Youtor
Brood parasitism EGGSHELL TRAITS IN COWBIRD HOSTS
>> YOUR LINK HERE: ___ http://youtube.com/watch?v=k8BR-oiDCAE
PhD thesis (PDF document) is available in: • https://www.researchgate.net/profile/... https://figshare.com/articles/thesis/... • A comparative study of the structural and mechanical properties of avian eggshells among hosts of obligate brood parasitic cowbirds (genus Molothrus) . • Biological Journal of the Linnean Society. • https://doi.org/10.1093/biolinnean/bl... • ABSTRACT: Obligate avian brood parasites depend on hosts for parental care, which in turn suffer fitness losses as a result of parasitism. Mechanisms by which brood parasitic cowbirds (Molothrus spp.) reduce host breeding success include the puncture (M. rufoaxillaris and M. bonariensis) or removal (M. ater) of the eggs of the host. Our working hypothesis is that the host eggs’ mechanical strength and their size and shape in species with higher frequency of parasitism covaries with the cowbird’s strategy to reduce host clutch size. Our results, obtained through phylogenetic analyses based on egg 2D geometric morphometry and eggshell mechanical and ultrastructural measurements, suggest that egg-puncturer behaviour has led to an increase in the strength of the host’s eggshell, which might make them more difficult to be pierced. We also characterized larger, more rounded and asymmetrical eggs in frequent hosts of M. ater, which might be more difficult to be removed. These interspecific host egg and shell traits were also positively affected by the frequency of parasitism, indicating that species-specific patterns of parasitic costs select for respective anti-parasitic defences in hosts. • ................... • Video: • SONG • Nuestro Amo Juega al Esclavo - Patricio Rey y sus Redonditos de Ricota - \\m/ • • Patricio Rey y sus Redonditos de Rico... • IMAGES • Min: 00:01 • Alan Nelson. • Cowbird Takes Phoebe Egg • Brown-headed Cowbird (Molothrus ater) removing Phoebe (Sayornis phoebe) egg • Min: 00:05 • doggietreats2go. • Cowbird removing Song Sparrow Egg • Brown-headed Cowbird removing Song Sparrow (Melospiza melodia) egg • Min: 00:09 • Kelin Ashley. • Cowbird removes egg from wren nest • Brown-headed Cowbird removing Carolina Wren (Thryothorus ludovicianus) egg • Min: 00:17 • Gloag el al., 2014. Shiny cowbirds share nests, but not mothers, in multiply parasitized mockingbird broods. Behavioral Ecology and Sociobiology 68: 681-689. • Min: 00:33 • Analía V. López. • Nest of Brown-and-yellow marshbird (Pseudoleistes virescens) parasitized with two eggs of Shiny Cowbird (Molothrus bonariensis). • Min: 00:33 • Analía V. López • Nest of American Robin (Turdus migratorius) parasitized with an egg of Brown-headed Cowbird (Molothrus ater). • Min: 00:42 • Fig. 1 in López et al. 2021 • Phylomorpho-space projection of the first two principal components performed on shape descriptors of egg outlines. Each dot represents one species. The dots are connected by lines that indicating phylogeny. • Min: 00:45 • Example of quasi-static egg puncture test. • Micrograph by scanning electron microscope (SEM) of eggshell cross section (detail of a gas exchange pore) • Min: 00:49 • Michael Bagg. • Bluebirds aggressively attack a Cowbi... • Bluebirds aggressively attack a Brown-headed Cowbird • Min: 00:53 • Gloag et al., 2014. Shiny cowbirds share nests, but not mothers, in multiply parasitized mockingbird broods. Behav. Ecol. Sociobiol. 68: 681-689. • Min: 00:57 • Gloag et al., 2012. Brood parasite eggs enhance egg survivorship in a multiply parasitized host. Proc. R. Soc. B.2791831–1839 • Min: 01:02 • NestCamsArchivedVideos. • Video • Brown-headed Cowbird - Laying an egg in a Northern Cardinal nest • Min: 01:06 • Analía V. López. • Nest of Grayish baywing (Agelaioides badius) parasitized with an egg and a chick of Screaming Cowbird (Molothrus rufoaxillaris). • Min: 01:18 • Violencia es mentir - Violence is to lie • (blood-sucking parasite (clinging to my neck that I can't get rid of her): try using a tamagotchi to put your inoperative advice into practice, you might have better luck) • Su trabajo básicamente era perdurar, el mío aprender (In El líder menos pensado: por qué los inútiles llegan al poder ) • https://www.lanacion.com.ar/economia/... • Min: 01:24 • ... • Min: 01:28 • AirGunner Bob_O. • Airgunner by Choice, Pest Controller ... • • #cowbird #cuckoo #broodparasitism
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