Time‐lapse cameras reveal latitude and season influence breeding phenology durations in penguins

Abstract

Variation in the phenology of avian taxa has long been studied to understand how a species reacts to environmental changes over both space and time. Penguins (Sphenicidae) serve as an important example of how biotic and abiotic factors influence certain stages of seabird phenology because of their large ranges and the extreme, dynamic conditions present in their Southern Ocean habitats. Here, we examined the phenology of gentoo (Pygoscelis papua) and chinstrap penguins (Pygoscelis antarctica) at 17 sites across the Scotia arc, including the first documented monitoring of phenology on the South Sandwich Islands, to determine which breeding phases are intrinsic, or rather vary across a species range and between years. We used a novel method to measure seabird breeding phenology and egg and chick survival: time‐lapse cameras. Contrary to the long‐standing theory that these phases are consistent between colonies, we found that latitude and season had a predominant influence on the length of the nest establishment, incubation, and guard durations. We observe a trend toward longer incubation times occurring farther south, where ambient temperatures are colder, which may indicate that exposure to cold slows embryo growth. Across species, in colonies located farther south, parents abandoned nests later when eggs were lost or chicks died and the latest record of eggs or chicks in the nest occurred earlier during the breeding period. The variation in both space and time observed in penguin phenology provides evidence that the duration of phases within the annual cycle of birds is not fundamental, or genetic, as previously understood. Additionally, the recorded phenology dates should inform field researchers on the best timing to count colonies at the peak of breeding, which is poorly understood.

Un-crewed aerial vehicle population survey of three sympatrically breeding seabird species at Signy Island, South Orkney Islands

“…Fortunately, a number of developing technologies have recently become available to seabird researchers, all of them providing means of overcoming to some extent the challenges of accessing polar seabird populations. These include the use of remotely sensed satellite imagery to locate and estimate the size of colonially breeding bird populations (Fretwell et al 2012;Lynch et al 2012;Fretwell et al 2015), and autonomous time-lapse camera systems collecting spatially extensive phenological and reproductive data, replacing the need for direct observation (Southwell et al 2013;Lynch et al 2015;Black et al 2018;Hinke et al 2018). However, whilst satellites can achieve global coverage, P.N.…”

Applications of digital imaging and analysis in seabird monitoring and research

“…Most studies set cameras to record one image per hour and are only returned to once per year to change SD cards and batteries (Southwell & Emmerson 2015, Black et al . 2018a). This means that time‐lapse photography can improve temporal resolution and data accuracy with reduced time investment.…”

“…yearly maintenance) allows time‐lapse cameras to capture images in locations and at scales otherwise unfeasible in terms of time, money and human capabilities, such as in harsh conditions and remote places (Weller & Derksen 1972, Black et al . 2017, 2018a, 2018b, Black 2018, Pascalis et al . 2018).…”

“…This is typical of remote locations at high latitude with harsh environmental conditions and highlights how digital imaging technology can greatly increase the scale of monitoring (Black et al . 2017, 2018a, 2018b, Korczak‐Abshire et al . 2019).…”

The interaction between island geomorphology and environmental parameters drives Adélie penguin breeding phenology on neighboring islands near Palmer Station, Antarctica

“…The ability of a species to synchronize their breeding chronology to optimal local conditions is thus considered crucial to population and breeding success, especially in polar regions where strong variability in seasonality, both natural and climate‐driven, can lead to short periods of favorable or unfavorable conditions, the latter possibly amplifying the potential for ecological mismatch (Visser & Both, , Cushing, , Schwartz, ; Thackeray et al, ). The recent and rapid warming at the poles in particular has inspired a number of studies to not only investigate the drivers of phenological trends on both global and regional scales, but also to understand the processes that affect the extent to which a species may be vulnerable to climate change (Black et al, ; Dunn & Winkler, ; Keogan et al, ; Parmesan & Yohe, ; Youngflesh et al, ). While many studies suggest the climate signal controlling spring breeding phenology is well understood (Walther et al, ; Wormworth & Sekercioglu, ), other studies report difficulties in teasing out the degree to which environmental factors drive phenology (Youngflesh et al, ), indicating further research is still necessary (e.g., identifying the correct time window or obtaining climate data at the appropriate scale).…”