When things go wrong: intra‐season dynamics of breeding failure in a seabird

Abstract

T. Tveraa, and T. Boulinier. 2014. When things go wrong: intra-season dynamics of breeding failure in a seabird. Ecosphere 5(1):4. http://dx.doi.org/10.1890/ES13-00233.1Abstract. During breeding, long-lived species face important time and energy constraints that can lead to breeding failure when food becomes scarce. Despite the potential implications of intra-season dynamics in breeding failure for individual behavior, carry-over effects, dispersal decisions and population dynamics, little information is currently available on these dynamics at fine temporal scales. Here, we monitored the foraging behavior and the proportion of successful black-legged kittiwake pairs from nest construction to chick fledging in a colony of the southern Barents Sea, to relate foraging effort to the dynamics of breeding failure over an entire breeding season, and to infer the environmental conditions leading to this failure. Specifically, we tracked kittiwakes with GPS and satellite tags during incubation and early chick-rearing to document nest attendance, foraging range, time budgets and daily energy expenditures (DEE). We also monitored diet changes over time. We predicted that breeding failure would follow a non-linear trend characterized by a break point after which breeding success would drop abruptly and would be related to a substantial increase in foraging effort. Kittiwakes showed contrasting foraging patterns between incubation and chick-rearing: they extended their foraging range from 20 km during incubation to more than 450 km during chick-rearing and switched diet. They also increased their DEE and readjusted their time budgets by increasing time spent at sea. These changes corresponded to a break point in breeding dynamics beyond which the proportion of successful pairs abruptly dropped. At the end of the season, less than 10% of kittiwake pairs raised chicks in the monitored plots. This integrative study confirms that breeding failure is a non-linear process characterized by a threshold beyond which individuals face an energetic trade-off and cannot simultaneously sustain high reproductive and selfmaintenance efforts. In this way, the occurrence of sudden environmental changes complicates our ability to predict population dynamics and poses conservation challenges.

Causes and consequences of individual variability and specialization in foraging and migration strategies of seabirds

“…However, an important component of the breeding population comprises individuals that are not breeding or have failed in their breeding attempt, and an increasing number of studies aim to quantify the foraging dynamics of these groups and to test whether they show different behaviours compared to breeding adults. Much of the attention has been directed at failed breeders, whose failure may have been natural, a consequence of the deployment, or induced as part of a manipulative experiment (Phillips et al 2005, Bogdanova et al 2011, Ponchon et al 2014. Failed breeders often continue to associate with the colony, operating as central-place foragers but expanding their foraging areas (González-Solís et al 2007).…”

“…Failed breeders often continue to associate with the colony, operating as central-place foragers but expanding their foraging areas (González-Solís et al 2007). The spatial overlap with breeders varies among populations; it can be high (Ponchon et al 2014), moderate , or there may be marked segregation , Reid et al 2014, Clay et al 2016. Further, failed breeders may make visits to other colonies when breeders are still actively rearing chicks; this behaviour is interpreted as prospecting potential new breeding sites and may be motivated by having failed at the current location (Fijn et al 2014, Ponchon et al 2014.…”

“…The spatial overlap with breeders varies among populations; it can be high (Ponchon et al 2014), moderate , or there may be marked segregation , Reid et al 2014, Clay et al 2016. Further, failed breeders may make visits to other colonies when breeders are still actively rearing chicks; this behaviour is interpreted as prospecting potential new breeding sites and may be motivated by having failed at the current location (Fijn et al 2014, Ponchon et al 2014. In contrast, successful breeders do not undertake prospecting trips or only do so after breeding is finished (Fijn et al 2014, Ponchon et al 2014.…”

Telomere length is a strong predictor of foraging behavior in a long‐lived seabird

“…Since shortened telomeres indicate a deteriorated state or advancing age, we predict that birds with shorter telomeres will forage closer to the colony (Pelletier et al 2014), at shallower depths, and spend less time diving at night. However, in some species, foraging distance from the colony increases when poor conditions decrease food availability (Huettman and Diamond 2001, Buren et al 2012, Ponchon et al 2014, therefore colony conditions may also drive foraging distance, and poor quality birds may forage further from the colony. In addition, we predict birds with deteriorated telomeres will spend less time underwater, indicating decreased foraging efficiency.…”

Predicting the impacts of wind farms on seabirds: An individual‐based model

“…This is because adults in the model do not stop feeding the chick when their own mass decreases (as they would in reality, Ponchon et al, 2014), and this should be addressed in future model iterations.…”