Interactive effects of food shortage and predation on breeding failure of black-legged kittiwakes: indirect effects of fisheries activities and implications for indicator species

We investigated the roles of food shortage and predation in anticipated breeding failure of black-legged kittiwakes Rissa tridactyla at Great Island, Witless Bay, Newfoundland, Canada in 1992 and 1993, following widespread failure in 1991. Reduced and delayed availability of capelin Mallotus viIlosus, plus elimination of previously plentiful fish offal and discards following an eastern Canadian groundfish moratorium in 1992, induced food-stress on kittiwakes and on large predatory Larus gulls. Breeding was late, a low proportion of pairs laid eggs, and egg and clutch sizes were small, indicating that feeding conditions for kittiwakes were poor early in the season. Extreme food-stress resulted in low breeding success of Larus gulls that turned to kittiwake eggs as an alternate food source. Forced egg predation by great black-backed gulls Larus marinus was the primary cause of low hatching success (10 to 11%) in both years. Durations of incubation and chick-rearing shifts decreased following the inshore arrival of capelin, and chicks that hatched after capelin arrival survived longer than earlier hatched chicks. Unattended nests were uncommon, probably in response to predation. In 1992, earlier hatching, later capelin arrival, and apparent lack of alternate prey resulted in many chicks starving and poor fledging success (7%). In 1993, food appeared to be more available both before and after capelin arrival, parents were able to provision chicks, and fledging success was normal (68%). The interactive effects of food shortage and predation have important implications for the use of kittiwakes as indicator species and for the indirect effects of fishery activities on seabird interactions. Kittiwake productivity also reflects the resource base of their predators and caution is required when linking kittiwake breeding success to prey abundance. Moreover, fishery activities, such as the eastern Canadian groundfish moratorium that eliminated fish discards and offal for large scavenging gulls, can have profound second-order effects on other seabird species that are preyed on by scavengers.

[1]  Jean-François Rail,et al.  Relationship between cod fishery activities and the population of herring gulls on the North Shore of the Gulf of St Lawrence, Québec, Canada , 1997 .

[2]  J. Piatt,et al.  Allocation of Time and Energy FLEXIBLE TIME BUDGETS IN BREEDING COMMON MURRES: BUFFERS AGAINST VARIABLE PREY ABUNDANCE , 1990 .

[3]  E. Murphy,et al.  High Annual Variability in Reproductive Success of Kittiwakes (Rissa tridactyla L.) at a Colony in Western Alaska , 1991 .

[4]  J. Coulson,et al.  Incubation under natural conditions in the kittiwake gull, Rissa tridactyla , 1984, Animal Behaviour.

[5]  R. Furness,et al.  Seabird ecology in the north sea , 1990 .

[6]  P. Baird.  Influence of abiotic factors and prey distribution on diet and reproductive success of three seabird species in Alaska , 1990 .

[7]  W. Montevecchi.  Corvids Using Objects to Displace Gulls from Nests , 1978 .

[8]  S. Wanless,et al.  Breeding Success of British Kittiwakes Rissa tridactyla in 1986-88: Evidence for Changing Conditions in the Northern North Sea , 1990 .

[9]  William Threlfall,et al.  The Breeding Biology of the Black-Legged Kittiwake in Newfoundland , 1972 .

[10]  N. Buckley.  Diet and feeding ecology of great black‐backed gulls (Laws marinus) at a southern Irish breeding colony , 1990 .

[11]  R. Furness,et al.  The food requirements and ecological relationships of a seabird community in North Norway , 1985 .

[12]  R. Barrett,et al.  Growth and Survival of Nestling Kittiwakes Rissa tridactyla in Norway , 1980 .

[13]  Ransom A. Myers,et al.  What can be learned from the collapse of a renewable resource? Atlantic cod, Gadus morhua, of Newfoundland and Labrador , 1994 .

[14]  Mark P. Johnson,et al.  The attendance and absence of adult Kittiwakes Rissa tridactyla from the nest site during the chick stage , 1993 .

[15]  T. Pearson.  The feeding biology of seabird species breeding on the Farne Islands, Northumberland. , 1968 .

[16]  W. Montevecchi.  Birds as indicators of change in marine prey stocks , 1993 .

[17]  I. Nisbet.  Courtship-feeding and clutch size in Common terns Sterna hirundo , 1977 .

[18]  R. Pierotti.  Gull-Puffin Interactions on Great Island, Newfoundland , 1983 .

[19]  W. Montevecchi,et al.  Sampling methods for assessing the diets of Atlantic puffin chicks , 1996 .

[20]  John P. Ryder,et al.  The Influence of Age on the Breeding Biology of Colonial Nesting Seabirds , 1980 .

[21]  W. Sydeman,et al.  Breeding performance in the western gull : effects of parental age, timing of breeding and year in relation to food availability , 1991 .

[22]  R. Pierotti,et al.  Reproductive Consequences of Dietary Specialization and Switching in an Ecological Generalist , 1987 .

[23]  T. Birkhead,et al.  Incubation and brooding shift duration in the Common Murre, Uria aalge , 1987 .

[24]  D. Steele,et al.  The Managed Commercial Annihilation of Northern Cod , 1992 .

[25]  H. Regehr.  Breeding performance of black-legged kittiwakes on Great Island, Newfoundland, during periods of reduced food availability , 1994 .

[26]  R. Drent,et al.  The Prudent Parent: Energetic Adjustments in Avian Breeding 1) , 1980 .

[27]  R. Barrett,et al.  Variations in Egg Size and Incubation Period of the Kittiwake Rissa tridactyla in Norway , 1981 .

[28]  D. Oro.  Effects of trawler discard availability on egg laying and breeding success in the lesser black-backed gull Larus fuscus in the western Mediterranean , 1996 .

[29]  K. Drinkwater.  Atmospheric and Oceanic Variability in the Northwest Atlantic During the 1980s and Early 1990s , 1996 .

[30]  S. Hatch.  Individual Variation in Behavior and Breeding Success of Northern Fulmars , 1990 .

[31]  W. Montevecchi,et al.  Predation on adult Puffins Fratercula arctica by Great Black‐backed Gulls Larus marinus at a Newfoundland colony , 1996 .

[32]  J. Piatt,et al.  Seasonal abundance and vertical distribution of capelin (Mallotus villosus) in relation to water temperature at a coastal site off eastern Newfoundland , 1991 .

[33]  Stefan Garthe,et al.  Amounts of discards by commercial fisheries and their significance as food for seabirds in the North Sea , 1996 .