Substantial contribution of invertebrates to the diet of a winter seed‐eater,the reed bunting Emberiza schoeniclus,wintering in a sewage farm in south‐western Poland

We investigated whether the winter diet of a typical seed‐eating bird is hard‐wired in the context of evolutionary hypothesis for granivory. We examined the diet composition of ‘a small‐billed form’ of the reed bunting Emberiza schoeniclus wintering in a sewage farm in south‐western Poland (Central Europe), where unfrozen wastewater provides various groups of invertebrate prey. The analysis of droppings (N = 151) collected from four different feeding grounds located in reedbeds and grasslands inundated with waste‐water showed the substantial contribution of invertebrates in the diet of reed buntings. Across four sample areas, the frequency of invertebrates in faecal samples ranged between 37% to 80%. In total, we identified 194 animal prey, mainly spiders Araneae (53% of all identified invertebrate prey), and several taxa of Coleoptera (43%). Among plant food (N = 8357 identified items), the most numerous were shells of weed seeds, namely Amaranthus sp. (56.8%), Urtica dioica (22.6%), and Chenopodium sp. (19.6%). Our results showed that, during winter, the reed bunting is not an obligatory seed‐eater. This species may exploit both animal and plant food; hence, our results indicate that the reed buntings wintering in temperate Europe may feed more opportunistically than was previously assumed. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 108 , 429–433.     

Indexing European bird population trends using results of national monitoring schemes: a trial of a new method

Many European countries have annual breeding bird monitoring schemes based on nationwide samples; most are in northern and western Europe. We have developed a method to produce yearly population indices of bird species across countries by combining the results of existing national schemes. The method takes into account the differences in population sizes per country, as well as the differences in field methods, and the numbers of sites and years covered by the national schemes. In order to test the method, we collected raw data from a number of countries and applied an index method to produce scheme results per country. Data were collected for five farmland species (Lapwing Vanellus vanellus, Linnet Carduelis cannabina, Skylark Alauda arvensis, Whitethroat Sylvia communis and Yellowhammer Emberiza citrinella), from seven countries (UK, Netherlands, Denmark, Germany, Finland, Latvia and Estonia) for a 20-year period (1978–97). The trial demonstrated that it was possible to combine national indices to provide supra-national yearly totals and their standard errors; the results were similar to those produced when the raw data were used. Thus, yearly European indices can be produced by exchanging only limited amounts of information, that is the national yearly indices of each species or, preferably, the yearly population numbers and their standard errors. At a European scale, the populations of the five species selected have changed considerably. In western Europe (UK, Netherlands, Denmark and former West Germany combined), Linnet, Skylark and Yellowhammer have declined and Whitethroat has increased. Most changes occurred during the first ten-year period (1978–88). The changes in eastern Europe (the remaining countries) were less clear, in part because the statistical power of the national schemes is as yet limited.     

Seasonal variation in the diet of Redshank Tringa totanus in the Odiel Marshes,southwest Spain: a comparison of faecal and pellet analysis

Capsule Redshank diet from southern Europe during migration shows spatial and seasonal variations.

Aims To assess seasonal variation in Redshank diet at a major passage site, and to compare data derived from analysing pellets or faeces.

Methods At the Odiel Marshes in 2001, pellets from spring migration (39), autumn migration (121) and midwinter (15) were analysed, together with faecal samples from autumn (84).

Results The abundance of different invertebrate groups in pellets varied between seasons. In spring, Chironomus salinarius pupae and larvae dominated by volume, followed by Ephydridae larvae and the beetle Paracymus aenus. Polychaetes and molluscs dominated in autumn, and isopods in midwinter. In autumn, chironomid larvae, Mesembryanthemum nodiflorum seeds and Artemia cysts were relatively more abundant in faeces, whereas polychaetes, isopods, molluscs and cestode cysticercoids were more abundant in pellets. Harder and/or larger items were thus relatively more abundant in pellets than faeces. Pellet analysis gave more emphasis to mudflat prey, and faeces to saltpan prey.

Conclusion Pellet and faecal analysis give different results for wader diet, and it is useful to combine the two methods. However, they show significant correlations both in diet range and rank abundance of prey items. Redshank diet shows much seasonal and spatial variation in southern Europe.     

The significance of seed food in chick development re‐evaluated by tracking day‐to‐day dietary variation in the nestlings of a granivorous passerine

The dietary adjustment of nestlings of granivorous birds to a seed diet and the different morphological characteristics of ingested food have rarely been examined in natural conditions. It has been suggested that the provision of cereal grains to nestlings of some seed‐eating bird species in modern agroecosytems is the result of poor food conditions after agricultural intensification. We analysed the abundance of invertebrate prey in the main foraging habitat of parent birds, daily changes (from hatching to fledging) in the efficiency of cereal seed digestion, and the dietary characteristics, diet composition and prey type delivered to nestlings of the Yellowhammer Emberiza citrinella. Analysis of faecal sacs from nests located in breeding habitat with an abundant invertebrate fauna revealed no relationship between the proportion of cereal seeds in the diet of nestlings and the food supply in the main foraging sites of the parents. Neonate nestlings (1 day old) exclusively received weakly chitinized invertebrate prey (arachnids and flies), but from the second day of life the nestlings were fed a variety of highly chitinized invertebrate prey, the percentage biomass of which did not change for the remainder of the nesting period. Cereal grains started to be delivered to 3‐day‐old nestlings and were already efficiently digested, and the percentage biomass of this food type increased progressively with nestling age. We suggest that the provisioning of cereal grains to nestlings is not forced by external factors, such as modern agricultural intensification; rather, it is an intentional behaviour of parent birds aimed at achieving physiological adjustment to seed food in the early stages of ontogeny.     

A from‐benchtop‐to‐desktop workflow for validating HTS data and for taxonomic identification in diet metabarcoding studies

The main objective of this work was to develop and validate a robust and reliable “from‐benchtop‐to‐desktop” metabarcoding workflow to investigate the diet of invertebrate‐eaters. We applied our workflow to faecal DNA samples of an invertebrate‐eating fish species. A fragment of the cytochrome c oxidase I (COI) gene was amplified by combining two minibarcoding primer sets to maximize the taxonomic coverage. Amplicons were sequenced by an Illumina MiSeq platform. We developed a filtering approach based on a series of nonarbitrary thresholds established from control samples and from molecular replicates to address the elimination of cross‐contamination, PCR/sequencing errors and mistagging artefacts. This resulted in a conservative and informative metabarcoding data set. We developed a taxonomic assignment procedure that combines different approaches and that allowed the identification of ~75% of invertebrate COI variants to the species level. Moreover, based on the diversity of the variants, we introduced a semiquantitative statistic in our diet study, the minimum number of individuals, which is based on the number of distinct variants in each sample. The metabarcoding approach described in this article may guide future diet studies that aim to produce robust data sets associated with a fine and accurate identification of prey items.     

Distribution of invertebrates on foliage in forests of south-eastern Australia

Nearly 1500 foliage samples were collected from a total of 156 plant species, distributed at 16 study sites representing a wide range of forests and woodlands in south-eastern Australia. Samples were collected in all months. Invertebrates present in samples were counted, sorted into 13 categories, and the number present (> 3 mm in length) converted into density estimates. Densities of all invertebrates combined and invertebrate diversity were also calculated. Despite high variability there were some obvious distributional patterns for most categories. Three major dichotomies affected abundance and distribution of invertebrates: these were presence or absence of flowers, whether the plant species was Eucalyptus or other, and if Eucalyptus, whether the plant species was Symphyomyrtus or Monocalyptus. The presence of flowers in foliage samples increased the abundance of most invertebrate taxa. Compared to foliage of non-Eucalyptus species, Eucalyptus foliage had more lerp-forming psyllids and miscellaneous larvae, but fewer Arachnida, Coleoptera, Psocoptera, Hemiptera (other), Thysanoptera, Diptera, and total arthropods. Foliage of Symphyomyrtus species had higher densities of most categories (and particularly lerp-forming psyllids) than that of Monocalyptus. There were seasonal variations in abundance in most invertebrate taxa, but these patterns were different for Eucalyptus and non-Eucalyptus species. For most sites abundance of all arthropods combined was lowest in winter, but this decline was not especially pronounced, and was reversed at more xeric sites. For most categories there were significant differences between study sites in abundance and for some this was related to position of sites on a moisture gradient. In general total arthropod densities were highest at intermediate and xeric sites. There were some significant differences in arthropod communities for the same plant species at different study sites. Sample height, plant height, and the ratio of these were relatively unimportant variables. Likewise, the ratio of leaf width: leaf length was not significantly correlated with abundance for any invertebrate category across 128 plant species, but mean leaf size was negatively correlated with densities of Arachnida and total invertebrates. The distributions of some invertebrate categories were inter-correlated.     

A review of invertebrates and seed-bearing plants as food for farmland birds in Europe

Dietary information was reviewed for 22 bird species typically found in farmland areas across Europe using 100 references from the UK and other European countries for which quantitative data were presented. The number of studies and degree of taxonomic resolution available varied considerably between the species and, for some, dietary information was only available prior to agricultural intensification and may be unrepresentative of current feeding habits. Consequently, some caution is required in interpreting the results because of the different methods of data collection between the studies and the biases in analytical techniques for prey detectability. Food availability was rarely quantified in the study areas, and diet may have reflected availability or preference. Plant families and invertebrate orders were ranked in their importance separately for adult diet in the breeding and nonbreeding seasons and for chicks. The most important plant families overall were Poaceae, Polygonaceae, Caryophyllaceae, Cruciferae, Compositae, Chenopodiaceae and Labiatae, although the last two were unimportant for chicks. A number of key species were also identified. Similarities in dietary preferences were observed among Fringillidae (finches) and members of the Columbidae (doves and pigeons). Fringillidae and Carduelis cannabina (linnet) were associated with plants that occur in seminatural habitats, while Emberiza citrinella (yellowhammer), Phasianidae (partridges) and Columbidae were shown to be more closely associated with plants of agricultural environments. The most important invertebrate orders overall were Coleoptera adults, Hemiptera adults, Arachnida, Lepidoptera larvae/pupae, Diptera adults, Lepidoptera adults, Diptera larvae/pupae and Hymenoptera adults. During the nonbreeding season, a smaller number of invertebrate taxa were important. For adults in the breeding season and for chicks, there were 10 families of invertebrate that were important for four or more bird species (Aphididae, Carabidae, Chrysomelidae, Curculionidae, Elateridae, Formicidae, Scarabeidae, Staphylinidae, Tenthredinidae and Tipulidae). In the nonbreeding season, Curculionidae and Lumbricidae were important in the diet of three species. A few species exhibited a narrow diet range, selecting invertebrates from only one or two families. Similarities in dietary composition were observed among closely related bird species, while that of chicks and adults sometimes differed.     

Some aspects of frugivory by bird populations using coastal dune scrub in Lincolnshire

The fruit diets of Sylvia warblers, and some thrushes, were studied during 1989 at a coastal scrubland site, using faecal examination. Fruit feeding commenced as the earliest berries ripened in late July, but there were differences of timing between species. Amongst both warblers and thrushes, the larger species commenced earlier and ate more fruit. Almost all Blackcap and Garden Warbler faeces examined from early August contained some fruit remains, as did most Whitethroat faeces from mid-month. Mean fruit contents of faecal samples exceeded 80% infrequently, indicating that even the most frugivorous species always took other food, normally insects, to supplement their diet. Each species differed in their fruit diet: Blackcaps, and to a lesser extent Garden Warblers, ate Woody Nightshade berries in preference to Blackberries, as they are structurally adapted for feeding on the former plant. Only inexperienced juveniles of other species regularly chose the Nightshade berries. Elder berries, abundant from late August, became the preferred fruit for all Sylvia species. Using data from an earlier investigation, 1 it is shown that by feeding on Elder berries, migrating Blackcaps can obtain 75–90% of their daily energy requirements in 10% of daylight hours.     

Diet of nestling Barn Swallows <Emphasis Type="Italic">Hirundo rustica</Emphasis> in rural areas of Poland

Analysis of faecal sacs of nestling Barn Swallows Hirundo rustica from 52 breeding colonies located within fifteen spatially-separated villages in Poland has revealed that the basic component of the diet was Coleoptera (56.1% of all identified prey items), followed by Hymenoptera (24.1%), Diptera (16.1%) and Hemiptera (3.3%). The average mass of all prey items with known weight amounted to 3.40 mg (95% CL, 3.16–3.63 mg; median=0.49 mg) dry weight. Coleopterans associated with dung and manure jointly made up 23.5% of the number and 24.3% of the total biomass of all representatives of the order. Statistically significant negative relationships between the average weight of prey and number of prey found in 52 analyzed breeding sites suggest a particular need for Barn Swallows to find larger-bodied prey rather than to exploit the local abundance of smaller prey. The high percentage of Coleoptera in the diet of nestling Barn Swallows probably results from extensive or traditional farm management based on rules of organic farming in agricultural areas of central Europe, mainly commonly used organic fertilizers, and suggests the importance of these insects as a more easily accessible and larger-bodied prey in comparison to some small Diptera or Hymenoptera. We believe that a large number of randomly collected faecal samples from tens of breeding sites allow us to precisely describe variation in the diet of the Barn Swallow. Our work has great importance for documenting of the food composition of the Barn Swallow in traditional European countrysides, i.e. under environmental and agricultural conditions which, as a result of transformations of the system of farming, ceased to exist in the western and northern part of this continent.     

The effects of prey size on diet differentiation of seven passerine species at two spring stopover sites

Prey size was evaluated for seven passerine trans-Saharan migrant species at two spring stopover sites in Sardinia, Italy. The species considered were Pied Flycatcher Ficedula hypoleuca, Spotted Flycatcher Muscicapa striata, Redstart Phoenicurus phoenicurus, Garden Warbler Sylvia borin, Whitethroat Sylvia communis, Willow Warbler Phylloscopus trochilus and Wood Warbler Phylloscopus sibilatrix. The analysis was made for three prominent prey types: beetles (Coleoptera), ants (Hymenoptera: Formicidae) and “flying prey” (wasps and bees [Hymenoptera, excluding ants] and flies, Diptera, pooled), The prey size distribution in the diets of some species was very similar to that caught in our insect traps, showing that our estimates of availability are, at least partially, relevant. On the whole, diets deviated from food available in a species consistent way. The size distributions of “flying prey” differed between the two sites but were almost constant in the birds' diets. In contrast, size distributions of available beetles and ants at the sites were similar but were different in the birds' diets. Different feeding behaviour of the birds, in terms of physiological constraints during migratory stopovers, is discussed. Paired species comparisons show that the diets of most species differ significantly in the distribution of the size classes of at least some prey types. The conclusions drawn from the comparisons of the size distributions of all prey items collected from a bird species in one season are very similar to the conclusions drawn from comparisons based on the presence/absence of a size class per faecal sample. We compared the similarities of diet with and without using information on prey size. With the exception of the Pied Flycatcher and the Redstart at one of the study sites, size information did not add to diet segregation. Certain size classes within prey types tended to be common in the diet of these migrant passerines. However, specialization on certain size classes within broad taxonomic categories was not evident.     

Seed food preferences of granivorous farmland passerines

Capsule Large buntings prefer cereal grains whilst sparrows also take oily seeds.

Aims To determine seed food preferences of Tree Sparrow Passer montanus and Corn Bunting Emberiza calandra.

Methods Forty seed choice experiments were conducted at two sites over two winters. In each experiment, two seed types were provided and the number of visits made by birds to each type was recorded over a set period. At one site, Tree Sparrows were colour-ringed, allowing choices made by individual birds to be recorded. Data were also collected for House Sparrow Passer domesticus, Yellowhammer Emberiza citrinella and Reed Bunting E. schoeniclus.

Results All five species fed intensively on cereal grain, and wheat and oats were consistently preferred to barley. Sparrows and Reed Buntings also took maize, which was avoided by Corn Bunting and Yellowhammer. Tree Sparrow exhibited a broad diet, selecting cereal grain and oily seeds including sunflower and oilseed rape, but rye-grass seed was almost completely avoided.

Conclusion Cereal grain should be a key component of over-winter provision of seed for farmland passerines, especially when targeted at Corn Bunting and Yellowhammer. Oily seeds such as brassicas and sunflower will benefit species with more generalist diets, including Tree Sparrows.     

Molecular detection of invertebrate prey in vertebrate diets: trophic ecology of Caribbean island lizards

Understanding community assembly and population dynamics frequently requires detailed knowledge of food web structure. For many consumers, obtaining precise information about diet composition has traditionally required sacrificing animals or other highly invasive procedures, generating tension between maintaining intact study populations and knowing what they eat. We developed 16S mitochondrial DNA sequencing methods to identify arthropods in the diets of generalist vertebrate predators without requiring a blocking primer. We demonstrate the utility of these methods for a common Caribbean lizard that has been intensively studied in the context of small island food webs: Anolis sagrei (a semi‐arboreal ‘trunk‐ground’ anole ecomorph). Novel PCR primers were identified in silico and tested in vitro. Illumina sequencing successfully characterized the arthropod component of 168 faecal DNA samples collected during three field trips spanning 12 months, revealing 217 molecular operational taxonomic units (mOTUs) from at least nine arthropod orders (including Araneae, Blattodea, Coleoptera, Hemiptera, Hymenoptera, Isoptera, Lepidoptera and Orthoptera). Three mOTUs (one beetle, one cockroach and one ant) were particularly frequent, occurring in ≥50% of samples, but the majority of mOTUs were infrequent (180, or 83%, occurred in ≤5% of samples). Species accumulation curves showed that dietary richness and composition were similar between size‐dimorphic sexes; however, female lizards had greater per‐sample dietary richness than males. Overall diet composition (but not richness) was significantly different across seasons, and we found more pronounced interindividual variation in December than in May. These methods will be generally useful in characterizing the diets of diverse insectivorous vertebrates.     

The potential role of waterbirds in dispersing invertebrates and plants in arid Australia

1. The role of waterbirds as vectors of plants and invertebrates within and between arid‐zone wetlands is poorly understood. We present the first detailed study of passive dispersal by nomadic birds in Australasia. We investigated the numbers and types of invertebrate and plant propagules within freshly collected faecal samples as well as their viability. We compared dispersal among Grey Teal (Anas gracilis), Eurasian Coot (Fulica atra) and Black Swan (Cygnus atratus) in the Macquarie Marshes, a complex of temporary to semi‐permanent wetlands in New South Wales. 2. When faecal samples (n = 60) were inundated in the laboratory and monitored over 3 weeks, ciliates (75% of samples), nematodes (22%), ostracods (13%) and rotifers (5%) were recorded, with higher taxon richness in coot samples. Faecal samples (n = 71) were also sieved to quantify intact propagules, and ostracod eggs (70% of samples), large branchiopod eggs (31%) and bryozoan statoblasts (31%) were the most abundant invertebrates. Diaspores of 19 plant taxa were recorded, 14 of which were germinated in the laboratory or shown to be viable at the end of germination trials. The abundance and diversity of invertebrate propagules was highest in coot samples, whereas the abundance and diversity of diaspores was highest in teal samples. 3. One Australian Pelican (Pelecanus conspicillatus) sample was obtained and found to contain more taxa and far more propagules than any sample from other waterbirds, suggesting that piscivorous birds might have an important role in the indirect dispersal of propagules ingested by fish. 4. Our results support a role for birds in explaining the distributions of cosmopolitan plant genera such as Lemna, Typha, Myriophyllum and Nitella. The alien plants Ranunculus sceleratus, Medicago polymorpha and Polygonum arenastrum were recorded, demonstrating the potential role of waterfowl in the spread of exotic species. As the frequency and duration of flooding of arid‐zone wetlands decreases owing to human activities, the importance of waterbirds in facilitating recolonisation of temporary wetlands is likely to increase.     

Diet of the critically endangered Seychelles Scops Owl,Otus insularis

The only data previously recorded on the diet of the critically endangered, endemic Seychelles Scops Owl, Otus insularis, is from the stomach contents of a few museum specimens and analysis of one pellet. Data are presented on more than 400 prey items identified from pellets and video recordings of provisioning at two nests. Pellets comprised exclusively of invertebrate remains: Orthoptera (64%), Coleoptera (14%), arachnids (11%) and other invertebrates (11%). Similarly, 111 (76%) of all items identified during 145 provisioning visits at two nests were invertebrates. Seventy-three (66%) were identified to morphospecies and comprised Orthoptera (93%), arachnids (4%) and Lepidoptera (3%). The diet of scops owls inhabiting areas of different altitudes (180-700m asl) was similar. Identification of prey taxa and species suggests that a significant amount of foraging takes place from foliage and on tree trunks, not just on the ground.     

Manure heaps attract farmland birds during winter

Capsule: Abundance and species diversity of both common farmland birds and species of conservation concern were significantly higher at manure heaps compared to open farmland, especially for the Tree Sparrow Passer montanus and Yellowhammer Emberiza citrinella, two declining granivorous farmland birds.     

Arthropods in diet of Little Bustards Tetrax tetrax during the breeding season in western France

Capsule Seasonal, age- and sex-related variations in the diet were studied during March to October.

Aims To determine which arthropod orders contributed most during the laying–rearing period and those important in determining breeding success of the species in an intensive agricultural habitat.

Methods Faeces (n = 388, 345 g) and three gut samples were dissected to determine which arthropod orders contributed most to the diet, especially during the laying–rearing period.

Results Coleoptera were the most numerous prey followed by Orthoptera, Dermaptera and Hymenoptera. No difference was observed in the diet of adult males and females. Although adults ate arthropods throughout the breeding season, plant material contributed 97–99% of faecal contents by weight in each month. Chicks, however, only ate arthropods, notably Coleoptera and Orthoptera, at least until 2–3 weeks old.

Conclusion Increasing arthropod availability would be a useful management tool for maintaining endangered Little Bustard populations by potentially increasing chick survival.     

Mycophagy in small mammals: A comparison of the occurrence and diversity of hypogeal fungi in the diet of the long-nosed potoroo Potorous tridactylus and the bush rat Rattus fuscipes from southwestern Victoria,Australia

Abstract Three broad dietary categories—fungus, plant and arthropod—were identified from faecal samples of two species of small terrestrial mammal in forest vegetation in southwestern Victoria. Fungal material formed the major component of the diet of the long-nosed potoroo Potorous tridactylus throughout the year and of the bush rat Rattus fuscipes during autumn and winter. Fungal material was most abundant for both species during autumn and winter and significantly less common in spring and summer. These results confirm previous studies which found P. tridactylus to be highly mycophagous throughout the year and R. fuscipes to be strongly mycophagous seasonally. Particular consideration was given to the composition of fungi in the diet. Fungal spores in faecal material were assigned to spore classes, which represent one or more fungal species that have similar spore morphology. Twenty-four fungal spore classes were recorded, but for both animal species most of the fungi consumed were from seven major spore classes. The proportions of major spore classes in the diet of both animals were generally similar, even though the composition of spore classes differed markedly across seasons. Minor differences between species in the fungi consumed may be related to differences in selectivity, foraging, or microhabitat use. If fungal resources are limiting, competition for such resources may be important in this and other small mammal communities. The amount and diversity of hypogeal fungi consumed by the two animal species makes them both important spore dispersal agents in forest ecosystems. The capacity of R. fuscipes and other seasonally mycophagous mammals in this role may be more important than previously recognized, especially in habitats where species of the Potoroidae are absent.     

Feeding ecology of Tasmanian bat assemblages

The diets of seven of the eight species of insectivorous, vespertilionid bats found in Tasmania were studied in forest areas. The diet of the eighth species, Chalinolobus gouldii, was studied in riparian woodland surrounded by open pasture. Nyctophilus timoriensis was found to be a gleaner with most of its diet consisting of non-volant insects. Five of the species (Eptesicus vulturnus, Eptesicus regulus, Eptesicus sagittula, Nyctophilus geoffroyi and Chalinolobus morio) fed opportunistically, their diets reflecting local and temporal variations in insect abundance and diversity. Lepidoptera made up most of the diet of these species. The largest species, Falsistrellus tasmaniensis, appeared to be a selective feeder, with Coleoptera being the most important item in its diet. Coleoptera also made up the bulk of the diet of C. gouldii, but caterpillars were also important. For the species studied in forest areas, there was a highly significant correlation between the mean sizes of the lepidopterans (r= 0.95) and coleopterans (r = 0.96) eaten and the size of the bat. For all bats larger than E. sagittula, the mean size of beetles eaten was smaller than the mean size of moths eaten. These results are in accord with expectations from optimal foraging theory.     

Spring migration timing of Sylvia warblers in Tatarstan (Russia) 1957–2008

The timing of when migrant birds return to breed is a key component of studies of the impact of climate change upon bird populations. However, such data are not distributed evenly across the World, and in the Northern Hemisphere are underrepresented in Asia and the east of Europe. Therefore, to help rectify this bias, we analysed first arrival dates (FAD) of four species of Sylvia warblers (Blackcap Sylvia atricapilla, Whitethroat S.communis, Lesser Whitethroat S.curruca and Garden Warbler S.borin) collected in the Tatarstan Republic of Russia between 1957 and 2008. Over the whole period the species returned to their breeding sites between three and six days earlier; these trends were significant except for Whitethroat. Advances in arrival were especially apparent in the two earlier species, Blackcap and Lesser Whitethroat, mainly because local temperatures for March had risen substantially. Except for Whitethroat, FADs were significantly related to temperatures in the African wintering ground and/or in Tatarstan. Whilst significant correlations occurred between FADs of some of the species, there was considerable variability in these relationships indicating a species-specific response to rising temperatures. Changes in FADs in this eastern extremity of Europe were smaller than in Central and Western Europe.     

Environmental correlates of plant and invertebrate species richness in ponds

Ponds (lentic water bodies <2 ha) constitute a considerable biodiversity resource. Understanding the environmental factors that underlie this diversity is important in protecting and managing the habitat. We surveyed 425 ponds for biological and physical characteristics with 78 of those also surveyed for chemical characteristics. A total of 277 invertebrate species and 265 plant species were found. Species richness varied between 2 and 99 (mean 27.2 ± 0.6 SE) for invertebrates and 1 and 58 (mean 20.8 ± 0.4 SE) for plants. Generalised additive models were used to investigate variables that correlate with the species richness of plants and invertebrates, with additional models to investigate insect, Coleoptera, Odonata, Hemiptera, Trichoptera and Mollusca species richness. Models performed reasonably well for invertebrates in general (R ² = 30.3%) but varied between lower-order invertebrate taxa (12.7–34.7%). Ponds with lower levels of shading and no history of drying contained higher numbers of species of plants and all invertebrate groups. Aquatic plant coverage positively correlated with species richness in all invertebrate groups apart from Trichoptera and the presence of fish was associated with high invertebrate species richness in all groups apart from Coleoptera. The addition of chemistry variables suggested non-linear relationships between oxygen demand and phosphate concentration and higher-order richness. We demonstrate that the composition of biological communities varies along with their species richness and that less diverse ponds are more variable compared to more diverse ponds. Variables positively correlated with richness of one taxon may be negatively correlated with that of another, making comprehensive management recommendations difficult. Promoting a high landscape-level pond biodiversity will involve the management of a high diversity of pond types within that landscape.