Pied Flycatcher Ficedula Hypoleuca Research Articles

Wulst Neurons in Nestlings of the Pied Flycatcher Ficedula hypoleuca at the Pre-Visual Stage of Development

Neurons of the Wulst region, an analog of the mammalian visual cortex, were studied in Golgi-impregnated preparations of brain of non-precocial 1-day old nestlings of the pied flycatcher Ficedula hypoleuca. At this age, vision does not function in nestlings, their behavior is provided by an acoustic analyzer. Two populations of nerve cells, large and small juvenile neurons, were differentiated at visual examination. The comparative morphometry has shown these groups to differ significantly from each other by most studied parameters: the area of the profile field of their soma, the total length of dendrites, branching of the cell, the number of the maximal branching foci, the character of distribution of dendrite free endings in three concentric zones of the cell dendritic field. The distribution of dendrites in the dendritic neuron field was similar in the both groups of neurons. An increased density of dendrites was observed from the side of the afferent input. At the same time, study of orientation of the longest dendrite has shown it to be located parallel to the plane of the afferent input practically in all cells of the both groups. It is suggested that such orientation of the longest dendrite broadens the area of cell contacts, which is necessary for search for the maximal number of afferents. The predominant orientation of dendrites in the direction to the afferent input forms foundation for establishing a more extended zone of contacts with growing visual afferents.

Breeding occupancy and success of two hole‐nesting passerines: the impact of fragmentation caused by forestry

We studied the distribution and the reproductive success of the pied flycatcher Ficedula hypoleuca and the redstart Phoenieurus phoenicurus in relation to forest patch size, edge type (clearcut vs natural), distance from the forest edge, and vegetation characteristics in a forest‐dominated landscape. Breeding performances were recorded in up to 72 forest patches during 1992–1994 for birds breeding in nest‐boxes. In the spring, breeding individuals of both species arrived earlier in large forest patches (> 1 ha) than in smaller ones. Pied flycatchers arrived earlier on clearcut edges than natural edges but in the redstart there was no preference for a particular edge type. The territory distance from the forest to open land edge did not affect the arrival dates of either species. In the case of the pied flycatcher, the proportion of unpaired males was highest in patches < 1 ha in size and in the case of the redstart this applied to patches < 5 ha in size. Pairing success was not related to the forest edge type or the nest's distance from the edge. Nest predation was not patch‐size nor edge‐related for either of the species, but in the combined data for both species nest predation was higher at clearcut edges than at natural edges. Clutch size, brood size and the survival of nestlings to the fiedgling stage (fledgling/egg. %) were independent of the patch size, edge type and nest's “distance from the forest edge.

Female Hematozoan Infection Reduces Hatching Success but Not Fledging Success in Pied Flycatchers Ficedula hypoleuca

Female Hematozoan Infection Reduces Hatching Success but Not Fledging Success in Pied Flycatchers Ficedula hypoleuca

Female Hematozoan Infection Reduces Hatching Success but not Fledging Success in Pied Flycatchers Ficedula hypoleuca

Abstract We report association between female blood parasite prevalence (percentage of infected birds) just after egg laying and reproductive success in two successive breeding seasons, in a breeding population of Pied Flycatcher Ficedula hypoleuca in central Spain. Females infected with Trypanosoma spp. had a higher probability of deserting their clutches during the incubation period than noninfected females. Females infected with Haemoproteus balmorali hatched proportionally fewer eggs than noninfected females. Female infected with H. balmorali during the incubation period may have a decreased ability to thermoregulate which may affect their incubation capacity. Fledging success, breeding success, fledgling mass, and tarsus length were not associated with infection of the mother by blood parasites during the incubation period, suggesting that females and their mates may compensate during the nestling period for the negative effect of blood parasites during the incubation period.

Do female pied flycatchers seek extrapair copulations with familiar males? A test of the incomplete knowledge hypothesis

In birds with biparental care, great variation exists in the frequency of extrapair paternity. Several hypotheses have been proposed to account for this variation. We tested the incomplete knowledge hypothesis, which states that females are constrained in their knowledge of male quality and that this influences their willingness to engage in extrapair copulations (EPC). By selective removal and release of female pied flycatchers Ficedula hypoleuca, we created a situation where females finally settled with a social mate close to the site where a former social mate was breeding. According to the incomplete knowledge hypothesis, this would lower the threshold for females to seek extrapair copulations in cases where their former social mate was of higher quality than the one finally chosen. The hypothesis was not supported because manipulation of female settlement did not increase frequency of extrapair paternity, not even in cases where the female nested close to the previous mate and the current mate apparently was of lower quality because he was younger and more dull colored. However, we found that when extrapair paternity did occur, the cuckolder tended to be a familiar male (i.e., the female's initial social mate).

Adjustment to climate change is constrained by arrival date in a long-distance migrant bird.

Spring temperatures in temperate regions have increased over the past 20 years, and many organisms have responded to this increase by advancing the date of their growth and reproduction. Here we show that adaptation to climate change in a long-distance migrant is constrained by the timing of its migratory journey. For long-distance migrants climate change may advance the phenology of their breeding areas, but the timing of some species' spring migration relies on endogenous rhythms that are not affected by climate change. Thus, the spring migration of these species will not advance even though they need to arrive earlier on their breeding grounds to breed at the appropriate time. We show that the migratory pied flycatcher Ficedula hypoleuca has advanced its laying date over the past 20 years. This temporal shift has been insufficient, however, as indicated by increased selection for earlier breeding over the same period. The shift is hampered by its spring arrival date, which has not advanced. Some of the numerous long-distance migrants will suffer from climate change, because either their migration strategy is unaffected by climate change, or the climate in breeding and wintering areas are changing at different speeds, preventing adequate adaptation.

Experimentally reduced male attractiveness increases parental care in the pied flycatcher Ficedula hypoleuca

Experimentally reduced male attractiveness increases parental care in the pied flycatcher Ficedula hypoleuca

Female Hematozoan Infection Reduces Hatching Success but not Fledging Success in Pied Flycatchers Ficedula hypoleuca

Abstract We report association between female blood parasite prevalence (percentage of infected birds) just after egg laying and reproductive success in two successive breeding seasons, in a breeding population of Pied Flycatcher Ficedula hypoleuca in central Spain. Females infected with Trypanosoma spp. had a higher probability of deserting their clutches during the incubation period than noninfected females. Females infected with Haemoproteus balmorali hatched proportionally fewer eggs than noninfected females. Female infected with H. balmorali during the incubation period may have a decreased ability to thermoregulate which may affect their incubation capacity. Fledging success, breeding success, fledgling mass, and tarsus length were not associated with infection of the mother by blood parasites during the incubation period, suggesting that females and their mates may compensate during the nestling period for the negative effect of blood parasites during the incubation period.

Nest-attenders in the Pied Flycatcher (Ficedula hypoleuca) During Nestling Rearing: A Possible Case of Prospective Resource Exploration

Abstract Visits to nest holes by birds other than their owners is a familiar phenomenon for students of breeding biology. In this study, we evaluate that behavior using a transponder reading system. Eighty-five males and females were fitted with transponders at the end of the incubation period or just after hatching. Nest boxes were fitted with transponder readers from just after hatching until all nestlings fledged. That system revealed 123 visits by birds to nest boxes other than their own, a visit being defined as at least one visit to a separate nest box on a separate day. Males were more often detected at other nests than females (53% of males vs. 29% of females visited) and males on average made more visits than females did (4.8 vs. 2.5 visits). However, both males and females devoted time to visiting other nests while still feeding nestlings. That behavior is more common than previously suspected and is consistent with birds prospecting for future nest sites or investigating patch reproductive success.

NO EVIDENCE FOR EFFECTS OF BREEDING DENSITY AND MALE REMOVAL ON EXTRAPAIR PATERNITY IN THE PIED FLYCATCHER

Abstract Molecular methods have brought new insight to the study of mating patterns. Extrapair fertilizations (EPF) have proven to be widespread among bird species irrespective of social relationships. Ecological factors, such as breeding density and synchrony, have been suggested as contributors to variation in EPF rates. Absence of a male during the female fertile period may also increase the probability of EPFs. In this study, we examined experimentally whether breeding density and male absence before egg-laying influence the EPF rate in Pied Flycatchers (Ficedula hypoleuca). DNA fingerprinting revealed that 4.4% (10/225) of nestlings were the result of EPFs and 7.0% (3/43) of broods included at least one offspring sired by a male other than that attending the nest. We did not find any evidence of higher EPF rate with higher breeding density as stated by the density hypothesis. Contrary to expectation, EPFs were more frequent, though not quite statistically significantly, at low breeding density: all t...

Stages of development of retinal photoreceptor cells in postnatal ontogenesis of the pied flycatcherFicedula hypoleuca

Electron microscopic study of the retina of the altricial pied flycatcherFicedula hypoleuca nestlings has permitted identification, in the course of development of photoreceptor cells, of several consecutive stages, each characterized by the appearance in the cell of some new stagespecific structures. At the 1st stage (the presumptive photoreceptor stage), the cell is composed of the nucleus surrounded by a small amount of the cytoplasm and two processes. The 2nd stage is characterized by formation of the inner segment in the apical cell region, while in the distal region, of the cleft (electric) contacts between the photoreceptor axon terminal and the processes of the second neurons. At the 3rd stage, a pile of membrane disks of the outer segment is formed, while in the synaptic region, the first band synapses considered as the chemical ones. At the 4th stage, a lipid droplet appears in a part of the cells, and at the 5th stage, a paraboloid. The photoreceptors of the 6th stage are young cells that continue growing but are already capable for specific functioning. Closely connected with development of the photoreceptor cells is maturation of the Muller’s glia and pigment epithelium, so that every identified stage of the photoreceptor cell development corresponds to a certain structural state of these elements. The possibility of involvement of the forming retinal cells in performance of early behavioral forms is discussed.

Density dependence of avian clutch size in resident and migrant species: is there a constraint on the predictability of competitor density?

The presence of density dependence of clutch size is tested in 57 long‐term population studies of 10 passerine bird species. In about half of the studies of tit species Parus spp. density dependence of clutch size was found, while none was found in studies of two flycatcher species Ficedula spp. One hypothesis explaining this difference is that migrants are less able to predict the final competitor density, because new pairs are still settling when the first females start laying eggs. Such unpredictability is only a problem for early laying females. If this explanation is true, the commonly observed negative correlation between clutch size and laying date should be stronger in high‐density years. I tested this prediction in three populations of Pied Flycatcher Ficedula hypoleuca, and compared the results with three populations of Great Tit Parus major. In none of the six populations was there a significant correlation between the strength of the seasonal decline in clutch size and population density. Thus the lack of density dependence of clutch size in Pied Flycatchers was not consistent with the idea that this is caused by the unpredictability of final density at the time of egg‐laying of the earliest females in the population. Furthermore, density does not have any adverse effect on reproductive output of Pied Flycatchers, and therefore they do not adjust clutch size to density.

Recovery of breeding success in wild birds.

We have found that the breeding success of two insectivorous forest passerines, the great tit Parus major and the pied flycatcher Ficedula hypoleuca, has markedly improved in the vicinity of a copper-smelting plant during the seven years since it reduced its emissions of heavy metals. Our results demonstrate that reduced pollution loads can positively affect breeding performance of wild bird populations over a relatively short period, even in an area that has suffered decades of heavy-metal pollution.

Effect of Calcium Availability and Habitat Quality on Reproduction in Pied Flycatcher Ficedula hypoleuca and Great Tit Parus major

Recent studies have demonstrated that wild birds breeding in acidified areas may have difficulties in obtaining sufficient calcium for their eggshells, and that a shortage of land snails may be the cause. Here we present experimental evidence that calcium deficiency may affect reproductive traits also in birds breeding in non-acidified but naturally base-poor forest habitats. The study was conducted in Estonia in 1995 and 1996. We compared egg characteristics and other life-history traits of the Pied Flycatcher Ficedula hypoleuca and the Great Tit Parus major in two habitats differing in natural availability of calcium (base-poor pine forests and base-rich deciduous forests). In both species, egg volume was smaller in the poor than the rich habitat. Eggshell thickness also tended to be less in the poor habitat in 1996, but the difference was significant only in the Pied Flycatcher. An experimental supplementation of calcium was performed in the habitats to determine to what extent differences between rich and poor habitats might be caused by differences in calcium availability. Egg volume and shell thickness were positively affected by calcium supplementation in the Pied Flycatcher. The same tendency was observed in the Great Tit in 1996, although not significant. However, there was no effect of calcium provisioning on hatching success, nest desertion rate and number or quality of fledglings. Our results show that calcium limitation may occur in wild birds on naturally calcium-poor soils. Birds breeding in such habitats may be vulnerable to possible increases in acid deposition.

High rate of mismatched paternity in three communal bigynous Pied Flycatcher Ficedula hypoleuca broods

High rate of mismatched paternity in three communal bigynous Pied Flycatcher Ficedula hypoleuca broods

Maternal energy expenditure does not change with flight costs or food availability in the pied flycatcher ( Ficedula hypoleuca ): costs and benefits for nestlings

We manipulated parental work load without changing brood size in a population of pied flycatchers Ficedula hypoleuca by removing two primaries (7 and 9) from each wing of females, thus reducing wing area and increasing flight costs. At other nests, we offered supplementary food in the form of live mealworms (10–20 g daily from hatching) to reduce brood demand and thus parental foraging costs. Other nests were left as controls. The daily energy expenditure of females feeding 12-day-old nestlings was measured with doubly labelled water D218O. Females in both treatments expended the same amount of energy, fed at the same rate and had similar body masses to birds in the control group. No effect of treatment on male mass and feeding effort was detected. More nestlings, however, died in nests of handicapped females. Nestlings of handicapped females had significantly lower body mass and haematocrit values than nestlings in food-supplemented nests, with nestlings in control nests occupying an intermediate position. The effects of both treatments on nestling mass, haematocrit values and mortality rates were only noticeable in nests infested with mites. Maternal energy expenditure is apparently constrained and offspring pay the costs imposed by reduced provisioning rate or increased demand caused by ectoparasites, while receiving benefits when food supply improves. The presumption that avian reproductive costs derive from changes in a flexible energy output may not be met in many cases.

Environmental and genetic variation in the haematocrit of fledgling pied flycatchers Ficedula hypoleuca.

We report a field study of the haematocrit of pied flycatcher (Ficedula hypoleuca) nestlings when close to fledging. First a descriptive study was conducted of both fledgling and adult haematocrit over 2 years to analyse correlates of variation in this trait. Then a swapping experiment was performed to see whether variation among fledglings had a measurable genetic component. Average fledgling haematocrits were lower than those of their male and female parents. Intraclass correlations among sibships in fledgling haematocrit were high in both years, indicating that the estimates of resemblance were inflated, probably by common environmental effects. Fledgling haematocrits were unrelated to date and number of young in the nest. Fledglings with a high haematocrit were heavy and had thick breast muscles. There were no significant relationships between the average fledgling haematocrit and those of the adults caring for them. Nest mite ectoparasites negatively affected fledgling haematocrit. The haematocrits of adults did not differ between sexes or years and in both sexes were unrelated to breeding date, body mass, age, clutch size or number of young reared. Females, but not males, caring for fledglings in nests infested by mites had a lower haematocrit than those rearing young in mite-free nests. The cross-fostering experiment indicated that almost all measured variation in haematocrit was explained by the nest where the bird was reared (67.2% of the explained variance), not by their nest of origin (7.8%), meaning that there was a very small, non-significant resemblance in the haematocrit of genetically related sibs when reared in different environments while unrelated nestlings reared in the same nestbox had similar haematocrits. The low proportion of variance explained by the familial component may be due to the high connection of haematocrit to fitness.

First‐egg date fluctuations for the Pied Flycatcher Ficedula hypoleuca in the woodlands of mid‐Wales in the twentieth century

First‐egg date fluctuations for the Pied Flycatcher Ficedula hypoleuca in the woodlands of mid‐Wales in the twentieth century

Reproductive effort and T-lymphocyte cell-mediated immunocompetence in female pied flycatchers Ficedula hypoleuca

The physiological mechanism underlying the cost of reproduction may consist of immunodepression caused by increased parental effort. Here, we report effects of experimental manipulation of clutch size on T-lymphocyte cell-mediated immune response in female pied flycatchers, Ficedula hypoleuca. Parents with reduced broods provisioned at lower rates than those caring for control and enlarged broods three days after hatching. Parents caring for enlarged broods provisioned nests at higher rates 13 days after chick hatching than those feeding control and reduced broods. Females with enlarged broods weighed less than females with control or reduced broods. No effect of experimental treatment on nestling mass and size was found. The response to the injection of phytohaemagglutinin in the wing-web of females decreased with increasing brood size and with increasing provisioning rate when the chicks were three days old, when controlling for the negative effect of female mass on response. The T-lymphocyte cell-mediated response decreased from the reduced to the control, and from this to the enlarged group, when controlling for female mass. This effect of experimental manipulation of clutch size was significant and consistent with a trade-off between maternal effort and immunocompetence.

Does female aggression prevent polygyny? An experiment with pied flycatchers ( Ficedula hypoleuca )

The female aggression hypothesis states that resident females may be able to prevent polygyny by behaving aggressively towards intruding females. A critical test of the hypothesis is to provide prospecting females with a choice between displaying mated males some of which have initial mates with artificially reduced levels of aggressiveness. Here we present a mate choice experiment on pied flycatchers Ficedula hypoleuca. The species is a cavity nester, and resident females were prevented from behaving aggressively by enclosing them within their own nestboxes: narrowing the entrance hole so that they could not escape but could still let their head out and have some contact with their mate. This treament had only a minor influence on male behaviour. We studied whether the experimental males were better able to attract a new female than a control group of mated males. Four predictions from the female aggression hypothesis were supported. (1) Mating success of control males was positively related to the distance between their primary and secondary territory. (2) For experimental males, mating success was unrelated to interterritorial distance. (3) Experimental males had higher mating success than control males when the interterritorial distance was short but (4) not when it was long. Experimental males had much lower mating success than unmated males, as would be expected if prospecting females are able to discover male mating status from cues other than visits by primary females to their mates' secondary nest sites.