Linking phenology advances with abundance trends in order to better understand species range shifts
Dr Callum Macgregor1, Professor Chris Thomas1, Dr David Roy2, Dr James Bell3, Dr Jon Bridle4, Mr Richard Fox5, Dr Philip Platts1, Dr Ilik Saccheri6, Professor Jane Hill1
1University of York, York, United Kingdom, 2Centre for Ecology and Hydrology, Wallingford, United Kingdom, 3Rothamsted Research, Harpenden, United Kingdom, 4University of Bristol, Bristol, United Kingdom, 5Butterfly Conservation, Wareham, United Kingdom, 6University of Liverpool, Liverpool, United Kingdom
Responses of species to climate change include shifts in distributions, advances in phenology and/or altered abundances. We know that range expansion is contingent on stable or positive abundance trends, and we examine in turn how phenological advances under climate change affect species’ abundance trends. Using the British Lepidoptera as a model group (n = 1677 populations of 130 species from 141 sites), we show that species have advanced their phenology (timing of adult flight period) by 4 days on average over the period 1995-2014, but the consequences of phenological advances depended on species’ life-cycle flexibility. Species with multiple reproductive cycles per year (N = 39 species) increased population growth in second and subsequent generations by emerging earlier in warmer springs, resulting in abundance increases. However, this relationship was not evident in species with a single reproductive cycle per year (N = 91 species), which had reduced abundance in years following earlier emergence. Therefore, phenological advancement only benefits species with sufficient plasticity in their reproductive cycles to allow increased productivity in warmer years with longer growing seasons. Life-cycle flexibility may drive variation in the rate of range shifting under climate change, via its impacts on the benefits of phenology advances for abundance trends.
Dr Macgregor is an entomologist and ecologist, with a strong interest in the evolutionary ecology of organisms, in relation to both the abiotic factors impacting upon them and their biotic interactions with other species. He is keen to apply skills in sampling insects, detecting interspecific interactions (including by DNA-based methods), and using complex statistics on large datasets, to the study of insect responses to environmental change. He is interested in how species adapt when impacted by multiple drivers of change, and the coevolution of interacting organisms that form complex ecological networks. He is particularly driven by a passion for Lepidoptera. He completed his PhD at Newcastle University in 2017, receiving the Alfred Russel Wallace Award from the Royal Entomological Society for his thesis, and has ever since been working as a PDRA at the University of York, investigating evolutionary and plastic responses to 100 years of climate change in Britain’s butterflies and moths.