How small is too small? Incubation of large eggs by a small host

The Yellow Warbler ( Setophaga petechia (L., 1766)) is among the putative hosts of the Black-billed Cuckoo ( Coccyzus erythropthalmus (Wilson, 1811)), which is hypothesized to have once been an obligate brood parasite. Most parasites lay a small egg relative to their body size, possibly to prevent hosts from discriminating against the larger egg and to facilitate incubation. We tested whether warblers, which lay eggs ~17% of the volume of cuckoo eggs, could have potentially been suitable hosts of Coccyzus cuckoos by determining whether they accept and successfully incubate cuckoo-sized eggs. Warblers accepted 63% (n = 54) of cuckoo-sized eggs added into their nests and successfully incubated eggs as large as cuckoo eggs (surrogate American Robin ( Turdus migratorius L., 1766) eggs). This suggests that the lower limit to host size is not just related to egg size. Warblers are not ideal hosts because they rejected a high frequency of experimental eggs (37%). Nests from which eggs were rejected tended to have smaller volumes than nests at which eggs were accepted. The nest cups of warblers are oval, which may promote egg crowding more than round cups. Factors such as nest size, not host size, influence acceptance or rejection of large eggs by Yellow Warblers.

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Nest Defence By Yellow Warblers: Recognition of a Brood Parasite and an Avian Nest Predator

Behaviour ◽

10.1163/156853996x00143 ◽

1996 ◽

Vol 133 (3-4) ◽

pp. 263-282 ◽

Cited By ~ 56

Author(s):

Sharon A. Gill ◽

Spencer G. Sealy

Keyword(s):

Brood Parasitism ◽

Nest Defence ◽

Brood Parasite ◽

Yellow Warbler ◽

Nest Protection ◽

Yellow Warblers ◽

Avian Nest ◽

Defensive Behaviours ◽

And Control ◽

Nest Predator

AbstractYellow warblers (Dendroica petechia) were exposed to taxidermic mounts of a brood parasite (brown-headed cowbird, Molothrus ater), avian nest predator (common grackle, Quiscalus quiscula) and control (fox sparrow, Passerella iliaca) during their laying and nestling stages to determine whether nest owners distinguish between the threats of brood parasitism and predation. Yellow warblers responded more intensely to the cowbird at the laying stage, performing two unique behaviours (seet calling and nest-protection behaviour) in response to this threat. By contrast, yellow warbler responses to the grackle were greater at the nestling stage, consisting largely of alarm calls (chip, metallic chip and warble calls). The sparrow model infrequently elicited aggressive behaviour from nest owners at either stage. These responses support the hypothesis that yellow warblers discriminate between threats of brood parasitism and nest predation. Yellow warblers may perform specific behaviours to cowbirds because defensive behaviours used against predators may be incompatible with cowbird deterrence. Female nest owners responded more frequently than males at the laying stage, and more intensely than males at both nesting stages. The distance that females and males approached the models and several aggressive behaviours were positively correlated. The greater responsiveness of females may be because they dominate their mates and because females are more experienced with intruders near the nest.

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Seasonal dynamics of body mass of insectivorous passerines breeding on the forested dune ridge, Delta Marsh, Manitoba

Canadian Journal of Zoology ◽

10.1139/z85-249 ◽

1985 ◽

Vol 63 (7) ◽

pp. 1675-1682 ◽

Cited By ~ 4

Author(s):

Gloria C. Biermann ◽

Spencer G. Sealy

Keyword(s):

Body Mass ◽

Older Individuals ◽

Yellow Warbler ◽

American Robin ◽

Tyrannus Tyrannus ◽

Yellow Warblers ◽

Eastern Kingbird ◽

Empidonax Minimus ◽

Pattern Of Variation ◽

Dune Ridge

A total of 4669 body mass estimates was obtained between 1976 and 1983 from nine insectivorous passerine species that nest in a riparian habitat in southern Manitoba. The mass of individuals of the following species were obtained: eastern kingbird (Tyrannus tyrannus), least flycatcher (Empidonax minimus), house wren (Troglodytes aedon), gray catbird (Dumatella carolinensis), American robin (Turdus migratorius), veery (Catharus fuscescens), warbling vireo (Vireo gilvus), yellow warbler (Dendroica petechia), and northern oriole (Icterus galbula). The mass of most of these species varied during the summer and changes were correlated with breeding activity. Yearly differences in mass were significant for some species, but males and females of the same species did not always show the same pattern of variation from year to year. In species where the sexes could be identified, males were usually heavier than females. Yearling yellow warblers were significantly lighter than older individuals, but this trend was not found in the northern oriole.

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Riparian habitat disturbed by reservoir management does not function as an ecological trap for the Yellow Warbler (Setophaga petechia)

Canadian Journal of Zoology ◽

10.1139/z11-138 ◽

2012 ◽

Vol 90 (3) ◽

pp. 320-328 ◽

Cited By ~ 6

Author(s):

S.P. Quinlan ◽

D.J. Green

Keyword(s):

Habitat Selection ◽

Habitat Preferences ◽

Canopy Cover ◽

Ecological Trap ◽

Riparian Habitat ◽

Yellow Warbler ◽

Nest Sites ◽

Selection Decisions ◽

Yellow Warblers ◽

Setophaga Petechia

Ecological traps arise when anthropogenic change creates habitat that appears suitable but when selected reduces the fitness of an individual. We evaluated whether riparian habitat within the drawdown zone of the Arrow Lakes Reservoir, British Columbia, creates an ecological trap for Yellow Warblers ( Setophaga petechia (L., 1766)) by investigating habitat preferences and the fitness consequences of habitat selection decisions. Preferences were inferred by examining how habitat variables influenced settlement order, and comparing habitat at nest sites and random locations. Males preferred to settle in territories with more riparian shrub and tree cover, higher shrub diversity, and less high canopy cover. Females built nests in taller shrubs surrounded by a greater density of shrub stems. Habitat preferences were positively associated with fitness: nest sites in taller shrubs surrounded by higher shrub-stem densities were more likely to avoid predation and fledge young, whereas territories with more riparian cover, higher shrub diversity, and less high canopy cover had higher annual productivity. We therefore found no evidence that riparian habitat affected by reservoir operations functions as an ecological trap. Current habitat selection decisions may be associated with fitness because Yellow Warblers are adapted to breeding in a heterogeneous environment subject to periodic flooding.

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Facultative brood parasitism by an American Robin (Turdus migratorius) in the nest of a Gray Catbird (Dumetella carolinensis)

The Wilson Journal of Ornithology ◽

10.1676/1559-4491-132.1.202 ◽

2020 ◽

Vol 132 (1) ◽

pp. 202

Author(s):

Lucas J. Redmond

Keyword(s):

Brood Parasitism ◽

Turdus Migratorius ◽

American Robin ◽

Dumetella Carolinensis ◽

Gray Catbird

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Effect of two microalgae concentrations on body size and egg size of the rotifer Brachionus calyciflorus

Biologia ◽

10.2478/s11756-008-0068-1 ◽

2008 ◽

Vol 63 (3) ◽

Cited By ~ 4

Author(s):

Abdolmohammad Kennari ◽

Nasrollah Ahmadifard ◽

Maryam Kapourchali ◽

Jafar Seyfabadi

Keyword(s):

Body Size ◽

Population Growth ◽

Egg Size ◽

Scenedesmus Obliquus ◽

Exponential Phase ◽

The Body ◽

Brachionus Calyciflorus ◽

Food Level ◽

Chlorella Sp ◽

Rotifer Brachionus Calyciflorus

AbstractThe rotifer, Brachionus calyciflorus, was grown with two algae species (Chlorella sp. and Scenedesmus obliquus) at different concentrations (0.1, 1 and 10 × 106 cells ml−1). The body size (lorica biovolume) of individual rotifer and their egg size were measured when the populations were roughly in the exponential phase of population growth. The body size of the rotifers differed significantly (P < 0.05) among the two algae species used, however this effect was not observed for egg size. The body size of rotifers fed on higher densities of Chlorella sp. (10 × 106 cells ml−1) was significantly larger than for those fed on lower and medium densities (0.1 and 1 × 106 cells ml−1). Body size and egg size of rotifers fed with different amounts of Scenedesmus did not differ significantly. The egg size was significantly larger at higher food level of Chlorella. A significantly positive correlation was observed between the adult rotifer body size and their egg size.

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