The effect of kleptoparasite and host numbers on the risk of food‐stealing in an avian assemblage

Wood, Kevin A.; Stillman, Richard A.; Goss‐Custard, J. D.

doi:10.1111/jav.00705

Cited by 17 publications

(13 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Hartlaub's gulls generally target different prey from terns (Ryan 1987) and therefore may benefit by exploiting terns when the payoffs from self-foraging decline (Brockmann and Barnard 1979;Ens et al 1990;Flower et al 2013). Associating with gulls may entail greater costs when the ratio of kleptoparasitic individuals to hosts increases (Wood et al 2015). Consistent with this prediction, data in Table S1 suggest that Hartlaub's gull may steal a larger proportion of tern prey when relative tern numbers decline, though this pattern is unclear and is confounded by between year effects.…”

Section: Discussionmentioning

confidence: 99%

“…Increasing nest failure, or nest abandonment by terns under such circumstances might aggravate per capita kleptoparasitism on remaining breeders, potentially threatening colony persistence (Oro et al 1996;St. Clair et al 2001;Blackburn et al2009, Wood et al 2015, with profound consequences at the population level. However, this appears to be an unlikely threat to greater crested terns on Robben Island at present, as the species' breeding numbers have increased over the last few decades in this region (Crawford 2009).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The costs of kleptoparasitism: a study of mixed-species seabird breeding colonies

et al. 2018

View full text Add to dashboard Cite

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 impact 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.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

The costs of kleptoparasitism: a study of mixed-species seabird breeding colonies

et al. 2018

View full text Add to dashboard Cite

show abstract

“…2). Aggressive behaviours among birds typically become more common as the density of individuals within a habitat increases (Metcalfe and Furness 1987;Wood et al 2015). It is possible that Bewick's Swans would show increasing durations of aggression with rising swan numbers if observations could be made over a greater range of swan numbers; although with ongoing declines in Bewick's Swan numbers at wintering sites in the UK (Beekman et al 2019), obtaining such data may prove challenging.…”

Section: Table 4 Comparison Of Models Of the Time Spent In Aggressive Interactions Between Swansmentioning

confidence: 99%

“…As Peiman and Robinson (2010) reported that aggression is more likely between individuals with the greatest overlap in resource use, our first hypothesis (hereafter termed the 'conspecific hypothesis') was that swans would devote more time to intraspecific aggression compared with interspecific aggression. Aggressive behaviours among birds typically become more common as the density of individuals within a habitat increases (Metcalfe and Furness 1987;Wood et al 2015), thus our second hypothesis (hereafter termed the 'density hypothesis') was that swans would spend more time engaged in aggressive interactions when present in higher density flocks. Finally, we expected that as winter progressed, a dominance hierarchy would establish among individual swans within their flock, and so reduce further aggression; indeed, Scott (1981) reported that the frequency of fights between Bewick's Swans declined progressively over winter months.…”

Section: Introductionmentioning

confidence: 99%

Aggressive behavioural interactions between swans (Cygnus spp.) and other waterbirds during winter: a webcam-based study

et al. 2020

Self Cite

View full text Add to dashboard Cite

Background Our understanding of any impacts of swans on other waterbirds (including other swans), and potential effects on waterbird community structure, remain limited by a paucity of fundamental behavioural and ecological data, including which species swans interact aggressively with and how frequently such interactions occur. Methods Behavioural observations of aggression by swans and other waterbirds in winters 2018/2019 and 2019/2020, were carried out via live-streaming webcams at two wintering sites in the UK. All occurrence sampling was used to identify all aggressive interactions between conspecific or heterospecifics individuals, whilst focal observations were used to record the total time spent by swans on aggressive interactions with other swans. Binomial tests were then used to assess whether the proportion of intraspecific aggressive interactions of each species differed from 0.5 (which would indicate equal numbers of intraspecific and interspecific interactions). Zero-inflated generalized linear mixed effects models (ZIGLMMs) were used to assess between-individual variation in the total time spent by swans on aggressive interactions with other swans. Results All three swan species were most frequently aggressive towards, and received most aggression from, their conspecifics. Our 10-min focal observations showed that Whooper (Cygnus cygnus) and Bewick’s Swans (C. columbianus bewickii) spent 13.8 ± 4.7 s (means ± 95% CI) and 1.4 ± 0.3 s, respectively, on aggression with other swans. These durations were equivalent to 2.3% and 0.2% of the Whooper and Bewick’s Swan time-activity budgets, respectively. Model selection indicated that the time spent in aggressive interactions with other swans was best-explained by the number of other swans present for Whooper Swans, and an interactive effect of time of day and winter of observation for Bewick’s Swans. However, the relationship between swan numbers and Whooper Swan aggression times was not strong (R2 = 19.3%). Conclusions Whilst swans do exhibit some aggression towards smaller waterbirds, the majority of aggression by swans is directed towards other swans. Aggression focused on conspecifics likely reflects greater overlap in resource use, and hence higher potential for competition, between individuals of the same species. Our study provides an example of how questions relating to avian behaviour can be addressed using methods of remote data collection such as live-streaming webcams.

show abstract

“…Oystercatchers feeding on mussels need to open the shells in order to swallow the soft flesh of the prey (Goss-Custard and Dit Durell 1988), which requires relatively long handling times. As a result, the birds are sensitive to interference and allowing other individuals to steal prey (kleptoparasitism)(Ens and Goss-Custard 1984;Wood et al 2015). Within avian assemblages, gulls are known to steal food items from several wading bird species(Amat and Aguilera 1990;Ens et al 1990;…”

mentioning

confidence: 99%

Impact on bird fauna of a non-native oyster expanding into blue mussel beds in the Dutch Wadden Sea

Waser

Deuzeman

Kangeri

et al. 2016

Biological Conservation

View full text Add to dashboard Cite

26Intertidal mussel beds are important for intertidal ecosystems, because they feature a high 27 taxonomic diversity and abundance of benthic organisms and are important foraging grounds 28 for many avian species. After the introduction of the Pacific oyster (Crassostrea gigas) into 29 the European Wadden Sea, many mussel beds developed into oyster dominated bivalve beds. 30Despite the fact that oysters have been colonizing many European intertidal areas for about 31 two decades, their impact on the ecosystem is still poorly understood. Here, we investigated 32 the impact of oysters on the condition of mussels and on the spatial distribution of birds on 18 33 bivalve beds with different grades of oyster occurrence throughout the Dutch Wadden Sea. 34Moreover, in comparing bird densities on bivalve beds with densities expected on the total 35 intertidal area, we could detect which species exhibit a preference for the structured habitat. 36Overall, 50 different bird species were observed on the beds, of which about half regularly 37 frequent intertidal flats. Most of these species showed a preference for bivalve beds. The 38 condition of mussels decreased with the oyster dominance, whereas the majority of bird 39 species was not affected by the oyster occurrence. However, three of the four species that 40 were negatively affected depend on intertidal mussels as food source. Even though the 41 Pacific oyster is a nonnative species, attempts to fight it may do more harm to avian 42 biodiversity than good.

show abstract

The effect of kleptoparasite and host numbers on the risk of food‐stealing in an avian assemblage

Cited by 17 publications

References 50 publications

The costs of kleptoparasitism: a study of mixed-species seabird breeding colonies

The costs of kleptoparasitism: a study of mixed-species seabird breeding colonies

Aggressive behavioural interactions between swans (Cygnus spp.) and other waterbirds during winter: a webcam-based study

Impact on bird fauna of a non-native oyster expanding into blue mussel beds in the Dutch Wadden Sea

Contact Info

Product

Resources

About