scholarly journals Dietary composition of birds species at an inland airport in South Africa

2002 ◽  
Vol 21 (1) ◽  
pp. 16-18
Author(s):  
A. C. Kok ◽  
O. B. Kok
Keyword(s):  
Bird Species ◽  
Stomach Contents ◽  
Total Sample ◽  
Dry Mass ◽  
Food Sources ◽  
Mass Composition ◽  
Potential Threat ◽  
Important Prey ◽  
Lesser Kestrel ◽  
Main Food Source

Stomach contents of 51 bird species that posed a potential threat to aviation were collected at the Bloemfontein airport over a period of 11 years (1985-1995). Numerically the crowned plover (Vanellus coronatus), and the lesser kestrel (Falco naumanni), blacksmith plover (V. armatus), whitewinged korhaan (Eupodotis afraoides), doublebanded courser (Smutsornis africanus), spotted dikkop (Burhinus capensis), cattle egret (Bubulcus ibis), Swainson’s francolin (Francolinus swainsonii) and Orange River francolin (F. levaillantoides) in sequence of importance, constituted 91,0% of the total sample (3 544). In general insects can be considered the main food source of the birds concerned. Based on dry mass composition the Isoptera, followed by the Coleoptera and Orthoptera, constituted the most important component in the diet. The Isoptera, more specifically the harvester termite (Hodotermes mossambicus), is, moreover, the only important prey taxon showing a conspicuous utilisation peak during the relative food shortage of the dry season. Evidently, temporary superabundant food sources that periodically come about in grassland habitats are opportunistically utilised by the birds.

Food sources of common dolphinfish (Coryphaena hippurus) based on stomach content and stable isotopes analyses

2014 ◽  
Vol 95 (3) ◽  
pp. 579-591 ◽  
Author(s):  
A. Tripp-Valdez ◽  
F. Galván-Magaña ◽  
S. Ortega-García
Keyword(s):  
Stable Isotope ◽  
Stomach Content ◽  
Gulf Of California ◽  
Stomach Contents ◽  
Isotopic Analysis ◽  
Stomach Content Analysis ◽  
Food Sources ◽  
Important Prey ◽  
Opportunistic Predator ◽  
Ecological Importance

Dolphinfish (Mahimahi) are a high-demand resource for sport and coastal fisheries, mainly in the Pacific Ocean. Due to their economic and ecological importance, studies of their biology are very important to understand their function in ecosystems. We used stable isotope and stomach content analyses to determine the most important prey of the common dolphinfish, as well as the trophic level of this species in two areas of the southern Gulf of California. Stomach contents of 445 specimens were analysed. Using both techniques, we found that the most important prey for dolphinfish in the southern Gulf of California were three invertebrate species followed by fish. This contrasts with results from other authors who found that this species was mainly piscivorous in other locations. Stomach content analysis indicated differences in prey biomass by area, season and size class. The isotopic analysis did not show significant differences between seasons or sexes. Both stomach contents and stable isotope analyses showed that although this predator consumed a wide prey spectrum, only a few prey items made up the bulk of the diet, which resulted in a low SD in δ15N values and low Levin's index values. We conclude that this fish is an opportunistic predator that may consume a wide prey spectrum, but that it mainly consumes prey that are abundant in the area, such as crustaceans and cephalopods in the Gulf of California.

scholarly journals Changes in prey importance and prey niche overlap of sexes during the alpine newt breeding season

2020 ◽  
Vol 146 (2) ◽  
Author(s):  
Oldřich Kopecký
Keyword(s):  
Breeding Season ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Sexual Differences ◽  
Food Sources ◽  
Quantitative Composition ◽  
Important Prey ◽  
Alpine Newt ◽  
Prey Items

Urodeles, including European newts, are usually sexually dimorphic predators. Among newts, the alpine newt has the most pronounced sexual size dimorphism (in favour of females). Gender is a factor that is often associated with intra-specific diet differences. Despite the significant number of dietary studies on the alpine newt, some topics such as the breadth of the trophic niche and its overlap between sexes, or inter-sexual differences in qualitative and quantitative composition of prey remain unresolved. The present study dealing with these questions was conducted at two localities (ponds at an elevation of about 450 m) in the Czech Republic. Newts were captured from the banks during the entire breeding season using a dip net, and the stomach contents were extracted using a stomach flushing technique. Altogether 190 individuals were sampled, and a total of 1,417 prey items were obtained. The available food sources differed over the course of the breeding season, as newts changed the taxa they preyed on. This reflects the ability of newts to switch between several hunting strategies. The overall food niche overlap between the sexes was relatively large (C = 0.761, resp. C = 0.797). Inter-sexual differences were detected at both localities, mainly in the number of prey items consumed from the most important prey categories such as Rana eggs or Isopoda, which were consumed in higher numbers by females. The findings of this study suggest that females are more sensitive to the trade-off between energy intake and expenditure during the breeding season.

Dietary composition of cattle egrets (Bubulcus ibis) in the central Free State

2004 ◽  
Vol 23 (4) ◽  
pp. 90-98
Author(s):  
H. J.B. Butler
Keyword(s):  
Significant Contribution ◽  
Stomach Contents ◽  
Dry Mass ◽  
Free State ◽  
Food Sources ◽  
Frequency Of Occurrence ◽  
Adult Cattle ◽  
Bubulcus Ibis ◽  
Almost All ◽  
Prey Items

Analysis of 152 stomach samples of adult cattle egrets (Bubulcus ibis) collected over a period of five years in the central Free State showed this species to be mainly insectivorous. The Insecta, occuring in almost all stomach samples, are represented by prey items from 13 orders of which the Orthoptera, followed by the Coleoptera, Isoptera, Diptera and Lepidoptera, showed the highest frequency of occurrence. Amongst the non-insect invertebrates, the Araneae and Solifugae occured most frequently. Based on dry mass the Orthoptera and Isoptera constitute by far the most important components. Prey items of vertebrates combined represent only ca. 10% of the diet. Overall, the stomach contents of 75 chicks correspond with that of the adults, except that vertebrates make a significant contribution to the diet during the first week of the nesting phase. In general cattle egrets can be considered opportunistic feeders that concentrate on easily obtainable food sources which become sporadically available (partly because of their regular association with mammalian hosts).

scholarly journals Prey, management and landscape requirements of an endangered population of the Woodlark Lullula arborea in Southwest Germany

2021 ◽  
Author(s):  
Verena Rösch ◽  
Pascal Aloisio ◽  
Martin H. Entling
Keyword(s):  
Food Resource ◽  
Bird Species ◽  
Ground Cover ◽  
Main Food ◽  
Vegetation Height ◽  
Endangered Population ◽  
Rhine Valley ◽  
Territory Selection ◽  
Main Food Source ◽  
Upper Rhine

AbstractVineyards can be valuable habitats for biodiversity conservation. For example, in Rhineland-Palatinate (Germany) over a third of the state’s critically endangered Woodlark (Lullula arborea) population breeds in vineyards along the western margin of the Upper Rhine Valley. We here aim to elucidate how local ground cover management, food availability and the proximity to settlements affect territory selection by this bird species in the region. As climate, site conditions and management differ greatly from more continental or Mediterranean wine-growing areas, conditions for Woodlark conservation may differ as well.We compared 26 Woodlark territories in vineyards with 26 nearby reference areas from which Woodlarks were absent. We recorded vineyard ground cover in the inter-rows (% cover) as well as vegetation height and composition (forbs vs. grasses). Arthropods were sampled using pitfall traps, since they are the main food resource of Woodlarks during the breeding season. In addition, the distance to built-up areas was measured. The vegetation in Woodlark territories was shorter (mean 14.2 vs. 19.6 cm) and more dominated by forbs (39% vs. 27% cover) than in absence areas. The vegetation cover in the inter-rows had no effect on Woodlark territory presence or absence. Woodlarks also favoured areas with a higher abundance of arthropods (mean abundance 69.1 vs. 57.5) and a greater distance to built-up areas (mean distance 554 vs. 373 m). We conclude that to promote the Woodlark in wine-growing areas, short, forb-rich swards should be created, facilitating arthropod detectability. This is likely to require low levels of nitrogen fertilization since fertilizers favour tall-growing grasses that outcompete forbs. Pesticide applications should be kept at a minimum to enhance arthropods as the main food source for Woodlarks and their chicks. In addition, the expansion of settlements into breeding areas of Woodlarks should be avoided.

Summer foods of Atlantic walrus, Odobenus rosmarus rosmarus, in northern Foxe Basin, Northwest Territories

1997 ◽  
Vol 75 (7) ◽  
pp. 1166-1175 ◽  
Author(s):  
K. I. Fisher ◽  
R. E. A. Stewart
Keyword(s):  
Benthic Invertebrates ◽  
Stomach Contents ◽  
Male And Female ◽  
Foxe Basin ◽  
Important Prey ◽  
Odobenus Rosmarus ◽  
Serripes Groenlandicus ◽  
Gross Energy ◽  
Odobenus Rosmarus Rosmarus ◽  
Atlantic Walrus

Stomach contents of Atlantic walrus, Odobenus rosmarus rosmarus, taken by Inuit hunters in northern Foxe Basin in July 1987 and 1988 (n = 105) and September 1988 (n = 2) were examined. In July, 20 of 94 stomachs from immature and adult walrus contained > 5 g of food representing 17 prey taxa, including bivalves, gastropods, holothurians, polychaetes, and brachiopods. The bivalve Mya truncata contributed 81.4% of the total gross energy in the diet, with the bivalve Hiatella arctica, holothurians, and the polychaete Nereis sp. contributing 7.5, 3.5, and 2.8%, respectively. The diets of male and female walrus were similar except that females received a significantly (P < 0.05) greater percentage of gross energy in their diet from H. arctica than did males. Walrus less than 3 years old (n = 11) consumed mostly milk, although some benthic invertebrates were eaten. Analysis of the contents of two stomachs collected in September suggested that walrus may feed more intensively in the fall. Mya truncata was again the predominant prey, contributing 59.9% of total gross energy, with the bivalve Serripes groenlandicus (37.9%) replacing H. arctica (0.3%) as the second most important prey.

Production and Biomass of Pokea Clam (Batissa violacea var. celebensis von Martens, 1897) in the Langkumbe River Waters North Buton Southeast Sulawesi

2021 ◽  
Vol 5 (1) ◽  
pp. 14-24
Author(s):  
Tri Abdul Rahman ◽  
Bahtiar Bahtiar ◽  
Pramono Hery Santoso
Keyword(s):  
Sampling Method ◽  
Total Sample ◽  
Dry Mass ◽  
Annual Production ◽  
Fishing Gear ◽  
River Waters ◽  
The People ◽  
Length Width ◽  
Traditional Fishing ◽  
Swept Area

Langkumbe River is located in West Kulisusu District and has long been used by the community for various daily activities. One of the resources often used by the people around Langkumbe River is pokea clams. The aim of this study was to determine the production and biomass of pokea clams (B. violacea) in Langkumbe River Waters of North Buton Regency from August to October 2017. The sampling method used was swept area method using a traditional fishing gear "Tangge" (fishing gear). The samples were measured for the length, width and thickness.  The total weight was measured with the clam/total mass (MT) and the weight of the meat. The samples were dried using an oven for 24 hours at 70 °C to obtain the shell-free dry mass (SFDW). Data were analyzed using standard formulas. The total sample obtained was 1.307 individuals. The highest density of pokea clam was found in August at 596.8 ind/m². Annual production of pokea clam (B. violacea) in Langkumbe River with a total annual production of 1,107.33 gSFDW/m2/year. The highest and lowest production are 297.09 gSFDW/m²/year at size 2.19-2.54cm and -0.16 gSFDW /m²/year at size 4.70-5.05cm, respectively. The total population biomass was 528.03 gSFDW/m2 with the highest biomass 171.72 gSFDW/m²/year at size 2.55-2.90 cm and the lowest was 1.40 gSFDW /m²/year at size 4.70-5.05 cm, so that the recovery rate (P/B ratio) was 2.1 gSFDW/m2/year.

scholarly journals Prey consumed by Guiana dolphin Sotalia guianensis (Cetacea, Delphinidae) and franciscana dolphin Pontoporia blainvillei (Cetacea, Pontoporiidae) in an estuarine environment in southern Brazil

2012 ◽  
Vol 102 (2) ◽  
pp. 131-137 ◽  
Author(s):  
Marta J. Cremer ◽  
Pedro C. Pinheiro ◽  
Paulo C. Simões-Lopes
Keyword(s):  
Prey Species ◽  
Stomach Contents ◽  
Frequency Of Occurrence ◽  
Teleost Fishes ◽  
Southern Brazil ◽  
Sympatric Populations ◽  
Sotalia Guianensis ◽  
Important Prey ◽  
Pontoporia Blainvillei ◽  
Lolliguncula Brevis

The present study provides information about the diet of sympatric populations of small cetaceans in the Babitonga Bay estuary. This is the first study on the diet of these species in direct sympatry. The stomach contents of seven Guiana dolphins Sotalia guianensis and eight franciscanas Pontoporia blainvillei were analyzed. The prey of both cetaceans was mostly teleost fishes, followed by cephalopods. We identified 13 teleost fishes as part of the diet of the franciscanas, and 20 as part of the diet of Guiana dolphins. Lolliguncula brevis was the only cephalopod recorded, and was the most important prey for both cetaceans. Stellifer rastrifer and Gobionellus oceanicus were also important for franciscana, so as Mugil curema and Micropogonias furnieri were important for Guiana dolphins. Stellifer rastrifer and Cetengraulis edentulus were the fishes with the highest frequency of occurrence for franciscana (50%), while Achirus lineatus, C. edentulus, S. brasiliensis, Cynoscion leiarchus, M. furnieri, M. curema, Diapterus rhombeus, Eugerres brasilianus and G. oceanicus showed 28.6% of frequency of occurrence for Guiana dolphins. Franciscanas captured greater cephalopods than the Guiana dolphins in both total length (z= -3.38; n= 40; p< 0.05) and biomass (z = -2.46; n = 40; p<0.05). All of the prey species identified occur inside the estuary, which represents a safe habitat against predators and food availability, reinforcing the importance of the Babitonga Bay for these cetacean populations.

scholarly journals Food Habits and Diet Relationship in the Redbelly Tilapia (Tilapia zillii) and Guenther’s Mouthbrooder (Chromidotilapia guntheri) from an Abandoned Gold Mine Reservoir, Southwestern Nigeria

2018 ◽  
Vol 10 (2) ◽  
pp. 148-155
Author(s):  
Olusola Olaniyi KOMOLAFE ◽  
Timothy Olalekan AMOO ◽  
Michael Olufemi AWODIRAN
Keyword(s):  
Feeding Habits ◽  
Stomach Contents ◽  
Food Sources ◽  
Gold Mine ◽  
Southwestern Nigeria ◽  
Food Items ◽  
Tilapia Zillii ◽  
Gill Net ◽  
Food And Feeding ◽  
Index Value

The food and feeding habits of the redbelly Tilapia (Tilapia zillii) and Guenther’s mouthbrooder (Chromidotilapia guntheri) were investigated in an abandoned gold mine reservoir at Igun from June 2013 to May 2014. Using a cast net and gill-net fishing gears, 370 fish individuals were caught and their stomach contents were analysed by using the frequency of occurrence and numerical methods. Tilapia zillii comprised 53.78% (199 individuals), while Chromidotilapia guntheri covered up the remaining percentage (46.22%) which is made up of 171 individuals. Food items in the stomachs of T. zillii individuals predominantly consisted of detritus, mud and algae (77.97%), while those in C. guntheri individuals mostly consisted fish remains, detritus and algae (81.67%). T. zillii exploited more food items (23 of 27) as compared to C. guntheri (17 of 27). The Schoener’s index value for the species was 0.65. The study showed that T. zillii and C. guntheri exhibited benthopelagic exploitation and are mainly herbivorous and omnivorous respectively based on the food items observed in the stomach contents of these species. The fish species fed on related food items as confirmed by Schoener’s overlap index (0.65), suggesting that there was overlap in the dietary requirements of the two species. This index value, however, was probably not an indication of competition for food between these two species because they exploited abundant food sources.

The Diet of American Robins: An Analysis of U.S. Biological Survey Records

The Auk ◽  
1986 ◽  
Vol 103 (4) ◽  
pp. 710-725 ◽  
Author(s):  
Nathaniel T. Wheelwright
Keyword(s):  
Quantitative Description ◽  
Geographical Location ◽  
Bird Species ◽  
Stomach Contents ◽  
Time Of Day ◽  
Food Items ◽  
Biological Survey ◽  
American Robins ◽  
Differential Digestion ◽  
The U.S

Abstract I present a quantitative description of the diet of American Robins (Turdus migratorius) and consider how food habits (particularly the proportion of fruit eaten and the diversity of individual meals) are influenced by season, habitat, sex, and time of day. The study is based on an analysis of records of stomach contents compiled by the U.S. Biological Survey and the U.S. Fish and Wildlife Service. Across their entire range, robins ate fruits representing over 50 genera and invertebrates representing over 100 families. Diets were diverse even within local regions, and there was no obvious single feeding niche. The major food classes, consumed in every combination, were soft-bodied invertebrates, hard-bodied invertebrates, and fruits. The same taxa (especially fruits of the family Rosaceae and invertebrates of the orders Coleoptera and Lepidoptera) predominated in robins' diets, irrespective of habitat or geographical location, which presumably reflects both selective foraging and the availability of these widespread taxa. The proportion of fruit (by volume) in the diet was much higher in the fall and winter (median values >90%) than in the spring (<10%); summer values were intermediate. The transition from a diet dominated by invertebrates to a diet dominated by fruits occurred over a 1-2-month period. The number of distinct food items in stomachs, a measure of the species diversity of individual meals, was positively correlated with the fraction of invertebrates in the diet. Thus, at the time of year when robins were dependent on fruits for food, the diversity of their meals was also lowest. The degree of fullness of the stomach showed few consistent trends with season or habitat. Despite different sex roles and nutritional requirements, male and female robins did not differ in the proportion of fruit in the diet in any month or in any region. Nor did their stomachs contain different numbers of distinct food items, different amounts of food, or a different range or distribution of prey taxa. Habitat was an important variable explaining dietary differences. The Biological Survey records have unavoidable shortcomings, most notably problems of sampling biases and the inability to correct for differential digestion of food items. Nonetheless, they are a valuable and underused data base for testing hypotheses, generating new questions of ecological interest, and describing in detail the diets of North American bird species.

Diet, feeding behaviour and habitat utilisation of the blue stingray Dasyatis chrysonota (Smith, 1828) in South African waters

2003 ◽  
Vol 54 (8) ◽  
pp. 957 ◽  
Author(s):  
David A. Ebert ◽  
Paul D. Cowley
Keyword(s):  
Surf Zone ◽  
Stomach Contents ◽  
Size Class ◽  
Behaviour Pattern ◽  
Medium Size ◽  
Secondary Importance ◽  
Size Classes ◽  
Important Prey ◽  
Large Size ◽  
Large Size Class

Analysis of stomach contents for Dasyatis chrysonota revealed that diet varied with size and habitat. The diet of all size classes in the surf zone was comprised primarily of Callianassa spp., Donax spp. and unidentified polychaete species. The medium and large size classes fed primarily on Donax spp., whereas the very large size class fed mainly on Callianassa spp. Polychaetes were of secondary importance as prey for the medium size class. The diet of D. chrysonota in the nearshore zone consisted mainly of Balanoglossus capensis and Callianassa spp. Balanoglossus capensis decreased from an index of relative importance (IRI) of 75.3% for the medium size class to 59.9% for the very large size class, whereas Callianassa spp. increased from 22.8% to 39.4% between the medium and the very large size classes. The offshore zone was the only area in which small size class D. chrysonota were caught. The diet of these small D. chrysonota was primarily polychaetes and amphipods. Polychaetes increased in importance in the medium size class, but declined in each successively larger size class. Conversely, Pterygosquilla armata capensis became the single most important prey item for the very large size class, comprising an IRI of 50.9%. The behaviour pattern used by D. chrysonota to locate and extract prey is described.

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