Ring-billed Gull (Larus delawarensis)

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.

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Field evaluation of a visual barrier to discourage gull nesting

Pacific Conservation Biology ◽

10.1071/pc010143 ◽

2001 ◽

Vol 7 (2) ◽

pp. 143 ◽

Cited By ~ 1

Author(s):

P. A. Pochop ◽

J. L. Cummings ◽

R. M. Engeman

Keyword(s):

Columbia River ◽

Field Evaluation ◽

Management Technique ◽

Nesting Habitat ◽

Control Zone ◽

Larus Delawarensis ◽

Polypropylene Fabric ◽

Benton County ◽

Bird Management ◽

Salmon Smolt

Expanding gull populations along the Columbia River have been implicated in depredations to threatened and endangered migrating salmon smolt. We tested a visual barrier made of woven black polypropylene fabric to discourage gull nesting. The barrier was installed on Upper Nelson Island, Benton County, Washington, in parallel rows spaced 5 m apart. Gulls used 87% of the 7.9 ha island as nesting habitat and we estimated >21 000 gull nests, 80% Ring-billed Gull Larus delawarensis and 20% California Gull L. califomicus nests. The zone with fencing had 84% fewer nests than the control zone. Silt fencing showed potential as a nonlethal bird management technique.

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Avian Influenza Prevalence and Viral Shedding Routes in Minnesota Ring-Billed Gulls (Larus delawarensis)

Avian Diseases ◽

10.1637/11848-041718-reg.1 ◽

2018 ◽

Vol 63 (sp1) ◽

pp. 120 ◽

Cited By ~ 2

Author(s):

Todd Froberg ◽

Francesca Cuthbert ◽

Christopher S. Jennelle ◽

Carol Cardona ◽

Marie Culhane

Keyword(s):

Avian Influenza ◽

Viral Shedding ◽

Larus Delawarensis

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Effects of External Oiling and Rehabilitation on Hematological, Biochemical, and Blood Gas Analytes in Ring-Billed Gulls (Larus delawarensis)

Frontiers in Veterinary Science ◽

10.3389/fvets.2019.00405 ◽

2019 ◽

Vol 6 ◽

Cited By ~ 2

Author(s):

Nicholas G. Dannemiller ◽

Katherine E. Horak ◽

Jeremy W. Ellis ◽

Nicole L. Barrett ◽

Lisa L. Wolfe ◽

...

Keyword(s):

Blood Gas ◽

Larus Delawarensis

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Head-bobbing in the Ring-billed Gull (Larus delawarensis)

The Canadian Field-Naturalist ◽

10.22621/cfn.v130i2.1843 ◽

2016 ◽

Vol 130 (2) ◽

pp. 174

Author(s):

Thomas J Lisney ◽

Nikolaus F Troje

Keyword(s):

Visual Perception ◽

Significant Role ◽

Strong Evidence ◽

Functional Significance ◽

Visual Detection ◽

Food Items ◽

Larus Delawarensis ◽

Head Bobbing ◽

Common Behaviour ◽

Do So

Many birds bob their head as they walk or run on the ground. The functional significance of this behaviour is unclear, but there is strong evidence that it plays a significant role in enhancing visual perception. If head-bobbing is advantageous, however, then it is a puzzle that some birds do not head-bob. As a group, gulls (Laridae) are among the birds that reportedly do not head-bob,yet here we report head-bobbing among Ring-billed Gulls (Larus delawarensis), observed and filmed in Ontario, when walking relatively slowly while foraging on the ground. This suggests that head-bobbing plays a key role in the visual detection of food items in this species. We suggest that head-bobbing may be a relatively common behaviour in foraging Ring-billed Gulls and speculate that other gulls (and indeed other birds) previously thought not to head-bob may in fact do so under certain circumstances.

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Differences in skeletal characters between the disjunct eastern and western populations of ring-billed gulls (Larus delawarensis)

Canadian Journal of Zoology ◽

10.1139/z84-153 ◽

1984 ◽

Vol 62 (6) ◽

pp. 1067-1074 ◽

Cited By ~ 2

Author(s):

Beatrice M. Termaat ◽

John P. Ryder

Keyword(s):

Discriminant Function ◽

Multivariate Analyses ◽

Correct Identification ◽

Adult Males ◽

Lake Of The Woods ◽

Larus Delawarensis ◽

Males And Females ◽

Two Populations ◽

Univariate Analyses ◽

Discriminant Function Analyses

Univariate analyses of variance, multivariate analyses of variance (Manova), and discriminant function analyses were performed on measurements of 51 skeletal characters of adult males and females from the disjunct eastern and western populations of the ring-billed gull (Larus delawarensis) in Canada. The analyses established sufficient differences in skeletal characters to permit correct identification of the origin of 34 of 38 males (90%) and 40 of 42 females (95%). The populations are now expanding in range to the extent where new colonies are established in the Lake of the Woods, Ontario region, the historical hiatus between the two populations. Further expansion and contact may well erase the existing skeletal differences of individuals in these populations.

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Combined usage of stable isotopes and GPS-based telemetry to understand the feeding ecology of an omnivorous bird, the Ring-billed Gull (Larus delawarensis)

Canadian Journal of Zoology ◽

10.1139/cjz-2013-0008 ◽

2013 ◽

Vol 91 (10) ◽

pp. 689-697 ◽

Cited By ~ 34

Author(s):

É. Caron-Beaudoin ◽

M.-L. Gentes ◽

M. Patenaude-Monette ◽

J.-F. Hélie ◽

J.-F. Giroux ◽

...

Keyword(s):

Stable Isotope ◽

Feeding Ecology ◽

Blood Cells ◽

Urban Areas ◽

Dietary Habits ◽

Treatment Plant ◽

Gps Tracking ◽

Food Items ◽

Larus Delawarensis ◽

Positive Correlations

The aim of the present study was to investigate the feeding ecology of an omnivorous bird, the Ring-billed Gull (Larus delawarensis Ord, 1815), breeding in a highly urbanized and heterogeneous landscape (Montréal area, Quebec, Canada). We used gastrointestinal (G.I.) tract content analysis, GPS-based tracking information, and stable isotope profiles of carbon (δ13C) and nitrogen (δ15N) in selected tissues and major food items. Based on GPS tracking data (1–3 days), Ring-billed Gulls were categorized according to their use of three main foraging habitats: agricultural, St. Lawrence River, and anthropogenic (comprising urban areas, landfills, and wastewater treatment plant basins). Ring-billed Gulls that foraged predominantly in anthropogenic habitats exhibited significantly lower δ15N in blood cells and higher total C to N ratios (C:N) in liver. These lower δ15N and higher C:N ratios were characteristic of profiles determined in food items consumed by Ring-billed Gulls at these urbanized sites (e.g., processed foods). The strong positive correlations between δ13C and δ15N in Ring-billed Gull tissues (plasma, blood cells, and liver) that differed in isotopic turnover times, as well as the strong positive correlations in both δ13C and δ15N between tissue pairs, indicated that Ring-billed Gulls exhibited conserved dietary habits throughout the nesting period. This study demonstrates that combining conventional dietary examination, tissue stable isotope analysis, and fine-scale GPS tracking information may improve our understanding of the large intrapopulation variations in foraging behaviour (and isotopic profiles) commonly observed in omnivorous birds.

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