Elevated metabolic costs while resting on water in a surface feeder: the Black-legged Kittiwake Rissa tridactyla

Measurements of the energy costs of individual behaviours provide insights into how animals trade-off resource allocation and energy acquisition decisions. The energetic costs while resting on water are poorly known for seabirds but could comprise a substantial proportion of their daily energy expenditure. We measured the cost of resting on water in Black-legged Kittiwakes Rissa tridactyla , a species which does not fly during the night and for which estimating energy expenditure while resting on the water is therefore important. Their resting metabolic rate on water at 12.5 °C was at least 40% higher compared with resting at the same temperature in air. This indicates that, at comparable temperatures, metabolic costs are elevated for birds resting at sea compared with on land. We argue that Kittiwakes meet much of this extra thermoregulatory demand by dedicated metabolic activity. During the winter months, their costs are likely to be even higher owing to lower sea temperatures. Accordingly, we suggest that migration to milder latitudes, following breeding, will provide enhanced benefits, particularly to seabirds such as Kittiwakes which rest on the sea surface during darkness.     

Sensitivity of breeding parameters to food supply in Black-legged Kittiwakes Rissa tridactyla

We fed Herring Clupea pallasi to pairs of Black-legged Kittiwakes Rissa tridactyla throughout the breeding season in two years at a colony in the northern Gulf of Alaska. We measured responses to supplemental feeding in a wide array of breeding parameters to gauge their relative sensitivity to food supply, and thus their potential as indicators of natural foraging conditions. Conventional measures of success (hatching, fledging and overall productivity) were more effective as indicators of food supply than behavioural attributes such as courtship feeding, chick provisioning rates and sibling aggression. However, behaviour such as nest relief during incubation and adult attendance with older chicks were also highly responsive to supplemental food and may be useful for monitoring environmental conditions in studies of shorter duration. On average, the chick-rearing stage contained more sensitive indicators of food availability than prelaying or incubation stages. Overall, rates of hatching and fledging success, and the mean duration of incubation shifts were the most food-sensitive parameters studied.     

Adult survival of Black-legged Kittiwakes Rissa tridactyla in a Pacific colony

Breeding Black-legged Kittiwakes Rissa tridactyla survived at a mean annual rate of 0.926 in four years at a colony in Alaska. Survival rates observed in sexed males (0.930) and females (0.937) did not differ significantly. The rate of return among nonbreeding Kittiwakes (0.839) was lower than that of known breeders, presumably because more nonbreeders moved away from the study plots where they were marked. Individual nonbreeders frequented sites up to 5 km apart on the same island, while a few established breeders moved up to 2.5 km between years. Mate retention in breeding Kittiwakes averaged 69% in three years. Among pairs that split, the cause of changing mates was about equally divided between death (46%) and divorce (54%). Average adult life expectancy was estimated at 13.0 years. Combined with annual productivity averaging 0.17 chick per nest, the observed survival was insufficient for maintaining population size. Rather, an irregular decline observed in the study colony since 1981 is consistent with the model of a closed population with little or no recruitment. Compared to their Atlantic counterparts, Pacific Kittiwakes have low productivity and high survival. The question arises whether differences reflect phenotypic plasticity or genetically determined variation in population parameters.     

Population trends in Kittiwake Rissa tridactyla colonies in relation to tick infestation

Parasite and disease transmission has long been considered one of the main costs of group living, but there is still little empirical evidence. Most seabird species breed in dense colonies and occupy the same breeding sites for many years and thus could be exposed to deleterious levels of haematophagous ectoparasite infestations. The aims of this study were to provide information on the epidemiology of the tick Ixodes uriae and to investigate the relationship between Kittiwake Rissa tridactyla colony population trends and local levels of tick infestation in chicks. It is based on a cross-sectional survey of a large sample of British Kittiwake colonies (22 colonies more than 30 years old and situated on natural cliffs). Ixodes uriae was by far the most common ectoparasite detected and was found in all colonies examined. Ticks were aggregated between nests, but not between siblings. Very young and old chicks were far less parasitized than chicks of intermediate age and were excluded from the analysis. Among colonies for which we had good data on population trends in Kittiwakes, those decreasing in number had a higher prevalence and density of ticks than those which were increasing. We suggest that this correlation reveals a cause-and-effect relationship. By influencing the local reproductive success, ectoparasites can affect the recruitment of new breeders and the breeders' site fidelity in the following year, thus influencing the local trend of numbers. This causal link highlights the potential effect of parasites on their host population and thus needs to be investigated further.     

Parental attendance and squatting in the Kittiwake Rissa tridactyla during the rearing period

Parental attendance was studied in 1991 in the Cap Sizun Kittiwake colonies (Brittany, France). After a period of continuous guarding lasting on average 22 days, parents left their chicks unattended. Thereafter, parental attendance decreased regularly until fledging. The chick age when first left alone was on average 3 days lower for large broods than for single-chick broods. Moreover, whatever the brood size, chicks from late nests were younger when left unattended. Parental age affected the initiation of first absence. Younger parents reduced their attendance sooner than older parents. About 80% of the nests with chicks were visited by other adults at least once during the absence of the parents, and 50% were visited in the 3 days following the first absence of the breeders. These squatters were mainly failed breeders and prebreeders looking for a future breeding site. The results are discussed in terms of costs and benefits of chick neglect and comparisons were made with data from other studies in North Atlantic and Alaskan colonies. This reflected the flexibility of adult behaviour in relation to brood size and food availability.     

Individual Vocal Recognition in the Kittiwake Gull,Rissa tridactyla (L.)

Breeding Kittiwake Gulls recognized their partners by voice alone. The voices of all individuals in the population showed consistent differences in their tonal and temporal structures. The role of calling behaviour in a cliff-nesting context is discussed.     

The energy economy of the arctic-breeding Kittiwake (Rissa tridactyla): a review

The present paper reviews recent studies on changes in body mass, body composition and rates of energy expenditure during the breeding season in the black-legged Kittiwake (Rissa tridactyla) on Svalbard (79 degrees N). The main characteristic of the energy budget is a pronounced decrease in body mass as well as basal metabolic rate (BMR) after the eggs have hatched. While most internal organs lose mass in direct proportion to the general decrease in body mass, the liver and kidney masses decrease to a disproportionately greater extent. Since both the liver and the kidney have high intrinsic metabolic rates, these results support an earlier notion that the reduction in body mass is an adaptation to reduce maintenance costs. Alternatively, the reduced BMR is due to a decrease in energy uptake from the gastrointestinal tract, thereby ensuring that undigested food is ready to be regurgitated to the chicks. At the end of the chick-rearing period, the field metabolic rate (FMR) reaches its highest level, probably due to an increased workload associated with chick feeding. This occurs at a time of low body mass and BMR. A pronounced increase in the metabolic scope (FMR/BMR) during the latter part of the chick-rearing period demonstrates that BMR and FMR may change independently of each other and that the ratio FMR/BMR may not be a good measure of energy stress.     

The influence of pair-status on the breeding behaviour of the Kittiwake Rissa tridactyla before egg-laying

The breeding behaviour of individually marked Kittiwakes Rissa tridactyla that retained mates from the previous year (SAME) was compared, over the period from pair-formation to egg-laying, with those that changed mates (CHANGE). Position of nest-site in colony and breeding experience did not differ in the two groups studied. Hirds in CHANGE pairs attended the nest-site more frequently and as a result probably had less 'off-duty' time during which to forage. Rates of greeting were higher in CHANGE pairs. Differences between the two groups were usually greatest during the first two weeks after pair-formation an decreased toward egg-laying. CHANGE pairs copulated over a longer period before egg- laying, but stopped copulating sooner than SAME pairs. Copulation rates were higher in SAME pairs immediately before egg-laying. The causation of the behavioural differences between the two groups is discussed in terms of mate familiarity. It is suggested that the recorded differences explain the lower reproductive success in CHANGE pairs reported by other workers.     

Attendance off breeders and prospectors reflects the quality off colonies in the Kittiwake Rissa tridactyla

Attendance of breeders and prospectors (prebreeders, failed breeders and non-breeding adults) was studied from the time of hatching to the end of the breeding season in parts of two neighbouring Kittiwake Rissa tridactyla colonies in Brittany (France). Many clutches in one subcolony had been predated by a Carrion Crow Corvus corone , leading to a lower breeding success. Attendance of breeders and prospecting activity were greater in the more successful colony, and the number of breeding pairs increased in the following year in this colony only. Local reproductive success and social behaviour contributed to the attraction exerted by a colony. The demographic trend was explained by a performance-based conspecific attraction mechanism, acting through the effect of local reproductive success on recruitment, non-breeding and fidelity. Study of breeding success and prospecting activity allowed both evaluation of the quality of a colony and prediction of local demographic trends for the following year.     

Breeding ecology of the Fulmar Fulmarus glacialis and the Kittiwake Rissa tridactyla in high-arctic northeastern Greenland, 1993

The breeding ecology of the Fulmar Fulmarus glacialis and the Kittiwake Rissa tridactyla in the high Arctic was studied in relation to the occurrence of the northeast water polynya in northeasternmost Greenland (80̀N). Mean laying dates were 31 May in the Fulmar and 18 June in the Kittiwake; the total nesting season for the Fulmar just matched the time window of the polynya opening period. Fulmar colony attendance fluctuated within a period of 11.6 days because of variation in nonbreeding prospectors but showed no clear diurnal variation. Fulmar incubation shifts, on average, lasted 6.1 days (range 1–13 days), which is significantly longer than elsewhere, and the average chick-guard period of 10.9 days (range 1–17 days) was significantly shorter than in other studies. Egg neglect occurred in 18% of Fulmar nests or 0.7% of nests per day. Overall breeding success (chicks fledged per egg laid) was 0.56 in the Fulmar and 0.67 in the Kittiwake; the latter produced 1.4 young per active nest or 1.2 per completed nest. Mean Kittiwake clutch size was 2.03; larger clutches were laid early. Nest site characteristics (presumably reflecting nest predation risk) and breeding behaviour affected breeding success. in the Fulmar, hatching success was negatively correlated with laying date and the proportion of egg neglect, while overall breeding success was correlated negatively with distance to nearest neighbouring site and positively with the length of the chick-guard period. Kittiwake breeding success was negatively correlated with laying date. Using seabirds as indicators of marine food supply, breeding success in both species suggested moderate to good food supply in the northeast water polynya in 1993, although at least in the Fulmar the high reproductive output appeared partly maintained by behavioural buffering; long incubation shifts, egg neglect and short chick-guard periods were symptoms of foraging constraints.     

Diet of Black-legged Kittiwakes (Rissa tridactyla) feeding chicks at two Irish colonies highlights the importance of clupeids

Capsule We examined regurgitates from Black-legged Kittiwakes during the early chick-rearing period over two breeding seasons at two colonies in Ireland where diet has not been studied previously. Clupeids were the dominant food source at both colonies, which contrasts with other studies throughout the British Isles that suggest Kittiwakes feed mainly on sandeels during this period. Our study is limited by sample size and restricted to the early breeding season, but suggests a link between reproductive success and dietary composition which should be investigated further.     

Reproductive success of the Kittiwake Rissa tridactyla: the roles of clutch size, chick growth rates and parental quality

Kittiwake growth rates and breeding success are examined in relation to survival between fledging and breeding and to adult survival rates. High chick growth rates lead to increased survival after fledging. Broods of three (the maximum brood size) did not suffer lower fledging success than broods of two and clutches of three fledged appreciably more chicks per pair than did clutches of two or one. On average, the a- and b -chicks in broods of three grew at a faster rate and had a higher survival before breeding than those from smaller broods. Chicks from broods of two with experienced female parents grew at a faster rate than those of inexperienced female parents. Female parents which laid three egg clutches had a higher survival rate than those which laid clutches of two or one. We contend that three egg clutches were laid by higher quality individuals. We believe that clutch size indicates the condition of the Kittiwakes forming the pair. This condition probably has a genetical component, but is modified by environmental factors.     

Maternal Androgens Increase Sibling Aggression,Dominance, and Competitive Ability in the Siblicidal Black-Legged Kittiwake (Rissa tridactyla)

Animals and plants routinely produce more offspring than they can afford to rear. Mothers can favour certain young by conferring on them competitive advantages such as a leading position in the birth sequence, more resources or hormones. Avian mothers create hatching asynchrony within a clutch and at the same time bestow the eggs with different concentrations of androgens that may enhance or counteract the competitive advantage experienced by early-hatching “core” young. In siblicidal birds, core young assume a dominant social position in the nest due to their size advantage and when threatened with starvation fatally attack subdominant later-hatching “marginal” young. A role for maternal androgens in siblicidal aggression has frequently been suggested but never tested. We studied this in the facultatively siblicidal black-headed kittiwake. We found that marginal eggs contain higher instead of lower concentrations of androgens than core eggs. Surprisingly, exposure to experimentally elevated yolk androgens increased sibling aggression and dominance, even though in nature marginal eggs never produce dominant chicks. We propose the “adoption facilitation hypothesis” to explain this paradox. This cliff-nesting colonial species has a high adoption rate: ejected marginal kittiwake chicks frequently fall into other nests containing chicks of similar or smaller size and exposure to yolk androgens might help them integrate themselves into a foster nest.     

Measuring immigration and philopatry in seabirds; recruitment to Black-legged Kittiwake colonies

The degree of philopatry in two new Black-legged Kittiwake Rissa tridactyla colonies in northeast England was studied for 36 and 16 successive years, respectively. There was a tendency in both colonies for the number of recruits to the breeding group to increase with the age (and size) of the colony, but by an average of only one additional recruit each year. In the two new colonies, it was 7 and 9 years respectively before the first young birds bred in their natal colony. By that time, over 100 immigrants had recruited and bred in each colony. Thereafter, new philopatric birds were recorded annually. But these formed only an average of 23% of the recruits during 36 years (1955–90) at North Shields, and 4.2% over 16 years (1991–2006) at Coquet Island. In every year at both colonies the number of new immigrants exceeded the number of philopatric recruits. Males formed 82% of philopatric birds. The low degree of philopatry in the Kittiwake will result in appreciable gene flow between colonies and this is consistent with little geographic variation in the species. Each immigrant has to make a choice of which colony to enter, but the criteria for this selection are not understood. It is argued that many measures of philopatry in birds are biased towards high values because of the greater ease in identifying philopatric individuals. The generalization that there is a high degree of philopatry in colonial seabird species is not justified, as there is considerable variation between species, and possibly between colonies. More estimates based on unbiased data are needed.     

Prerequisites for recruitment of Kittiwakes Rissa tridactyla

Observations at the North Shields Kittiwake colony between 1982 and 1984 showed over 100 potential recruits (birds of breeding age) associated with the colony, only about 40% of which were actually recruited. In addition, there were younger birds which visited the colony. The origins, age structure and intercolony movements of members of the pool of prospectors have been examined. Porter & Coulson (1987) demonstrated that recruits are heavier than prospectors, implying that they are in better body condition. Three further prerequisites for breeding in Kittiwakes are recognized: the age of recruits is at least three years; all birds which recruit are present at the colony at least one year prior to breeding; and recruits show a high degree of attachment to colony as illustrated by their colony and nest site tenacity, attendance and early arrival. The results suggest that there is considerable selection of individuals at the time of recruitment; the mechanism for this has yet to be examined.     

The adrenocortical stress-response of Black-legged Kittiwake chicks in relation to dietary restrictions

In this study we examined hormonal responses of Black-legged Kittiwake (Rissatridactyla) chicks to experimental variations in energy content and nutritional quality (low or high lipid to protein ratio, LPR) of their food. Starting at the age of 10 days, chicks were fed either high or low LPR fish at 30, 50, 70 and 100% of ad libitum energy intake. After 20 days of treatment, chicks were exposed to a standardized acute handling and restraint stress protocol, where a baseline sample was taken immediately after taking a chick from the nest, and three additional blood samples were taken at intervals up to 50 min. Testosterone and corticosterone titres in plasma were measured via radioimmunoassay. We found that baseline testosterone levels were not significantly affected by the experimental treatments. Food-restricted chicks had elevated baseline and acute stress-induced levels of corticosterone compared to chicks fed ad libitum. An elevation of circulating levels of corticosterone in energetically stressed individuals was further magnified by low nutritional quality of food. Baseline and acute stress-induced corticosterone levels of chicks were negatively correlated with their fat reserves. We conclude that the physiological condition of Black-legged Kittiwake chicks can be assessed reliably by measuring circulating levels of corticosterone. We discuss short- and long-term effects of elevated corticosterone secretion in food-stressed nest-bound chicks. Accepted: 13 April 1999     

The incidence of the tick parasite Ixodes uriae in Kittiwake Rissa tridactyla colonies in relation to the age of the colony, and a mechanism of infecting new colonies

Kittiwakes Rissa tridactyla (683 chicks and 64 adults) were examined for ectoparasites in three breeding areas: Isle of May (Firth of Forth, Scotland; eight colonies of approximately known age of occupation on natural sites), North Shields and Gateshead (Tyne and Wear, England; well established colonies of known age on buildings). All the 208 ticks collected were Ixodes uriae. On the Isle of May, a colony which had only been established for 7 years was already infested by ticks. Tick incidence increased significantly with the length of colonization of the area during the first 30 years. Age of colonization did not have an effect after 30 years. In Gateshead only a single adult among the 127 birds examined had a tick. No ticks were found on the 106 chicks born at North Shields checked in 1987 or in 1988. However, among nine visiting newly-fledged chicks from neighbouring colonies caught at the North Shields colony, six had either ticks or scars of previous infestation. Some visiting chicks remained for several days in the host colony and were even fed by the owners of visited nests. Ixodes uriae may thus spread from one colony to another during visits of newly-fledged infested chicks to neighbouring colonies. The absence of any infestation in old colonies (38 years in North Shields and 17 years in Gateshead) on buildings that are regularly visited by newly fledged infested chicks, suggests that buildings may lack the rock refuges necessary for tick survival from one year to the next. In this respect Kittiwake colonies on buildings are rather atypical.     

Repeatability of basal metabolism in breeding female kittiwakes Rissa tridactyla

We studied kittiwakes (Rissa tridactyla) breeding near Ny-Ålesund (79° N, 12° E) on Svalbard. In 1997, the basal metabolic rates (BMRs) of 17 breeding females were measured during the incubation and chick-rearing periods. The mean body mass of the kittiwakes decreased significantly (by 10%) between the incubation and chick-rearing periods. At the same time, both the whole-body and mass-specific BMRs decreased significantly. There was a positive and significant relationship between the BMR residuals from the incubation period and those from the chick-rearing period. Thus, the BMR of incubating female kittiwakes is a significant predictor of their BMR during the chick-rearing period. New BMR data were collected in 1998 from ten of these females, measured around the chick-hatching date. Repeatability values were calculated using either (i) the data for eight individuals for which three BMR measurements existed, or (ii) all the data from both years, yielding significant repeatabilities of 0.52 and 0.35, respectively. These values indicate that between 48 and 65% of the observed variation in BMR is due to intraindividual variability, while between-individual variability accounts for 35 to 52% of the variation in the BMR. This is the first report of a significant repeatability of the BMR of an endothermic organism across an elapsed time of more than one day.     

Polymorphic microsatellites in the black‐legged kittiwake Rissa tridactyla

We isolated seven microsatellite sequences from a library of recombinant clones in Rissa tridactyla (Laridae). We investigated their polymorphism in one population from France. Preliminary results indicate that these markers should prove valuable tools for the study of mating systems, population genetic structure and dispersal abilities in this seabird species. We present the results of cross‐species amplification for two seabird species: Uria aalge (Alcidae) and Stercorarius parasiticus (Stercorariidae). Some of the microsatellites isolated in R. tridactyla might be useful for studies on other seabird species.