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Understanding the frequency, spatiotemporal dynamics and impacts of parasite coinfections is fundamental to developing control measures and predicting disease impacts. The European turtle dove (Streptopelia turtur) is one of Europe’s most threatened bird species. High prevalence of infection by the protozoan parasite Trichomonas gallinae has previously been identified, but the role of this and other coinfecting parasites in turtle dove declines remains unclear. Using a high-throughput sequencing approach, we identified seven strains of T. gallinae, including two novel strains, from ITS1/5.8S/ITS2 ribosomal sequences in turtle doves on breeding and wintering grounds, with further intra-strain variation and four novel sub-types revealed by the iron-hydrogenase gene. High spatiotemporal turnover was observed in T. gallinae strain composition, and infection was prevalent in all populations (89–100%). Coinfection by multiple Trichomonas strains was rarer than expected (1% observed compared to 38.6% expected), suggesting either within-host competition, or high mortality of coinfected individuals. In contrast, coinfection by multiple haemosporidians was common (43%), as was coinfection by haemosporidians and T. gallinae (90%), with positive associations between strains of T. gallinae and Leucocytozoon suggesting a mechanism such as parasite-induced immune modulation. We found no evidence for negative associations between coinfections and host body condition. We suggest that longitudinal studies involving the recapture and investigation of infection status of individuals over their lifespan are crucial to understand the epidemiology of coinfections in natural populations.

Logistical constraints concerning parasite sample storage can hinder progress with the discovery of genetic variation on a global scale. New storage methods are being developed to address this, but require testing in order to understand how widely applicable these methods are. Whatman FTA cards have been tested previously under laboratory conditions for storing low-concentration Trichomonas gallinae isolates with the conclusion that they are not suitable, but have not been tested under field conditions. Here, we conducted a field-test, comparing FTA cards with storage in ethanol for T. gallinae samples collected and cultured from wild Columbiformes in Africa using standard field methods, before transportation to the UK. After 6 months storage, both methods resulted in an overall prevalence of 100% following PCR amplification (n = 59), suggesting that FTA cards are suitable for estimation of T. gallinae prevalence. However, samples stored in ethanol produced more, and longer, sequences than those stored on FTA cards. These data suggest storage in ethanol is preferable for the acquisition of high quality genetic strain data, but that FTA cards can be used successfully to ascertain infection prevalence and identify parasite strains under field conditions.

Funder: Royal Society for the Protection of Birds, Agri‐environment schemes (AES) are the primary policy mechanism for addressing farmland biodiversity declines across Europe. Despite previous studies on the impacts of AES on biodiversity, there is little empirical evidence on the scale of provision required to reverse declines. Across three regions of lowland England with contrasting farm systems (arable, pastoral, mixed), we estimated avian population growth rates (PGRs) on farmland with high AES provision (‘higher‐tier’: average bird‐friendly option cover = 7.4%), low AES provision (‘lower‐tier’: 2.3%) and no bird‐friendly AES (‘no AES’). Ten‐year PGRs were derived for 24 species and three multi‐species groups comprising farmland‐associated species (‘farmland birds’), species of conservation concern (‘priority birds’) and species restricted to farmland (‘specialist birds’). We used PGRs to simulate the proportion of the regional farmland landscape that would have to be assigned to higher‐ and lower‐tier agreements to stabilise or increase populations. In the arable and pastoral regions, 13/23 and 13/22 species, respectively, had more positive PGRs under higher‐tier AES than on no AES farmland (none had more negative PGRs), compared to 4/22 (positive) and 1/22 (negative) in the mixed region. Only two to four species per region exhibited more positive PGRs under lower‐tier AES compared to no AES farmland. Multi‐species PGRs in the arable and pastoral regions increased from no AES (strong decline), to lower‐tier (decline or stability) to higher‐tier (moderate or strong increase). There was no overall AES effect in the mixed region. To increase regional farmland bird populations by 10% over 10 years, 47% and 26% of the farmed landscape would need to be devoted to higher‐tier agreements in arable and pastoral landscapes respectively. This falls to 34% and 17% when higher‐tier is targeted at localities supporting higher abundances of target species, and to 29% and 10% when 30% of the farmed landscape is also devoted to lower‐tier. Priority and specialist birds require higher provision levels. Policy implications. Where farmland bird recovery is an AES objective, farms should prioritise higher‐tier agreement delivery over lower‐tier. Farmland bird responses to AES provision are likely to vary regionally, but careful targeting will reduce the amount needed in the landscape.

SummaryConservation measures providing food-rich habitats through agri-environment schemes (AES) have the potential to affect the demography and local abundance of species limited by food availability. The European Turtle Dove Streptopelia turtur is one of Europe’s fastest declining birds, with breeding season dietary changes coincident with a reduction in reproductive output suggesting food limitation during breeding. In this study we provided seed-rich habitats at six intervention sites over a 4-year period and tested for impacts of the intervention on breeding success, ranging behaviour and the local abundance of territorial turtle doves. Nesting success and chick biometrics were unrelated to the local availability of seed-rich habitat or to the proximity of intervention plots. Nestling weight was higher close to human habitation consistent with an influence of anthropogenic supplementary food provision. Small home ranges were associated with a high proportion of non-farmed habitats, while large home ranges were more likely to contain seed-rich habitat suggesting that breeding doves were willing to travel further to utilize such habitat where available. Extensively managed grassland and intervention plot fields were selected by foraging turtle doves. A slower temporal decline in the abundance of breeding males on intervention sites probably reflects enhanced habitat suitability during territory settlement. Refining techniques to deliver sources of sown, natural, and supplementary seed that are plentiful, accessible, and parasite-free is likely to be crucial for the conservation of turtle doves.

We present a genome assembly from an individual female Streptopelia turtur (the European turtle dove; Chordata; Aves; Columbidae). The genome sequence is 1.18 gigabases in span. The majority of the assembly is scaffolded into 35 chromosomal pseudomolecules, with the W and Z sex chromosomes assembled.

Agri‐environment schemes (AES) are the main policy mechanism available for reversing the widespread declines of European farmland biodiversity. We assessed the impact of AES land management on the abundance of bird species whose populations have declined as a consequence of agricultural intensification. The AES involved the deployment of a whole‐farm package of wildlife‐friendly land management options covering an average of 7% of the farmed area. The study was conducted across three English regions and focused on species of conservation concern and on a wider suite of farmland birds comprising the UK Government's Farmland Bird Indicator (FBI). Changes in avian abundance on AES farms were compared with those measured across the wider farmed landscape as part of a national bird monitoring scheme. Twelve out of 17 priority species, and the FBI, showed more positive changes in abundance on AES farms in at least one region. Eight species exhibited sustained responses to AES management in at least one region, and eight species exhibited a temporary enhancement in abundance in at least one region. Temporary responses to AES management followed a large scale failure of key AES options to establish during successive wet and cold summers, and involved species known to depend on the habitats provided by these options. In order to offset ongoing declines of FBI species in the wider farmed countryside of 2.3–4.1% per annum, we estimate 26–33% of FBI populations would need to be subject to AES‐type management. This study demonstrates the potential for AES land management to substantially enhance the abundance of priority farmland birds and highlights the need for option packages that are resilient to the impacts of variable weather conditions.

SummaryPost-fledging survival plays a vital role in the dynamics of bird populations and yet is the least-studied avian life-stage. Habitat requirements post-fledging may have important implications for behaviour and survival, especially for declining populations in landscapes that have undergone wide-scale anthropogenic modification, resulting in an altered distribution and composition of habitats. The European Turtle Dove is a widespread but rapidly declining species both within the UK and across Europe. Reduced seed food availability is thought to influence breeding success of this species, but it is not known whether post-fledging survival may also be influenced by seed availability. Here, we use leg-ring radio-tag attachments to monitor post-fledging survival and movements in 15 Turtle Dove nestlings from eight nests monitored during 2014 as part of a wider autecological study. Fledglings remained in close proximity to their nest for three weeks post-tagging, spending more than half their time in the immediate vicinity (within ∼20 m) of the nest. 95% of foraging trips during this period were within 329 m of the nest and fledglings selected seed-rich habitat (semi-natural grassland, low-intensity grazing, fallow and quarries). Fledglings that were heavier and in better body condition at seven days old were more likely to survive for 30 days post-fledging, and the proportion of available seed-rich habitat was a strong predictor of nestling weight and condition at seven days old. Whilst our sample size is modest, this study highlights the crucial role of food availability in juvenile survival, both while adults are feeding nestlings, and to recently fledged young, and the potential for agri-environment schemes providing foraging and nesting habitats in close proximity to provide important benefits.

European farmland hosts a species assemblage of animals and plants which have undergone declines through the late twentieth and early twenty-first centuries, at least partly as a result of increased productivity. Further increases in human populations, changes in availability and cost of raw materials, policy constraints, price volatility and climatic changes will further drive greater efficiency and high yields in agriculture, with the risk of further adverse environmental impacts. We assess the effects of different management priorities (production-driven cropping vs. wildlife-friendly farming) at an arable farm in eastern England on food production, greenhouse gas (GHG) emissions and biodiversity. We modelled one actual and three alternative cropping scenarios using actual yields from the farm over 13 years, to calculate total yields and those foregone for agri-environmental measures. We measured crop yields, relative abundance of 19 farmland bird species, and CO2 and N2O emissions related to crop prod...

Agri-environment schemes (AES) are the main policy mechanism available to reverse the widespread losses of farmland biodiversity across Europe. Previous examples of AES enhancing the abundance of farmland birds have been restricted to targeted species recovery programmes, often with bespoke habitat management and high levels of advisory support for landowners. Here, we tested whether standard higher-tier AES agreements targeted at multiple species and with lower levels of advisory support than targeted species recovery programmes can enhance the breeding densities of farmland birds. Surveys of breeding birds were undertaken during 2008 and 2011 on 65 farms under higher level stewardship (HLS) and 21 farms lacking AES interventions, in three regions of England. After allowing for any impacts of predator control, changes in density were more positive on HLS farms in at least one region for six priority species. Five of the six species had mixed diets and were predominantly associated with field edges; the other (lapwing) probably responded to the provision of field-centre fallow plots. Changes in bird numbers were not consistently related to the extent of AES habitat provision. This is the first study to demonstrate that standard AES management without substantial ongoing advisory support can increase or maintain the densities of widespread declining species.

Agri-environment schemes (AES) are increasingly being employed to mitigate biodiversity loss in agricultural environments. The European Turtle Dove Streptopelia turtur is an obligate granivorous bird in rapid decline within both the UK (−96% since 1970) and across continental Europe (−77% since 1980), despite widespread uptake of AES. Here, we assess the efficacy of a potentially new, sown agri-environment option designed to provide abundant, accessible seed for S. turtur during the breeding season. During summer 2011 we compared vegetation structure and seed provision on trial plots to control habitat types (existing agri-environment options thought to potentially provide S. turtur foraging habitat) to assess whether trial plots performed better for foraging S. turtur than control habitats. In September 2011 all trial plots were topped (cut) and half of a subset of trial plots were then scarified (60% of soil surface disturbed). Vegetation structure on topped, and topped and scarified trial plots was measured during summer 2012 to determine which management regime was most effective in maintaining suitable sward structure and seed provision into the second year. No control habitat type produced as much seed important in S. turtur diet as trial plots at any point during year one. Trial plots provided accessible vegetation structure early in the season with no difference in vegetation metrics between trial plots and previously published data on S. turtur foraging locations. However, to allow later access, management is required during mid-June to open up the sward through localized topping or scarification. Vegetation structure during year two was generally too dense to attract foraging S. turtur. However, scarifying trial plots during the September following sowing encouraged self-seeding of Fumaria officinalis (a plant species historically forming a significant proportion of S. turtur diet during the breeding season) into the second year, with this species present in 16% of scarified trial plots compared to only 4% of topped trial plots during year two. Thus, autumn scarification, possibly followed by topping or scarification of part of the trial plots in June, is necessary for trial plots to provide more seed and access for S. turtur than existing agri-environment options during year two. We recommend modifications to our original seed mix in order to reduce vegetation density and improve vegetation structure. The study provides an example of the need to strike the right balance between food abundance and accessibility, through vegetation structure, when designing agri-environment scheme management options that provide food for birds.

Dietary changes linked to the availability of anthropogenic food resources can have complex implications for species and ecosystems, especially when species are in decline. Here, we use recently developed primers targeting the ITS2 region of plants to characterize diet from faecal samples of four UK columbids, with particular focus on the European turtle dove (Streptopelia turtur), a rapidly declining obligate granivore. We examine dietary overlap between species (potential competition), associations with body condition in turtle doves and spatiotemporal variation in diet. We identified 143 taxonomic units, of which we classified 55% to species, another 34% to genus and the remaining 11% to family. We found significant dietary overlap between all columbid species, with the highest between turtle doves and stock doves (Columba oenas), then between turtle doves and woodpigeons (Columba palumbus). The lowest overlap was between woodpigeons and collared doves (Streptopelia decaocto). We show considerable change in columbid diets compared to previous studies, probably reflecting opportunistic foraging behaviour by columbids within a highly anthropogenically modified landscape, although our data for nonturtle doves should be considered preliminary. Nestling turtle doves in better condition had a higher dietary proportion of taxonomic units from natural arable plant species and a lower proportion of taxonomic units from anthropogenic food resources such as garden bird seed mixes and brassicas. This suggests that breeding ground conservation strategies for turtle doves should include provision of anthropogenic seeds for adults early in the breeding season, coupled with habitat rich in accessible seeds from arable plants once chicks have hatched.

SUMMARYStudies of blood parasite infection in nestling birds rarely find a high prevalence of infection. This is likely due to a combination of short nestling periods (limiting the age at which nestlings can be sampled) and long parasite prepatent periods before gametocytes can be detected in peripheral blood. Here we examine rates of blood parasite infection in nestlings from three Columbid species in the UK. We use this system to address two key hypotheses in the epidemiology of avian haemoparasites: first, that nestlings in open nests have a higher prevalence of infection; and second, that nestlings sampled at 14 days old have a higher apparent infection rate than those sampled at 7 days old. Open-nesting individuals had a 54% infection rate compared with 25% for box-nesters, probably due to an increased exposure of open-nesting species to dipteran vectors. Nestlings sampled at 14 days had a 68% infection rate compared with 32% in nestlings sampled at 7 days, suggesting that rates of infection in the nest are high. Further work should examine nestlings post-fledging to identify rates of successful parasite infection (as opposed to abortive development within a dead-end host) as well as impacts on host post-fledging survival and behaviour.

Trichomonosis, caused by the protozoan Trichomonas gallinae, is an emerging infectious disease in finches, and is more commonly found in columbids and raptors. Infections can be sub-clinical or cause morbidity and mortality, but the parasite is currently only detectable by incubation of an oral swab. Here, we test whether T. gallinae parasites can be detected by PCR from faecal or non-cultured samples from the oral cavity and gastrointestinal tract of infected Turtle Doves (Streptopelia turtur). PCR did not detect T. gallinae parasites in any faecal samples screened, and in only 1 of 11 oral/gastrointestinal samples (from the mouth of a nestling suspected to have died from trichomonosis). We conclude that both oral swabs and parasite culture are still necessary to detect the sub-clinical presence of T. gallinae infection in birds.

Capsule At two demonstration farms, Game & Wildlife Conservation Trust's Loddington Farm in Leicestershire and Royal Society for the Protection of Birds's Hope Farm in Cambridgeshire, targeted management led to much faster increases in avian abundance than in the surrounding regions. Aims To compare changes in avian abundance at Loddington Farm since 1992 and Hope Farm since 2000, and relate these to regional trends in bird abundance and to the habitat and predator management conducted at the two sites. Methods Loddington Farm is a mixed arable 292-ha farm in a partially wooded landscape in Leicestershire. It was managed as a shoot from 1993 to 2002, combining habitat management with predator control (stopped in 2002) and winter grain provision (ceased in 2006). Hope Farm comprises a 181-ha mainly arable farm in an open landscape in Cambridgeshire, where habitat management for farmland birds has taken place since 2002. At both sites, breeding bird abundance has been monitored annually. Information on farm management was translated into three variables measuring annual provision of nesting cover, summer food and winter food. The number of Carrion Crow and Magpie territories was used as an index of predator abundance. Results Avian abundance increased at both farms much faster than within their respective regions. Recovery of priority species was positively correlated with the provision of summer foraging habitats and negatively correlated with the provision of supplementary grain during winter. The latter finding was counterintuitive and may reflect an increase in hedgerow provision that coincided with the cessation of grain provision at both farms. The increase in bird abundance was not sustained at Loddington Farm in the absence of predator control, although it was at Hope Farm where predator densities were markedly lower. Conclusion The data from Hope Farm suggest that where predator densities are relatively low (2 locally, 2 in spring regionally), recovery of farmland birds can be achieved through habitat management alone. Where predator densities are high (>5 corvid pairs/km2 and >1.1 foxes/km2), as at Loddington Farm, species recovery, particularly of open-cup nesting species, may require predator control as well as habitat management. Further study is needed to confirm this tentative conclusion from only two sites.