Biology subjects

Wilde, J. A.

Publications and source records attributed to Wilde, J. A..

3 recordsLinked to original sources

bioRxiv2026

A spatial analysis of Common Pheasant (Phasianus colchicus) abundance with reference to Protected Area coverage in England

The release of tens of millions of common pheasants (Phasianus colchicus) across the UK for shooting may pose an ecological risk to native species and sensitive habitats, particularly if the birds move into protected areas (PAs) such as Special Areas of Conservation (SAC), Special Protection Areas (SPA), and Sites of Special Scientific Interest (SSSI). The extent of this ecological risk depends on the abundance of pheasants in these sensitive sites, especially if they are attracted there after the shooting season when game management efforts to retain the birds cease. We used relative pheasant abundance measures derived from British Trust for Ornithology bird atlas data from 3793 2km tetrads across four English counties (Berkshire, Cornwall, Devon, and Hertfordshire) to determine if pheasants preferentially disperse into or reside in areas with greater PA coverage. We analysed relative abundance in both the winter shooting season and the breeding season using a Bayesian occupancy-abundance model, controlling for habitat type and diversity. Our results showed a strong influence of habitat on pheasant abundance, consistent with known habitat preferences. However, we found no evidence of a relationship between relative pheasant abundance and the proportion of ecologically relevant PA coverage in a tetrad. This lack of a relationship was consistent across all four counties and across both the winter and breeding seasons. Our finding suggests that common pheasants do not preferentially disperse into or reside in protected areas compared to surrounding, unprotected land, suggesting that the ecological impacts caused by released pheasants are no more likely to occur in protected areas than in non-protected areas.

ecology↗

bioRxiv2026

The dispersal of released pheasants and the risk of their intrusion into English protected areas

Large-scale annual releases of pheasants Phasianus colchicus and their subsequent management for recreational shooting create various ecological impacts in the UK. While effects at release sites are fairly well understood, dispersing birds may influence areas farther away. If they enter ecologically important but sensitive protected areas (PAs), any negative impacts could be especially harmful. Using tracking data, from 766 birds across 10 sites, we estimated survival and dispersal of released pheasants and applied these patterns to gamebird release records near English PAs to gauge intrusion risk. Of 2,885 registered release sites, just over half lay within 2 km of a PA. A large number of shoots release relatively few birds while a small number release many birds. Thus, numbers expected to enter a particular PA likely depend both on the size of releases and proximity to the PA. We estimate that, at a national level, a maximum of between 525,000 and 784,000 pheasants might be found within PAs very soon after release, representing around 1.7% of all the pheasants released annually. This number declines over the months after release until in February, we estimate that there are between 131,000 and 196,000 pheasants (0.4% of the total release) might be found within PAs. The critical metric by which ecological damage might occur is their density within PAs. Mean densities soon after release averaged 12.0 birds/ha in PAs within 250 m of release sites. This density declined markedly both in time (as birds died) and space (as they moved further from the pen as potential areas increased). By November, densities in PAs 500-1000m from release sites peaked at 0.5 birds/ha, falling to 0.16 birds/ha in February. These estimated densities are around two orders of magnitude lower than those known to cause strong, lasting impacts within release pens. The results are subject to assumptions about movement behaviour, game management and bias in registration. Despite these constraints, considerable local variation exists, with a minority of high-volume release sites very near PAs posing the greatest potential ecological risk.

ecology↗

bioRxiv2023

Biomimetic robots reveal flexible adjustment of sexual signalling in a wild invertebrate.

Sexual signals are often structured in bouts, which can be adjusted in response to changes in the signallers physical and social environment. For example, we might expect individuals to adjust their own signalling behaviour in response to changes in the signalling behaviour of rivals, because this can affect their relative attractiveness to potential mates. In this study, we used a biomimetic robot to experimentally manipulate rival waving behaviour in a wild population of fiddler crabs (Afruca tangeri), and investigated whether this leads to changes in the activity and waving behaviour of a focal male. Analysing the focal males behaviour using hidden Markov models and linear hurdle models, we found no evidence that the focal males waving rate changed in response to changes in the behaviour of the robotic rival. However, bouts of waving lasted longer when the robotic rival was waving at a fast rate. Focal males were also less likely to enter their burrow when the robotic rival was waving, and spent less time in their burrow if they did enter. These results reveal tactical adjustment of behaviour by competing signallers, and highlight the flexible nature of bout-structured sexual displays.

animal behavior and cognition↗