Geographic variation in the intensity of warming and phenological mismatch between Arctic shorebirds and invertebrates

Abstract

Responses to climate change can vary across functional groups and trophic levels, leading to a temporal decoupling of trophic interactions or “phenological mismatches.” Despite a growing number of single‐species studies that identified phenological mismatches as a nearly universal consequence of climate change, we have a limited understanding of the spatial variation in the intensity of this phenomenon and what influences this variation. In this study, we tested for geographic patterns in phenological mismatches between six species of shorebirds and their invertebrate prey at 10 sites spread across ~13° latitude and ~84° longitude in the Arctic over three years. At each site, we quantified the phenological mismatch between shorebirds and their invertebrate prey at (1) an individual‐nest level, as the difference in days between the seasonal peak in food and the peak demand by chicks, and (2) a population level, as the overlapped area under fitted curves for total daily biomass of invertebrates and dates of the peak demand by chicks. We tested whether the intensity of past climatic change observed at each site corresponded with the extent of phenological mismatch and used structural equation modeling to test for causal relationships among (1) environmental factors, including geographic location and current climatic conditions, (2) the timing of invertebrate emergence and the breeding phenology of shorebirds, and (3) the phenological mismatch between the two trophic levels. The extent of phenological mismatch varied more among different sites than among different species within each site. A greater extent of phenological mismatch at both the individual‐nest and population levels coincided with changes in the timing of snowmelt as well as the potential dissociation of long‐term snow phenology from changes in temperature. The timing of snowmelt also affected the shape of the food and demand curves, which determined the extent of phenological mismatch at the population level. Finally, we found larger mismatches at more easterly longitudes, which may be affecting the population dynamics of shorebirds, as two of our study species show regional population declines in only the eastern part of their range. This suggests that phenological mismatches may be resulting in demographic consequences for Arctic‐nesting birds.

Phenological mismatch in Arctic‐breeding shorebirds: Impact of snowmelt and unpredictable weather conditions on food availability and chick growth

“…Previous studies have also noted high, but variable levels of phenological mismatch within shorebird species breeding throughout the Arctic (Kwon et al, 2019;McKinnon et al, 2012;Reneerkens et al, 2016;Senner et al, 2017). Previous studies have also noted high, but variable levels of phenological mismatch within shorebird species breeding throughout the Arctic (Kwon et al, 2019;McKinnon et al, 2012;Reneerkens et al, 2016;Senner et al, 2017).…”

“…Our results indicate that Arctic-breeding shorebirds have experienced increased phenological mismatch under earlier snowmelt conditions, with shorebirds tending to hatch after peak insect emergence in early snowmelt years, but before peak insect emergence in late snowmelt years. Previous studies have also noted high, but variable levels of phenological mismatch within shorebird species breeding throughout the Arctic (Kwon et al, 2019;McKinnon et al, 2012;Reneerkens et al, 2016;Senner et al, 2017). Although recent studies suggest shorebirds have some capacity to advance laying dates (Gill et al, 2014;Grabowski et al, 2013;Liebezeit et al, 2014;Saalfeld & Lanctot, 2017), advancement rates are likely limited by low plasticity in the start and progression of migration, which is controlled by a combination of endogenous and photoperiod cues (Karagicheva et al, 2016;Piersma et al, 2008).…”

“…In fact, several studies have shown that both Subarctic-and Arctic-breeding shorebirds (Gill et al, 2014;Grabowski, Doyle, Reid, Mossop, & Talarico, 2013;Liebezeit, Gurney, Budde, Zack, & Ward, 2014;Saalfeld & Lanctot, 2017) and their invertebrate prey (Braegelman, 2016;Tulp & Schekkerman, 2008) have advanced their phenologies with recent climate change. Thus, there now appears to be several instances of phenological mismatch between the timing of shorebird hatch and peak invertebrate availability, although variability exists among species and sites (Kwon et al, 2019;McKinnon, Picotin, Bolduc, Juillet, & Bêty, 2012;Reneerkens et al, 2016;Senner, Stager, & Sandercock, 2017). Thus, there now appears to be several instances of phenological mismatch between the timing of shorebird hatch and peak invertebrate availability, although variability exists among species and sites (Kwon et al, 2019;McKinnon, Picotin, Bolduc, Juillet, & Bêty, 2012;Reneerkens et al, 2016;Senner, Stager, & Sandercock, 2017).…”

“…Shorebird advancement rates, however, have not kept pace with advancing conditions (Grabowski et al, 2013;Saalfeld & Lanctot, 2017). Thus, there now appears to be several instances of phenological mismatch between the timing of shorebird hatch and peak invertebrate availability, although variability exists among species and sites (Kwon et al, 2019; McKinnon, Picotin, Bolduc, Juillet, & Bêty, 2012;Reneerkens et al, 2016;Senner, Stager, & Sandercock, 2017).…”

Shorebird Reproductive Response to Exceptionally Early and Late Springs Varies Across Sites in Arctic Alaska

“…In response to recent climate warming, many migratory bird species have adjusted the timing of arrival and breeding efforts to coincide with earlier spring conditions (Crick et al, 1997;Forchhammer et al, 1998;Stenseth et al, 2002;Walther et al, 2002;Parmesan and Yohe, 2003). Other studies indicate that species that are unable to advance their arrival dates may experience negative population consequences (Møller et al, 2008;Kwon et al, 2019); arrival dates may be further constrained by migratory life history, diet, or breeding habitat (Both and Visser, 2001;Jonzén et al, 2006;Both et al, 2010). Disentangling the factors that affect the timing of avian reproductive efforts is especially complex in an era of climate warming (Miller-Rushing et al, 2010;Mortensen et al, 2016).…”