AN INVESTIGATION OF COURTSHIP FEEDING IN HERRING GULLS LARUS ARGENTATUS

Ibis ◽  
2008 ◽  
Vol 123 (2) ◽  
pp. 218-223 ◽  
Author(s):  
Virginia Niebuhr
1983 ◽  
Vol 91 (3) ◽  
pp. 437-443 ◽  
Author(s):  
J. C. Coulson ◽  
J. Butterfield ◽  
C. Thomas

SUMMARYThis paper presents evidence for the involvement of herring gulls (Larus argentatus) as vectors in the recent outbreaks of Salmonella montevideo in sheep and cattle in Scotland and suggests that the transfer can take place over considerable distances. The breeding area in Scotland of herring gulls which overwinter in N.E. England is remarkably similar to the geographical distribution of the outbreaks. This pattern, together with the feeding behaviour of herring gulls on farmland, the presence of S. montevideo in herring gulls just before their departure from the wintering area and the timing of the return just before the peak of outbreaks are all circumstantial evidence implicating this gull in the outbreaks. The rapid return of these gulls to their breeding areas means that S. montevideo can be transported long distances in one day and raises the possibility that the original source of S. montevideo could have been in N. E. England rather than in Scotland.


1983 ◽  
Vol 61 (12) ◽  
pp. 2880-2898 ◽  
Author(s):  
Edward H. Miller

Sable Island, Nova Scotia, is the southernmost significant nesting area of the Least Sandpiper. Many birds nest around a single pond complex, which supports a lush vegetation that is heavily grazed by horses. Nests occur there and in nearby dry, sparsely vegetated habitat. Birds start arriving by mid-May (males first), and clutches (including replacement clutches) are completed in a period of 4–5 weeks, from late May to late June. Most eggs are laid in the morning, at intervals averaging 1.2 days. Incubation increases gradually through laying and is ~100% beginning with the last egg. Incubation lasts 20–21 days. Nest and chick mortality is high, mostly due to predation by Herring Gulls (Larus argentatus). Mortality of siblings is contagious. Females which nest successfully begin to migrate south by late June, followed by successful males in early July; individuals of both sexes are seen for about 3 days after the completion of parental behavior. Unsuccessful breeders leave earlier, and fledglings later. On average, males are seen for about 10 days and females for about 7 days following final breeding failure. Adults and fledglings tend to flock assortatively in late summer. General features of the breeding cycle seem to be highly conservative throughout the species' range.


1979 ◽  
Vol 57 (7) ◽  
pp. 1452-1457 ◽  
Author(s):  
Roger M. Evans

Young herring gulls (Larus argentatus) are known to emit vocalizations and approach their mew-calling parents when the latter return lo the colony with food for their chicks. In contrast, laboratory-reared young deprived of experience with adults approach and vocalize only rarely lo parental mew calls, although they will respond more strongly to the mew calls of two other species. These results suggest that posthatch experience, such as receipt of food from a calling parent, may be important for the normal development of responses to species typical calls. I tested the effects of food training by exposing young herring gulls, in the laboratory, lo mew calls during feedings. By 7 days of age, responses to herring gull calls increased significantly for young trained with these calls, and the initial tendency for the young to respond selectively to mew calls of the ring-billed gull (L. delawarensis) was reversed. Food training also influenced approach and vocal responses to a visual stimulus (my hand) used to deliver food. Results suggest that approach and vocal responses of young herring gulls may be strongly and adaptively influenced by food conditioning during the first few days after hatching.


2008 ◽  
Vol 71 (21) ◽  
pp. 1448-1456 ◽  
Author(s):  
Glen A. Fox ◽  
Rebecca Lundberg ◽  
Carolina Wejheden ◽  
Lars Lind ◽  
Sune Larsson ◽  
...  

1994 ◽  
Vol 72 (3) ◽  
pp. 427-432 ◽  
Author(s):  
Myra O. Wiebe ◽  
Roger M. Evans

Endothermic thermoregulation is absent in birds until after hatching, and usually requires several hours or days to become fully functional in the young. Cold-induced vocalizations that elicit brooding by a cooperative parent or surrogate constitute an additional thermoregulatory mechanism potentially available to neonates of some avian and probably some mammalian species. We show that newly hatched ring-billed gulls (Larus delawarensis) and herring gulls (Larus argentatus) exposed in the laboratory to moderate chilling (20 °C) had a significantly improved ability to regulate body temperature when rewarmed (34 °C) for brief, 4-min periods in response to cold-induced vocalizations. Spontaneous calling by unchilled yoked controls was ineffective in maintaining body temperature. When chicks reached 3 days of age, vocally regulated temperaturee did not differ from that attained by thermogenesis, but vocally induced periods of rewarming reduced the duration of temperature challenge. The ability to regulate body temperature through vocalizations precedes the development of endothermy in gulls and other species so far examined, and in some species extends functional thermoregulation back to the late embryonic (pipped egg) stage of development.


2019 ◽  
Vol 48 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Agnieszka Grajewska ◽  
Lucyna Falkowska ◽  
Andrzej Reindl

Abstract Mercury enters the body of seabirds in its most toxic organic form, i.e. methylmercury, mainly via the alimentary tract. Inside the body, mercury is transformed into less toxic forms and accumulates in the internal organs. The process of mercury removal from the body, most effective during the formation of new feathers and claws, is beneficial for the bird. The presented research was undertaken on account of the high affinity of mercury to keratin – a protein that forms feathers and claws – to compare the concentration levels (HgTOT) in these structures and to assess their contribution to the purification of the body of herring gulls (Larus argentatus) Bird feathers are the only epidermal structure that is extensively described in the literature, whereas the claws have so far been poorly researched. The study has shown that mercury in claws is built in as effectively as in feathers, and the obtained concentrations were within a wide range of 127.2–5341.5 ng HgTOT g–1 of dry weight. In addition, the concentrations of total mercury accumulated in the claws were a better reflection of Hg levels in internal organs compared to feathers.


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