Austin, Jane E.; Mitchell, Carl D.
March 2010
Northwestern Naturalist;Spring2010, Vol. 91 Issue 1, p23
Academic Journal
Common Ravens (Corvus corax) are considered an important predator of Sandhill Crane (Grus canadensis) eggs, but direct observations of predation events are rare. We observed 25 events of Common Ravens at or near artificial nests with infertile crane eggs; 15 of those events resulted in predation. Reconnaissance time averaged 1.8 ± 3.0 rain, egg handling averaged 5.8 ± 3.9 min, and total time to reconnoiter, approach, and consume or remove eggs from a nest averaged 8.4 ± 5.7 min. Ravens consumed 67% of the eggs at the nest and cached the other 33%. To eat an egg, ravens always punched a hole in the surface, but hole sizes and shapes differed. To cache eggs, ravens carried eggs away intact, leaving no evidence in the nest, and concealed them 5.5 to 180 m from the nest. The rapidity of some raven depredation events indicates a high potential for success of taking crane eggs from an active but unattended nests. Given the diverse patterns of eggshell remains and ravens' ability to carry whole eggs, distinguishing egg predation by ravens from other predators would be very difficult.


Related Articles

  • Experimental Evidence That Scare Tactics and Effigies Reduce Corvid Occurrence. Peterson, Sara A; Colwell, Mark A // Northwestern Naturalist;Autumn2014, Vol. 95 Issue 2, p103 

    Common Ravens ( Corvus corax) and American Crows ( C. brachyrhynchos) are important predators of eggs and chicks of the Snowy Plover ( Charadrius nivosus), which compromises population recovery of this federally listed species. We used a before-after, control-impact experiment over a 4-d...

  • Ad Libitum Water Source for a Common Raven. Hanks, Lawrence M.; Barbour, James D.; Kratz, Kim; Webb, William C. // Wilson Journal of Ornithology;Mar2009, Vol. 121 Issue 1, p210 

    We report a Common Raven (Corvus corax) that learned to turn on a water faucet in a campground at Death Valley National Park, Inyo County, California, USA, and drink from it. Ad libitum availability of water has important implications for survival and reproductive success of desert birds. Ravens...

  • Predation on Artificial Nests in Small Grassland Patches in East-Central Illinois. Newton, Julianne L.; Heske, Edward J. // American Midland Naturalist;Jan2001, Vol. 145 Issue 1, p29 

    Presents information on a study which measured predation on artificial bird nests in 11 grassy fields. Relationships between number of nests depredated and distance to woody edges; Summary of data on study sites and depredation of artificial nests; Comparison of depredation of artificial nests...

  • Factors Affecting Predation on Wood Turtle ( Glyptemys insculpta) Nests in the Upper Peninsula of Michigan. Rutherford, Jenny L.; Casper, Gary S.; Graves, Brent // Chelonian Conservation & Biology;Dec2016, Vol. 15 Issue 2, p181 

    Depredation rates on turtle nests can be very high, resulting in low recruitment to populations. Understanding predator foraging habits and nesting ecology of turtles is essential for the long-term management of threatened turtle species. Cues used by predators to locate wood turtle ( Glyptemys...

  • Preliminary observations on the diet of leopards (Panthera pardus) from a conservation area and adjacent rangelands in the Baviaanskloof region, South Africa. Ott, Theresia; Kerley, Graham I. H.; Boshoff, André F. // African Zoology;Apr2007, Vol. 42 Issue 1, p31 

    Pastoralists on rangelands adjacent to the Baviaanskloof Provincial Nature Reserve, Eastern Cape, report stock losses through predation by leopards (Panthera pardus). This leads, in certain cases, to persecution of the leopards. This study attempted to quantify livestock depredation by leopards...

  • Can differences in incubation patterns of Common Redshanks Tringa totanus be explained by variations in predation risk? Cervencl, Anja; Esser, Wiebke; Maier, Martin; Oberdiek, Nadine; Thyen, Stefan; Wellbrock, Arndt; Exo, Klaus-Michael // Journal of Ornithology;Oct2011, Vol. 152 Issue 4, p1033 

    The effects of predation on Common Redshanks Tringa totanus incubation patterns and behaviour was investigated in 2006 and 2007 at three mainland study sites at the Jadebusen and at one study site on the island Wangerooge, Wadden Sea National Park Lower Saxony (Germany), using temperature data...

  • Parents, predators, parasites, and the evolution of eggshell colour in open nesting birds. Hanley, Daniel; Cassey, Phillip; Doucet, Stéphanie // Evolutionary Ecology;May2013, Vol. 27 Issue 3, p593 

    The colourful surface of birds' eggshells varies dramatically between species, but the selective pressures driving this variation remain poorly understood. We used a large comparative dataset to test several hypotheses proposed to explain the evolution of eggshell colouration. We tested the...

  • Evaluation of a glossmeter for studying the surface appearance of avian eggs. Maurer, Golo; Cassey, Phillip // Journal of Ornithology;Jan2011, Vol. 152 Issue 1, p209 

    Gloss is a striking characteristic of avian eggshells that may affect both egg recognition and clutch predation. Previously, gloss has proved difficult to quantify objectively. Newly developed handheld glossmeters seem to offer a solution. We evaluated the use of a handheld glossmeter for a...

  • Deadly hunters. Johnson, Jinny // Birds (1-59084-447-5);2003, p30 

    The article presents information on birds of prey. The golden eagle is one of the fiercest hunters of all birds. The sea eagle feeds on fish that it snatches from the water surface. Eagles have very keen eyesight and sharp talons. The raven is the biggest of all the songbirds, and it is a...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics