Brown pelican siblicide and the prey-size hypothesis

  title={Brown pelican siblicide and the prey-size hypothesis},
  author={Daniel Pinson and Hugh Drummond},
  journal={Behavioral Ecology and Sociobiology},
SummaryWe asked whether the brown pelican (Pelecanus occidentalis) practices facultative brood reduction and tested two predictions of Mock's (1985) prey-size hypothesis: (1) if chicks take food directly from the parental mouth, nestmates should compete aggressively; (2) aggression between nestmates should increase during the developmental transition from indirect feeding (parents deposit food on the substrate) to direct feeding (parents pass food from mouth to mouth). Eggs in two-egg and three… 
Behavior of Parent and Nestling Brown Pelicans During Early Brood Rearing
Parent and nestling behavior during early chick rearing were examined at a colony in Charleston Harbor, South Carolina and suggested that any spatial or temporal comparisons of parent or chick behavior should be assessed in relation to the age category of the parent and the age of the chicks.
Is broodmate aggression really associated with direct feeding
Neither the assumption nor either of the predictions of the FMH was supported and, if anything, senior broodmates were more aggressive early in the nestling period when feeding was indirect, casting doubt on the ultimate influence of feeding method on use of aggression and, especially, on the role of direct feeding as a proximate trigger for aggression.
Growth of Brown Pelican Nestlings Exposed to Sublethal Levels of Soft Tick Infestation
It is suggested that the cohabitation of ectoparasites and seabirds within colonies may result in behavioral or physiological adaptations of adults or nestlings that inhibit the expected negative effect of ectoplasites on nestling growth at sublethal levels of infestation.
Diet composition and provisioning rates of nestlings determine reproductive success in a subtropical seabird
It is concluded that quantity rather than quality of prey, particularly small schooling fish, is the main driver of brown pelican reproductive success in this system, and that environmental perturbations affecting biomass, distribution, and abundance of forage fish could substantially affect brown pelicans reproductive success.
Begging Versus Aggression in Avian Broodmate Competition
Observations of boobies and diverse species suggest that aggression limits the effectiveness of begging by subordinate young by confining its timing, location or form.
A kaleidoscope of mammal, bird and fish: habitat use patterns of top predators and their prey in Florida Bay
Habitat selection by top predators that are largely free from predation pressures is a function of prey availability and interspecific competition, and habitat overlap among predators implies currently adequate resource availability and/or niche dimensions among interspecific competitors.
Dominance in Vertebrate Broods and Litters
  • H. Drummond
  • Biology, Psychology
    The Quarterly Review of Biology
  • 2006
An evolutionary framework in which the species‐typical dominance relationship is determined by feeding mode, confinement, cost of subordination, and capacity for individual recognition, can be extended to mammalian litters and account for the aggression‐submission and aggression‐resistance observed in distinct populations of spotted hyenas.
Parent–offspring conflict in avian families
A brief review of the research on parent–offspring conflict in birds is provided, aimed primarily at ornithologists not already familiar with this area of research.
The Evolution of Begging
It is suggested that costly and cost-free signalling models face difficulties in accounting for observed begging behaviour, and that these difficulties may best be tackled by developing more realistic models that incorporate more of the complexities of parent-offspring interaction revealed by empirical studies of begging.


Siblicidal Brood Reduction: The Prey-Size Hypothesis
  • D. Mock
  • Biology
    The American Naturalist
  • 1985
In a comparison of two species of herons in a Texas colony, great egret nestlings fought 18 times more often than adjacent great blue herons during the first month, and a general hypothesis is advanced, linking adaptive siblicidal aggression to delivered food size (specifically, monopolizability).
Brood reduction in the American white pelican (Pelecanus erythrohynchos)
Results support the hypothesis that the second egg functions as a form of “insurance” against early loss of the first egg or chick, and reveal that the presence of a second chick contributes significantly to the reproductive success of the parents.
Breeding Behaviour and Ecology of the Australian Pelican, Pelecanus Conspicillatus, in New South Wales.
Australian pelicans (Pelecanus conspicillatus) were studied in colonies at 2 lakes in New South Wales; food was mainly fish; the most abundant fish was goldfish (Carassius auratus); a minor item was perch (Perca fluviatilis).
Parent-offspring cooperation in the blue-footed boody (Sula nebouxii): social roles in infanticial brood reduction
Reproduction in the blue-footed boody was examined for evidence of parent-offspring conflict over infanticidal reduction of the brood, and provisional tolerance of the junior chick by its underweight senior sib is consistent with “self-sacrifice” to increase the latter's inclusive fitness.
Growth and Development of Nestling Brown Pelicans
This study analyzes growth data of four nesting seasons for the Brown Pelican (Pelecanus occidentalis) to determine the age and growth parameters for this species and examine weight, and other characters such as bill, wing, and tarsus lengths as a measure of growth in this species.
Sexual Size Dimorphism and Sibling Competition: Implications for Avian Sex Ratios
These observations contradict the prevailing hypothesis that in sexually dimorphic birds that practice siblicidal brood reduction the smaller sex suffers differential mortality as the result of its disadvantage in sibling conflict in mixed-sex broods.
Brown pelicans: influence of food supply on reproduction
From 1970 through 1979, availability of northern anchovies Engraulis mordax, the major food source for breeding brown pelicans Pelecanus occidentalis californicus, was the most important determinant
Variation in reproductivity with age in the brown pelican
This study found a relatively high incidence of breeding birds in immature plumage in a population of Brown Pelicans in South Carolina, and described the reproductive success and characteristics of the immature-plumaged cohort in comparison to the adult-plunaged cohort.
Observations on the breeding behaviour of the Pink-backed Pelican Pelecanus rufescens at Rakewa, Nyanza Province, Kenya, where the species has bred for at least 200 years are summarized.