26 research outputs found
Do atmospheric events explain the arrival of an invasive ladybird (Harmonia axyridis) in the UK?
Species introduced outside their natural range threaten global biodiversity and despite greater awareness of invasive species risks at ports and airports, control measures in place only concern anthropogenic routes of dispersal. Here, we use the Harlequin ladybird, Harmonia axyridis, an invasive species which first established in the UK from continental Europe in 2004, to test whether records from 2004 and 2005 were associated with atmospheric events. We used the atmospheric- chemistry transport model SILAM to model the movement of this species from known distributions in continental Europe and tested whether the predicted atmospheric events were associated with the frequency of ladybird records in the UK. We show that the distribution of this species in the early years of its arrival does not provide substantial evidence for a purely anthropogenic introduction and show instead that atmospheric events can better explain this arrival event. Our results suggest that air flows which may assist dispersal over the English Channel are relatively frequent; ranging from once a week from Belgium and the Netherlands to 1–2 times a week from France over our study period. Given the frequency of these events, we demonstrate that atmospheric-assisted dispersal is a viable route for flying species to cross natural barriers
Wildflower Strip Establishment for the Delivery of Ecosystem Services in Sweet Cherry Orchards
The practice of introducing wildflower habitats in cropped areas is an approach that can be used to enhance ecosystem services. The value of such an approach will be affected by the establishment success of the sown species. To investigate this, 12 strips of wildflower habitat were established in alleyways between rows of cherry trees at three sites in the West Midlands (UK). The establishment of plants in sown strips was compared to six untreated alleyways that received conventional management. Eight forb species and one grass species was sown in strips measuring 1 m × 95 m. The establishment success of the sown species and their contribution to the vegetation of the alleyway was determined using percentage cover assessments in replicate quadrats. Dactylis glomerata, Leucanthemum vulgare, Prunella vulgaris and Lotus corniculatus established most consistently and with greater cover values in the sown strips. However, the sown strips were also associated with a greater abundance of unsown species, some of which are classed as weeds
Developing perennial wildflower strips for use in Mediterranean orchard systems
To support sustainable food production and the delivery of ecosystem services through ecological intensification, wildflower strips have become a popular strategy. Despite their success in temperate orchard systems, they remain understudied in Mediterranean ecosystems, which poses a significant barrier to uptake. In order to further promote their adoption, seed mixes must be optimised for commercial orchard systems and for the Mediterranean climate. Plant species should be selected for their consistent performance, whilst the availability of resources for ecosystem service providers determines the quality of the wildflower strip. In this study, the suitability of 12 native perennial forbs and two tussock-forming grass species for wildflower strips in commercial Citrus orchards was assessed over a 3-year period. Distinct resources for natural enemies according to the different plant growth stages were used an indicator of wildflower strip quality. The wildflower strips were managed under two different cutting strategies: (i) standard management, in which wildflower strips were cut once annually in February, and (ii) active management, in which wildflower strips were cut two additional times each year. The establishment and success of the sown species were compared. The influence of wildflower strips and their management on plant species richness, community structure, and the provision of resources was com -pared with a control treatment, in which alleyways were managed conventionally by cutting any naturally occurring vegetation to a height of ≤5 cm, four to five times annual. For the first time, the performance of native perennial plant species has been assessed in Mediterranean orchard systems and a seed mix developed for targeting pest regulation services. The wildflower strips were successful in increasing plant species richness and the available resources expected to support natural enemies. However, only wildflower strips managed with cutting once annually enhanced vegetation cover relative to the control, whilst extending the flowering period. This study therefore provides crucial tools for the further development of sustainable approaches to food production in Mediterranean orchard systems
Recommended from our members
The potential of wildflower strips to enhance pollination services in sweet cherry orchards grown under polytunnels
Sweet cherry production benefits from insect pollination, but the extent to which wildflower strips can boost pollinator visitation under polytunnels is unknown. Wildflowers were established in alleyways between tree rows under polytunnels in 10 commercial cherry orchards. Their management involved either a single cut in September (Standard Wildflower Strips (SWS)) or being actively maintained to 20 cm with regular cutting (Actively Managed Wildflower Strips (AMWS)), compared with unsown Control Strips (CS). Flower visitors of cherry and wildflowers were recorded by visual observations for 3 years (2017–2019), while cherry production (quantity and quality) was assessed in 2019. In total, 67 visitor species were identified; managed commercial species (Apis mellifera and Bombus terrestris) made up ~74% of all records. During the cherry blossom period (anthesis), AMWS had the highest visitor density to cherry blossoms compared with CS and SWS but no significant difference in harvestable fruit was recorded. After anthesis, greater visitor density, diversity and richness were observed in both wildflower treatments compared with CS, being greatest in SWS, which was consistent with differences in floral communities between treatments. Although visitor density was not correlated with fruit set, pollinating insects were key for fruit yields and quality. Fruit set was ~17% from blossoms exposed to visitors compared with <1% when excluded. Furthermore, hand pollination resulted in ~32% fruit set, indicating greatest pollination deficits in CS (~50%) compared with AMWS (~28%) and SWS (~35%). Synthesis and applications. Sweet cherry is highly dependent on pollinators to underpin commercial yields, and pollination deficits exist under polytunnels. Growers should, therefore, reconsider their pollination strategies and look to combine effective pollinator management with polytunnel use to mitigate deficits; establishing and actively managing wildflowers in alleyways could enhance wild visitors and pollination
Evaluating Promotional Approaches for Citizen Science Biological Recording: Bumblebees as a Group Versus Harmonia axyridis as a Flagship for Ladybirds
Over the past decade, the number of biological records submitted by members of the public have increased dramatically. However, this may result in reduced record quality, depending on how species are promoted in the media. Here we examined the two main promotional approaches for citizen science recording schemes: flagship-species, using one charismatic species as an umbrella for the entire group (here, Harmonia axyridis (Pallas) for Coleoptera: Coccinellidae), and general-group, where the group is promoted as a whole and no particular prominence is given to any one species (here, bumblebees, genus Bombus (Hymenoptera: Apidae)). Of the two approaches, the
general-group approach produced data that was not
biased towards any one species, but far fewer records
per year overall. In contrast, the flagship-species
approach generated a much larger annual dataset, but
heavily biased towards the flagship itself. Therefore,
we recommend that the approach for species promotion
is fitted to the result desired
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication
Hitting the buffers: conspecific aggression undermines benefits of colonial breeding under adverse conditions
Colonial breeding in birds is widely considered
to benefit individuals through enhanced protection
against predators or transfer of information
about foraging sites. This view, however, is
largely based on studies of seabirds carried out
under favourable conditions. Recent breeding
failures at many seabird colonies in the UK
provide an opportunity to re-examine costs and
benefits of coloniality under adverse conditions.
Common guillemots Uria aalge are highly colonial
cliff-nesting seabirds with very flexible
parental care. Although the single chick is
normally never left alone, more than 50 per cent
of offspring were left unattended at a North Sea
colony in 2007, apparently because poor conditions
forced both parents to forage simultaneously.
Contrary to expectation, unattended
chicks were not killed by avian predators.
Rather, although non-breeders and failed breeders
sometimes provided alloparental care, unattended
chicks were frequently attacked by
breeding guillemots at neighbouring sites, often
with fatal consequences. These results highlight
a previously unsuspected trade-off between provisioning
chicks and avoiding conspecific
attacks, and indicate that understanding how
environmental conditions affect social dynamics
is crucial to interpreting costs and benefits of
colonial breeding
Using Dietary Analysis and Habitat Selection to Inform Conservation Management of Reintroduced Great Bustards Otis tarda in an Agricultural Landscape
Capsule: Reintroduced Great Bustards achieve dietary and habitat diversity despite living in an intensive
agricultural setting.
Aims: To investigate dietary composition and habitat use of reintroduced Great Bustards Otis tarda released
in southwest England and the impact of supplemental feed on autumn dietary selection.
Methods: Faecal samples were collected from a mixed group of free-ranging bustards without (July 2012,
May, September, and November 2013) and with (October and December 2012) access to supplemental
feeds. Concurrently, diurnal land use observations were recorded for all months but September and
December. Composite monthly faecal samples were micro-histologically analysed to assess dietary
composition. Year-round landscape-level habitat use was determined using re-sightings and satellite
telemetry data for birds surviving more than 182 days post-release. Generalized linear models were
used to test for differences in habitat selection across the year, by sex and within and outside release
areas for each habitat type, and habitat diversity was quantified using the Shannon–Weaver Index.
Results: Dietary composition varied depending on plant availability and phenological stage, and
invertebrates were rarely selected. Agricultural crops – primarily oil-seed rape, mustard, barley grass,
lucerne, and barley seed – comprised the bulk of the diet, but grassland and weedy forbs were always
important secondary foods (>25%), except when provided extruded pellets. Monthly changes in habitat
use suggest sex-based habitat segregation, with females living in higher habitat diversity settings.
Grasslands were used across the year. When supplemental food was provided, it came to dominate
dietary intake.
Conclusion: Great Bustards can adapt to an intensive agricultural setting, but require unrestricted access to
adjacent grasslands. They would be best served with small-scale habitat mosaics. If supplemental foods are
to be provided to juvenile birds, quantities must be limited and the birds weaned off before dispersal to
maximize reintroduction success