Pre-breeding Period Research Articles

Spatio-temporal variation in nestling sex ratio among the Black Stork Ciconia nigra populations across Europe

Sex ratio is an indicator of population health as unexpected biases may indicate potential threats. We studied nestling sex ratio in Black Stork Ciconia nigra populations in order to check potential biases and differences along east–west and north–south gradient across its distribution range in Europe. We also studied variation between years, and checked potential correlations with weather variables. The overall sex ratio of nestlings in Europe was nearly equal with a non-significant deficiency (47.1 %) of males, the larger sex. Although yearly fluctuations in sex ratio were detected, no significant effect of the year alone was found, only simultaneously with population and brood size. There was a tendency to have a higher proportion of female nestlings in larger broods, but the pattern was probably scattered by the effect of reduction of largest broods. Compared to Western and Eastern Europe, a significant deficiency of male nestlings was found in Central Europe (Poland), whereas no differences were found along the north–south gradient. We did not find any effect of temperature, but rainfall during the incubation period was negatively correlated with the proportion of male nestlings in Central (Poland) and Western Europe (France) whereas in North-Eastern Europe (Latvia) the same effect of the precipitation in pre-breeding period was found.

Diet of the Little Owl (Athene noctua) during the pre-reproductive period in a semi-arid Mediterranean region

The assessment of feeding conditions and variations in diet composition over the pre-breeding period of birds plays a keyrole in the understanding of reproductive performance. Pellets regurgitated by the Little Owl, Athene noctua, were collected from Boulhilet (Batna, north-east Algeria). The analysis of 48 pellets resulted in the identification of 471 prey-items of 38 different species classified into 6 classes, 7 orders, 21 families, and 35 genera. Although the diet of the Little Owl mainly consists of arthropods, it is highly diverse (Food Niche Breadth = 14.5, Shannon index = 4.4 bits). Insects are made up 90% of the consumed food; however, they accounted only for 8% of the total biomass. Small mammal prey constituting a rich source of energy during the pre-breeding period, when other kinds of prey are not available due to cold conditions, made up 72% of the diet biomass. We found no significant variation in rodents as a component (number of prey-individuals, biomass, and prey-species richness, prey-s...

Dawn singing of Eastern Phoebes varies with breeding stage and brood number

The dawn chorus is a daily period of continuous singing by male songbirds that begins prior to sunrise. It is relatively less studied than daytime singing, and particularly in suboscine birds. We analyzed dawn singing of 14 Eastern Phoebes (Sayornis phoebe) in Echo Bay, Ontario over the 2011–2012 breeding seasons. We measured time of first song, length of dawn bout, time of final song, average song rate, and peak song rate and compared these characteristics among breeding stages. Results indicated that breeding stage was a significant predictor of all five dawn song features. Our results suggest that dawn singing of Eastern Phoebes is directly related to female fertility. We show that males begin singing significantly earlier when females are fertile. Males sang significantly longer during fertile and incubation stages than while feeding young. Males began singing later and sang for the shortest duration during the pre-breeding period. Song rates were higher in first broods than in second broods. We showed that suboscine dawn signaling patterns vary across breeding seasons in ways similar to oscine songbirds.

Effects of climate on the productivity of desert truffles beneath hyper-arid conditions.

Desert truffles are edible hypogenous fungi that are very well adapted to conditions of aridity in arid and semi-arid regions. This study aims to highlight the influence of climatic factors on the productivity of desert truffles under hyper-arid climatic conditions of the Sahara Desert in Algeria, with assumptions that the more varying climatic factors, mainly rainfall, are more crucial for the development and production of desert truffles. At seven separate sites, desert truffles were collected by systematic sampling between 2006 and 2012. The effects of climate parameters of each site on the productivities (g/ha/year) of desert truffle species were tested using generalized linear models (GLMs). The annual mean of the total production recorded for all three harvested species (Terfezia arenaria, Terfezia claveryi, and Tirmania nivea) was 785.43 ± 743.39 g/ha. Tirmania nivea was commonly present over the sampled sites with an occurrence of 70 ± 10.1%. GLMs revealed that total and specific productivities were closely positively related to autumnal precipitations occurring during October-December, which is the critical pre-breeding period for both desert truffles and host plant species. The other climatic parameters have statistically no effect on the annual variation of desert truffle productivity.

Prey density in non-breeding areas affects adult survival of black-legged kittiwakes Rissa tridactyla

In migratory birds, environmental conditions in both breeding and non-breeding areas may affect adult survival rates and hence be significant drivers of demographic processes. In seabirds, poor knowledge of their true distribution outside the breeding season, however, has severely limited such studies. This study explored how annual adult survival rates of black-legged kittiwakes Rissa tridactyla on Hornoya in the southern Barents Sea were related to temporal vari- ation in prey densities and climatic parameters in their breeding and non-breeding areas. We used information on the kittiwakes' spatiotemporal distribution in the non-breeding season gained from year-round light-based tracking devices (geolocators) and satellite transmitters, and kittiwake annual adult survival rates gained from a multistate capture-mark-recapture analysis of a 22 yr time series of colour-ringed kittiwakes. In the post-breeding period, kittiwakes concen- trated in an area east of Svalbard, in the winter they stayed in the Grand Banks/Labrador Sea area, and in the pre-breeding period they returned to the Barents Sea. We identified 2 possible prey categories of importance for the survival of kittiwakes in these areas (sea butterflies Theco- somata in the Grand Banks/Labrador Sea area in winter and capelin Mallotus villosus in the Bar- ents Sea in the pre-breeding season) that together explained 52% of the variation in adult survival rates. Our results may have important implications for the conservation of kittiwakes, which are declining globally, because other populations use the same areas. Since they are under the influ- ence of major anthropogenic activities including fisheries, international shipping and the offshore oil and gas industry, both areas should be targeted for future management plans.

Seasonal feeding activity of the tree-hole tick, Ixodes arboricola

Bird-specific ticks do not infest humans and livestock, but these ticks often share their avian hosts with generalist ticks that do. Therefore, their feeding activity may have an impact on the transmission of pathogens outside bird-tick transmission cycles. Here we examined the seasonal feeding activity of the tree-hole tick (Ixodes arboricola) in relation to the activity of its hole-breeding hosts (Parus major and Cyanistes caeruleus). We analysed data on ticks derived from birds, on the abundance of engorged ticks inside nest boxes, and on bird nests that were experimentally exposed to ticks. We observed a non-random pattern of feeding associated with the tick instar and host age. The majority of adult ticks fed on nestlings, while nymphs and larvae fed on both free-flying birds and nestlings. Due to their fast development, some ticks were able to feed twice within the same breeding season. The highest infestation rates in free-flying birds were found during the pre-breeding period and during autumn and winter when birds roost inside cavities. Except during winter, feeding of I. arboricola overlapped in time with the generalist Ixodes ricinus, implying that tick-borne microorganisms that are maintained by I. arboricola and birds could be bridged by I. ricinus to other hosts.

Duration of the prebreeding period and its relation to social organization of the sandpipers (Charadrii, Aves) nesting in northeastern Yakutia

The work was performed at two stations of the Ornithological Unit with the Institute of Biological Problems of the North, Far East Branch, Russian Academy of Sciences in the Nizhnekolymsk raion, Yakutia, staring from May 18–20 in 1984, 1985, 1987, 1988, and 1990. The timing of the prebreeding period has been determined for 11 sandpiper species differing in their social organization and compared using allometric equations. Body weight was chosen as the characteristic for bird size. Sandpipers arrive to the tundra at almost critical temperatures to begin breeding as early as possible. The timing of breeding depends on the foraging mode and distance to the overwintering areas. The duration of the prebreeding period is constant for each individual species and sex. The jointly nesting sandpipers display sex-dependent differences in the time spent for the prebreeding period. The exponents in allometric equations that relate duration of the prebreeding period with body weight are constant for a particular sex and differ between males and females. The time spent for prebreeding by the birds of different sexes depends on mating, parental, and territorial systems. The type of social organization of a species determines the time spent by male and female sandpipers for the prebreeding period. Relatively large-sized sandpiper species tend to reduce the calendar period for prebreeding, which imposes constraints on their social organization. Monogamy and joint parental care requires that the spatial structure of the population is more strictly controlled and retained for a longer time, thereby extending the time spent by males for this type of behavior.

Group display in the socially monogamous Northern Double-collared Sunbird (Cinnyris reichenowi)

Several sunbird species (Nectariniidae) exhibit group display, but the function of this behaviour still remains unclear. We test two hypotheses (reproductive tactic and joint territory defence) to explain the function of this behaviour using data gathered on Northern Double-collared Sunbirds (Cinnyris reichenowi) from the Cameroon Mountains. Sunbirds exhibited group display throughout the breeding cycle. Groups of birds were mainly comprised of neighbouring pairs aggregated at territory boundaries. The frequency of group displays varied significantly among individuals and over the breeding cycle, with the highest frequency during the pre-breeding period and the lowest during egg-laying (∼female's fertile period). Time spent on group display was significantly longer at the end of breeding. Off-territory forays were recorded for both males and females, males significantly increased the time spent on these forays during incubation. Extra-pair copulations were recorded only in five cases for females (4%) suggesting that most off-territory forays were motivated by feeding on nectar in neighbouring territories. Therefore, we suggest that the behaviour is used for joint territory defence rather than as an information centre for choosing mates for extra-pair copulations. Its function for choosing primary mates is also unlikely, because group displays were mainly observed in complete pairs.

Sympatric breeding auks shift between dietary and spatial resource partitioning across the annual cycle.

When species competing for the same resources coexist, some segregation in the way they utilize those resources is expected. However, little is known about how closely related sympatric breeding species segregate outside the breeding season. We investigated the annual segregation of three closely related seabirds (razorbill Alca torda , common guillemot Uria aalge and Brünnich’s guillemot U . lomvia ) breeding at the same colony in Southwest Greenland. By combining GPS and geolocation (GLS) tracking with dive depth and stable isotope analyses, we compared spatial and dietary resource partitioning. During the breeding season, we found the three species to segregate in diet and/or dive depth, but less in foraging area. During both the post-breeding and pre-breeding periods, the three species had an increased overlap in diet, but were dispersed over a larger spatial scale. Dive depths were similar across the annual cycle, suggesting morphological adaptations fixed by evolution. Prey choice, on the other hand, seemed much more flexible and therefore more likely to be affected by the immediate presence of potential competitors.

The effect of supplementary feeding in early spring on the breeding performance of the Great Spotted Woodpecker Dendrocopos major

Capsule The provision of supplementary food in early spring led to an advance in laying date and increased productivity for the Great Spotted Woodpecker. Aims To use the experimental provision of supplementary food in the prebreeding period to investigate the role of food supply in determining laying date, subsequent synchrony with natural food availability and the impact on productivity for the Great Spotted Woodpecker. Methods Supplementary food in the form of fat blocks was provided at 13 feeding stations distributed over half of a 100-ha study wood from early February until late April 2011 with the other half of the wood left unfed. The breeding parameters (first egg date, clutch size, number of young fledged per nest and nest success) of Great Spotted Woodpeckers were monitored throughout the wood and data from the ‘fed’ and ‘unfed’ zones compared. The same breeding parameters collected throughout the wood in the five preceding years (2006–10) when there was no supplementary feeding were used to provide control data. The temporal pattern in the abundance of the main natural prey was monitored using caterpillar frass traps. Results In 2011, the mean first egg date for woodpecker nests in the fed zone of the wood was 4–5 days earlier than for those nests in the unfed zone. Nests in the fed zone were almost twice as productive as those in the unfed zone even though the supplementary feeding stopped before the main period of chick rearing. There were no differences in the breeding parameters in the two zones of the wood in the control years when there was no supplementary feeding. 2011 was a very warm spring and the natural prey abundance peaked very early so that none of the woodpeckers were well synchronized with their main breeding season prey. However, the small advancement in first egg date meant the supplemented birds were better synchronized than the controls. Conclusion The response of Great Spotted Woodpeckers to supplementary feeding suggests they may be limited in their ability to shift their breeding period to maintain synchrony with their natural prey in the breeding season. This has important implications for the response of the birds to warm springs which are expected to be more frequent under future climate change. Use of garden feeders by Great Spotted Woodpeckers has the potential to increase breeding success and may be one of the many factors contributing to their current population increase.

Summer pre-breeding movements of Eleonora’s Falcon Falco eleonorae revealed by satellite telemetry: implications for conservation

SummaryRecent advances in bird tracking technologies are revealing that migratory birds use temporal staging sites other than breeding and wintering areas, and these areas deserve conservation efforts. Eleonora’s Falcon Falco eleonorae is a long-distance migratory raptor that breeds colonially on islands and is considered a priority species for conservation. Anecdotal observations indicate that during the pre-breeding period, Eleonora’s Falcons stay in inland areas far away from the colonies, but, to date there are no detailed data concerning the connectivity between these areas and breeding colonies. Using satellite telemetry, we analysed data from four summering events belonging to three individuals breeding in two colonies in the Western Mediterranean (Spain). All of them made inland movements in areas up to c.400 km distant from the respective breeding colonies, visiting several habitats, from forests to arable lands, probably taking advantage of high densities of insects. Perturbations occurring in these areas could threaten Eleonora’s Falcons with serious consequences at the population level. We suggest that conservation measures implemented at breeding and wintering grounds may not suffice and that temporary staging areas should be identified at a larger scale and deserve protection as well.

Sharing mates and nest boxes is associated with female “friendship” in European starlings, Sturnus vulgaris.

Breeding decisions in birds involve both mate and nest choice, and there is increasing evidence that social influences may modulate individual choices. Female preferences may be affected by other females' preferences and mutual choice cannot always be excluded, which makes the whole pattern more complex than assumed by most sexual selection models. Social transmission may be facilitated by particular social bonds, therefore prebreeding social networks may influence later mate choices. The other case where females share mate or resources is polygyny, generally viewed to only benefit males. If mutual benefits may arise then mechanisms should evolve to reduce the reproductive cost for females such as to reduce the cost of aggression by sharing their mate with a preferred same-sex social partner. We tested the hypothesis that females' mating decisions may be influenced by the prebreeding social network and that social partner relations established prior to breeding may share decisions (mate/sites) in a facultatively polygynous species, the European starling. Two experiments were designed to test the relative importance of male or nest by following the whole dynamics of the breeding cycle from the prebreeding period until mate and nest selection. In both cases socially isolated females tended to be excluded from breeding, while prebreeding social partners tended to share mates and to nest in close proximity, mate copying leading in some case to polygyny. The final pattern resulted both from female "likes and dislikes" and male preferences for some females. Aggressive interactions between females were rare. Vocal sharing between females may have been a clue for males as to the degree of social integration of these females.

圈养尖吻蝮雌体大小、窝卵数和卵大小之间的关系

尖吻蝮(<em>Deinagkistrodon acutus</em>)野生资源日益枯竭,食用和药用压力巨大,亟需开展人工养殖。目前尖吻蝮的人工养殖技术还不够成熟,大多数养殖场采用半地下室饲养尖吻蝮,有关该条件下尖吻蝮的繁殖特性报道较少。为促进尖吻蝮的人工养殖,2010年4-9月,在湖南永州市对半地下室圈养的尖吻蝮成体的体型指标、窝卵数、窝卵重、卵重等繁殖特征之间的关系进行了研究。结果表明:圈养尖吻蝮成年雌体产单窝柔性卵,平均窝卵数为23.0±7.8(13-37)枚 (<em>n</em>=23);将产后雌体体重和窝卵重相加记为产前雌体体重,采用SPSS 13.0软件处理数据,设置α=0.05和α=0.01,发现产前雌体体重分别与窝卵数、窝卵重、卵重均呈显著相关性;产前雌体体长分别与窝卵数、窝卵重、卵重无显著相关性;窝卵数与卵重无显著相关性,卵重分别与卵短径、卵长径均呈显著相关性。产前体重在1000-1200 g之间的雌蛇所产窝卵数和单枚卵重的数值均较大且最集中,这保证了雌体繁殖输出后代的生存优势,对尖吻蝮人工养殖挑选雌性种蛇有一定的指导意义。;Wild populations of the five-paced pit-viper (<em>Deinagkistrodon acutus</em>) are increasingly threatened due to overhunting by local human populations, who kill the snakes mostly for food and medicinal use, and to a lesser extent for their skin to use in handiwork. Because <em>D. acutus</em> is currently classified as a highly vulnerable species in China, there is increased urgency to develop artificial breeding technology to ensure the long-term survival of the species. Although a number of farms currently breed<em> D. acutus</em> under semi-basement captive conditions, the artificial breeding technology for this species is still in its infancy, and few studies have empirically investigated the reproductive characteristics of <em>D. acutus</em>. In order to increase our understanding of the reproduction of <em>D. acutus</em>, and hence improve prospects of artificially breeding the species, we studied the body size, clutch size, clutch mass and other reproductive characteristics of adults under semi-basement captive conditions in Yongzhou City of Hunan Province from April-September 2010. We collected 42 healthy <em>D. acutus</em> (14♂28♀) adults and housed them in semi-basement conditions within Yongzhou YISHE Technology Co., Ltd. The snakes' housing consisted of seven cement pools (1.5 m length, 1.0 m width, 1.2 m height), which each had a 20 cm-thick layer of soil on the bottom and a nylon net covering the top. Six individuals (2♂4♀) were put into each pool, in which the temperature was 16-29℃ and relative humidity was 78%-96%, and housed from April 15-September 15. Because <em>D. acutus</em> are typical sit-and-wait foragers, adults were fed on house mice (<em>Mus musculus</em>), domestic ducks and chickens. Captive <em>D. acutus</em> mainly preyed on live, small animals during the pre-breeding period, predating on live mice, live ducklings and live chicks in decreasing order. Oviposition season was from 2-21 August, and during this time we measured female body weight after oviposition (postpartum mass), snout-vent length (SVL), tail length (TL), oviposition time, clutch size, clutch mass, egg mass, egg length, egg width and relative clutch mass (RCM). All adult females laid a single clutch (mean egg number=23.0±7.8; (13-37); <em>n=</em>23) during the breeding season and maintained a larger nest egg output. Clutches were made up of eggs with flexible shells and females displayed parental care behaviors to protect them. Clutch size, clutch mass and egg mass were positively correlated with female prenatal mass, but not with female size (SVL) (using SPSS 13.0 to process data with significance level α=0.05 and α=0.01, and taking the sum of both the postpartum mass and the clutch mass as the prenatal mass). Egg mass was positively correlated with egg width and egg length, but not with clutch size. From our analysis, we show that females with prenatal mass of 1000-1200g produced clutches of eggs that were more numerous and heavier, which in turn guaranteed the survival of the resulting offspring. We suggest that female prenatal mass could be a criterion used in artificial breeding programs for <em>D. acutus</em>, and selecting females with prenatal mass of 1000-1200g could help produce greater numbers of healthy young in semi-basement farms that are seeking to breed the species.

Foraging behaviour of common murres in the Baltic Sea, recorded by simultaneous attachment of GPS and time-depth recorder devices

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 475:277-289 (2013) - DOI: https://doi.org/10.3354/meps10125 Foraging behaviour of common murres in the Baltic Sea, recorded by simultaneous attachment of GPS and time-depth recorder devices Thomas J. Evans1,*, Martina Kadin2, Olof Olsson2, Susanne Åkesson1 1Centre for Animal Movement Research, Department of Biology, Lund University, Ecology Building, 22362 Lund, Sweden 2Stockholm Resilience Centre, Stockholm University, 10691 Stockholm, Sweden *Email: tom.evans@biol.lu.se ABSTRACT: Global positioning system and time-depth recorders were deployed in combination to investigate the foraging behaviour of common murres Uria aalge breeding at Stora Karlsö Island, Baltic Sea, during the chick-rearing period. In the pre-breeding period the main prey species of murres, sprat Sprattus sprattus, is targeted by commercial fisheries, likely reducing prey availability during the breeding season. Foraging trips typically consisted of a short flight followed by a period sitting on the sea surface (0.39 ± 0.48 h), followed by several (5.3 ± 3.8) diving bouts interspersed by flights and water surface activity. Following the final diving bout, murres returned directly to the colony. Overnight foraging trips lasted longer than daytime trips, and that result corresponded with greater diving activity and reduced dive depths around dawn and dusk, likely times of high prey accessibility. High outward flight groundspeeds (20.0 ± 2.8 m s-1) were aided by tailwinds, and lower inward flight groundspeeds (15.1 ± 2.5 m s-1) were impeded by headwinds. Flights following the wind direction may reflect a strategy to reduce crosswind drift. Foraging intensity was lower than reported by most other studies of murres, suggesting more abundant or aggregated prey. KEY WORDS: Foraging behaviour · Diving behaviour · Uria aalge · Common murre · Wildlife telemetry · Data loggers · Baltic Sea Full text in pdf format Supplementary material PreviousNextCite this article as: Evans TJ, Kadin M, Olsson O, Åkesson S (2013) Foraging behaviour of common murres in the Baltic Sea, recorded by simultaneous attachment of GPS and time-depth recorder devices. Mar Ecol Prog Ser 475:277-289. https://doi.org/10.3354/meps10125 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 475. Online publication date: February 14, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Pre-breeding foraging and nest site habitat selection by Lesser Spotted Woodpeckers Dendrocopos minor in mature woodland blocks in England

Lesser Spotted Woodpeckers Dendrocopos minor have dramatically declined and retracted in range in Britain. Pre-breeding foraging may be critical and, although work has been carried out elsewhere in Europe our knowledge of habitat requirements for British birds is limited.We aim to describe foraging behaviour and selection of foraging locations in the pre-breeding period; and to provide descriptions of nest sites and wider habitat selection for nesting.We recorded foraging behaviour, attributes of foraging trees and nest site characteristics and compared them with random areas within woods. Small branches of live oaks at heights usually in the upper third of the tree were most frequently used for foraging. At a wider scale, areas selected contained more deadwood. Nest cavities were usually placed in the upper half of a tree, and oak was commonly used. For nesting, open areas were selected with more dead trees and a mature structure. Many of the attributes important for foraging and nesting have changed in English woodlands in the direction expected to have negative impacts on this species, except for deadwood. Further work shouldmeasure food availability in areas of differing structures. Knowledge of declining species' resource requirements allows targeted and informed management for conservation.

Protracted Reproductive Seasonality in the Male Giant Panda (Ailuropoda melanoleuca) Reflected by Patterns in Androgen Profiles, Ejaculate Characteristics, and Selected Behaviors1

The female giant panda (Ailuropoda melanoleuca) experiences a brief (24-72 h) seasonal estrus, occurring once annually in spring (February-May). Our aim was to determine the existence and temporal profile of reproductive seasonality in the male of this species. The study was facilitated by 3 yr of access to eight giant panda males living in a large breeding center in China. Seasonal periods for the male were defined on the basis of female reproductive activity as prebreeding, breeding (early, peak, late), and nonbreeding seasons. Testes size, fecal androgen excretion, ejaculated sperm density, and frequency of reproductive behaviors (i.e., locomotion, scent marking, vocalizations) increased (P < 0.05) from the prebreeding period (October 1-January 31) to the early breeding season (February 1-March 21). Testes volume and sperm concentration were maximal from March 22 through April 15, a period coinciding with maximal female breeding activity. The occurrence of male reproductive behaviors and fecal androgen concentrations began declining during peak breeding and continued from April 16 through May 31 (late breeding period), returning to nadir throughout the nonbreeding interval (June 1-September 30). Reproductive quiescence throughout the latter period was associated with basal testes size/volume and aspermic ejaculates. Our results reveal that testes morphometry, fecal androgen excretion, seminal quality, and certain behaviors integrated together clearly demonstrate reproductive seasonality in the male giant panda. The coordinated increases in testes size, androgen production, sperm density, and sexual behaviors occur over a protracted interval, likely to prepare for and then accommodate a brief, unpredictable female estrus.

Baltic Dunlin (Calidris alpina schinzii Brehm) on Kurgalsky Peninsula: features of biology, the annual cycle, and factors of the environment limiting its distribution in the eastern part of the Gulf of Finland

This paper presents the description of the breeding biology of Baltic Dunlin on the Kurgalsky Peninsula (eastern part of the Gulf of Finland). Variability of terms of the arrival and start of reproduction and their dependence from the process of spring events in the Baltic region was studied. These parameters were compared with data from other parts of the area. The essential delay of terms of the arrival and start of reproduction of Baltic Dunlins is observed in process of movement to the north-east of the breeding area. At that, the time of the termination of eggs laying everywhere is dated for the last dates of May – beginning of June, and flying away of young and adult birds everywhere finished by the end of June – beginning of July. In north-east areas, there is an essential reduction of the period of eggs laying and, especially, the prebreeding period. Important factors of dynamics of natural habitats of Baltic Dunlins are the effect of winter shearing of ice and of the autumn storms, interrupting vegetative successions at early stages of their development. Recommendations to the protection of this subspecies are given.

Poorer breeding by little penguins near Perth, Western Australia is correlated with above average sea surface temperatures and a stronger Leeuwin Current

Using 20 years of data (1986 to 2008), we examined relationships between oceanographic variables (Fremantle sea level (FSL) – a proxy for the strength of the Leeuwin Current – and sea surface temperature (SST)) and five measures of little penguin, Eudyptula minor, breeding performance near Perth, Western Australia: namely (1) the laying date, (2) the number of chicks produced per pair, (3) the proportion of eggs that hatched, (4) the overall breeding success, defined as the proportion of total eggs laid that resulted in successful fledglings and (5) chick mass at fledging. The next three years of data (2009 to 2011) were used to test the performance of our statistical predictive models. FSL provided more accurate predictions of timing of laying, whereas SST provided more accurate predictions of breeding success. A later end to laying was associated with a high FSL during the summer (December to February) before breeding. Higher SSTs in the pre-breeding period from April to May corresponded to reduced breeding success, with lower fledgling success, fewer chicks per pair and generally a lower mean mass of chicks at fledging. The models predict that future oceanographic warming is expected to reduce the breeding success of this colony of little penguins.

The first observation of the Levant sparrowhawk Accipiter brevipes (Severtzov, 1850) in Slovakia

Abstract On May 1 5, 201 2 an individual of Levant sparrowhawk Accipiter brevipes was observed at the southern edge of Trebišov town in eastern Slovakia, situated in the Východoslovenská rovina Lowlands. The sighting was documented with photographs. This is the first recorded occurrence of this species in terms of the bird fauna of Slovakia. The present article describes in detail its distribution and breeding in eastern Hungary and western Romania, based on an isolated population in the Pannonian Basin at the north-western edge of its breeding range. The occurrence of the Levant sparrowhawk beyond the boundaries of its breeding range and outside the Pannonian Basin consists mostly of rare movements by young individuals (northern Moravia, central and northern Poland) far north of its breeding range. An adult male was observed in south-eastern Poland in the pre-breeding period, and in Slovakia an adult female was observed in the breeding period.

Selection on laying date is connected to breeding density in the pied flycatcher

Timing of reproduction and clutch size are important determinants of breeding success, especially in seasonal environments. Several recent bird population studies have shown changes in breeding time and in natural selection on it. These changes have often been linked with climate change, but few studies have investigated how the traits or natural selection are actually connected with climatic factors. Furthermore, the effect of population density on selection has been rarely considered, despite the potential importance of density in demographic processes. We studied variation in natural selection on laying date and on clutch size in relation to measures of spring phenology and population density in a long-term study of pied flycatchers in SW Finland. The phenological stage of the environment at mean egg-laying did not affect the direction of selection on either laying date or on clutch size. There was, however, stronger selection for earlier laying date when the breeding density of the population was high, suggesting that early breeding is not necessarily beneficial as such, but that its importance is emphasized when high population density increases competition. In addition, early breeding was favoured when the pre-breeding period was cool, which may indicate an increased advantage for the fittest individuals in harsher conditions. In the middle of the twentieth century, there was selection for large clutch size, which subsequently ceased, along with an overall decrease in recruit production. Our results indicate that attention should be paid to demographic factors such as breeding density when studying natural selection and temporal changes in it.