Incubation and hatching periods in a Mediterranean Great Tit Parus major population

Incubation behavior adjustments, driven by ambient temperature variation, improve synchrony between hatch dates and caterpillar peak in a wild bird population

“…Earlier layers displayed the strongest negative temperature—onset relationship, supporting previous findings that early layers are most able to alter their timing (Cresswell & McCleery, ). This suggests that temperatures around laying do act as a cue for the onset of incubation, supporting several previous findings (Álvarez & Barba, ; Cresswell & McCleery, ; Stenning, ). However, the cues for incubation behavior were not found to be uniform across different aspects.…”

“…The most commonly studied aspects of reproductive phenology have been those which are easily observable: clutch initiation date (Charmantier et al., ; Lack, ; Nussey et al., ; Schaper et al., ; Visser et al., ), clutch size (Balen, ; Haartman, ; Haftorn, ; Kluiver, ; Lack, , ; Perrins, , ), birth date (Plard et al., ), flowering date (Menzel et al., ), and hatch date (Cresswell & McCleery, ; Tomas, ). However, it is well established that there is also considerable variation in other aspects of the reproductive cycle, such as incubation behavior (Álvarez & Barba, ; Ardia, Pérez, & Clotfelter, ; Cresswell & McCleery, ; García‐Navas & Sanz, ; Hepp, Kennamer, & Johnson, ; Lord, McCleery, & Cresswell, ; Matthysen, Adriaensen, & Dhont, ; Stenning, ), conception date (Scott, Asher, Archer, & Littlejohn, ), and gestation length (Asher et al., ; Moyes et al., ; Racey & Swift, ; Scott et al., ). The phenology of many of these reproductive behaviors cannot be observed directly; nonetheless, they could have a significant role in determining the timing of the peak energetic demands of reproduction, usually during offspring rearing.…”

“…Second, the duration of the incubation period can be adjusted based on the intensity of incubation effort. Variability in the relative onset of incubation has been demonstrated across a diverse range of bird species (e.g., Paridae and Anatidae ) and can vary by up to a week either side of clutch completion (Álvarez & Barba, ; Cresswell & McCleery, ; García‐Navas & Sanz, ; Hepp, ; Loos & Rohwer, ; Lord et al., ; Matthysen et al., ; McClintock, Hepp, & Kennamer, ; Stenning, ). Such changes are also known to have knock‐on impacts on reproductive success.…”

“…Beginning incubation prior to completion of a clutch can increase hatching asynchrony and lead to rapid brood reduction in years of poor resources (Álvarez & Barba, ; Ardia et al., ; García‐Navas & Sanz, ; Lord et al., ; Stenning, ). Variation in incubation onset has been linked to changes in spring temperatures both experimentally (Álvarez & Barba, ; Bryan & Bryant, ; Vedder, ) and through observational studies (Cresswell & McCleery, ; Matthysen et al., ). Incubation duration and intensity have been less extensively studied but have also been shown to vary with temperatures and potentially with individual condition (Ardia et al., ; Conway & Martin, ; McClintock et al., ).…”

A recipe for postfledging survival in great titsParus major: be large and be early (but not too much)

“…We used data collected during a long-term study of a great tit population breeding in nest boxes within an extensive orange monoculture in Sagunto (Valencia), Eastern Spain (39°42 0 N, 0°15 0 W, 30 m a.s.l.). Wooden nest boxes were placed each year for the birds to breed, and were visited with the periodicity necessary (at least weekly, and daily at some stages) to record basic breeding parameters (Greño et al 2008;Alvarez and Barba 2014). Relevant to this work were exact hatching dates, obtained for all nests through daily visits around the expected date of hatching (day 0), and fledgling mass (digital balance, 0.01 g accuracy) and tarsus length (digital calliper, 0.01 mm accuracy), obtained from 15-day-old nestlings.…”