Pied Flycatcher Ficedula Hypoleuca Research Articles

Testosterone levels in relation to size and UV reflectance of achromatic plumage traits of female pied flycatchers

In a substantial number of species, females show some development of secondary sexual characters. These traits can function as signals of individual phenotypic or genetic qualities and status to conspecifics. Individuals may benefit potentially from expressing signals or badges of status if they are reliable and honest signals of individual quality. In many species, badge sizes have been shown to correlate with dominance rank, which may be mediated by testosterone (T) levels. Here, we explored geographic variation in the size and properties of the white wing patch of female pied flycatchersFicedula hypoleucaand its relation to circulating T levels in three populations (two southern populations in central Spain and a northern population in Finland). Furthermore, we aimed at detecting if the size of the white wing patch and its ultraviolet (UV) reflectance indicate individual quality. We found that females in Spain had larger, brighter and more UV reflecting wing patches than those in Finland. Females with higher UV reflectance and larger primary white patches bred earlier. Younger females and females with larger primary white wing patches showed higher T levels. In contrast, higher values of UV reflectance in feathers from these patches were associated with low T levels. Despite genetic differentiation and differences in trait expression between populations, female pied flycatchers from different populations may converge and use the size of white wing patches to signal their T levels and thereby their social dominance.

Nest‐dwelling ectoparasites reduce begging effort in Pied Flycatcher Ficedula hypoleuca nestlings

Parasitized nestlings might be expected to increase begging effort to obtain additional resources to compensate for those sequestered by their parasites. However, begging is costly and chicks harbouring parasites may find it more difficult to attain high begging levels. Consequently, we predicted that, for the same level of nutritional need, nestlings that are parasitized will invest less in begging than those that are not parasitized. We tested this prediction by measuring begging in Pied Flycatcher Ficedula hypoleuca nestlings parasitized with haematophagous mites Dermanyssus gallinoides and Dermanyssus gallinae and blowfly larvae Protocalliphora azurea, and subjected to different levels of food deprivation in order to control for short‐term nutritional need. Nestlings from nests with ectoparasites spent less time begging than those from nests without parasites, especially when very hungry, although there was no association with latency to beg or begging intensity. Our results suggest that time invested in begging may indicate not only the level of need, but also nestling parasitism status.

Are changes in breeding habitat responsible for recent population changes of long-distance migrant birds?

ABSTRACTCapsule: The direction and magnitude of changes in structure of UK woodlands since the 1980s, are inconsistent with them playing a causative role in the declines of four migrant bird species in upland oak woods.Aims: To investigate whether changes in woodland structure were a possible cause of population changes of four Afro-Palearctic migrants (Wood Warbler Phylloscopus sibilatrix, Tree Pipit Anthus trivialis, Pied Flycatcher Ficedula hypoleuca and Common Redstart Phoenicurus phoenicurus) in the upland oakwoods of western and northern Britain.Methods: Bird population estimates and measures of woodland structure were recorded in two time periods 1982–85 and 2003–04 across six regions of the UK. We modelled the effect of habitat change and initial habitat state on population changes between the two time periods. The predicted effects of habitat change on populations were then compared with observed population changes across the different regions.Results: All four species underwent population declines; there were also significant increases in ground cover and understorey cover. The number of birds in 2003–04 was influenced by habitat structure at this time in addition to showing regional differences. Change in bird numbers varied between regions and was affected by both the initial habitat state and change in habitat structure, with regional variation in the effect of habitat change. There was however no relationship between the predicted effect of change in habitat structure on population size and observed regional population changes.Conclusions: Changes in woodland structure are unlikely to be the main driver of population change in these four migrant bird species, and large-scale factors affecting demographics in other parts of their breeding range or in their wintering areas are likely reasons for local population declines.

Maternal transfer of androgens in eggs is affected by food supplementation but not by predation risk

Mothers may affect the future success of their offspring by varying allocation to eggs and embryos. Allocation may be adaptive based on the environmental conditions perceived during early breeding. We investigated the effects of food supplementation and predation risk on yolk hormone transfer in the pied flycatcher Ficedula hypoleuca. In a food supplementation experiment, females were food‐supplemented prior to and during egg‐laying and androgen concentrations were measured throughout the laying order. Predation risk was investigated in three different studies combining both correlative data, where flycatchers bred in close proximity to two different predator species that prey upon adult flycatchers (either Tengmalm's owl Aegolius funereus or pygmy owl Glaucidium passerinum), and an experimental manipulation, where flycatchers were exposed to cues of a nest predator (least weasel Mustela nivalis). Females receiving food supplementation laid eggs with lower concentrations of androstenedione (A4) than females not receiving food supplements. Yolk testosterone (T) concentration showed the same pattern but the difference was not statically significant. Testosterone (but not A4) concentration increased within clutches, from the first to the last egg, independently of the food supplementation. Females breeding under high predation risk did not differ from control females in their yolk androgen levels (A4, T or progesterone). However, concentrations of A4 tended to be lower in the proximity of pygmy owls, which could indirectly increase offspring survival after fledging. Food supplementation during egg‐laying seems to have a stronger impact on maternal transfer of androgens than predation risk. Food availability and predation risk could differentially affect the trade‐offs of androgen allocation for the offspring when raised in good vs. dangerous environments.

Species replacement reduces community participation in avian antipredator groups

Individuals living in diverse communities often depend on understanding the alarm signals of other species to gain critical information about predators. Here, we show that songbirds more rarely respond to the alarms of a colonizing songbird than those of the closely related species it is replacing. These results suggest that even small changes in community composition may have large impacts on species interactions and community antipredator behaviors.In diverse communities, recognizing other species' alarm signals is critical for evading predators. Recognition among community members is thought to build up predictably and quickly as individuals learn to associate previously unrecognized calls with the presence of a predator. Here, we use a natural range expansion in which a songbird species, the pied flycatcher (Ficedula hypoleuca), is being gradually displaced on a Baltic island by an ecologically similar congeneric, the collared flycatcher (Ficedula albicollis), to test this prediction. We conducted 2 field experiments to evaluate the abilities of both species to recruit local heterospecifics to antipredator groups, called mobs. First, we stimulated mobs by exposing breeding collared and pied pairs to taxidermied predators. Second, to isolate the effect of alarm call recognition from other potential confounds, such as behavioral cues or differences in the locations of pied and collared flycatcher nests, we broadcast alarm calls of both species in breeding areas and measured the responses of heterospecifics. We found that pied flycatcher pairs were more likely to attract heterospecifics than were collared flycatcher pairs. This difference is driven by weak responses of community members to collared flycatcher alarm calls: The alarm calls of the native pied flycatcher were much more likely to attract heterospecifics than those of the colonist, collared flycatchers. Our results show that subtle changes in species composition may have large, unpredictable consequences on community-wide communication. Because many avian breeding communities are heavily affected by predation, disturbed communication networks may, in turn, have cascading effects on community composition.

Pied Flycatchers Ficedula hypoleuca prefer ectoparasite-free nest sites when old nest material is present

Nest-dwelling ectoparasitic arthropods may have detrimental effects on avian breeding success and fitness. Birds should therefore be selected to avoid nest sites where the risk of being infested by ectoparasites is high. However, studies testing this hypothesis have produced mixed results. We performed an experiment in south Norway to test whether Pied Flycatchers Ficedula hypoleuca select nest site according to the presence of ectoparasites. We used artificial nest boxes in this experiment which had all been successfully used by conspecifics in the previous breeding season and still contained the old nest material. Five different groups of ectoparasites were recorded in flycatcher nests in the study area, of which the haematophagous hen flea Ceratophyllus gallinae and mites (Dermanyssus sp.) occurred in all examined nests. We offered each flycatcher pair (n = 13) a choice between 1) a box where ectoparasites had been removed by insecticide fumigation and 2) a box in which the old nest had not been fumigated. Flycatchers were highly selective in their choice of nest site, all but one settling in the fumigated, parasite-free nest box. This finding differs from a similar Swedish study (Olsson & Allander 1995) which did not find any evidence that Pied Flycatchers avoided nest boxes with ectoparasites. A likely explanation for this discrepancy is between-population differences in parasite abundance, as the mean number of hen fleas per infested nest was about five times higher in Norway than in Sweden.

Variation and significance of egg mass in a Pied Flycatcher Ficedula hypoleuca population in subalpine habitats in Swedish Lapland

Newly laid eggs of Pied Flycatchers Ficedula hypoleuca breeding in subalpine birch forest in Swedish Lapland were weighed in the field in 1965–1976. The main objective of the study was to get knowledge of the egg production capacity and its relation to the environmental conditions in the northern periphery of the breeding range of the species. The eggs were on average smaller than what is known from other Pied Flycatcher populations. Egg mass was non-linearly related to ambient temperature, and smallest at temperatures <10°C. About 70% of the eggs were laid at those temperatures. Variation in temperatures during the egg formation contributed to a significant egg mass variation between years. Average egg mass was lowest in the biggest clutches (7 or 8 eggs). Egg mass did not vary significantly within clutches, was not significantly related to the female mass, and did not vary between years in the same female. Hatching and fledging success were non-significantly related to the mean egg masses, indicating that egg sizes were not decisive for the breeding output.

A spring cold snap is followed by an extreme reproductive failure event in a mountain population of Pied Flycatchers Ficedula hypoleuca

Capsule Very low and anomalous temperatures in early spring of 2010 were followed by the only massive reproductive failure event recorded in 24 years in a population of Pied Flycatchers Ficedula hypoleuca breeding at 1200 m altitude in central Spain.Aim To estimate the effects of an extreme climatic event on reproductive success in a montane population of a long-distance migratory bird.Methods We compared nestling growth and mortality in nests of different brood sizes in the context of a brood manipulation experiment.Results Total failure affected 36% of the broods and only 2.5 nestlings on average were raised to fledging age. Most mortality affected broods in the second week of nestling life. Fledglings attained very low values for mass and wing length compared with long-term averages. Subsequent local recruitment was the lowest for any cohort in 24 years. The typical date-dependent decrease in breeding success in the population was inverted.Conclusion Breeding success was markedly affected by a weather event happening one month before hatching and lasting only a few days. An increased frequency of extreme weather events as predicted by some climate change scenarios may dramatically affect insectivorous avian populations in the future.

An experimental test of whether pied flycatchers choose the best territory for rearing the young

Abstract It is often assumed that birds are able to choose a breeding territory that will later on have the most food for nestlings. Studies on this essential question are, however, few. We studied territory choice of a long-distance migrant, the pied flycatcher Ficedula hypoleuca in southwestern Finland. In one study area, we monitored the territory choice of males via the order of territory settlement. Female territory choice was studied experimentally in another study area where the correlation between male and territory quality was removed by not allowing males a free choice of territory. We defined several habitat characteristics and estimated the abundances of invertebrate prey from air, ground and trees with appropriate traps from the surroundings of the nest sites in both study areas. Against the expectation that parent birds would choose an arthropod-rich territory, neither males nor females seemed to choose those territories that later had the most food for nestlings. There was, however, some evidence that more eggs were laid in territories with more aphids and that more fledglings were produced in territories with high ant abundance. Our findings thus suggest that while it would be beneficial for birds to be able to choose food-rich territories, they may not be able to detect the right cues for doing so early in the breeding season. The possibility and importance of detecting the territories with the best prospects of rearing young may, however, vary among and within seasons and more studies on this topic are clearly needed.

Bacterial degradability of white patches on primary feathers is associated with breeding date and parental effort in a migratory bird

We compared the in vitro bacterial degradability of the white patch and melanized area of primary feathers of breeding male and female Pied Flycatchers Ficedula hypo-leuca and related this variation to laying date, brood size and brood mass. Bacterial degradability of male and female white feather patches, but not of melanized areas, was positively correlated with laying date. Male Pied Flycatchers showed a positive correlation between bacterial degradability of the white patch, though not of the melanized patch, and brood size and brood mass. Feather degradability appears to be negatively related to individual quality and positively related to reproductive effort.

Thermal Properties of Bird Nests Depend on Air-Gaps between the Materials

Four species of songbird, Great Tits Parus major, Blue Tits Cyanistes caeruleus, Pied Flycatchers Ficedula hypoleuca and Wood Warblers Phylloscopus sibilatrix, have nests that have similar insulatory properties, but are made of widely differing materials. This study used a novel technique to investigate the role of air-gaps between component materials of the nest wall on the insulatory properties of the whole nest. Nests of four passerine species were investigated by measuring the rate of warming of a temperature logger within the wall materials before and after vacuum-packing, which removed the air and compressed the nest. After vaccum-packing nest volume was estimated to have decreased by 90% and the measured insulatory values decreased by an average of 20% irrespective of the nest materials. Nest maintenance behaviors that may serve to ensure that air-gaps are maintained within the nest wall, which perhaps maximises its insulatory properties, are discussed.

Variation in Egg Sizes of Pied FlycatchersFicedula hypoleucain Central Poland: A Long-Term Decreasing Trend

Abstract. Sequentially laid eggs of small songbirds are built from the current income of resources and therefore can be subject to different environmental influences on the short-term and long-term time scales. In this paper we study variation in egg length, breadth, volume and shape in Pied Flycatchers Ficedula hypoleuca in Łodź, central Poland, during 2002–2012, in relation to climatic and habitat-related factors. We found a significant decreasing trend in egg length, breadth and volume across the study years and a slight tendency for eggs to be a little more elongated in a forest site than in an urban parkland site. Even though mean monthly temperature in May is known to have increased since the 1970s in the area of Łodź, the average ambient temperature during the time of formation of eggs in particular clutches tended to decrease, with increasing variability at the same time, in 2002–2012. Egg size traits showed a positive association with average temperature and a negative relation with variability i...

Selection of Nest Site and Nesting Material in the Eurasian NuthatchSitta europaea

The selection of nest sites and nesting material may have important implications for avian reproductive behaviour and performance. Nest construction may involve costs arising from transporting material that may be reduced considerably if nest materials are located close to the nest site. Eurasian Nuthatch Sitta europaea nests in our nest box study area are mainly composed of pine bark flakes or alternatively of strips of bark of the widespread shrub Cistus laurifolius, with variable amounts of mud being used for plastering the entrance. Several small streams run through the area — an oak Quercus pyrenaica forest with a few scattered pines Pinus sylvestris. Here we show that Nuthatches collected pine bark only when nest sites were situated close to pines, used more mud when breeding close to streams and selected nest sites closer to streams than a sympatric species not using mud, the Pied Flycatcher Ficedula hypoleuca. Nuthatches used pine bark only when there was a pine tree less than 100 m away from the nest box and selected Cistus bark when transport distance was greater. We suggest that the selection of nest sites and nest materials in this species may be constrained by the costs of transporting nest material.

Female aggressiveness towards female decoys decreases with mate T level in the pied flycatcher

Social selection is expected to favour the evolution of female aggressive defence of nesting resources in cavity-nesting birds, which may be also mediated by testosterone (T) levels. Male T levels could express male dominance and thereby territorial safety for female partners and thereby reduce their need for aggressive defence. Here, we explored the role of T levels in female-female competition in a songbird, the pied flycatcher Ficedula hypoleuca. In an experiment with female decoys placed close to the nestbox at the end of laying, we explored if female aggressiveness is related to their own T level or to mate T level. T levels of males and females were measured in the middle of the nestling period. Mean female aggressiveness towards decoys in three presentations was estimated through proximity to the decoy and number of attacks by females, two variables which were positively associated. Aggressiveness by female nest owners to female decoys was negatively related to male T level but unrelated to own T level. There was no assortative mating with respect to T level. Female aggressiveness is more strongly related to the hormonal status of mates than to their own.

Nest-dwelling ectoparasites reduce antioxidant defences in females and nestlings of a passerine: a field experiment.

Ectoparasites may imply a cost in terms of oxidative stress provoked by inflammatory responses in hosts. Ectoparasites may also result in costs for nestlings and brooding females because of the direct loss of nutrients and reduced metabolic capacity resulting from parasite feeding activities. These responses may involve the production of reactive oxygen and nitrogen species that may induce oxidative damage in host tissues. Our goal was to examine the effect of ectoparasites in terms of oxidative stress for nestlings and adult females in a population of pied flycatchers Ficedula hypoleuca. We manipulated the entire nest ectoparasite community by reducing ectoparasite loads in some nests through a heating treatment and compared them with a control group of nests with natural loads. A marker of total antioxidant capacity (TAS) in plasma and total levels of glutathione (tGSH) in red blood cells as well as a marker of oxidative damage in plasma lipids (malondialdehyde; MDA) were assessed simultaneously. Levels of tGSH were higher in heat-treated nests than in controls for both females and nestlings. Higher TAS values were observed in females from heat-treated nests. In nestlings there was a negative correlation between TAS and MDA. Our study supports the hypothesis that ectoparasites expose cavity-nesting birds to an oxidative challenge. This could be paid for in the long term, ultimately compromising individual fitness.

Patterns of year-to-year variation in haemoglobin and glucose concentrations in the blood of nestling Pied Flycatchers Ficedula hypoleuca

Physiological tools can be used to identify the sources and consequences of stressors on animals. Understanding the influences of variation in habitat quality and anthropogenic disturbance on organism condition and health may improve future management and conservation. We present results concerning variation in haemoglobin and glucose concentrations in the blood of about 14-day-old nestling Pied Flycatchers Ficedula hypoleuca in central Poland over a 4-year period, 2011–2014, in a deciduous forest. The most important findings of the study are: (1) the concentration of haemoglobin and glucose of the nestlings from the same brood tended to be consistently similar, with much variation occurring among broods; (2) repeatability of haemoglobin concentration was higher than repeatability of glucose concentration; (3) mean levels of haemoglobin and glucose varied among years; (4) haemoglobin and glucose concentrations were negatively correlated; and (5) there was a positive relationship between haemoglobin levels and breeding success.

Sympatric divergence and clinal variation in multiple coloration traits of Ficedula flycatchers.

Geographic variation in phenotypes plays a key role in fundamental evolutionary processes such as local adaptation, population differentiation and speciation, but the selective forces behind it are rarely known. We found support for the hypothesis that geographic variation in plumage traits of the pied flycatcher Ficedula hypoleuca is explained by character displacement with the collared flycatcher Ficedula albicollis in the contact zone. The plumage traits of the pied flycatcher differed strongly from the more conspicuous collared flycatcher in a sympatric area but increased in conspicuousness with increasing distance to there. Phenotypic differentiation (PST ) was higher than that in neutral genetic markers (FST ), and the effect of geographic distance remained when statistically controlling for neutral genetic differentiation. This suggests that a cline created by character displacement and gene flow explains phenotypic variation across the distribution of this species. The different plumage traits of the pied flycatcher are strongly to moderately correlated, indicating that they evolve non-independently from each other. The flycatchers provide an example of plumage patterns diverging in two species that differ in several aspects of appearance. The divergence in sympatry and convergence in allopatry in these birds provide a possibility to study the evolutionary mechanisms behind the highly divergent avian plumage patterns.

Long-term recovery of clutch size and egg shell quality of the pied flycatcher (Ficedula hypoleuca) in a metal polluted area

We explored if breeding parameters and egg shell quality of an insectivorous passerine, pied flycatcher Ficedula hypoleuca, have fully recovered after c.a. 99% decrease in dust emissions from a non-ferrous smelter in the course of the 23 year study period. Some potentially important population characteristics (density, phenology, age) and environmental variables (habitat, inter-specific competition) were taken into account in the analysis. We found marked increase in reproductive parameters (egg shell quality, clutch size, hatchability, and fledgling number) in the metal polluted area especially in 1990's when metal-rich dust emissions from the smelter were markedly reduced. Still clutch sizes and fledgling numbers remain below the levels of the reference area. There is currently very little evidence of direct toxic effects of metals in our study population but full recovery of breeding parameters may not be reached until the full recovery of food chains, which is likely to be a slow process.

Extra-Pair Paternity Declines with Female Age and Wing Length in the Pied Flycatcher

Despite many studies of how male characteristics affect paternity in predominantly monogamous birds, relatively little attention has been given to the traits of females that may influence extra-pair paternity (EPP). However, the occurrence of EPP may be the result of behavioural interactions in which both male and female traits are important for determining the outcome. If EPP is driven mainly by female choice of extra-pair sires, older, more experienced or larger females would be better able to evade mate guarding tactics and more capable of selecting extra-pair mates and resisting unwanted suitors. This would be especially noticeable in females paired with unattractive mates. On the other hand, if EPP is driven mainly by male pursuit, we should expect that young, inexperienced or small females would be more exposed to coercive male approaches independently of social mate traits. In a study of an Iberian population of the pied flycatcher Ficedula hypoleuca, we found that EPP affected 38% of the broods and 17% of the nestlings. These values are relatively high, allowing a relatively large number of affected within-pair mates to be included. We found that EPP is related to both female and male traits although not to any interaction between male and female traits. EPP was higher at nests tended by both younger and short-winged females and by browner males. Older females may be more experienced and dominant while long-winged females may be faster fliers, these traits enabling them to avoid extra-pair copulations, while brown males are less aggressive towards male intruders. In our study population, EPP appears to be caused by male pursuit, which in some cases may overwhelm female attempts to avoid extra-pair copulations and their social partner's ability to prevent them.

Bacteria on nestling skin in relation to growth in pied flycatchers

The association between skin bacterial communities and nestling growth is poorly understood. We estimated the abundance of heterotrophic bacteria on skin of nestlings and their association with growth in the pied flycatcher Ficedula hypoleuca. At two different nestling ages, we swabbed a delimited area of the naked belly skin of nestlings and measured them. Skin bacterial loads on day 13, but not on day 7, were positively associated with brood size and with nestling wing length. Larger broods develop in less hygienic conditions, which may stimulate bacterial growth. Skin bacteria may favor wing feather growth through competition with harmful bacteria, or faster feather growth may facilitate bacterial growth through the accumulation of remains on the skin surrounding growing feathers.