Brown Booby Sula Leucogaster Group Size as a Defense Against Kleptoparasitism (original) (raw)
Related papers
The Condor, 1997
We investigated the importance of kleptoparasitism in a population of Redfooted Boobies (Sula sula) sympatric with frigatebirds (Great and Lesser Frigatebird Fregatu minor and F. ariel) and identified the responses adopted by boobies. Less than 1% of the boobies lost their food by kleptoparasitism. Birds flying in a group X0 m high or after dusk were less likely to be chased than others. We compared the way boobies returned to land and the rate of successful chases in this population with another population of Red-footed Boobies where kleptoparasitic attempts were rare. Birds were more nocturnal in the former population and were better able to resist chases. These observations suggest that the coexistence of boobies with frigatebirds may have led to avoidance responses. Comparison of the behavior of the Masked Booby (Sula dactylatra) to that of the Red-footed Booby showed that the former should be more vulnerable when returning to land than the latter. Further investigations are needed on the way Masked Boobies interact with frigatebirds in a place where both coexist in large numbers and to determine if this species has adopted other avoidance tactics.
The costs and benefits of kleptoparasitism in frigatebirds: An integrative review
Kleptoparasitism is a foraging strategy that involves stealing food from other animals. Frigatebirds are seabirds that are known to engage in kleptoparasitism, especially on other nesting seabirds such as boobies and tropicbirds. This paper reviews the kleptoparasitic behavior of frigatebirds, focusing on the factors that influence its occurrence, frequency and success. The ecological and evolutionary implications of kleptoparasitism for frigatebirds and their prey is also assessed. The paper draws on evidence from various studies conducted in different regions of the world, including the Indian Ocean, the Pacific Ocean and the Caribbean Sea. The review indicates that kleptoparasitism is a complex and dynamic behavior that reflects the interactions between frigatebirds and their environment.
The costs of kleptoparasitism: a study of mixed-species seabird breeding colonies
Behavioral Ecology, 2018
Mixed-species assemblages are common in nature, providing mutual benefits to associating species including anti-predator advantages or resource facilitation. However, associating with other species may also impose costs through kleptoparasitism (food theft). Identification of these costs, and how they vary when different species breed alongside one another, is essential to understand the payoffs of mixed-species assemblages. We explore the costs of kleptoparasitism for greater crested terns Thalasseus bergii provisioning offspring at a single-species colony, where individuals suffer kleptoparasitism from conspecifics, and at a mixed colony where terns breed alongside Hartlaub's gulls Chroicocephalus hartlaubii and are vulnerable to both intra and interspecific kleptoparasitism. Gull presence likely contributes to increases in both kleptoparasitic attacks and the proportion of prey lost or stolen during provisioning, relative to the single-species colony. Provisioning adults suffered additional energetic costs in response to gull kleptoparasitism, requiring more attempts to deliver prey, taking longer to do so, and swallowing more prey (to the detriment of their offspring). Gulls also appear to increase the duration of tern vulnerability to kleptoparasitism, because they continued to steal food from adults and chicks after precocial chicks left the nest, when intraspecific kleptoparasitism is negligible. Terns breeding in a mixed colony, therefore, suffer direct and indirect costs through decreased provisioning and increased provisioning effort, which may ultimately affect reproductive success, resulting in colony decline where kleptoparasitism is frequent. This study illustrates how forming a mixed-species seabird breeding assemblage has costs as well as benefits, potentially fluctuating between a parasitic and a mutualistic relationship.
Piracy at the nest: factors driving kleptoparasitic behaviour of Common Tern Sterna hirundo chicks
Acta Ornithologica, 2012
Stealing of provisioned food items by adult conspecifics (intraspecific kleptoparasitism or piracy) is common among birds, can reduce breeding success and may be one disadvantage of colonial breeding. Theft by chicks from neighbouring broods has rarely been quantified but may have similar reproductive consequences and the factors that influence it require further study. We took advantage of unusually diverse weather during the critical early stages of growth to elucidate the factors driving kleptoparasitic behavior of Common Tern Sterna hirundo chicks. Kleptoparasitism was restricted to misty days when large chicks were fed much smaller fish than on other days, inducing them to steal from neighbouring broods with young chicks. Our study indicates that kleptoparasitism by chicks could be a way to overcome shortfalls in parental provisioning, and may be a net cost of colonial breeding. Our results both provide evidence of a potential mechanism behind food-stealing by chicks and suggest hypotheses for future testing.
Specific targeting of host individuals by a kleptoparasitic bird
Kleptoparasitism is a tactic used to acquire food opportunistically and has been shown to provide several benefits, including greater food intake rate and the acquisition of items not normally available during selfforaging. Host individuals may differ in their ability to defend themselves against kleptoparasitic attacks and therefore identifying those host individuals that are particularly vulnerable to attack could both provide energetic benefits and increase the efficiency of kleptoparasitism as a foraging strategy. Here, we show that the kleptoparasitic fork-tailed drongo (Dicrurus adsimilis) specifically targets juveniles when following groups of cooperatively breeding pied babblers (Turdoides bicolor). Drongos give alarm calls upon sighting a predator, thus providing extra predator vigilance to foraging pied babblers. However, drongos also use alarm calls to steal food items. During kleptoparasitic attacks, drongos give false alarm calls and then swoop down to steal food items dropped by alarmed babblers. Juvenile pied babblers are particularly vulnerable to attack because they (a) spend a longer period handling prey items prior to consumption and (b) respond to alarm calls primarily by immediately moving to cover, in contrast to adults who respond by looking up and visually scanning the surrounding area. Drongos attack juvenile babblers significantly more often than adults, with attacks on juveniles more likely to result in the successful procurement of a food item. This patterns of attack suggests that drongos are able to differentiate between individuals of different age when targeting pied babblers, thus increasing the efficiency of kleptoparasitism as a foraging strategy.
The Wilson Journal of Ornithology, 2012
The House Crow (Corvus splendens) is a bioinvader to the Red Sea region and has been shown to negatively impact indigenous species. We describe attempts by House Crows to acquire an ordinarily inaccessible, high quality food source by mobbing Western Osprey (Pandion haliaetus) in large coordinated groups. The crows mobbed perched Osprey that had successfully caught fish in 176 observed attempts to steal the otherwise inaccessible food source. However, crows succeeded in forcing Osprey to abandon fish on only seven occasions (,4%). The crows then jointly fed on the abandoned fish. The consistency in mobbing Osprey and the low rate of success suggests House Crows are aware of the energetic value of fish.
Kleptoparasitism by Brown-hooded Gulls and Grey-hooded Gulls on American Oystercatchers
Waterbirds, 2002
This study describes qualitatively and quantitatively the kleptoparasitic behavior of the Brown-hooded Gull ( Larus maculipennis ) and Grey-hooded Gull ( Larus cirrocephalus ) on the American Oystercatcher ( Haematopus palliatus ), and considers the influence of environmental variables on the occurrence and success of the kleptoparasitism. Focal and scan samplings were performed, recording a total of 358 kleptoparasitic attempts. The overall occurrence rate was 1.2 ± 1.3 attempts per 5 min., of which 42% of attempts were successful. All kleptoparasitic attempts were performed when oystercatchers were feeding on Stout Razor Clams ( Tagellus plebeius ). Gulls stole food from Oystercatchers by two kleptoparasitic tactics; running (used in 40% of cases) and flying (used in 60% of cases). A significant difference in the rate of success of kleptoparasitism and an increase in the use of flying kleptoparasitism were observed under windy conditions. Gulls showed limited ability to open clams by themselves, and never swallowed whole clams. Kleptoparasitic attacks occurred within three seconds of the clam being ingested by the host, indicating the accurate kleptoparasitic skills of hooded gulls. Possible factors that affected the decisions taken by gulls about when and how to start the robbing behavior are discussed. Features of the kleptoparasitic behavior performed by hooded gulls on oystercatchers provide some relevant questions regarding the "generalist" or "specialist" character of these parasites.