Grasshopper species’ seasonal timing underlies shifts in community phenological overlap in response to climate gradients, variability, and change

1. Species with different life histories and communities that vary in their seasonal constraints tend to shift their phenology (seasonal timing) differentially in response to climate warming.

2. We investigate how these variable phenological shifts aggregate to influence phenological overlap within communities. Phenological advancements of later-season species and extended durations of early-season species may increase phenological overlap, with implications for species’ interactions such as resource competition.

3. We leverage extensive historic (1958-1960) and recent (2006-2015) weekly survey data for communities of grasshoppers along a montane elevation gradient to assess the impact of climate on shifts in the phenology and abundance distributions of species. We then examine how these responses are influenced by the seasonal timing of species and elevation, and how in aggregate they influence degrees of phenological overlap within communities.

4. In warmer years, abundance d...