The identification and morphological variation of Diplostomum baeri bucculentum from two gull species, using metacercarial infections from least cisco from the Northwest Territories

1987 ◽  
Vol 65 (9) ◽  
pp. 2287-2291 ◽  
Author(s):  
Allen W. Shostak ◽  
Jean C. Tompkins ◽  
Terry A. Dick
Keyword(s):  
Northwest Territories ◽  
Ventral Sucker ◽  
Morphological Variation ◽  
Anterior Margin ◽  
Morphological Characters ◽  
Larus Argentatus ◽  
Geographic Variability ◽  
Size And Shape ◽  
Herring Gulls ◽  
Larus Delawarensis

Metacercariae of the genus Diplostomum, recovered from the eyes of the least cisco, Coregonus sardinella, were used to experimentally infect chicks of ring-billed gulls, Larus delawarensis, and herring gulls, Larus argentatus. Adults recovered from the intestine of these gulls were identified as Diplostomum baeri bucculentum based on size characteristics and the position of the anterior margin of the vitellaria to at least the level of the ventral sucker. An analysis of morphological characters from 258 gravid specimens showed a greater range in measurements than previously reported for this species. Moreover, characters such as egg numbers and size and shape components were strongly influenced by host effects. There does not appear to be the extensive geographic variability in morphology that is known for other helminth groups.

Development of temperature regulation in young birds: evidence for a vocal regulatory mechanism in two species of gulls (Laridae)

1994 ◽  
Vol 72 (3) ◽  
pp. 427-432 ◽  
Author(s):  
Myra O. Wiebe ◽  
Roger M. Evans
Keyword(s):  
Body Temperature ◽  
Temperature Regulation ◽  
Regulatory Mechanism ◽  
Mammalian Species ◽  
Larus Argentatus ◽  
Herring Gulls ◽  
Stage Of Development ◽  
Larus Delawarensis ◽  
Regulate Body Temperature

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.

scholarly journals Morphological Variation Among Herring Gulls (Larus argentatus) and Great Black-Backed Gulls (Larus marinus) in Eastern North America

Waterbirds ◽  
2016 ◽  
Vol 39 (sp1) ◽  
pp. 253-268 ◽  
Author(s):  
Gregory J. Robertson ◽  
Sheena Roul ◽  
Karel A. Allard ◽  
Cynthia Pekarik ◽  
Raphael A. Lavoie ◽  
...  
Keyword(s):  
North America ◽  
Morphological Variation ◽  
Larus Argentatus ◽  
Eastern North America ◽  
Herring Gulls ◽  
Larus Marinus

scholarly journals The herring gull Larus argentatus as a likely transmitting agent of Salmonella montevideo to sheep and cattle

1983 ◽  
Vol 91 (3) ◽  
pp. 437-443 ◽  
Author(s):  
J. C. Coulson ◽  
J. Butterfield ◽  
C. Thomas
Keyword(s):  
Geographical Distribution ◽  
Feeding Behaviour ◽  
Circumstantial Evidence ◽  
Larus Argentatus ◽  
Herring Gull ◽  
Breeding Area ◽  
Original Source ◽  
Herring Gulls ◽  
Wintering Area

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.

Habitat and breeding cycle of the Least Sandpiper (Calidris minutilla) on Sable Island, Nova Scotia

1983 ◽  
Vol 61 (12) ◽  
pp. 2880-2898 ◽  
Author(s):  
Edward H. Miller
Keyword(s):  
Nova Scotia ◽  
Parental Behavior ◽  
Late Summer ◽  
Species Range ◽  
Larus Argentatus ◽  
Breeding Cycle ◽  
Herring Gulls ◽  
Egg Incubation ◽  
Breeding Failure

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.

Further Observations on the Morphology of Heterodera schachtii, with Remarks on the Bionomics of a strain attacking Mangolds in Britain

1929 ◽  
Vol 7 (3) ◽  
pp. 119-140 ◽  
Author(s):  
Marjorie J. Triffitt
Keyword(s):  
Sugar Beet ◽  
Developmental Stages ◽  
Morphological Characters ◽  
Heterodera Schachtii ◽  
Adult Males ◽  
Morphological Variations ◽  
Size And Shape ◽  
Morphological Studies ◽  
Comparative Survey

In a previous publication the morphological characters of a strain of H. schachtii specialised on the potato in Lincolnshire were discussed. The size and shape of the brown cysts, size of the eggs and first stage larvæ and the general characters of the adult males of this strain were compared with those of a strain attacking potatoes in Rostock, Mecklenburg, for which the specific name H. rostochiensis was suggested by Wollenweber 1923.Considerable dimensional variations were found to exist in the Lincolnshire strain, and a study of the literature on the morphological characters of H. schachtii specialised on sugar-beet and oats, showed equally wide divergencies between the findings of different workers. A certain amount of preserved material of infected roots of beet and oats being available to the writer, as many developmental stages as possible were extracted from these, on which similar morphological studies were carried out. Thus a fairly complete comparative survey of H. schachtii specialised on beet, oats and potatoes was completed, and the morphological variations between the strains were found to be insufficient to justify the separation of the strain specialised on potato from those on beet and oats. The name H. rostochicnsis was, therefore, deemed a synonym for H. schachtii.

Responsiveness of young herring gulls to stimuli from their own and other species: effects of training with food

1979 ◽  
Vol 57 (7) ◽  
pp. 1452-1457 ◽  
Author(s):  
Roger M. Evans
Keyword(s):  
Visual Stimulus ◽  
Normal Development ◽  
Larus Argentatus ◽  
Herring Gull ◽  
Vocal Responses ◽  
Herring Gulls ◽  
Species Effects ◽  
Initial Tendency ◽  
Food Conditioning

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.

scholarly journals Health of Herring Gulls (Larus argentatus) in Relation to Breeding Location in the Early 1990s. III. Effects on the Bone Tissue

2008 ◽  
Vol 71 (21) ◽  
pp. 1448-1456 ◽  
Author(s):  
Glen A. Fox ◽  
Rebecca Lundberg ◽  
Carolina Wejheden ◽  
Lars Lind ◽  
Sune Larsson ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Larus Argentatus ◽  
Herring Gulls ◽  
Breeding Location
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