Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? /
The Common Tern (Sterna hirundo) is a ground nesting colonial seabird. Terns rely primarily on small prey fishes which they obtain through plunge diving for their survival as well as the survival of their offspring during the breeding season. The zebra mussel (Dreissena polymorpha) is a small bivalv...
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ftbrockuniv:oai:dr.library.brocku.ca:10464/1353 2024-06-09T07:45:28+00:00 Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? / Game, Rob F. Department of Biological Sciences 2009-05-21T13:54:26Z http://hdl.handle.net/10464/1353 eng eng Brock University http://hdl.handle.net/10464/1353 Common tern Zebra mussel Electronic Thesis or Dissertation 2009 ftbrockuniv 2024-05-16T06:33:42Z The Common Tern (Sterna hirundo) is a ground nesting colonial seabird. Terns rely primarily on small prey fishes which they obtain through plunge diving for their survival as well as the survival of their offspring during the breeding season. The zebra mussel (Dreissena polymorpha) is a small bivalve mollusk that invaded North American waters in the late 1980's. Through its suspension feeding, the zebra mussel has the ability to alter the entire aquatic ecosystem, ultimately leading to a reduction in pelagic organisms including small prey fish. The objective of the study was to determine what (if any) indirect effects the invasion of the zebra mussel has had on fish prey captured by terns. The study took place in two separate two-year periods, 1990-91 and 1995-96 on a concrete breakwall off the north shore of Lake Erie near Port Colborne, Ontario. Daily nest checks revealed clutch initiation dates, egg-laying chronology, hatching success and morphological egg characteristics (length and breadth). Behavioural observations included time each sex spent in attendance with its brood, the frequency of feeding chicks and the prey species composition and size fed to chicks as well as to females (courtship feeding). Egg sizes did not differ between study periods, nor did feeding rates to chicks, suggesting that food was not a limiting resource. Terns spent less time with their broods (more time foraging) in the 1995-96 period. However, they also had significantly larger broods and fledged more offspring. The time of each individual foraging trip decreased, suggesting that fish were easier to obtain in 1995 and 1996. Lastly, kleptoparasitism rates decreased, suggesting that the costs of foraging (time, energy) actually decreased as fewer birds adopted this strategy to compensate for what I assumed to be a lack of available food (fish). The only significant difference between the periods of 1990, 1991 and 1995, 1996 was a change in diet. Terns delivered significantly fewer rainbow smelt and more emerald shiner in 1995 and ... Thesis Common tern Sterna hirundo Brock University Digital Repository |
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Open Polar |
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Brock University Digital Repository |
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ftbrockuniv |
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English |
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Common tern Zebra mussel |
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Common tern Zebra mussel Game, Rob F. Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? / |
topic_facet |
Common tern Zebra mussel |
description |
The Common Tern (Sterna hirundo) is a ground nesting colonial seabird. Terns rely primarily on small prey fishes which they obtain through plunge diving for their survival as well as the survival of their offspring during the breeding season. The zebra mussel (Dreissena polymorpha) is a small bivalve mollusk that invaded North American waters in the late 1980's. Through its suspension feeding, the zebra mussel has the ability to alter the entire aquatic ecosystem, ultimately leading to a reduction in pelagic organisms including small prey fish. The objective of the study was to determine what (if any) indirect effects the invasion of the zebra mussel has had on fish prey captured by terns. The study took place in two separate two-year periods, 1990-91 and 1995-96 on a concrete breakwall off the north shore of Lake Erie near Port Colborne, Ontario. Daily nest checks revealed clutch initiation dates, egg-laying chronology, hatching success and morphological egg characteristics (length and breadth). Behavioural observations included time each sex spent in attendance with its brood, the frequency of feeding chicks and the prey species composition and size fed to chicks as well as to females (courtship feeding). Egg sizes did not differ between study periods, nor did feeding rates to chicks, suggesting that food was not a limiting resource. Terns spent less time with their broods (more time foraging) in the 1995-96 period. However, they also had significantly larger broods and fledged more offspring. The time of each individual foraging trip decreased, suggesting that fish were easier to obtain in 1995 and 1996. Lastly, kleptoparasitism rates decreased, suggesting that the costs of foraging (time, energy) actually decreased as fewer birds adopted this strategy to compensate for what I assumed to be a lack of available food (fish). The only significant difference between the periods of 1990, 1991 and 1995, 1996 was a change in diet. Terns delivered significantly fewer rainbow smelt and more emerald shiner in 1995 and ... |
author2 |
Department of Biological Sciences |
format |
Thesis |
author |
Game, Rob F. |
author_facet |
Game, Rob F. |
author_sort |
Game, Rob F. |
title |
Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? / |
title_short |
Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? / |
title_full |
Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? / |
title_fullStr |
Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? / |
title_full_unstemmed |
Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? / |
title_sort |
trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? / |
publisher |
Brock University |
publishDate |
2009 |
url |
http://hdl.handle.net/10464/1353 |
genre |
Common tern Sterna hirundo |
genre_facet |
Common tern Sterna hirundo |
op_relation |
http://hdl.handle.net/10464/1353 |
_version_ |
1801374837594128384 |