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Warren, D. A.

Publications and source records attributed to Warren, D. A..

3 recordsLinked to original sources

Dispersal Behaviour and Movement Patterns of Pheasants from Woodland Release Pens.

The large-scale release of ring-necked pheasants, Phasianus colchicus, for recreational shooting in the UK raises concerns about ecological impacts, particularly on sensitive ecological sites. Current assumptions suggest dispersal is typically <500m from release pens, yet empirical evidence is limited. This study tracked 110 GPS-tagged pheasants from 11 woodland release pens across nine shooting estates, monitoring movements through pre-shooting, shooting and post-shooting phases. Most birds (73%) travelled a maximum distance beyond 500m during at least one of the three phases, with mean maximum distances of 863m, 1,493m and 1,307m per phase. During at least one phase, 26% of the 110 tagged birds spent most of their time (>50%) beyond 500m and 16% beyond 1,000m from their release pens. Early post-release movements were concentrated near pens, but ranging behaviour expanded during subsequent phases, with the percentages of birds spending >50% of their time beyond 500m and 1,000m, respectively: pre-shooting 6%, 2%; shooting 24%, 16%; post-shooting 13%, 9%. Accounting for mortality, the percentages of surviving birds spending >50% of their time beyond 500m and 1,000m increased: pre-shooting (n=110) 6%, 2%; shooting (n=71) 37%, 25%; post-shooting (n=27) 52%, 37%. Dispersal was greater with earlier release dates, higher pen and estate stocking densities and lower vegetative habitat quality in pens. Movements were directional rather than uniform, with most cohorts concentrating activity within a limited directional arc specific to the release site. Conservation site incursions occurred in 28 (25%) tagged birds, particularly where pens were closest to site boundaries; although 10 (36%) tagged birds encroached on conservation sites 872-2,319m from their release pen. These findings show that dispersal of released pheasants is further, more directed, and persistent than currently assumed.

ecology↗

Identifying and prioritising conflicts between human and wildlife interests in Great Britain

O_LIA literature review was conducted to identify human-wildlife conflicts associated with British terrestrial mammal species. Conflicts were classified as economic, health, environmental or social, divided into 32 subcategories, and ranked using a Generic Impact Scoring System (GISS). C_LIO_LIWe identified 48 species associated with 200 conflicts. Sika deer were involved in the most conflicts. The highest ranked conflicts were measurable on an economic scale (involving rabbits, badgers, brown rats, grey squirrels), with the total estimated cost of all economic conflicts exceeding {pound}0.5 billion. C_LIO_LIThe most common conflicts were reservoirs of disease and zoonotic disease, with non-native species scoring statistically higher than native species for the latter. Generally, we scored these conflicts low, deemed localised and mild, but highlighted the importance of surveillance to monitor and control disease spread. C_LIO_LIMost species caused minimal conflict, likely due to their limited distribution. We identified potential impact increased as a function of biomass and population size, therefore a GISS may help identify species capable of expanding beyond their current range, such as recently reintroduced beavers. C_LIO_LIA GISS is useful for identifying conflict species but there is also the need to understand the value of British wildlife. We identified costs-to-benefits trade-offs for several high impact species, including rabbits, deer, badgers and foxes, which underlie human-conflict and/or coexistence and are critical for informed decision-making. As one in four British mammal species face local extinction, the emphasis should encourage focus away from conflict resolution to acceptance and/or tolerance where wildlife and people coexist. C_LI

ecology↗

Predicting West Nile Virus risk across Europe for the current and future conditions

Vector-borne diseases have significant impacts on animal and human health globally, and these impacts are likely to increase in the future due to environmental and climate change. Understanding where to target surveillance and control measures to mitigate the impacts of emerging vector-borne diseases can be challenging when pathogens or disease is absent. In this study, we utilise a species distribution modelling approach previously applied to the UK to predict areas at higher risk of mosquito-borne disease across Europe, using West Nile Virus (WNV) as a case study. WNV is an Orthoflavivirus that is naturally transmitted between Culex mosquitoes and a range of avian species. However, it can spread to hosts such as humans and horses where it has the potential to lead to severe illness and mortality. Suitability predictions for Culex (Cx. pipiens and Cx. modestus) and avian hosts (mainly Passerine species) are made across Europe to determine potential risk of WNV circulation and establishment. These maps are then combined with information on human and horse density to determine risk to human and equine health. The resulting risk maps reveal that across Europe, there are areas of higher and lower risk that are predominantly driven by vector suitability as avian hosts are widespread. These predictions are projected into the future in 2100 using best- and worst-case Shared Socioeconomic Pathways (SSP1 and SSP5 respectively) to determine how risk may change over time, revealing that some areas see an increase in suitability for both vectors and hosts leading to higher risk (e.g., central England and northern Belgium) whilst other areas see a decline in suitability and consequently lower WNV risk (e.g., northern Italy and western Germany). Overall, this work will improve understanding of mosquito-borne disease risk in changing environments and demonstrates how species distribution modelling can be used to aid contingency preparedness by highlighting areas at higher risk of emerging disease.

pathology↗