Some Winter and Nesting Season Foods of the Common Raven in Virginia

Harlow, Richard F.; Hooper, Robert G.; Crawford, Hewlette S.

doi:10.2307/4084558

Cited by 25 publications

(15 citation statements)

References 3 publications

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“…There have been studies of the diet of Ravens in many places including Virginia, USA (Harlow et al 1975), Merioneth, Wales (Bolam 1913), mid-Wales (Newton, Davis & Davis 1982), Cumbria, northern England (E. Blezard, in Ratcliffe 1962, southern uplands of Scotland (Marquiss et al 1978) and Shetland (Ewins, Dymond & Marquiss 1986). Considered together some general points emerge.…”

Section: Discussionmentioning

confidence: 99%

The diet of RavensCorvus coraxin Orkney

Marquiss¹,

Booth²

1986

Bird Study

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Section: Discussionmentioning

confidence: 99%

The diet of RavensCorvus coraxin Orkney

Marquiss¹,

Booth²

1986

Bird Study

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“…For example, some jays begin caching seeds (Stotz and Balda 1995;Johnson et al 1997), and while common ravens (Corvus corax) frequently take eggs during their nestling period (Stiehl 1985;Marquiss and Booth 1986), after fledging they forage intensively for terrestrial invertebrates in grasslands and agricultural fields (Harlow et al 1975;Stiehl 1978;Ewins et al 1986;Engel and Young 1989;Kilham 1989;Stiehl and Trautwein 1991;Nogales and Hernández 1997). In general, much of the postbreeding decline in nest-predation behavior of corvids is probably due to a lessening availability of nest contents as avian breeding activity wanes.…”

Section: Discussionmentioning

confidence: 98%

A temporal shift in Steller's jay predation on bird eggs

Sieving¹,

Willson²

1999

Can. J. Zool.

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Artificial-nest experiments conducted near Juneau, Alaska, indicated that Steller's jays (Cyanocitta stelleri) may undergo a marked shift in foraging pattern and possibly nest-predation behavior triggered by fledging of their own chicks. In an early-June sampling of predation on artificial nests containing quail eggs, egg losses and jay activity levels were significantly higher in forest adjacent to human-created edge than in undisturbed interior forest. In a lateJune sampling, however, nest predation near edges was significantly reduced, and this was correlated with a drop in jay activity (detected via predator censuses and remote-controlled camera stations baited with artificial nests). Steller's jays in natural nests monitored during the study fledged their chicks between the two samplings, which suggests that quail eggs were an important food for jays during their nestling period (early June) but not after (late June). Nests in the two plots in interior forest, where jays were rarely detected, had consistently low nest predation rates in both samplings. These data support the hypothesis that during their nestling period, adult Steller's jays in southeast Alaska may prey intensively on the contents of other birds' nests in the vicinity of their own nests, but that fledging of jay chicks abruptly changes foraging patterns, including possibly reducing nest-predation behavior. Given the short breeding season in southeast Alaska, it is likely that during the postfledging period, jay families concentrate on obtaining foods (e.g., conifer seeds) that are more important for over-winter survival of the juveniles than nest contents, which decrease rapidly in abundance during July.Résumé : Des expériences sur des nids artificiels près de Juneau, Alaska, indiquent que les Geais de Steller (Cyanocitta stelleri) peuvent subir un changement radical de leurs habitudes de quête de nourriture et peut-être aussi de leur comportement de prédation des nids, changement engendré par l'envol de leurs propres oisillons. Dans un cas de prédation observé au début de juin sur des nids artificiels contenant des oeufs de cailles, les pertes d'oeufs et l'activité des geais se sont avérées significativement plus élevées dans une forêt adjacente à une bordure créée par l'activité humaine qu'au milieu non perturbé d'une forêt. Dans un échantillon de la fin de juin, cependant, la prédation exercée sur les nids près des bordures était significativement moins importante et cette diminution était reliée à une baisse de l'activité des geais (telle que détectée par dénombrement des prédateurs et grâce à des postes ou ont été aménagés des nids artificiels et des appareils-photo télécommandés). Dans les nids des geais observés en nature au cours de cette étude, les oisillons ont pris leur envol entre les deux périodes de relevés, ce qui semble indiquer que les oeufs de cailles ont été une importante source de nourriture pour les geais au cours de leur période de nidification (début de juin), mais pas après (fin de juin). Les deux sites au milieu de l...

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“…Raven flocks sustained by refuse have been noted elsewhere, e.g. in Wales (Newton et al 1982) and Virginia, USA (Harlow et al 1975).…”

Section: The Survey Found 196 Raven Territories Inmentioning

confidence: 92%