Hatching delays in great tits and blue tits in response to an extreme cold spell: a long-term study

Abstract

Variation in ambient temperature affects various life stages of organisms. It has been suggested that climate change not only implies higher global temperatures but also more unpredictable weather and more frequent extreme weather events. Temperature has a major influence on the optimal laying-incubation-hatching dates of insectivorous passerines, because it poses energetic constraints and affects the timing of food abundance. We have been studying breeding characteristics of great tits Parus major and blue tits Cyanistes caeruleus in two areas, an urban parkland and a deciduous forest, around the city of Łódź since 2002. During the egg-laying period in 2017, both tit species at both study areas faced an unusual cold spell as reflected by a sudden decrease in the mean ambient temperature to ca. 2–3 °C for about 5 days, which caused mean hatching delays of up to 6 days. Since flexibility of behavior plays a major role in adjusting to unpredictable weather conditions, examining its limits may be an important goal for future research.

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

“…The large temperature drop in 2017 was also recorded in many tit populations (and other bird populations, Shitikov et al 2019) all over the Europe: in Belgium, England, France, Germany, Hungary, the Netherlands, Poland (Figs. 1, 2), Sweden, and others (see Glądalski et al 2018a). The critical period of the temperature drop during the layingincubating period in April of 2017 lasted for about 5 days.…”

“…There is still little information about how climate change and extreme weather events may influence breeding traits and reproduction parameters in animals (Charmantier et al 2008;Pipoly et al 2013;Charmantier and Gienapp 2014;Glądalski et al 2016Glądalski et al , 2018aMainwaring et al 2017;van de Pol et al 2017;Wingfield et al 2017). Therefore, it was suggested that those extreme weather events may be treated as natural experiments that could shed light on the mechanisms by which birds adjust their breeding characteristics to environmental variability (Jentsch et al 2007;Bailey and van de Pol 2016;Marrot et al 2017).…”

“…In birds, extremely cold spells may induce egg rejection behavior (this behavior could serve as a mechanism for maternal clutch size adjustment in passerines in response to extreme cold periods, Shitikov et al 2019), negatively influence hatching success (in white storks, Ciconia ciconia, frost during incubation may negatively influence the hatching success, Tobolka et al 2015), or lead to higher nest mortality (extreme weather events may cause high late mortality even for stork nestlings older than 30 days, Tobolka et al 2015; extreme drought may alter breeding success in willow flycatchers, Empidonax traillii, Theimer et al 2018). Extremely cold spell may also cause much lower biomass of nestlings (low temperatures and long-lasting heavy and frequent rain may cause lower amount of food and may cause difficulty with feeding nestlings, Whitehouse et al 2013), cause large hatching delay (Whitehouse et al 2013;Glądalski et al 2018a), or even cause egg freezing and egg cracking, resulting in the loss of whole clutches (Hale 1933, Musselman 1939, Indykiewicz 2015. Little is known about the flexibility of the hatching delay (a difference between the expected date and the observed hatching date was considered as a hatching delay) and its consequences on breeding parameters (Kluen et al 2011;Lee and Lima 2017).…”

“…In insectivorous passerines, like tits, temperature has a crucial influence on the optimal laying date and reproduction, because it affects trophic conditions for egg formation, conditions for incubation, and the timing of peaks in spring caterpillar abundancethe main food source for the nestlings (Perrins 1991). 2017 was not, in general, an abnormally colder year, but a sudden drop of temperatures for several daysa cold snapduring the laying-early incubating period in Polish populations of the great tit (Parus major) caused a marked hatching delay (Glądalski et al 2018a). That harsh period was followed by completely opposite, warm and invariable breeding season of 2018.…”

Extreme hot weather has stronger impacts on avian reproduction in forests than in cities

“…due to loss of some of their actual offspring. If several extreme events occur or an extreme event takes long time in a single breeding season, majority of breeding individuals may die or may not successfully raise offspring which then can have population-level consequences (Møller 2011;Glądalski et al 2018).…”