Rapidly increasing urbanisation requires mitigation against associated losses of biodiversity and species abundance. In urban-breeding birds, altered food availability for nestlings is thought to reduce reproductive success compared to forest populations. To compensate for shortages of preferred foods, urban parents could increase their search effort for optimal diets or provision other foods. Here, we used telemetry and faecal metabarcoding on blue tits from one urban and one forest populations to compare parental effort and comprehensively describe nestling diet. Urban parents travelled on average 30% further than those in the forest, likely to offset limited availability of high-quality nestling food (i.e. caterpillars) in cities. Metabarcoding, based on a mean number of 30 identified taxa per faeces, revealed that the diets of urban chicks were nonetheless substantially shifted to include alternative foods. While in the forest caterpillars comprised 82 ± 11% of taxa provisioned to nestlings, in the city they constituted just 44 ± 10%. Pre-fledging chick mass as well as offspring numbers were lower in urban than in forest-reared broods. Thus, at least in our comparison of two sites, the hard labour of urban parents did not fully pay off, suggesting that improved habitat management is required to support urban-breeding birds.

The role of cellular immunity in the establishment and progression of immunosuppressive lentivirus infection remains equivocal. To develop a model system with which these aspects of the host immune response can be studied experimentally, we examined the responses of cats to a hybrid peptide containing predicted Tand B-cell epitopes from the gag and env genes of feline immunodeficiency virus (FIV). Cats were immunized with an unmodified 17-residue peptide incorporating residues 196 to 208 (from gag capsid protein p24) and 395 to 398 (from env glycoprotein gp120) of the FIV Glasgow-8 strain by using Quil A as an adjuvant. Virus-specific lymphocytotoxicity was measured by chromium-51 release assays. The target cells were autologous or allogeneic skin fibroblasts either infected with recombinant FIV gag vaccinia virus or pulsed with FIV peptides. Effector cells were either fresh peripheral blood mononuclear cells or T-cell lines stimulated with FIV peptides in vitro. Cytotoxic effector cells from immunized cats lysed autologous, but not allogeneic, target cells when they were either infected with recombinant FIV gag vaccinia virus or pulsed with synthetic peptides comprising residues 196 to 205 or 200 to 208 plus 395. Depletion of CD8+ T cells, but not CD4+ T cells, from the effector cell population abrogated the lymphocytotoxicity. Immunized cats developed an antibody response to the 17-residue peptide immunogen and to recombinant p24. However, no antibodies which recognized smaller constituent peptides could be detected. This response correlated with peptide-induced T-cell proliferation in vitro. This study demonstrates that cytotoxic T lymphocytes specific for FIV can be induced following immunization with an unmodified short synthetic peptide and defines a system in which the protective or pathological role of such responses can be examined.

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Water vole (Arvicola amphibius) populations have undergone a serious decline throughout the UK, and yet a stronghold of these small mammals is found in the greater Easterhouse area of Glasgow. The water voles in this location are mostly fossorial, living a largely subterranean existence in grasslands, rather than the more typical semi-aquatic lifestyle in riparian habitats. In this study, we carried out capture-mark-recapture surveys on water voles at two sites: Cranhill Park and Tillycairn Drive. We made a total of 62 captures including retraps, and the resulting population estimates were 78 individuals (95% confidence interval 41-197) for Cranhill Park and 42 individuals (20-141) for Tillycairn Drive. From these figures we estimated a population density of water voles, which appeared to be higher than other reports from the UK. Despite the difficulties of sampling in urban environments that resulted in relatively low capture rates, our data suggest that the greater Easterhouse area of Glasgow holds water voles at relatively high population densities. These results will inform future conservation in the City of Glasgow and surrounding areas, as well as raise awareness of important water vole populations in urban environments.

Abundance estimation methods that combine several types of data are becoming increasingly common because they yield more accurate and precise parameter estimates and predictions than are possible from a single data source.These beneficial effects result from increasing sample size (through data pooling) and complementarity between different data types. Here, we test whether integrating mark-recapture data with passive acoustic detections into a joint likelihood improves estimates of population size in a multi-guild community. We compared the integrated model to a mark-recapture-only model using simulated data first and then using a data set of mist-net captures and acoustic recordings from an Afrotropical agroforest bird community. The integrated model with simulated data improved accuracy and precision of estimated population size and detection parameters. When applied to field data, the integrated model was able to produce, for each bird guild, ecologically plausible estimates of population size and detection parameters, with more precision compared with the mark-recapture model. Overall, our results show that adding acoustic data to mark-recapture analyses improves estimates of population size. With the increasing availability of acoustic recording devices, this data collection technique could readily be added to routine field protocols, leading to a cost-efficient improvement of traditional mark-recapture population estimation.

The use of mist nets is the most widespread technique to capture bats; however, no study has compared if the type of ground-level mist net used during sampling affects bat captures. We sampled bats using three different types of mist nets that varied in mesh (16, 18, and 20 mm) and denier/ply (45/1 and 75/2) sizes over 76 half-night surveys. We used 17–20 mist nets and checked them at intervals of 15–20 min. Capture rate for echolocating bats was higher in the two mist nets with the biggest denier/ply and smaller mesh sizes. “Ultrathin bat mist nets” showed the lowest capture rates (1.5 times less than “Regular bat mist nets”), whereas “Bird mist nets” had capture rates only 1.2 times smaller than “Regular bat mist nets.” Our results showed that “Bird mist nets” can sample echolocating bats almost as well as “Regular bat mist nets,” and that thinner mist nets may not be the best solution to capture bats that echolocate at high frequencies in this type of surveys. We highlight the importance of considering the efficiency, durability, and longevity of mist nets when choosing the ideal mist-net type for a bat survey.

Wood Warblers, an Afro-Palearctic migrant species, are declining steadily in Europe likely due to mortality outside their breeding grounds. However, little is known about their overwintering, and records about the sensitive life-cycle stage of moult in Africa are practically absent. To fill this gap, we report on moult of Wood Warblers captured over two winters (January–February) in 2019–2020 in Cameroon. We caught 14 individuals, of which 12 were monitored for flight feather moult. All inspected individuals showed advanced stages of flight feather renewal. Despite low sample sizes, Underhill-Zucchini moult models aptly explained variation in primary and secondary moult (R2 = 0.61). Estimated moult onset date was 26 December, completion date was 25 February, and moult duration was 61 days. These findings fit well with experimental data on the annual cycle and the timing of recently published migration tracks of Wood Warblers. Jointly, the data suggest that moult timing is set by an internal programme, which enables Wood Warblers to organise their multi-stage migration such that they reach suitable moulting habitat in time, and can depart in time with a fresh plumage for the breeding grounds. In our study, moult occurred during the peak of the dry season, which in Cameroon nonetheless shows high relative humidity. During our mist-netting on 28 cocoa plantations of varying shade cover, Wood Warblers were caught on 6 farms whose canopies were comparatively open. These data suggest that the birds encounter in Cameroon relatively stable climatic conditions for moult, and do not measurably prefer closed-canopy forests. Our findings are important, because successful moult increases survival prospects and because moult needs to be safely embedded in a migratory life cycle. Hence, information on moult timing and location is essential for identifying year-round vulnerabilities of Wood Warblers.