Senior Research Ecologist

Callum works as a Senior Research Ecologist analysing quantitative data from a range of projects from Wales.
Callum’s interests as an ecologist are broad, but centre on how organisms (at individual, population and community scales) respond to changes in their environment, especially when those changes are induced by human activity.
He completed his PhD at Newcastle University, studying how light pollution at night affects the role of moths as pollinators, and undertook two subsequent postdoctoral research positions in Yorkshire investigating the impacts of climate change on butterflies (York) and the ecological value of brownfield sites to birds, plants, and insects (Hull) respectively, before joining the BTO in May 2021.
Callum is based within the BTO Cymru office looking at Welsh bird populations and their conservation.
BA (Hons.) Biological Sciences, University of Oxford, 2013.
PhD Ecology: “The role of moths as pollinators, and the effects of environmental change”, Newcastle University, 2017.
Recent BTO Publications
- Macgregor, C.J., Pearce-Higgins, J.W., Siriwardena, G.M., Wilson, M.W. & Robinson, R.A. Assessment of recent Hen Harrier population trends in England through population modelling View at journal website( DOI: )
- Hereward, H.F.R., Macgregor, C.J., Gabb, O., Connell, A., Thomas, R.J., Cross, A.V. & Taylor, R.C. Modelling population-level impacts of wind farm collision risk on Welsh Red Kites View at journal website( DOI: )
- Macgregor, C.J., Gillings, S., Balmer, D.E., Boersch-Supan, P.H., Harris, S.J., Hereward, H.F.R., Humphreys, E.M., Pearce-Higgins, J.W., Taylor, R.C., Troost, G. & Atkinson, P.W. Impacts of highly pathogenic avian influenza on seabird populations in the North Sea are detectable in sea-watchers’ migration counts 10.1080/00063657.2024.2440826 View at journal website( DOI:10.1080/00063657.2024.2440826 )
- Hereward, H.F.R., Brenchley, A., Facey, R.J., Hughes, J., Lindley, P.J., Taylor, R.C., Wilson, M.W. & Macgregor, C.J. Status and distribution of Rook Corvus frugilegus in Wales in 2022/23 View at journal website( DOI: )
- Kenobi, K., Read, W., Bowgen, K., Macgregor, C., Taylor, R., Cámaro García, W., Hodges, C., Dennis, P. & Holloway, P. Lasso Penalisation identifies consistent trends over time in landscape and climate factors influencing the wintering distribution of the Eurasian Curlew (Numenius arquata) 10.1016/j.ecoinf.2023.102244 View at journal website( DOI:10.1016/j.ecoinf.2023.102244 )