Erratum: The breeding biology of two Lake Erie herring gull colonies

1977 ◽  
Vol 55 (10) ◽  
pp. 1766-1766
Author(s):  
Ralph D. Morris ◽  
Gerard T. Haymes

1977 ◽  
Vol 55 (5) ◽  
pp. 796-805 ◽  
Author(s):  
Ralph D. Morris ◽  
Gerard T. Haymes

The breeding biology of two Lake Erie herring gull colonies was studied from 1973 to 1976, emphasizing effects of clutch size and time of clutch initiation on reproductive success. In 1976, incubation attention of two-egg and three-egg clutches started early and late in the season was measured with a 20-pen event recorder. Chlorinated hydrocarbon residues in eggs were assessed in 2 years. Nest density was greater, clutch initiation more synchronized, and hatching success higher at one of the colonies. Hatching success and fledging success were independent of clutch size bin early nesters were more successful than late nesters. Differences in hatching success between two-egg and three-egg clutches were a function of time of clutch initiation such that the clutch size with the greater proportion of its nests in the early period had a higher hatching success. The reproductive success of the Lake Erie colonies was intermediate among rates reported for other Great Lakes colonies but below those of most eastern North American or European colonies. There were no significant differences in the incubation attention between two-egg clutches and three-egg clutches or between early and late three-egg clutches. Most clutches were incubated greater than 95% of the time although clutches incubated less than 75% realized the same hatching success.



1985 ◽  
Vol 63 (3) ◽  
pp. 607-611 ◽  
Author(s):  
Ralph D. Morris ◽  
John W. Chardine

The substrate at a herring gull (Larus argentatus) colony on Lake Erie near Port Colborne, Ontario (Lighthouse), was completely covered by a thick layer of ice throughout April and early May 1982. Egg laying normally begins at this location in mid-April. An adjacent herring gull colony (Canada Furnace) was ice free. Herring gull pairs at the Lighthouse colony defended territories on top of the ice but only 3 of about 90 pairs built nests on the ice. Birds neither deserted the colony nor moved within it to ice-free areas as these became available. The mean date of egg laying at the Lighthouse colony in 1982 was about 2 weeks later than in the previous year. At the adjacent Canada Furnace colony, there was no difference in the mean date of egg laying between the 2 years. There were no differences in the distribution of clutch sizes, mean clutch sizes, or hatching success of three-egg clutches laid within ± 1 SD of the mean date of egg laying at either colony in the 2 years. By these measures, the ice-induced delay in breeding chronology of birds at the Lighthouse colony in 1982 did not adversely effect reproductive performance in that year.





The Auk ◽  
1975 ◽  
Vol 92 (4) ◽  
pp. 678-697 ◽  
Author(s):  
William Threlfall




1999 ◽  
Vol 56 (2) ◽  
pp. 323-338 ◽  
Author(s):  
Craig E Hebert ◽  
J Laird Shutt ◽  
Keith A Hobson ◽  
DV Chip Weseloh

Stable nitrogen (δ15N) and carbon (δ13C) isotope values were measured in lipid-free homogenates of herring gull (Larus argentatus) eggs collected from the Laurentian Great Lakes during 1974-1995. δ15N values provided an indication of adult gull trophic position during egg formation. After adjustment of egg δ15N values for interlake differences in baseline food web δ15N signatures, significant differences in gull trophic position were found among colonies. These results were attributed to differing proportions of fish in the diets of gulls from the various colonies. Aquatic foods available to gulls had greater δ15N values than terrestrial foods. δ13C measurements provided some support for our hypothesis that terrestrial foods, particularly garbage, were more enriched in 13C than aquatic foods. As the proportion of fish in the diet decreased, the fraction consisting of terrestrial food increased, resulting in an increase in δ13C values and a decline in δ15N values. Stable isotope values for gull eggs from Lake Erie changed significantly during the study period and may have reflected a decline in fish availability.



2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.





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