Biology subjects

Phillimore, A. B.

Publications and source records attributed to Phillimore, A. B..

3 recordsLinked to original sources

bioRxiv2026

The impact of phenological mismatch varies across woodland food-web interactions

Climate warming is altering the timing of seasonal events across ecosystems, impacting the temporal synchrony of interactions among species1,2. For trophic interactions, the match-mismatch hypothesis predicts that when consumers become phenologically asynchronous with key ephemeral resources their fitness will decline3-5. Most studies of mismatch focus on single resource-consumer species pairs, and implicitly assume trophic specialisation. However, many consumers exploit more than one resource species, giving rise to several mechanisms whereby the negative impacts of mismatch on individuals and populations could be buffered6. Here we experimentally manipulate phenological asynchrony across 48 plant-caterpillar interactions in a spring woodland food-web system and assay caterpillar performance. As asynchrony increases, we find strong evidence for a decline in survival that generalises across host-caterpillar interactions, whereas caterpillar growth and development are largely unaffected. We also show that focus in the literature on a single model interaction (Oak-Winter Moth)7,8 has likely overestimated the general impact asynchrony in this system. The strength of the effect of mismatch varies markedly among host-plants, caterpillars, and their interactions--with a small number of interactions showing little or no decline in consumer performance despite substantial asynchrony. Our results demonstrate that the fitness consequences of phenological mismatch are widespread but interaction-specific, revealing substantial heterogeneity in how trophic interactions are expected to respond to climate-driven shifts in seasonal timing. This variation in response could allow resource diversity and resource switching to buffer consumer guilds against the phenological impacts of ongoing climate change, stabilising the abundance of caterpillars for higher trophic levels.

ecology↗

bioRxiv2026

Widespread evidence for plasticity and recent evolution of plasticity in the breeding phenology of Finnish birds

Phenological shifts under climate change often arise through phenotypic plasticity and, where this is insufficient to track shifts in optimum timing, genetic adaptation may also play a role. Understanding the contributions of these two processes is critical for predicting species persistence in a changing climate. While many species show phenological plasticity, we know surprisingly little about the contributions that genetic adaptation of the plasticity reaction norm elevation (timing in the mean environment) and slope (shift in timing as a response to temperature) make to phenological shifts. With the aim of disentangling plasticity from adaptation in temperature-phenology reaction norms, we applied a statistical approach to long-term first egg-laying data from 44 Finnish bird species represented by 69 populations spanning six decades. Applying phylogenetic meta-analysis to parameter estimates obtained from the individual time series, we estimated average plasticity and adaptation effect sizes and tested whether migratory strategy, generation length, and mean laying-date explained among-species variation. Egg-laying phenology was strongly plastic, advancing by 2.5 days {degrees}C{square}{superscript 1}. We found no evidence for a steeper reaction norm between 5-year periods versus within them, consistent with no adaptation of the reaction norm elevation. However, we detected a significant steepening of slopes over time (-0.04 days {degrees}C{square}{superscript 1} year{square}{superscript 1}), consistent with plasticity across the whole study area increasing from -2.5 to -5.1 days {degrees}C{square}{superscript 1} and in the northernmost area (-0.07 days {degrees}C{square}{superscript 1} year{square}{superscript 1}) from -2 to -6.5 days {degrees}C{square}{superscript 1} over the 64-year study period. Trait analyses revealed no significant effect of migratory strategy, generation length, nor mean phenology on adaptation. We show that plasticity enables substantial short-term tracking of warming accompanied by noteworthy evidence consistent with widespread evolution of. Our approach demonstrates how observational data can help reveal evolutionary signals, offering a tool for improved understanding of the processes that underpin phenological responses.

ecology↗

bioRxiv2026

Thermal niche tracking in thirteen British temperate passerines

Identifying how and why species vary in their ability to adjust to rapidly changing climates is a key challenge in ecology. While phenological shifts are well documented for birds and often studied in the context of tracking resource availability, less is known about the extent to which adjustments in phenology allow populations to track a consistent thermal niche. In particular, there has been little examination of how the extent of phenological thermal niche tracking compares over time versus space; a comparison that has the potential to inform on the underlying mechanisms. Here, we use data on breeding phenology derived from BTO Nest Record Scheme data, to examine the extent to which 13 passerine bird species track a consistent incubation thermal niche across years (both interannually and a year gradient) and along latitudinal and elevational gradients, and whether migrant and resident species differ in their tracking ability. Overall, we found support across species for partial tracking, with all species showing trends consistent with partial tracking across one or more axis, though for one species we could not reject the null hypothesis of no tracking. When we looked at average trends across species, we found significant tracking across interannual variation, latitude, and elevation, but not across a year trend. However, we found no evidence that tracking differs between residents and migrants, and for only a few species did we found evidence that species incubation thermal niche impacts on fitness. Taken together, our findings highlight the extent to which shifts in phenology can allow birds to track a thermal niche in a changing climate. The timing of a thermal niche provides a useful and widely-applicable yardstick to examine how changes in climate will impact on the abiotic conditions that populations experience.

ecology↗