Fieldfare Research Articles

Wildfire influences species assemblage and habitat utilisation of boreal wildlife after more than a decade in northern Sweden

Fires can strongly change the vegetation structure and the availability of resources for wildlife, but fire suppression has long affected the natural role of fire in shaping boreal ecosystems in northern Europe. Recently, wildfires have increased in frequency, possibly due to global warming. In contrast to the boreal systems in North America, there have been few studies on responses of wildlife to wildfires in northern Europe. Based on the findings from North America, we predict that responses of wildlife to wildfire vary among wildlife species: where mammalian herbivores, such as moose Alces alces and mountain hare Lepus timidus, will be attracted to burnt areas following an increase in food availability, other species, such as reindeer Rangifer tarandus, are negatively impacted due to fire reducing their preferred food. We then tested our predictions by contrasting wildlife utilization of sites that burnt by wildfire in 2006 with nearby unburnt control sites in three areas in northern Sweden. To measure wildlife utilization, we used 72 camera traps, equally divided between the burnt and control sites, with two placement strategies: random and on wildlife trails. The cameras recorded 27 mammal and bird species during summer 2018. Species assemblage differed between burnt and control sites. Fieldfare Turdus pilaris used burnt sites more than control sites, while pine marten Martes martes and western capercaillie Tetrao urogallus used control sites more than burnt sites. We however did not find support for a positive effect of past forest fires on any of the observed wild mammals. We discuss how, due to the impact of forestry, forage‐rich habitat may not be as limiting in Scandinavia as in the North‐American context, potentially leading to recently burnt sites being less attractive to herbivores such as moose.

Facultative migration in two thrush species (Fieldfare and Redwing): Rowanberry abundance is more important than winter weather

Facultative migration is thought to be influenced by food and weather, with birds remaining in northern areas if food is abundant and weather conditions are benign, but migrating south when food is scarce and weather is harsh. However, the relative importance of these two factors has rarely been tested with long-term data, and effects of weather are poorly documented. Here, I assess whether winter numbers of the Fieldfare (Turdus pilaris) and the Redwing (T. iliacus) in southern Norway during the period 1980–2020 varied in relation to the abundance of an important source of winter food (rowanberries, Sorbus aucuparia) and indices of winter harshness (North Atlantic Oscillation index, temperature, duration of snow cover). Two regions with contrasting winter harshness (western Norway with a maritime climate, eastern Norway with a continental climate) were compared. Winter numbers of Fieldfare in both regions, and Redwing in eastern Norway, were highest in years with high rowanberry abundance. Weather had mixed influence on thrush winter numbers, but interacted with rowanberry abundance in several cases so that small numbers of thrushes occurred with the combination of low rowanberry abundance and harsh weather. Such interactions occurred both in eastern and western Norway, and for both species, including for the Redwing in western Norway. In conclusion, facultative migration was strongly related to food availability with large numbers wintering in years with large rowanberry crops, and with additional effects of harsh weather working in concert with low rowanberry abundance to reduce wintering numbers to low levels in some years.

Non-breeding ranging behaviour, habitat use, and pre-breeding migratory movements of Fieldfares (Turdus pilaris) wintering in southern Europe

Non-breeding ranging behaviour, habitat use, and pre-breeding migratory movements of Fieldfares (Turdus pilaris) wintering in southern Europe

Fieldfare (Turdus Pilaris L.) Nesting Ecology in the City of Stepanakert of the Republic of Artsakh and its Surrounding Territories

The present study delves into the nesting ecology of fieldfares within the avian population of Stepanakert, located in the Republic of Artsakh, alongside its contiguous regions. The research material encompasses observations and investigations carried out between 2017 and 2022 within the aforementioned geographic domains. In our specific conditions, the initiation of the fieldfare nesting process transpires under outdoor air temperatures exceeding +8°C to +10°C, while the first appearance of an egg within the nest during spring corresponds to temperatures of +15°C to +16°C. The nesting substrates encompass an array of broad-leaved and coniferous trees, in addition to various man-made structures. Nest placement exhibits diversity, situated at elevations of 0.5-1.2 meters above the ground within open areas proximate to the city, escalating to 3-4.5 meters within the central zones of Stepanakert, and subsiding to 1.5-2.5 meters in woodland environs adjacent to the city. The construction of nests unfolds over a median period of 5-7 days. On average, nests accommodate a clutch of 3-5 eggs. The morphological attributes of eggs reveal considerable variability. In our contextual setting, fieldfares engender two generations annually, with an incubation duration spanning 12-13 days. Hatchlings emerge from eggs within a single day, occasionally within two days, eventually taking their inaugural flights after 15-17 days. The percentages of losses occurring between the embryonic stage and the attainment of flying capability among chicks display distinct variations.

Adoption and feeding of fieldfare nestlings and fledglings by European blackbird.

Interspecific adoption is an intriguing topic in behavioral and evolutionary ecology. As it is a rare phenomenon, seldom documented in the literature, reports of interspecific adoption based on solid data are particularly valuable. A long-term and extensive monitoring programme involving a local population of European blackbirds (Turdus merula, hereafter blackbird) has yielded, among other things, observations of alloparental behavior exhibited by blackbirds toward fieldfare (Turdus pilaris) nestlings (a single nest, the first-ever record) and fledglings (12 cases in all). We discuss the observations in the context of the available literature.

Exo-erythrocytic development of Plasmodium matutinum (lineage pLINN1) in a naturally infected roadkill fieldfare Turdus pilaris

BackgroundSpecies of Plasmodium (Haemosporida, Plasmodiidae) are remarkably diverse haemoparasites. Information on genetic diversity of avian malaria pathogens has been accumulating rapidly, however exo-erythrocytic development of these organisms remains insufficiently addressed. This is unfortunate because, contrary to Plasmodium species parasitizing mammals, the avian malaria parasites undergo several cycles of exo-erythrocytic development, often resulting in damage of various organs. Insufficient knowledge on the exo-erythrocytic development in most described Plasmodium species precludes the understanding of mechanisms of virulence during avian malaria. This study extends information on the exo-erythrocytic development of bird malaria parasites.MethodsA roadkill fieldfare (Turdus pilaris) was sampled in Switzerland and examined using pathologic, cytologic, histologic, molecular and microbiologic methods. Avian malaria was diagnosed, and erythrocytic and exo-erythrocytic stages of the parasite were identified using morphologic characteristics and barcode DNA sequences of the cytochrome b gene. The species-specific characteristics were described, illustrated, and pathologic changes were reported.ResultsAn infection with Plasmodium matutinum lineage pLINN1 was detected. Parasitaemia was relatively low (0.3%), with all erythrocytic stages (trophozoites, meronts and gametocytes) present in blood films. Most growing erythrocytic meronts were markedly vacuolated, which is a species-specific feature of this parasite’s development. Phanerozoites at different stages of maturation were seen in leukocytes, macrophages, and capillary endothelial cells in most organs examined; they were particularly numerous in the brain. Like the erythrocytic meronts, growing phanerozoites were markedly vacuolated. Conspicuous exo-erythrocytic development and maturation in leucocytes suggests that this fieldfare was not adapted to the infection and the parasite was capable to escape from cellular immunity.ConclusionsThis is the first report of exo-erythrocytic development of the malaria parasite lineage pLINN1 during single infection and the first report of this lineage in the fieldfare. The findings of multiple phanerozoites in brain, skeletal muscle, and eye tissue in combination with signs of vascular blockage and thrombus formation strongly suggest an impaired vision and neuromuscular responsiveness as cause of the unexpected collision with a slowly moving car. Further studies on exo-erythrocytic stages of haemosporidian parasites are pivotal to understand the true level of populational damage of avian malaria in wild birds.

Трофічні консортивні зв’язки винограду дівочого чіпкого (Parthenocissus inserta) з птахами в культурфітоценозах Києва

The state of adaptation of alien species to new conditions of existence is expedient to investigate by elucidating the consortial relationships that these species form with aboriginal representatives of the biota. We studied a species with invasive characteristics: Parthenocissus inserta (A. Kern.) Fritsch., 1922. Purpose is to find out the species composition of P. inserta birds-consorts in the urban plantations of Kyiv; residence status and trophic specialization of consorts; to evaluate the synchronization of P. inserta phenodates with the key periods of the life of birds, in trophic consortial “P. іnserta – birds”, as an indicator of the inclusion of advent plants in the biocenoses of the Kyiv region. The material analyzed in the present study was observations of birds that feed on P. іnserta (n=11). The material was collected according to the widely accepted method of bird observation. In total, 218 P. іnserta were monitored in parks and streets of Kyiv in 2020–2022. Forty-one cases of bird feeding on the plant were recorded. Intensive phenological monitoring P. іnserta (n=5) was used. The distribution of birds by trophic groups was carried out according to a recognized classification. The trophic consortive relationships of P. inserta with 17 species of birds of 3 orders were revealed. They form 2 types of relationships: 1) direct, when feeding directly berries; 2) indirect, when they eat invertebrates on the vine, leaf, flowers and fruits. From 1 to 24 bird individuals on 1 plant fed per one observation, on average 5,90±0,95 (n=41). Consorts are birds of the following residence statuses: residents are the species living in Kyiv all year round; nesting – only during the reproductive period; wintering – in the winter period in the Kyiv; migratory – birds whose migration routes pass through the territory of Kyiv. Resident species were dominated (52,94%). The next species dominate in abundance: Columba livia, Passer montanus, Sturnus vulgaris, Turdus pilaris. Consorts of “P. іnserta – birds” formed from August up to mid-February.

Detection of tick-borne pathogens in wild birds and their ticks in Western Siberia and high level of their mismatch.

The Tomsk region located in the south of Western Siberia is one of the most high-risk areas for tick-borne diseases due to elevated incidence of tick-borne encephalitis and Lyme disease in humans. Wild birds may be considered as one of the reservoirs for tick-borne pathogens and hosts for infected ticks. A high mobility of wild birds leads to unpredictable possibilities for the dissemination of tick-borne pathogens into new geographical regions. The primary goal of this study was to evaluate the prevalence of tick-borne pathogens in wild birds and ticks that feed on them as well as to determine the role of different species of birds in maintaining the tick-borne infectious foci. We analysed the samples of 443 wild birds (60 species) and 378 ticks belonging to the genus Ixodes Latraille, 1795 collected from the wild birds, for detecting occurrence of eight tick-borne pathogens, the namely tick-borne encephalitis virus (TBEV), West Nile virus (WNV), and species of Borrelia, Rickettsia, Ehrlichia, Anaplasma, Bartonella and Babesia Starcovici, 1893, using RT-PCR/or PCR and enzyme immunoassay. One or more tick-borne infection markers were detected in 43 species of birds. All markers were detected in samples collected from fieldfare Turdus pilaris Linnaeus, Blyth's reed warbler Acrocephalus dumetorum Blyth, common redstart Phoenicurus phoenicurus (Linnaeus), and common chaffinch Fringilla coelebs Linnaeus. Although all pathogens have been identified in birds and ticks, we found that in the majority of cases (75.5 %), there were mismatches of pathogens in birds and ticks collected from them. Wild birds and their ticks may play an extremely important role in the dissemination of tick-borne pathogens into different geographical regions.

Зв’язки чужорідних видів птахів з адвентивними рослинами насаджень парків і ботанічних садів

Introduction. In urban conditions, alien species of biota have become an integral part of the cultural landscape. Today, an overall assessment of the influence of alien species on the functioning of ecosystems of their secondary range as is relevant. Such an assessment requires knowledge of the connections formed by alien species in the secondary habitat. The purpose of the study was to find the connections of alien bird species with alien plant species in the parks and botanical gardens of Kyiv. Methods. Assessment was carried out in 10 forest parks, 3 botanical gardens, and 14 urban parks. In parks and botanical gardens, there is a wide range of plants alien to Kyiv Region, in contrast to forest parks. The number and distribution of birds were determined using the method of transect counts. The total area under study was about 370 hectares. Principal Component Analysis of the characteristics of habitats on which the number of alien birds may depend has been carried out. In the research, α-diversity indices of bird communities; number of people (individuals/km); number of pets (individuals/km); park’s area (ha); part of the territory; under the trees (%); part of alien species on plants communities (%) were analyzed. Results. Parus major, Turdus merula, Erithacus rubecula, Fringilla сoelebs dominate in all communities. Columba palumbus, Ficedula albicollis, Turdus pilaris, Columba livia, Apus apus, Sturnus vulgaris, Passer domesticus sometimes dominate in bird communities in parks and botanical gardens. There are no alien species in forest parks. 4 alien species nest in parks and botanical gardens: Streptopelia decaocto, Dendrocopos syriacus, Phoenicurus ochruros, Serinus serinus (from the last century). Phylloscopus trochiloides was observed for the first time. Nesting of Ph. trochiloides was not confirmed. Alien birds are not evenly distributed (0–3 species). Nest density is low: S. decaocto 0.013±0.01–0.021±0.01, D. syriacus 0.031±0.01–0.043±0.04, Ph. ochruros 0–0.034±0.02, S. serinus 0.013±0.01–0.017±0.01. We assume that alien bird species is an element that replaces the species that were eliminated from the community. Their nesting in forest parks is an indicator of a disruption of the functioning of the forest ecosystem as a result of anthropogenic transformation of the forest. The presence of alien species of birds in modern parks and botanical gardens is normal. Their biotopes were created on the sites of destroyed landscapes and with using alien plant species. Conclusion. In parks and botanical gardens, a specific structure of the plant community has developed due to the introduction of alien plant species, with a tree height of 3–5 m. As a consequence, alien birds find nesting stations in communities of nesting birds, which were not occupied by native species due to the absence of many species of tree canopy nesters and ground nesters birds. Alien species of birds also get access to vacant food resources. Alien birds use vacant resources. It was found that the area of parks has the most profound positive impact on the number of species of alien birds (+0.517), as well as the ratio of alien birds (+0.227). Other important correlations observed were the following: the number of species of alien birds in the bird communities – a part of alien species in plant communities (+0.084), the ratio of alien birds – part of alien species in plant communities (+0.041). The strongest negative connection is as follows: the number of species of alien birds in the bird communities – the number of pets (-0.213), the ratio of alien birds – the number of pets (-0.384).

Формирование сообществ гнездящихся птиц парков Киева по градиенту антропического воздействия в мегаполисе

In settlements, safe places for birds nesting and feeding need to be created. The purpose of the work is to assess the state and identify vectors of the formation of nesting bird communities in parks under the pressure of anthropic load in the metropolis. In parks of Kyiv 62 species of birds nest. Such faunogenetic complexes like European nemoral (25.0–53.3%), Desert-mountain (12.0–27.8%) and Forest-steppe (6.9–25.0%) prevail. The number of community species in each of parks is 49–12, the average nesting density is 0.08±0.02–0.9±0.19 pairs / ha, and the dispersion is 0.12–1.62. With the combination of anthropic load on biotopes of more than 140 points with a small area of parks (2.0–16.5 ha), the species composition of communities decreases, and the average nesting density and density dispersion increase. Dominated by density: Parus major, Columba livia, Sturnus vulgaris, Turdus merula, Passer domesticus, Passer montanus, Fringilla coelebs, Columba palumbus, Apus apus, Ficedula albicollis, Erithacus rubecula, Turdus pilaris. All birds in communities are obligate synanthropes (12.9%; n=62) or hemisinanthropes. Obligate synanthropes are distributed in communities of 0-7 species. According to the gradient of increasing anthropic load on parks, logarithmic trends show a slight increase in the percentage share of obligate synanthropes in the species composition and in the number of breeding pairs. 47–70% nest on trees, 0–14.3% in shrubs, 0–13.0% on ground and in buildings. In parks, birds (16–38% of the species composition), in addition to using species-specific stations, nest in the cavities of buildings. Such species like Motacilla alba L., Sturnus vulgaris, Ficedula albicollis, Muscicapa striata Pallas, Erithacus rubecula, Parus major, Passer domesticus, Passer montanus nest in this way. Due to this nesting strategy, the need of the birds in hollows and the dependence on the woodpeckers in the community decreases. High parameters of the Shannon index (1.51–3.14) and Pielou index (0.61–0.95) were revealed, with low data of the Berger-Parker index (0.15–0.61). With an anthropic load of more than 160 points, there is a sharp decrease in species diversity, evenness of species, and increased dominance pressure. Cluster analysis showed the division of bird communities into similarity groups according to the area of the parks, the proximity of parks to the outskirts of the city and large forest tracts of the area and specifics of the anthropic load.

Opening a can of worms: Can the availability of soil invertebrates be indicated by birds?

Abstract Recently detected invertebrate population declines are likely to have far-reaching impacts for ecosystem function. However, very little large-scale monitoring of invertebrates, especially soil invertebrates, has taken place. To address this gap, we established a school-based citizen science project to collect data on soil invertebrate abundance and bird counts across the UK. We examined the association between earthworms (which comprised 93% of the total soil invertebrate biomass in the surface soil) and 15 bird species on school playing fields over three years. We also tested whether simple bird counts of species that rely on earthworms could be used to indicate the earthworm abundance in soil. We found a clear link between earthworm abundance and counts of robins (Erithacus rubecula), blackbirds (Turdus merula) and other thrushes (Turdus pilaris, Turdus viscivorus, Turdus philomelos and Turdus iliacus), all of which rely on earthworms as an important component of their diet. None of these relationships varied with season. There were no correlations found between earthworm abundance and bird counts for species that do not rely on earthworms. We found that the total thrush count (including blackbirds) could be used as a simple indicator of earthworm abundance, explaining up to 20% of the variation in earthworm counts. In spite of the uncertainties associated with the data, these results raise the possibility that existing, robust, long-term bird monitoring data could, with further research, be used to infer changes in soil invertebrates, such as earthworms, and therefore aspects of soil health. We conclude by identifying a series of criteria that would need to be fulfilled in order for such inference to be robust.

Parental investment and the coordination of parental activity in the Fieldfare Turdus pilaris

We investigated the division of provisioning between Fieldfare Turdus pilaris mates as well as synchronisation and alternation of parental feeding trips. We found that parents equally participated in provisioning of older nestlings, but males provisioned young nestlings more than their mates. Synchronisation between parents was higher during the early nestling stage, when they alternated more than during the whole nestling stage. During the early nestling stage alternation was correlated with parental share in provisioning, suggesting that alternation may ensure more equal participation of each parent in provisioning. However, we did not find an analogous relationship between alternation and provisioning during the late nestling stage.

Host dispersal shapes the population structure of a tick-borne bacterial pathogen.

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B.burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T.merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B.valaisiana (24%), B.afzelii (9%), B.turdi (5%) and B.lusitaniae (0.5%). A novel Borrelia genospecies "Candidatus Borrelia aligera" was also detected. Multilocus sequence typing (MLST) analysis of B.garinii isolates together with the global collection of B.garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B.garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts.

Elevating the Impacts of Research in Agricultural Education

Dissemination of research is a critical part of the research process. Researchers in agricultural education have long embraced this process. However, the Internet has changed the ways in which research is disseminated, with the potential for much broader impacts around the world. The purpose of this study was to provide a benchmark of the current impact of research in agricultural education by examining how journals and researchers in the field fare on commonly used research metrics. It was concluded that many of the common journals in agricultural education are not even listed in the indices that provide metrics to assess journals. It was also concluded that many researchers in agricultural education are not taking steps to provide public profiles of their research and thus do not have individual researcher metrics. In some ways, we are invisible to the broader scientific community. Practical suggestions are provided to elevate the reputations of our journals and the reputations of our researchers.

Migration and wintering of Fieldfare (Turdus pilaris) in southeastern Hungary

Abstract The Fieldfare is a bird species widely distributed in the Palearctic region. In Hungary, the species is considered as a rare breeder and common, sometimes abundant migrant in autumn and spring, and also as winter visitor. It is prone to invasion, since northern breeding populations leave the breeding sites in large numbers only when the available food is inadequate or inaccessible to the birds. Most populations follow a southern-southwestern migration pattern, and in the course of their movement they also migrating through the Carpathian Basin. In this study, we examined the migration and wintering of the species in an area of southeast Hungary between 2004 and 2019. Data were collected between the beginning of October and the middle of April and during that period we saw Fieldfares a total of 416 times. In addition to the description of migration, the effect of weather on bird numbers was also investigated. According to our results, the species appears in the area in October and disappears in late March and the first half of April. The individuals that migrate in October are likely belonging to the Central European breeding population, while from November the Scandinavian birds can be seen. The maximum number of birds observed during the different years showed significant differences, as did the patterns of movements within the seasons. The relationship between the local weather and the number of birds has been demonstrated over several seasons, which is typical of species with an escape migration.

Parental Investment and the Coordination of Parental Activity in the Fieldfare Turdus pilaris

We investigated the division of provisioning between Fieldfare Turdus pilaris mates as well as synchronisation and alternation of parental feeding trips. We found that parents equally participated in provisioning of older nestlings, but males provisioned young nestlings more than their mates. Synchronisation between parents was higher during the early nestling stage, when they alternated more than during the whole nestling stage. During the early nestling stage alternation was correlated with parental share in provisioning, suggesting that alternation may ensure more equal participation of each parent in provisioning. However, we did not find an analogous relationship between alternation and provisioning during the late nestling stage.

Extra-pair paternity and sperm length variation in the socially monogamous Fieldfare Turdus pilaris

Basic knowledge about the genetic mating system is lacking for the great majority of the approximately 10,000 extant bird species. Filling this knowledge gap is not only critical for a comprehensive understanding of the reproductive ecology of each particular species, but also for increasing the power of comparative approaches to uncover and explain interspecific patterns of variation in avian reproductive traits. Using six polymorphic microsatellite markers, we here present the first parentage study in the socially monogamous Fieldfare Turdus pilaris. In parallel, we also examine variation in sperm morphology and relationships between sperm traits and paternity loss of social males. Across two study years, extra-pair paternity was detected in 46.4% (95% CI: 28.9–64.9%) of 28 broods, and on average 27.6% (95% CI: 16.8–41.9%) of nestlings per brood were extra-pair offspring in a population in central Norway. These observed extra-pair paternity rates fall within the range of reported estimates of extra-pair paternity for four congeneric Turdus species (between 36 and 65% of broods and 27 and 46% of nestlings). Sperm total length was 87.0 ± 2.9 (SD) μm (range 79.7‒96.8 μm) and 59.3% (95% CI: 37.1–73.3%) of the total phenotypic variation in sperm total length was explained by differences between sperm samples collected from 17 different males. The among-sample coefficient of variation in mean sperm total length was 2.70% (95% CI: 1.99–3.17%). We found no evidence for effects of sperm total length or relative midpiece length on loss of paternity among broods of 13 males.

On the biology of the bird parasite Neottiophilum praeustum (Meigen, 1826) (Diptera, Neottiophilidae)

The first data on blood-sucking ectoparasitic larvae of Neottiophilum praeustum (Meig.) which develop in bird nests are presented in Russia, with the fieldfare Turdus pilaris L. as a host example. Larval development takes not more than 10–12 days but no puparia are formed until late autumn. The larvae of Neottiophilum resemble those of calliphorid flies both in body structure and life mode. The main diagnostic characters of Neottiophilum larvae distinguishing them from calliphorid ones are the spiracular disk of the posterior spiracles being positioned dorsal rather than ventral to the stigmal plate and lying outside rather than inside its peritreme. In addition, the anterior spiracles have 14–15, rather than 3–8 spiracular chambers.

Effects of roads on fruit crop and removal rate from rowanberry trees (Sorbus aucuparia) by birds in urban areas of Finland

Roads destroy natural habitats. To reduce erosion, support wildlife and decorate surroundings, ornamental trees are planted near the roadside. However, it is inadequately understood how roads influence fruit production of trees and birds that consume their fruits, within urban landscapes. During the autumn and winter of 2012–2013, we studied the extent to which birds used the fruit from rowanberry trees (Sorbus aucuparia), in two cities along a 700km latitudinal gradient in Finland. In matched pair design (total of 35 pairs), we compared roadside trees (approximately 8m from main roads) with trees grown away from roads (control trees; approximately >80m from the roads). During the autumn, each rowanberry tree pair was photographed, and frugivorous birds were surveyed twice per month until all of the rowanberry fruit-crop was consumed. There was no difference in fruit crop size between roadside trees and control trees. A total of eight frugivorous bird species and 960 individuals were observed foraging in roadside trees. The three most abundant species were Bohemian waxwing (Bombycilla garrulus, 56.4%), Pine Grosbeak (Pinicola enucleator, 28.9%) and Fieldfare (Turdus pilaris, 10.5%). Total abundance and species richness of frugivorous birds were lower around roadside trees than control trees during most of the study period. Fruits were consumed later from roadside trees than from control trees, probably due to human-caused disturbance. Therefore, roadside rowanberry trees extended the period when frugivorous birds stayed in urban habitats. Later consumption of fruits in northern areas than in southern areas was related to earlier peak abundance of frugivorous birds in south than in north. Our results indicated that rowanberry is a suitable ornamental tree for urban and roadside landscaping and may additionally benefit birds and other frugivorous wildlife.

Characteristics of body mass growth in semialtricial and altricial bird species during the nestling period

The dynamics of body mass growth were studied in nestlings of 22 semialtricial and altricial bird species based on materials collected in seven regions of Russia in the years 1976–2013. The bird species belong to four orders and 13 families. The results of the study indicate the nonuniform growth of nestlings in different bird species. Of the species investigated, only seven were found to reach or exceed the mass of adult birds. Over the nestling period, the nestlings of open-nesting species, such as the hooded crow (Corvus cornix), rook (Corvus frugilegus), magpie (Pica pica), fieldfare (Turdus pilaris), song thrush (Turdus philomelos), and goldfinch (Carduelis carduelis), do not reach the weight of adult birds and their growth continues after they leave the nest. In closed-nesting species, only the nestlings of the barn swallow (Hirundo rustica) reach or exceed the definitive mass, whereas the nestlings of the jackdaw (Corvus monedula), starling (Sturnus vulgaris), wryneck (Jynx torquilla), tree sparrow (Passer montanus), and great tit (Parus major) continue to grow after leaving the nest. The body mass of birds on the day of their hatching and before their departure from the nests and the mass of adult birds depend on the nesting type, duration of the nestling period, size groups of species, and their definitive size. The average specific growth rate of body mass and its maximum values for different species are also associated with these factors. The maximum specific growth rate in small-sized and medium-sized bird species was observed on the 0–1st days of life; in large bird species, on the 2nd–4th days. The specific growth rate did not depend on the type of nesting, but it was inversely related to the duration of the nestling period and the definitive sizes of birds.