Extreme temperature drop alters hatching delay, reproductive success, and physiological condition in great tits

Abstract

It has been suggested that extreme weather events may be treated as natural experiments that may unravel the mechanisms by which birds adjust their phenology and breeding parameters to environmental variability. In 2017, a sudden and heavy drop of temperatures for several days affected many European bird populations. This event occurred during the laying-early incubation period in the great tit (Parus major) population in central Poland, causing a large delay in hatching and had sustained reproductive consequences. This cold snap occurring once breeding activity had already started in 2017 was followed by the warm and invariable breeding season of 2018. This natural experiment had an essential influence on great tit reproductive parameters. We found a significant difference in hatching date, number of fledglings, hatching success, and fledging success between 2017 and 2018. In 2017, there were about two fledglings per nest fewer than in 2018. Fledging success was positively associated with hatching delay in 2017, while the relation was negative in 2018. Hatching success differed significantly between both years, being higher in 2018. Mean level of hemoglobin (used as index of body, physiological condition) in the blood of nestling great tits was higher in 2017 than in 2018. We argue that the moment of hatching may be (at least in some years) more tightly related to the moment of maximum food demand of tit nestlings than the traditionally used laying date. Also in extreme years, phenotypic plasticity of hatching delays may be insufficient to adjust the timing of breeding to the upcoming extreme weather events. Further examining its limits may be an important goal for future research.

Elevational Gradients as a Model for Understanding Associations Among Temperature, Breeding Phenology and Success

“…Nevertheless, in house sparrows (Passer domesticus), hatching success was negatively affected by extremely cold days during incubation (Pipoly et al, 2013). Likewise, wintery conditions are known to cause delays to the onset of incubation and hatching and to be associated with reduced reproductive success in Polish great tit and blue tit populations (Kluen et al, 2011;Gladalski et al, 2018Gladalski et al, , 2020. That blue tits in our population can suffer from challenging meteorological conditions, including early in the season, comes from at least two sources.…”

The Impact of Weather on the Behavior and Ecology of Birds

“…Nevertheless, in house sparrows (Passer domesticus), hatching success was negatively affected by extremely cold days during incubation . Likewise, wintery conditions are known to cause delays to the onset of incubation and hatching and to be associated with reduced reproductive success in Polish great tit and blue tit populations Gla ¸dalski et al, 2018Gla ¸dalski et al, , 2020. That blue tits in our population can suffer from challenging meteorological conditions, including early in the season, comes from at least two sources.…”

Recent changes in the reproductive success of farmland birds: conservation and management implications. The declining grey partridge Perdix perdix as a case study

“…However, further research is needed to characterize the impact of such extreme weather events on the demographic parameters of this particular species (adult and chick survival, egg hatching rate). Besides, a growing body of literature shows the importance of extreme meteorological events in population conservation for avian (Frederiksen et al 2008, Glądalski et al 2020, Piatt et al 2020), mammal (Chan et al 2005) or amphibian (Scheele et al 2012) species. This is a topical concern since such events result from climate change and are hence predicted to continue or even get worse in the future (IPCC 2013).…”