Feeding ecology of ring-billed gull (Larus delawarensis) chicks

1979 ◽  
Vol 57 (5) ◽  
pp. 1086-1090 ◽  
Author(s):  
Ian R. Kirkham ◽  
Ralph D. Morris
Keyword(s):  
Seasonal Variation ◽  
Feeding Ecology ◽  
Food Type ◽  
High Humidity ◽  
Principal Objective ◽  
Larus Delawarensis ◽  
Chick Development ◽  
Provincial Park

The feeding ecology of ring-billed gull chicks from hatching to fledging was studied on an insular colony near Presqu'ile Provincial Park, Ontario, during the summer of 1977. A principal objective was to determine changes in food type and frequency of feedings during chick development and among temporally spaced broods.Two daily peaks in chick feeding occurred with the first shortly after sunrise and the second just prior to sunset. The frequency at which chicks were fed peaked when they were 4 days old and declined steadily thereafter. Chicks younger than 5 days were fed insects and fish while chicks older than 5 days were fed mainly fish. Seasonal variation in food type fed to chicks changed from insects and fish early in the season to predominantly fish late in the season. The incidence of earthworms in feedings correlated with preceding periods of high humidity or rain.

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

2013 ◽  
Vol 91 (10) ◽  
pp. 689-697 ◽  
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.

scholarly journals An ordination technique for fish diet comparisons

2000 ◽  
Vol 43 (1) ◽  
Author(s):  
Tadeusz Penczak ◽  
Angelo A. Agostinho ◽  
Norma S. Hahn
Keyword(s):  
Solar Energy ◽  
Temporal Variation ◽  
Fish Species ◽  
Feeding Ecology ◽  
Food Preferences ◽  
Food Type ◽  
Spatial And Temporal Variation ◽  
Fish Diet ◽  
Taxonomic Affinity ◽  
Herbivorous Species

The frequency of nine food types in the guts of 58 fish species from the Paraná River and its floodplain was compared using similarity definition. A synthetic table ordered on the basis of this definition, with fish species on axis y, and food types on axis x, enabled easy reading numerous kinds of information on feeding ecology of fish in the catchment. For example: 1) which fish species were generalists, specialists or opportunists, 2) those classified as herbivorous species consumed small amounts of animal food, 3) that fish consumed any food type that contained transformed solar energy and matter, 4) what are food preferences dependent on fish taxonomic affinity. The possibility of employing synthetic tables for investigating spatial and temporal variation in fish diet has also been indicated.

Seasonal variation in the feeding ecology of the grey-cheeked mangabey (Lophocebus albigena) in Cameroon

2001 ◽  
Vol 54 (2) ◽  
pp. 91-105 ◽  
Author(s):  
John R. Poulsen ◽  
Connie J. Clark ◽  
Thomas B. Smith
Keyword(s):  
Seasonal Variation ◽  
Feeding Ecology ◽  
Lophocebus Albigena

Grinding away in feeding ecology: Exploring sexual and seasonal variation in chimpanzees

2016 ◽  
Vol 81 ◽  
pp. 17
Author(s):  
Julia Stuhlträger ◽  
Kornelius Kupczik ◽  
Roman Wittig ◽  
Ellen Schulz-Kornas
Keyword(s):  
Seasonal Variation ◽  
Feeding Ecology

scholarly journals Feeding ecology of bonobos living in forest-savannah mosaics: Diet seasonal variation and importance of fallback foods

2015 ◽  
Vol 77 (9) ◽  
pp. 948-962 ◽  
Author(s):  
Adeline Serckx ◽  
Hjalmar S. Kühl ◽  
Roseline C. Beudels-Jamar ◽  
Pascal Poncin ◽  
Jean-François Bastin ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Feeding Ecology ◽  
Fallback Foods

scholarly journals Latest seasonal trend of aerosol, particulate matter and ozone in Delhi

MAUSAM ◽  
2021 ◽  
Vol 67 (3) ◽  
pp. 619-624
Author(s):  
D. K. CHAKRABARTY ◽  
S. K. PESHIN
Keyword(s):  
Particulate Matter ◽  
Seasonal Variation ◽  
Gas Phase ◽  
Total Ozone ◽  
Surface Ozone ◽  
High Humidity ◽  
Gangetic Plain ◽  
Pm2.5 And Pm10 ◽  
Indo Gangetic Plain ◽  
Surface O3

In this work, latest seasonal variation of aerosol, particulate matter and ozone in Delhi has been studied. Observations show that during winter, concentration of surface O3 is low and that of PM2.5 and PM10 is high. Aerosol size and aerosol content increases during winter. Decrease in surface ozone is explainable by gas phase and heterogeneous chemistry.  An interesting feature is, along with surface ozone, total ozone also shows a low value during winter. This is a characteristic of ozone in Indo-Gangetic plain. Indo-Gangetic plain is covered by mild to heavy fog during most of the days in winter. It is possible that increase in size and content of aerosol and PM particles coupled with low temperature, low solar flux and high humidity is the cause of fog formation during winter in Indo-Gangetic plain.

Feeding ecology of two megrims Lepidorhombus boscii and Lepidorhombus whiffiagonis in the western Mediterranean (Gulf of Valencia, Spain)

1999 ◽  
Vol 79 (1) ◽  
pp. 161-169 ◽  
Author(s):  
Salomé Morte ◽  
Manuel J. Redón ◽  
Antonio Sanz-Brau
Keyword(s):  
Seasonal Variation ◽  
Species Composition ◽  
Feeding Ecology ◽  
Stomach Contents ◽  
Western Mediterranean ◽  
Eastern Coast ◽  
Dietary Overlap ◽  
Main Food ◽  
Food Consumed

The stomach contents of 344 four-spotted megrim, (Lepidorhombus boscii) and 159 megrim (Lepidorhombus whiffiagonis), off the eastern coast of the Gulf of Valencia (Spain), were analysed. The two species examined do not appear to have very similar diets, based on the species composition of prey. The vacuity coefficient is not high for any of the species, the main food being Crustacea (Decapoda and Mysidacea). Also Amphipoda and Teleostei are components of the diet. Variations in the food of both fish related to their length show few small crustaceans as prey of the major specimens. Finally, there was evidence for seasonal variation of the quality and quantity of the food consumed. There was no great dietary overlap between these two species.

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