Some aspects of feeding and foraging behaviour of three corvids in Newfoundland
Research began with a study of nest predation by a pair of Common Ravens in a colony of cliff-nesting kittiwakes during summer, 1979. Patrols by single ravens were twice as successful as when both birds hunted together. Kittiwake anti-predator defense was important in reducing predation. Results of...
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Memorial University of Newfoundland
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ftmemorialuniv:oai:research.library.mun.ca:5824 2023-10-01T03:57:38+02:00 Some aspects of feeding and foraging behaviour of three corvids in Newfoundland Maccarone, Alan David 1981 application/pdf https://research.library.mun.ca/5824/ https://research.library.mun.ca/5824/1/Maccarone_AlanDavid.pdf https://research.library.mun.ca/5824/3/Maccarone_AlanDavid.pdf en eng Memorial University of Newfoundland https://research.library.mun.ca/5824/1/Maccarone_AlanDavid.pdf https://research.library.mun.ca/5824/3/Maccarone_AlanDavid.pdf Maccarone, Alan David <https://research.library.mun.ca/view/creator_az/Maccarone=3AAlan_David=3A=3A.html> (1981) Some aspects of feeding and foraging behaviour of three corvids in Newfoundland. Masters thesis, Memorial University of Newfoundland. thesis_license Thesis NonPeerReviewed 1981 ftmemorialuniv 2023-09-03T06:45:34Z Research began with a study of nest predation by a pair of Common Ravens in a colony of cliff-nesting kittiwakes during summer, 1979. Patrols by single ravens were twice as successful as when both birds hunted together. Kittiwake anti-predator defense was important in reducing predation. Results of a cost/benefit analysis suggest that the ravens obtained sufficient prey to meet daily energy requirements. -- A series of feeding and foraging experiments, designed to test several basic assumptions of Optimal Foraging Theory, was carried out between September 1979 and June 1980, using freeliving Gray Jays and Common Crows and artificial prey populations. Both species became more discriminating in bait selection when relative and absolute abundances of profitable baits were increased. When populations of artificial baits consisted of two and three different types, jays differentially selected bait types on the basis of net energy value. Individuals differed in food preference and foraging efficiency. The possible influences of social status and prior experience are discussed. -- Three experiments were designed to induce switching of prey preferences among the jays by decreasing the profitability of a preferred food. Manipulations that produced increases in handling, search, and recognition times caused the jays to switch to an alternate bait, but they were reluctant to take a second alternate that was low in net energy value. Many of these data support current models of Optimal Foraging Theory. -- In a final experiment, a Great Horned Owl decoy was used to disrupt the feeding behaviour of a family of Gray Jays. Differences were found between juveniles and adults in anti-predator behaviour and food preference, juveniles being less cautious in the presence of the decoy and less discriminating in bait preference. Possible reasons for these differences are discussed. Thesis Newfoundland Memorial University of Newfoundland: Research Repository The Ravens ENVELOPE(-55.681,-55.681,53.217,53.217) |
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Memorial University of Newfoundland: Research Repository |
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ftmemorialuniv |
language |
English |
description |
Research began with a study of nest predation by a pair of Common Ravens in a colony of cliff-nesting kittiwakes during summer, 1979. Patrols by single ravens were twice as successful as when both birds hunted together. Kittiwake anti-predator defense was important in reducing predation. Results of a cost/benefit analysis suggest that the ravens obtained sufficient prey to meet daily energy requirements. -- A series of feeding and foraging experiments, designed to test several basic assumptions of Optimal Foraging Theory, was carried out between September 1979 and June 1980, using freeliving Gray Jays and Common Crows and artificial prey populations. Both species became more discriminating in bait selection when relative and absolute abundances of profitable baits were increased. When populations of artificial baits consisted of two and three different types, jays differentially selected bait types on the basis of net energy value. Individuals differed in food preference and foraging efficiency. The possible influences of social status and prior experience are discussed. -- Three experiments were designed to induce switching of prey preferences among the jays by decreasing the profitability of a preferred food. Manipulations that produced increases in handling, search, and recognition times caused the jays to switch to an alternate bait, but they were reluctant to take a second alternate that was low in net energy value. Many of these data support current models of Optimal Foraging Theory. -- In a final experiment, a Great Horned Owl decoy was used to disrupt the feeding behaviour of a family of Gray Jays. Differences were found between juveniles and adults in anti-predator behaviour and food preference, juveniles being less cautious in the presence of the decoy and less discriminating in bait preference. Possible reasons for these differences are discussed. |
format |
Thesis |
author |
Maccarone, Alan David |
spellingShingle |
Maccarone, Alan David Some aspects of feeding and foraging behaviour of three corvids in Newfoundland |
author_facet |
Maccarone, Alan David |
author_sort |
Maccarone, Alan David |
title |
Some aspects of feeding and foraging behaviour of three corvids in Newfoundland |
title_short |
Some aspects of feeding and foraging behaviour of three corvids in Newfoundland |
title_full |
Some aspects of feeding and foraging behaviour of three corvids in Newfoundland |
title_fullStr |
Some aspects of feeding and foraging behaviour of three corvids in Newfoundland |
title_full_unstemmed |
Some aspects of feeding and foraging behaviour of three corvids in Newfoundland |
title_sort |
some aspects of feeding and foraging behaviour of three corvids in newfoundland |
publisher |
Memorial University of Newfoundland |
publishDate |
1981 |
url |
https://research.library.mun.ca/5824/ https://research.library.mun.ca/5824/1/Maccarone_AlanDavid.pdf https://research.library.mun.ca/5824/3/Maccarone_AlanDavid.pdf |
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ENVELOPE(-55.681,-55.681,53.217,53.217) |
geographic |
The Ravens |
geographic_facet |
The Ravens |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_relation |
https://research.library.mun.ca/5824/1/Maccarone_AlanDavid.pdf https://research.library.mun.ca/5824/3/Maccarone_AlanDavid.pdf Maccarone, Alan David <https://research.library.mun.ca/view/creator_az/Maccarone=3AAlan_David=3A=3A.html> (1981) Some aspects of feeding and foraging behaviour of three corvids in Newfoundland. Masters thesis, Memorial University of Newfoundland. |
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thesis_license |
_version_ |
1778529516839239680 |