Foraging trip time-activity budgets and reproductive success in the black-legged kittiwake

A comparison of foraging behaviour in the North Sea by Black-legged KittiwakesRissa tridactylafrom an inland and a maritime colony

“…Studies on Kittiwakes using radiotrackers, activity loggers or similar GPS loggers to the ones used here have not shown any effect of the devices on foraging behaviour or breeding success (Irons 1998, Daunt et al 2002, Kotzerka et al 2009, Chivers et al 2012. Due to access constraints, we were not able to compare trip durations of tagged and untagged birds.…”

“…These species all rely predominately on sandeels or other small fish but competition for local resources may be mitigated by different foraging strategies. For example, Kittiwakes can range over large areas in search of food (Kotzerka et al 2009, Chivers et al 2012. Kittiwakes also nest along the Northumberland/ Tyne and Wear coastline, even venturing inland where the River Tyne holds important colonies, notably the furthest inland colony of around 600 pairs nesting on the Tyne Bridge and adjacent buildings (Turner 2010).…”

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“…During poor years, it may be harder for adults to maintain provisioning rates, even with buffering by the untagged partner, which may lead to lower nestling growth rates, lighter adult body mass, and, ultimately, lower adult survival (Igual et al 2005). Such effects may be particularly pertinent to kittiwakes, which increase foraging range when food availability is low and have a limited ability to increase foraging effort because, during the breeding season, they work close to maximum capacity and have little spare time to redirect to foraging (Hamer et al 1993, Furness and Tasker 2000, Enstipp et al 2006, Chivers et al 2012. In this study, adult body condition was maintained during tagging, which may explain why there was no apparent impact of tags on survival (Jacobsen et al 1995).…”

“…The use of tags of~5% body mass or less (often termed the '5% rule') is widely accepted (Barron et al 2010, Fair et al 2010) and has been used by kittiwake researchers in the past (Daunt et al 2002 [4-6%], Kotzerka et al 2010, Chivers et al 2012. However, there is another school of thought whose adherents refer to the '3% rule, ' which developed from a study on albatrosses and petrels (Phillips et al 2003).…”

“…Neither 'rule' has been thoroughly examined, and recent research and guidelines advise that, as tag impacts depend on many aspects of an animal's biology, there should be no arbitrary 'rule' for all animals, or groups of animals, and that species-specific studies should be carried out (Casper 2009, Vandenabeele et al 2012. Given that researchers continue to use tags of~5% body mass (Daunt et al 2002, Kotzerka et al 2010, Chivers et al 2012, Elliott et al 2014b, it is important that the effects of tags up to that range continue to be examined.…”