albicollis is assumed to be dispersed into sympatry with F. h. hypoleuca. The differences in song between the nominate albicollis and F. hypoleuca are accentuated in their zone of sympatry and are mostly due to divergence in the albicollis song. The song is primarily an epigamic vocalization in the two species and conforms to the pattern characteristic of divergent character displacement associated with reproductive behaviour. Two alarm calls are quite similar in the two species and are the main vocalizations associated with territorial combat. Their interspecific territorial behaviour has apparently not been affected in areas of sympatry.