Individual variation in winter supplementary food consumption and its consequences for reproduction in wild birds

Crates, Ross; Firth, Josh A.; Farine, Damien R.; Garroway, Colin J.; Kidd, Lisa; Aplin, Lucy M.; Radersma, Reinder; Milligan, Nicole D.; Voelkl, Bernhard; Culina, Antica; Verhelst, Brecht; Hinde, Camilla A.; Sheldon, Ben C.

doi:10.1111/jav.00936

Cited by 38 publications

(43 citation statements)

References 60 publications

(86 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…R 2 (CONDITIONAL) -R 2 (MARGINAL) gives the random effect component of the variance, R 2 (RANDOM) . R 2 (RANDOM) is analogous to repeatability (Nakagawa and Schielzeth, 2010;Crates et al, 2016). Note, estimating the variance components of fixed vs. random effects for negative binomial models required refitting models using the "glmmPQL" function of the MASS package (which uses penalized quasilikelihood for parameter estimation; Venables and Ripley, 2002), as glmmADMB objects cannot be passed to "r.squaredGLMM."…”

Section: Individual Visitation (Pit-tag Data)mentioning

confidence: 99%

“…in woodland habitat in Oxford, UK, during winter (Crates et al, 2016) and the other examining visitation patterns of six species at a university campus in Cornwall, UK (Jack, 2016). These studies both reported individual and interspecific variation in use of supplementary food at experimental feeders over a comparatively shorter timeframe (c. 3 months).…”

Section: Summary Of Findingsmentioning

confidence: 99%

“…Few studies, though, have looked at individual variation in supplementary food use or how species associations at feeders affect resource access in an urban context specifically (but see Cowie and Hinsley, 1988;Crates et al, 2016;Jack, 2016). Bird populations in urban habitats are subject to different pressures than those in more natural environments, frequently resulting in differences in ecology, behavior, and life history (Chace and Walsh, 2006;Chamberlain et al, 2009;Seress and Liker, 2015;Garcia et al, 2017;Lepczyk et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Urban Bird Feeders Dominated by a Few Species and Individuals

et al. 2017

View full text Add to dashboard Cite

The practice of garden bird feeding is a global phenomenon, involving millions of people and vast quantities of food annually. Many people engage in the practice of feeding assuming that birds gain some benefit from the food they provide, yet recent studies have revealed the potential for detrimental impacts as well. However, there is still a paucity of information on the impacts of feeding, including the ubiquity of these impacts among and within feeder-visiting species. Consistency in feeder use among birds is likely an important determinant of this. Individual birds and species that make frequent use of feeders are more likely to experience both the benefits and detrimental impacts of supplementary food. We investigated patterns of feeder use by garden birds visiting experimental feeding stations in Auckland, New Zealand, with the specific aim of determining whether use of supplementary food was consistent or variable among individuals and species. We used camera traps as well as Radio Frequency Identification (RFID) technology to examine intra-and interspecific feeder visitation patterns and to discern species associations. Eleven bird species were detected using feeding stations, however, two introduced species (house sparrow Passer domesticus and spotted dove Streptopelia chinensis) dominated visitation events. These species were present at feeders most frequently, with the largest conspecific group sizes. Significant associations were detected among a number of species, suggesting interspecific interactions are important in determining feeder use. We also found within-species differences in feeder use for all focal species, with individual variation greatest in house sparrows. Furthermore, season had an important influence on most visitation parameters. The observed individual and species-specific differences in supplementary food resource use imply that the impacts of garden bird feeding are not universal. Crucially, particularly given the avifaunal context in New Zealand, resource dominance by introduced species could have potential negative outcomes for native species conservation in cities.

show abstract

Section: Individual Visitation (Pit-tag Data)mentioning

confidence: 99%

Section: Summary Of Findingsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Urban Bird Feeders Dominated by a Few Species and Individuals

et al. 2017

View full text Add to dashboard Cite

show abstract

“…A recent study on our population showed that the number of visits to feeders over the whole winter has no effect on these measures of fitness (Crates et al . ), but the fitness consequences of alterative foraging tactics were not explored. Variation in the timing of feeding is also likely to be caused by differences in physiological state and the environment, so it will be important to investigate the effects of condition, perceived predation risk, temperature and flock structure in future studies.…”

Section: Discussionmentioning

confidence: 99%

To graze or gorge: consistency and flexibility of individual foraging tactics in tits

Milligan

Radersma

Cole

et al. 2017

Journal of Animal Ecology

Self Cite

View full text Add to dashboard Cite

An individual's foraging behaviour and time allocated to feeding have direct consequences for its fitness. Despite much research on population-level foraging decisions, few studies have investigated individual differences in fine-scale daily foraging patterns among wild animals. Here, we explore the consistency and plasticity of feeding tactics of individual great tits (Parus major) and blue tits (Cyanistes caeruleus), using a grid of 65 automated feeding stations in a 385-ha woodland, during three winters. We use a principal component analysis to describe individual variation in six feeding parameters and examine how these differences covary with dominance-linked attributes (species, age and sex), the personality trait 'exploration behaviour', distance to territory and local competition intensity. Analysis of 933 086 feeder visits by 3134 individuals revealed that the majority of variation in the timing of feeding was explained by two principal components. PC1 ('binge-eating'), accounting for 38% of variation, captured temporal clustering of feeding, with high repeatability both within and between years (r range: 0·42-0·55). PC2 ('transience'), accounting for 27% of variance, described how much individuals used feeders and was also repeatable (r: 0·34-0·62). While exhibiting consistent individual differences, birds also showed flexibility in foraging patterns, binge-eating less and using feeders more when they experienced greater local competition. Individuals in behaviourally dominant states (great tits, males and adults) binged more than subordinate birds (blue tits, females and juveniles) when their territories were distant from feeding stations. Moreover, great tits and males used feeders more than blue tits and females respectively, while birds feeding further from their territory used feeders less than those feeding closer. 'Exploration behaviour' was unrelated to both measures of daily foraging behaviour. This study presents some of the first evidence that birds use consistent alternative foraging tactics at a fine temporal scale. Individuals are consistent in their tactics, and also adjust their foraging behaviour with changes in local competition. Hence, studies of foraging behaviour should consider the extent to which such individual-level variability in foraging behaviour is under selection.

show abstract

“…As such, recent research has begun to investigate the consequences of winter supplementary feeding on subsequent avian productivity, reporting both beneficial (Robb et al., ) and detrimental effects on breeding performance at the population level (Plummer, Bearhop, Leech, Chamberlain, & Blount, ,b). It has been assumed that such carry‐over effects are mediated via the impacts of winter supplementary food on overwinter survival and/or on avian condition during the breeding season (Brittingham & Temple, ; Crates et al., ; Gosler, ; Plummer et al., ; Robb et al., ), although this remains to be studied in detail. Given the enormity of anthropogenic bird feeding activities, and as provisioning of food for wild birds is often advocated as a method for conserving declining populations (Ewen, Walker, Canessa, & Groombridge, ; Jones & Reynolds, ; RSPB, ), it is imperative that the mechanisms driving any negative carry‐over effects of winter feeding are investigated.…”

Section: Introductionmentioning

confidence: 99%

Effects of winter food provisioning on the phenotypes of breeding blue tits

Bearhop

Leech

Chamberlain

et al. 2018

Ecology and Evolution

View full text Add to dashboard Cite

Throughout the Western World, huge numbers of people regularly supply food for wild birds. However, evidence of negative impacts of winter feeding on future reproduction has highlighted a need to improve understanding of the underlying mechanisms shaping avian responses to supplementary food. Here, we test the possibility that carry‐over effects are mediated via their impact on the phenotypes of breeding birds, either by influencing the phenotypic structure of populations through changes in winter survival and/or by more direct effects on the condition of breeding birds. Using a landscape‐scale 3‐year study of blue tits (Cyanistes caeruleus), we demonstrate the importance of nutritional composition of supplementary food in determining carry‐over effect outcomes. We show that breeding populations which had access to vitamin E‐rich foods during the previous winter were comprised of individuals with reduced feather carotenoid concentrations, indicative of lower pre‐feeding phenotypic condition, compared to fat‐fed and unfed populations. This suggests that supplementary feeding in winter can result in altered population phenotypic structure at the time of breeding, perhaps by enhancing survival and recruitment of lower quality individuals. However, supplementation of a fat‐rich diet during winter was detrimental to the oxidative state of breeding birds, with these phenotypic differences ultimately found to impact upon reproductive success. Our findings demonstrate the complex nature by which supplementary feeding can influence wild bird populations.

show abstract

Individual variation in winter supplementary food consumption and its consequences for reproduction in wild birds

Cited by 38 publications

References 60 publications

Urban Bird Feeders Dominated by a Few Species and Individuals

Urban Bird Feeders Dominated by a Few Species and Individuals

To graze or gorge: consistency and flexibility of individual foraging tactics in tits

Effects of winter food provisioning on the phenotypes of breeding blue tits

Contact Info

Product

Resources

About