Latitudinal variation in arrival and breeding phenology of the pied flycatcher Ficedula hypoleuca using large‐scale citizen science data

Abstract

Many species have advanced the timing of annual reproductive cycles in response to climatic warming, sometimes leading to asynchrony between trophic levels, with negative population consequences. Long‐distance migratory birds, reliant on short seasonal food pulses for breeding, are considered particularly susceptible to such disjunction because late arrival may preclude optimal timing of egg‐laying. It is unknown whether the relative timing of arrival and egg‐laying is sufficiently plastic, in time and space, to enable an adaptive response when arrival times change relative to local food resources. We used citizen science data, describing pied flycatcher Ficedula hypoleuca arrival and egg‐laying dates, to explore temporal (2013–2016) and spatial (across Great Britain) variation in the phenology of arrival, laying and their difference. To assess the long‐term trend in arrival and laying at a single location, we used data from a long‐term field study. The arrival‐laying interval was consistently shorter in the north, driven by the contrast between spatial variation in arrival date and spatial invariance in laying date. To understand whether a short arrival‐laying interval may have consequences for productivity, we assessed the association between this interval and clutch size. We found no statistically significant correlation between these two variables. To examine long‐term changes in arrival and laying dates, we focussed on a single location in southwestern England. Both dates of first male arrival and first egg laid in a season advanced since 1986, with no evidence of interval shortening. Together, our results demonstrate spatial and annual variation in the arrival‐laying interval, with no detected effect on fecundity. Thus, the interval from arrival to laying is likely dictated by spatially and temporally varying local conditions, suggesting these migrant birds may have the ability to adapt this interval to align with local conditions and mitigate potential mismatch impacts.

Early Breeding Conditions Followed by Reduced Breeding Success Despite Timely Arrival in an Alpine Migratory Songbird

“…However, the adjustment via shortening the arrival-breeding interval might not be flexible enough, as birds seem to be unable to advance egg laying sufficiently and thus may need to arrive even earlier to have the same arrival-breeding interval as in average years. The arrival-breeding interval is needed for recovering after migration, territory choice and defence, and mating (Kristensen et al, 2015;Nicolau et al, 2021). A shortening of this interval could be driving the observed lower fledging success.…”

“…Nevertheless, the advance in lay dates still seems insufficient to track the advance of spring, which might be the result of the inflexibility in their migration onset, that is triggered by day length rather than temperature (Both and Visser, 2001), as well as migration speed (Fraser et al, 2013;Schmaljohann and Both, 2017). Within the same species, flexible adjustment to earlier springs seemed to be realised by shortening the arrival-breeding interval (Nicolau et al, 2021). McDermott and DeGroote (2017) analysed data on 17 migratory species, and found a positive relationship between earlier arrival at the breeding grounds and earlier breeding in four species, whereas in six species, the arrival-breeding interval shortened in warmer springs, as occurred in our Alpine wheatear population in 2020 (Figure 2B).…”

High nest failure but better nestling quality for early breeders in an alpine population of Northern Wheatear (Oenanthe oenanthe)

“…Recent literature reflects that climate-driven adaptations in breeding phenology are evident in several songbird species in that they advance the onset of breeding in warmer springs (Kluen et al 2011, Fossøy et al 2015, Bründl et al 2020, Hoover & Schelsky 2020, Shipley et al 2020, Nicolau et al 2021. The arrival of migrants at the breeding grounds is strictly connected to their migration schedule (Schmaljohann 2019), bringing an additional challenge to the successful timing of life-history events and determining the ability to adjust lay date to the local green-up (Low et al 2019, Amélineau et al 2021, Lamarre et al 2021, Sander et al 2021.…”

Territory-level temperature influences breeding phenology and reproductive output in three forest passerine birds

“…The spatial pattern of temperature across the study area was consistent between years, and territories that were relatively cool in 2015-2018 had the highest occupancy rates since 1980, indicating that relatively cooler territories have probably been preferentially selected for almost 40 years. The territory selection relationships we found in our study years probably hold historically as, despite a warming of ambient temperature over these years, breeding phenology at the population level has advanced in response (Nicolau et al 2021), and so the spatial patterns of temperature at the territory scale at the onset of the breeding period remain the same. The models also showed that adult pied flycatchers with greater previous breeding experience (i.e.…”

“…We found no significant temperature relationship for pied flycatcher lay date, suggesting temperature may not be a direct cue to egg laying in this species. Pied flycatcher egg laying phenology shows less spatial and inter-annual variation compared with arrival phenology (Nicolau et al 2021), indicating that in years with early arrival individual birds can build nests well in advance of egg laying. This is supported by our results, as in cool years nests were initiated significantly earlier at warmer territories with this pattern reversed in warm years, but these temperature patterns did not significantly impact laying date.…”