Chiffchaff Phylloscopus Collybita Research Articles

Host Cells of Leucocytozoon (Haemosporida, Leucocytozoidae) Gametocytes, with Remarks on the Phylogenetic Importance of This Character.

Leucocytozoon parasites remain poorly investigated in comparison to other haemosporidians. The host cell inhabited by their blood stages (gametocytes) remains insufficiently known. This study aimed to determine the blood cells inhabited by Leucocytozoon gametocytes in different species of Passeriformes and to test if this feature has a phylogenetic importance. We microscopically analyzed blood films stained with Giemsa from six different bird species and individuals and used PCR-based methods for parasite lineage identification. The DNA sequences obtained were applied for phylogenetic analysis. Leucocytozoon parasite from the song thrush Turdus philomelos (cytochrome b lineage STUR1), the blackbird Turdus merula (undetermined lineage), the garden warbler Sylvia borin (unknown lineage) inhabited erythrocytes, a parasite from the blue tit Cyanistes caeruleus (PARUS4) infects lymphocytes, while in the wood warbler Phylloscopus sibilatrix (WW6) and the common chiffchaff Phylloscopus collybita (AFR205) they were found inhabiting thrombocytes. Parasites infecting thrombocytes were closely related, while the parasites infecting erythrocytes were placed in three different clades, and the one found in lymphocytes was placed in a separate clade. This shows that the determination of host cells inhabited by Leucocytozoon parasites can be phylogenetically important and should be considered in future species descriptions. Noteworthy, phylogenetic analysis might be used for the prediction of which host cells parasite lineages might inhabit.

Breeding ground temperature rises, more than habitat change, are associated with spatially variable population trends in two species of migratory bird

Habitat loss and climate change are key drivers of global biodiversity declines but their relative importance has rarely been examined. We attempted to attribute spatially divergent population trends of two Afro‐Palaearctic migrant warbler species, Willow Warbler Phylloscopus trochilus and Common Chiffchaff Phylloscopus collybita, to changes in breeding grounds climate or habitat. We used bird counts from over 4000 sites across the UK between 1994 and 2017, monitored as part of the BTO/JNCC/RSPB Breeding Bird Survey. We modelled Willow Warbler and Common Chiffchaff population size and growth in relation to habitat, climate and weather. We then used the abundance model coefficients and observed environmental changes to determine the extent to which spatially varying population trends in England and Scotland were consistent with attribution to climate and habitat changes. Both species' population size and growth correlated with habitat, climate and weather on their breeding grounds. Changes in habitat, in particular woodland expansion, could be linked to small population increases for both species in England and Scotland. Both species' populations correlated more strongly with climate than weather, and both had an optimum breeding season temperature: 11°C for Willow Warbler and around 13.5°C for Common Chiffchaff (with marginally different predictions from population size and growth models). Breeding ground temperature increases, therefore, had the potential to have caused some of the observed Willow Warbler declines in England (where the mean breeding season temperature was 12.7°C) and increases in Scotland (mean breeding season temperature was 10.2°C), and some of the differential rates of increase for Common Chiffchaff. However, much of the variation in species' population abundance and trends were not well predicted by our models and could be due to other factors, such as species interactions, habitat and climate change in their wintering grounds and on migration. This study provides evidence that the effect of climate change on a species may vary spatially and may switch from being beneficial to being detrimental if a temperature threshold is exceeded.

Parameters of the autumn migration stopover of the chiffchaff (Phylloscopus collybita Vieillot, 1817) (Sylviidae, Aves) in the conditions of the middle taiga in the Eastern Russian plain

Parameters of the autumn migration stopover of the chiffchaff Phylloscopus collybita (Vieillot, 1817) in the taiga zone of the Eastern Russian plain were estimated. The studies were carried out in 2015–2019, a total of 1,634 birds were included in our analysis. It has been established that migrating chiffchaffs can be conditionally divided into two groups. The first group consists of transit individuals leaving their stopover just on the day of arrival, without delay. The other group includes individuals who make stopovers for a longer period (4.87 days on average). For the birds of both groups, changes in their body weight and fat accumulation rate were revealed during one day and throughout the entire migration stopover. During an average migration stopover, birds retain their energy reserves at a certain level. In general, they accumulate no more than 5% of the average body weight in the population during the average stop period. A smaller proportion of migrants make multi-day stops when the fat accumulation rate is low. Every day of staying at a migration stopover leads to temporary surges and losses in body weight, with no increase in body fat. Birds, at the end of their migration season, spend more time and energy for looking for food. The part of migratory birds deciding to stop finds themselves in the most optimal conditions. This small group is the main reserve for preserving the population during the difficult period of migration.

Seasonality and social factors, but not noise pollution, influence the song characteristics of two leaf warbler species.

Changes in the acoustic signalling of animals occupying urban ecosystems is often associated with the masking effects of noise pollution, but the way in which they respond to noise pollution is not straightforward. An increasing number of studies indicate that responses can be case specific, and some species have been found to respond differently to high levels of natural versus anthropogenic noise, as well as different levels of the latter. While the perception of noise between species may vary with its source, amplitude and temporal features, some species may possess broader environmental tolerance to noise pollution, as they use higher frequency vocalizations that are less masked by low-frequency urban noise. In this study, we explored the song variation of two closely related leaf warblers, the Common Chiffchaff Phylloscopus collybita and the Willow Warbler Phylloscopus trochilus, inhabiting urban green spaces and nonurban forests. The main goal of our study was to evaluate the impact of moderate levels of noise pollution on the songs of species which use higher frequency vocalizations and large frequency bandwidth. Previous studies found that the Common Chiffchaff modified their song in response to intense noise pollution, while no such data is available for the Willow Warbler. However, the majority of urban green spaces, which serve as wildlife hot spots in urban environments are usually polluted with moderate noise levels, which may not mask the acoustic signals of species that communicate with higher frequency. We analysed the spectral and temporal song parameters of both warblers and described the ambient noise present in males’ territories. Additionally, we looked at the social and seasonal aspects of bird song, since there is more than just noise in urban ecosystems which may affect acoustic communication. We found no evidence for noise-related bird song divergence in either species, however, we showed that social factors, time of day and season influence certain Common Chiffchaff and Willow Warbler song characteristics. Lack of noise-related bird song divergence may be due to the relatively low variation in its amplitude or other noise features present within the song frequency range of the studied species. Similar results have previously been shown for a few songbird species inhabiting urban ecosystems. Although in many cases such results remain in the shadow of the positive ones, they all contribute to a better understanding of animal communication in urban ecosystems.

Breeding Ecology of the Iberian Chiffchaff Phylloscopus ibericus: First Data from North Africa

Till now, the breeding biology of several North African bird populations has been little studied, particularly that of the southern populations of Iberian chiffchaff Phylloscopus ibericus. In the present study, total of 31 nests of Iberian chiffchaff were monitored in the northeastern Algeria during 2013–2017. The nesting period, clutch and brood sizes, and reproductive success of the species were determined. The first egg-laying dates of the first broods were spread over the first twenty days of April. There were significant among-year variations in nesting seasons. The Iberian chiffchaff clutch sizes averaged 4.51 eggs. The number of hatchlings and fledglings averaged 4.09 and 3.54 nestlings, respectively. There is no correlation between the nest height above the ground and the hatching and the breeding success of the species. Predation and nest abandonment were the main causes of the breeding failure of the Iberian chiffchaff in studied population, however, in general the breeding success was high – 80.7%. Breeding data for the Iberian chiffchaff at the southern edge of its breeding range in North Africa show smaller clutches and production of fewer young compared to the common chiffchaff Phylloscopus collybita in Europe.

Contrasting use of space by two migratory Afro-Palearctic warblers on their African non-breeding grounds

In migratory birds, constraints due to breeding are relaxed during the non-breeding season and thus, social behaviours and spatial associations are potentially more directly coupled to food resources and habitats. Use of space and territorial behaviour has rarely been studied in Afro-Palearctic migrants. Variation in strategies could exist among species within the same habitat because of differences in foraging, diet and microhabitat. We compare use of space and association with conspecifics in Common Chiffchaffs Phylloscopus collybita and Subalpine Warblers Sylvia cantillans at a non-breeding site in northern Senegal using radio telemetry and playback experiments. Home ranges of Chiffchaffs were larger and overlapped more than those of Subalpine Warblers. Though Chiffchaffs were often close together, we found no signs of spatial association among individuals in either species. Chiffchaffs showed no clear pattern of territorial response to conspecific song; whereas, playback elicited a territorial response in most Subalpine Warblers. Our results suggest species-specific differences in use of space that might reflect differences in foraging ecology and microhabitat.

Consequences of spring arrival dates for the breeding phenology of migratory warblers

ABSTRACT Capsule Early male arrival on the breeding grounds results in early pairing but not early nesting in Chiffchaffs Phylloscopus collybita, and Chiffchaffs can nest, fail, and re-nest before Willow Warblers Phylloscopus trochilus begin nesting. Aims To quantify the consequences of timing of arrival for the subsequent timing of pairing, nesting, and re-nesting of short-distance (Chiffchaff) and long-distance (Willow Warbler) migrants. Methods The arrival dates of 118 Chiffchaffs and 20 Willow Warblers were measured from March to June over 10 weeks in Foxley Wood nature reserve, Norfolk. Colour-ringing of 56 Chiffchaffs (55 males, 1 female) and 11 Willow Warblers (10 males, 1 female) was used to relate individual arrival dates to timing of male pairing, clutch initiation, and re-nesting. Results Male Chiffchaffs started to arrive in early March and increased rapidly in number until early April, while the arrival of male Willow Warblers began in early April. Early-arriving male Chiffchaffs paired earlier than later-arriving individuals, but timing of clutch initiation was unrelated to male arrival dates. Early nesting by Chiffchaffs allowed replacement clutches following nest loss, the earliest of which occurred 12 days after the first Willow Warbler male had paired. Conclusions Although early arrival in male Chiffchaffs does not translate into earlier nesting, timing of nesting in Chiffchaffs was sufficiently early to allow time for replacement clutches following nest loss. The later arrival of Willow Warblers is likely to mean fewer opportunities for replacement clutches following nest loss. This difference in breeding phenology could therefore contribute to differences in productivity between the species, especially if nest failure rates are high.

The use of wing length for sexing Common Chiffchaffs Phylloscopus collybita in a local breeding population

ABSTRACT Common Chiffchaffs Phylloscopus collybita caught at Wicken Fen during the breeding season showed a strongly bimodal distribution of wing length, with females being typically shorter-winged than males. Studying wing length in a local population helped to control the effects of variables other than sex, and provided the opportunity to compare behavioural and other breeding-related sexing criteria with the sex indicated by the wing length. All records of brood patch and female-related behaviour were for short-winged birds, and all records of cloacal protuberance and male-related behaviour for long-winged birds. An overlap of wing length between the sexes existed at 58 mm.

Migratory passerine birds in Britain carry Phytophthora ramorum inoculum on their feathers and “feet” at low frequency

AbstractIn this study, we investigated whether birds could be vectors facilitating long‐distance spread of Phytophthora ramorum in Britain. Migratory bird species associated with the main sporangium‐producing host plants and most likely to pick up P. ramorum spores were considered. Swabs were taken from the flank and “feet” of 1,014 birds over a 12‐month period (April 2011–March 2012) in the west of Britain and subsequently analyzed for the presence of P. ramorum using nested PCR. Ten positive samples from 10 birds were identified: three in Cornwall, one in Devon, three in Gloucestershire, two in north Wales and one in Merseyside. Phytophthora ramorum was detected on samples from four species of thrushes (Redwing Turdus iliacus, Fieldfare T. pilaris, Blackbird T. merula and Song Thrush T. philomelos) and one species of warbler (Chiffchaff Phylloscopus collybita). All birds that tested positive were sampled in late autumn and winter (October–February), when long‐distance movements (over 100 km) would have stopped. The low incidence of P. ramorum found using PCR suggests that the incidence of inoculum, whether viable or not, on birds was low. The apparently low incidence of inoculum on birds suggests migratory passerine birds can carry P. ramorum inoculum on their feathers and “feet,” albeit at low frequency. The dates of positive samples indicate that birds would not have been moving long distances at the time but further work is needed to estimate the extent of their contribution to the spread of P. ramorum in Britain.

Aircraft sound exposure leads to song frequency decline and elevated aggression in wild chiffchaffs.

The ubiquitous anthropogenic low‐frequency noise impedes communication by masking animal signals. To overcome this communication barrier, animals may increase the frequency, amplitude and delivery rate of their acoustic signals, making them more easily heard. However, a direct impact of intermittent, high‐level aircraft noise on birds’ behaviour living close to a runway has not been studied in detail.We recorded common chiffchaffs Phylloscopus collybita songs near two airports and nearby control areas, and we measured sound levels in their territories at Manchester Airport. The song recordings were made in between aircraft movements, when ambient sound levels were similar between airport and control populations. We also conducted playback experiments at the airport and a control population to test the salience of airport, and control population specific songs.In contrast to the general pattern of increased song frequency in noisy areas, we show that common chiffchaffs at airports show a negative relationship between noise exposure level and song frequency.Experimental data show that chiffchaffs living near airports also respond more aggressively to song playback.Since the decrease in song frequency results in increased overlap with aircraft noise, these findings cannot be explained as an adaptation to improve communication. The increased levels of aggression suggest that chiffchaffs, like humans, might be affected behaviourally by extreme noise pollution. These findings should influence environmental impact assessments for airport expansions globally.

Time‐keeping programme can explain seasonal dynamics of leukocyte profile in a migrant bird

It has been proposed that immune functioning in wild animals is shaped by the trade‐off between a probability of encountering pathogens and an availability of resources for maintaining immune system in active state. Due to resources’ seasonality one can expect that immune functioning, e.g. absolute and relative counts of white blood cells, WBC (leukocyte profile) also follows an annual cycle. However, dynamics of the seasonal changes of leukocyte profile are controversial and specific inquiries so far addressed only a portion of annual cycle. To study the seasonal dynamics of the leukocyte profile and to test its possible endogenous basis we experimentally simulated annual cycle in a migratory passerine bird, chiffchaff Phylloscopus collybita abietinus. We report here a clear seasonal pattern of leukocyte profile in that species. The highest WBC counts were observed during pre‐alternate moult and the lowest during the subsequent spring migration; the seasonal dynamics of HL ratio showed the opposite tendency. Surprisingly, HL ratios during autumn migration were relatively low, indicating little to no stress. Observed seasonal changes in controlled experimental conditions suggest an existence of time‐keeping programme underlying these variations. Additionally we found negative relationship between the body condition index and WBC counts and positive relationship with HL (heterophil to lymphocyte) ratio; these findings are controversial with the data obtained with other bird species in wild populations. Understanding the origins of variation of leukocyte profile per se and in relation with other parameters of physiological condition can be a useful tool in studying physiological response to environmental changes.

Domestic Cat Predation on Garden Birds: An Analysis from European Ringing Programmes

Domestic Cat Felis silvestris catus populations have been increasing since the 1970s in Western Europe. This increase is particularly notable in human habitats, such as gardens and parks, where Cats have locally become the most abundant carnivore. In urban contexts, understanding Cat behaviour could be important for biodiversity management. In this study, we analysed Cat predation on garden birds, using existing data from ringing programmes in France and Belgium. These types of data permit us to (1) investigate the bird species killed by Cats, (2) analyse changes in the proportion of birds killed by Cats over the years 2000–2015, and (3) compare the causes of bird mortality as reported by observers. The most affected species were passerines, both granivorous and insectivorous (Europian Robin Erithacus rubecula, Dunnock Prunella modularis, Greenfinch Carduelis chloris), who can frequently be found feeding on the ground or visiting feeders in the winter. Perched birds (Chiffchaff Phylloscopus collybita, Blackcap Sylvia atricapilla) were less represented. Ground-dwelling habits were significantly correlated to predation rates. Between 2000 and 2015, Cat-related mortality in garden birds increased by at least 50%, depending on the ringing programme studied, which coincided with an increase in Cat populations. Cat-related mortality is one of the leading causes of death reported by observers (12.8–26.3% of total dead birds) and occurs at the same order of magnitude as deaths due to collisions with windows. These results underline the need to consider Cats and their potential impacts on urban biodiversity management at garden and urban levels.

Trophic consequences of mast seeding for avian and mammalian seed and non-seed consumers in European temperate forests

Resource pulses are wide-ranging, influential ecosystem processes with effects permeating throughout the food web, sometimes over several years. In temperate forests, resource pulses may be triggered by mast seeding of one or several tree species, providing a key food source to a multitude of species. However, direct and indirect consequences of mast seeding for various seed and non-seed consumers, and interactions among them, are often poorly understood. Based on a 16-year data set from Germany, we evaluated several hypotheses concerning the relationships between (1) mast seeding and seed consumers, (2) seed and non-seed consumers, and (3) seed or non-seed consumers and extrinsic factors other than mast seeding. Abundances of Eurasian Jays Garrulus glandarius correlated negatively, but abundances of voles positively, with mast seeding of oak in the previous fall, while the abundances of Great Tits Parus major did not appear to be linked to mast seeding. The abundance of non-seed consumers, such as Wood Warblers Phylloscopus sibilatrix, but not Chiffchaffs Phylloscopus collybita, appeared to be linked indirectly to mast seeding of oak via voles. Specifically, Wood Warbler abundance negatively correlated with abundances of voles. Extrinsic factors other than mast seeding appeared to be unimportant. This study shows how the set of factors affecting a species at a large spatial scale may vary from the set of factors acting at smaller spatial scales, as obtained from the literature. Lastly, we illustrate how several taxa at various trophic levels of a temperate forest ecosystem in Central Europe are linked via resource pulses. Assessing ecological processes revolving around seed-based resource pulses is pivotal to understanding how changing mast seeding dynamics may alter an ecosystem.

Geographic patterns of mtDNA and Z-linked sequence variation in the Common Chiffchaff and the 'chiffchaff complex'.

The Common Chiffchaff Phylloscopus collybita is an abundant, polytypic Palearctic bird. Validity of some of its subspecies is controversial and birds from some parts of the species range remain unclassified taxonomically. The relationships among populations from different geographic areas have not been sufficiently explored with molecular data. In this study we analyzed the relationships among the four species in the ‘chiffchaff complex’ (Common Chiffchaff, Iberian Chiffchaff P. ibericus, Canary Islands Chiffchaff P. canariensis and Mountain Chiffchaff P. sindianus), and the patterns of intraspecific geographic variation in the mtDNA ND2 gene and intron 9 of the Z-linked aconitase gene (ACO1I9) across the Common Chiffchaff range, including a recently discovered population breeding on Mt. Hermon (Anti-Lebanon mountains). Our data supported the monophyly of the chiffchaff complex and its current systematics at the species level. Within the Common Chiffchaff, the Siberian race P. c. tristis was the most differentiated subspecies and may represent a separate or incipient species. Other Common Chiffchaff subspecies also were differentiated in their mtDNA, however, lineages of neighboring subspecies formed wide zones of introgression. The Mt. Hermon population was of mixed genetic origin but contained some birds with novel unique lineage that could not be assigned to known subspecies. All Common Chiffchaff lineages diverged at the end of the Ionian stage of Pleistocene. Lineage sorting of ACO1I9 alleles was not as complete as that of mtDNA. Chiffchaff species were mostly distinct at ACO1I9, except the Common and Canary Islands Chiffchaffs that shared multiple alleles. An AMOVA identified geographic structure in Common Chiffchaff ACO1I9 variation that was broadly consistent with that of mtDNA ND2 gene. The genetic and other data suggest the chiffchaff complex to be a group of evolutionarily young taxa that represent a paradigm of ‘species evolution in action’ from intergrading subspecies through to apparently complete biological speciation.

Correction to: Cues to individual identity in songs of songbirds: testing general song characteristics in Chiffchaffs Phylloscopus collybita

Correction to: Cues to individual identity in songs of songbirds: testing general song characteristics in Chiffchaffs Phylloscopus collybita

Diversity and structure of avian communities in extensive lowland pine forests in relation to the distance from the forest edge

Most studies on edge effect are related to the forest-field edge, i.e. to the ecotone. However, there is a lack of studies attempting to investigate the effect of the distance from the forest/field edge on the avian communities in large continuous forests. The purpose of this study was to investigate this issue. The study area comprised a continuous coniferous forest, the so called Niemodlin Forest, situated in Opole Silesia, SW Poland. The line transect method has been employed in this study. In total, 54 breeding bird species were recorded. On particular 0.5 km section, the numbers varied from 34 to 48. Both the number of species and number of breeding pairs only slightly decreased with the distance from the forest/field edge. Overall, the differences between the mean densities of breeding species on 10 sections were not statistically significant. The Chaffinch Fringilla coelebs was by far the most numerous bird species, recorded as eudominant in 164 out of 165 sections. The Chiffchaff Phylloscopus collybita, Willow Warbler Phyloscopus trochilus and Blackap Sylvia atricapilla were dominants in all 10 sections, while the Blackbird Turdus merula dominated in nine (90%) and the Robin Erithacus rubecula in eight (80%) sections. The communal dominance slightly increased, but the number of dominant species and Pielou’s Evenness Index remained stable with the increase of the distance from the forest/field edge. While Shannon’s Diversity Index remained constant, Simpson’s Diversity Index decreased markedly with the increase in distance from the forest/field edge. The proportion of long-distance migrants slightly decreased, while that of short-distance migrants and residents remained constant with the increase in the distance from the forest/field edge. Strikingly, no such changes in the proportion of all feeding guilds were shown. More than half of all breeding bird species show a negative correlation between population density and the distance from the forest/field edge. The dominance of some species decreased with the increase of the distance from the forest/field edge: Hawfinch Coccothraustes coccothraustes, Starling Sturnus vulgaris, Blue Tit Parusa caeruleus, Raven Corvus corax, Wren Troglodytes troglodytes, Wood Pigeon Columba palumbus, and Wood Lark Lullula arborea. With the exception of the Yellowhammer Emberiza citrinella, the clearcuts in this study, not only failed to increase, but most probably caused a decrease in the number of both species and individuals. It is because clearing not only creates edges, but also causes loss of forest habitat and often results in forest fragmentation. Edge and area effect may in fact interact, in such way that the edge effect may drive out the area effect, causing the increase.

Characterization of Plasmodium relictum, a cosmopolitan agent of avian malaria

BackgroundMicroscopic research has shown that Plasmodium relictum is the most common agent of avian malaria. Recent molecular studies confirmed this conclusion and identified several mtDNA lineages, suggesting the existence of significant intra-species genetic variation or cryptic speciation. Most identified lineages have a broad range of hosts and geographical distribution. Here, a rare new lineage of P. relictum was reported and information about biological characters of different lineages of this pathogen was reviewed, suggesting issues for future research.MethodsThe new lineage pPHCOL01 was detected in Common chiffchaff Phylloscopus collybita, and the parasite was passaged in domestic canaries Serinus canaria. Organs of infected birds were examined using histology and chromogenic in situ hybridization methods. Culex quinquefasciatus mosquitoes, Zebra finch Taeniopygia guttata, Budgerigar Melopsittacus undulatus and European goldfinch Carduelis carduelis were exposed experimentally. Both Bayesian and Maximum Likelihood analyses identified the same phylogenetic relationships among different, closely-related lineages pSGS1, pGRW4, pGRW11, pLZFUS01, pPHCOL01 of P. relictum. Morphology of their blood stages was compared using fixed and stained blood smears, and biological properties of these parasites were reviewed.ResultsCommon canary and European goldfinch were susceptible to the parasite pPHCOL01, and had markedly variable individual prepatent periods and light transient parasitaemia. Exo-erythrocytic and sporogonic stages were not seen. The Zebra finch and Budgerigar were resistant. Neither blood stages nor vector stages of all examined P. relictum lineages can be distinguished morphologically.ConclusionWithin the huge spectrum of vertebrate hosts, mosquito vectors, and ecological conditions, different lineages of P. relictum exhibit indistinguishable, markedly variable morphological forms. Parasites of same lineages often develop differently in different bird species. Even more, the variation of biological properties (parasitaemia dynamics, blood pathology, prepatent period) in different isolates of the same lineage might be greater than the variation in different lineages during development in the same species of birds, indicating negligible taxonomic value of such features. Available lineage information is excellent for parasite diagnostics, but is limited in predictions about relationships in certain host-parasite associations. A combination of experiments, field observations, microscopic and molecular diagnostics is essential for understanding the role of different P. relictum lineages in bird health.

Estimating mortality rates among passerines caught for ringing with mist nets using data from previously ringed birds.

Mist netting is the most commonly used method for catching birds for scientific ringing, but despite decades of use, there have been few attempts to quantify the associated potential risks to the individuals caught. Any incidence of mortality through capture and handling, however low, is of potential ethical concern and may also introduce biases into the data. We estimate the mortality rate associated with capture of previously ringed (recaptured) passerines from the British and Irish Ringing Scheme (c. 1.5 million records) caught using mist nets. The importance of species, age, mass, month, time, previous captures, and an index of predator occurrence was tested using generalized linear mixed‐effects models. The average mortality rate was 0.0011, most of which was reported to occur before the individuals had been extracted from the nets (c. 70% of incidents). Juveniles appeared to be at higher risk and the incidence of predation from mist nets was seasonal, with increased risk during the winter. Species differed in their reported mortality rates with the apparent risk being greatest for Chiffchaff Phylloscopus collybita (0.0029) and Bullfinch Pyrrhula pyrrhula (0.0027). To improve our understanding (and hence minimize risk in future), we recommend collecting more complete data on incidences of mortality, and also injuries; exercising increased care when the species we have identified as being at greater risk are likely to be captured, and ensuring there are robust procedures for the checking of nets (as most reported incidents of mortality occur before handling). We also recommend that all Ringing Schemes should collate and make available data on capture‐related mortality. Overall rates of mortality associated with capture, although, were low and support the use of mist netting as a safe capture technique, without undue bias from mortality, when used by appropriately trained individuals.

Structure of avian communities in lowland coniferous forests in Opole Silesia (SSW Poland)

Abstract In Poland, forests comprise 31% of the total surface area, while the lowland coniferous forests comprise 51% of 94 000 km2 afforested areas. The line transect method was employed in 2002 and 2004 to estimate population densities and dominance of all bird species breeding in a selected fragment of such forest (eight transects with 165 sections and 77.7 km in total length). In total, 54 breeding bird species were recorded. The numbers varied between 37 and 44 on the particular transect. The number of breeding pairs per 10 ha varied on each transect from 41.0 to 93.6 (x=64.8; SD=102.22). Shannon’s diversity index varied between 1.2 and 1.4 on particular transects, while Simpson’s diversity index varied between 0.7 and 0.9. Also Pieleau’s evenness index varied slightly between 0.05 and 0.07. In overall, the differences between densities of breeding species on 8 transects were not statistically significant. The Chaffinch Fringilla coelebs was by far the most numerous bird species, recorded as eudominant in all eight transects and present in all 165 sections. The second to the Chaffinch was the Chiffchaff Phylloscopus collybita; also recorded in all sections and as a dominant in all transects. Three other species, namely the Blackbird Turdus merula, Willow Warbler Phylloscopus trochilus and Blackcap Sylvia atricapilla were recorded each one in more than 90% sections (N=165), and on particular transects their dominance varied between 4 and 11%. Residents comprised 57.5% of all breeding pairs. Short-distance migrants were almost twice more common than long-distance migrants. Insectivores were by far the most numerous feeding guild represented 88.9% of all breeding pairs. Overall density, cumulative dominance, diversity and evenness were unexpectedly very similar in this study (managed forest) and in natural primeval lowland coniferous forests of Białowieża.

Bird ringing and nest recording in Britain and Ireland in 2016

ABSTRACTThis is the 80th annual report of the British Trust for Ornithology's Ringing Scheme, incorporating the report of the Nest Record Scheme and covering work carried out and data processed in 2016. BTO and JNCC have used seabird population data to investigate how demographic processes drive population changes, enabling improved population models to be produced. These population models were used to help quantify the risks associated with large-scale infrastructure projects (e.g. windfarms) and recommendations were made concerning approaches to be used in particular circumstances. Density dependence in seabirds, and its potential impact on population models, was also reviewed but little evidence of significant effects was found. Research on the demographic causes of declines in migratory species, undertaken in collaboration with the University of East Anglia, focused on population changes in Willow Warblers Phylloscopus trochilus. Data from the Nest Record Scheme (NRS), Constant Effort Sites scheme (CES) and the Breeding Bird Survey were combined; the results showed that reduced productivity levels in Willow Warblers in the south of Britain were driving the decline. In 2016, 134 CE sites submitted data. Five migrant and two resident species exhibited long-term (1984–2015) declines in abundance while four migrant and six resident species showed declines in productivity. Compared to the five-year mean (2011–15), the abundance of 10 species increased significantly in 2016 with Cetti's Warbler Cettia cetti, Chiffchaff Phylloscopus collybita, Wren Troglodytes troglodytes and Robin Erithacus rubecula abundance at its highest since CES monitoring began. The abundance of three species fell significantly in 2016. Productivity increased for one species in 2016 and decreased significantly for 16 species. Survival rates increased significantly for three species and fell significantly for one. For the first time, the number of Retrapping Adults for Survival submissions passed 200. A total of 59 species were monitored and 24 projects ran for the first time. The most-studied species were Pied Flycatcher Ficedula hypoleuca (23 projects), House Sparrow Passer domesticus (17), Sand Martin Riparia riparia (15) and Starling Sturnus vulgaris (13). Over a million birds (1 051 629) were ringed during the year, comprising 157 653 nestlings, 490 796 first-year birds, 370 019 adults (birds in their second calendar year or older) and 33 161 birds where the age could not be determined. In addition, there were 255 898 recaptures of ringed birds at or near the ringing site. In total, 40 257 recoveries (birds found dead, or recaptured or resighted at least 5 km from the place of ringing) of BTO-ringed birds were reported in 2016. The Appendix highlights a selection of recoveries that have extended our knowledge of movements, as well as longevity records established during the year. NRS submissions in 2016 exceeded 45 000 for the third consecutive year, with a total of 46 514 records received. Mean laying dates for five species were significantly earlier than the five-year mean (2011–15) with 10 species laying significantly later. Three species displayed a significant increase in breeding success (fledglings per breeding attempt) in 2016 compared to the five-year mean, with four decreasing significantly. Permits/licences to disturb breeding birds on Schedule 1 of the Wildlife and Countryside Act 1981 (as amended), were prepared/issued to 587 ringers and nest recorders in 2016. During 2016, the use of special methods was authorised for 559 marking projects and 73 trapping projects, a 13% increase on 2015.