scholarly journals Deforestation May Trigger Black-and-Chestnut Eagle (Spizaetus isidori) Predation on Domestic Fowl

2019 ◽  
Vol 12 ◽  
pp. 194008291983183 ◽  
Author(s):  
Juan Sebastián Restrepo-Cardona ◽  
César Márquez ◽  
María Ángela Echeverry-Galvis ◽  
Félix Hernán Vargas ◽  
Diana M. Sánchez-Bellaizá ◽  
...  
Keyword(s):  
Domestic Fowl ◽  
Forest Cover ◽  
Landscape Management ◽  
Domestic Animals ◽  
Educational Programs ◽  
Birds Of Prey ◽  
Total Biomass ◽  
Management Tools ◽  
Important Prey ◽  
Prey Items

In anthropogenically transformed habitats, some birds of prey feed on domestic animals, triggering conflict between people and predators. To manage this conflict, it is important to understand the ecological circumstances associated with the predation of domestic animals. We studied variation in the diet of the endangered Black-and-chestnut Eagle ( Spizaetus isidori) in four different Andean landscapes in Colombia. We analyzed 261 prey items brought to five S. isidori nests during the period when the nestlings were being raised. Domestic fowl are relatively frequent prey in the diet of S. isidori in three of the four localities studied (frequency: 9.3%–36%), representing 12.2% to 37.1% of the total biomass of prey consumed. In terms of biomass, in Ciudad Bolívar, Jardín, and Campohermoso, the sites with the greatest forest cover, mammals were the most important prey in the diet of S. isidori, while in Gachalá, the most deforested site, domestic fowl were the most important prey. We recommend that forest cover be maintained and increased to provide habitat for wild prey in the breeding territories of S. isidori using the landscape management tools best suited to the specific socioecological contexts of this eagle’s territories. We also suggest that the management of domestic fowl under controlled conditions or the use of some deterrent be examined as strategies to mitigate or prevent conflict between people and S. isidori. Socioecological research and educational programs should be carried out to increase the public’s understanding of this eagle and its benefits to the ecosystem.

scholarly journals Diet composition of the Pharaoh Eagle Owl, Bubo ascalaphus (Strigiformes, Strigidae) in a Steppe region of Algeria

2021 ◽  
Vol 29 (2) ◽  
pp. 177-182
Author(s):  
Naceur Benamor ◽  
Toufik Guetouache ◽  
Farid Bounaceur
Keyword(s):  
Diet Composition ◽  
Bird Species ◽  
Total Biomass ◽  
Food Items ◽  
Important Prey ◽  
Steppe Region ◽  
Eagle Owl ◽  
Western Algeria ◽  
North Western ◽  
Prey Items

Abstract The diet composition of Pharaoh Eagle Owl (Bubo ascalaphus) was investigated in a semiarid area of North-western Algeria. A total of 65 pellets regurgitated by the B. ascalaphus were analysed, 288 food items were composed primarily of mammal remains (4 rodents, 1 bat and insectivore, 93.7%), and 1 bird species (passerine, 6.3%). The most frequent prey among the mammals were rodents (83.3%), which included Mus musculus (59.7%), Meriones shawi (11.1%), Meriones libycus (11.1%) and Jaculus jaculus (1.4%). The rodents were the most important prey items in biomass (91.4%), M. shawi made up to 41.9% of the total biomass. We may conclude that the Pharaoh Eagle Owl relies, in its feeding, very broadly on small mammals, completed by other groups.

scholarly journals Density dynamics, diet composition and productivity of sparrowhawk Accipiter nisus L. population in central Poland

2018 ◽  
Vol 79 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Jakub Gryz ◽  
Dagny Krauze-Gryz
Keyword(s):  
Columba Livia ◽  
Average Height ◽  
Total Biomass ◽  
Important Prey ◽  
Accipiter Nisus ◽  
Nesting Sites ◽  
Forest Mosaic ◽  
Term Monitoring ◽  
Prey Items

Abstract Long-term monitoring of raptor populations can serve as a proxy for the evaluation of whole ecosystem health. The aim of the study was to compare the current abundance of the sparrowhawk Accipiter nisus L. with data from past decades. Additionally, we examined the diet of this species in the breeding season and recorded the number of fledglings. The study area encompassed 105 km2 of field and forest mosaic, located in the vicinity of the Rogów village (51°49'17,98''N, 19°53'54,5''E). Forests covered approximately 24% of the area and formed eight individual complexes ranging in size from 65 ha to 1000 ha. In the years 2011–2017, an average of 20.1 sparrowhawk pairs were recorded resulting in a population density of 19.1 pairs per 100 km2 of total area and 8.2/10 km2 of forested area. This is an increase of 26% compared to the years 2001–2003, when only 16 pairs nested in the same study area. Each successful pair of sparrowhawk produced between one and five fledglings with the average being 3.4. Larch Larix spp. and Scots pine Pinus sylvestris L. dominated as nesting trees accounting for 36.9 and 35.9% of nesting sites respectively. The average age of the nesting trees was 31 years and nests were built at an average height of 11.7 m. The sparrowhawk diet was dominated by birds, which amounted to 81.5% of prey items and over 95% of the consumed biomass. Among the birds identified to the species level, the domestic pigeon Columba livia f. domestica Gm. constituted the biggest share in biomass. Further important prey items were starling Sturnus vulgaris L., with 5.6% of prey items and 9.8% of the total biomass, and hawfinch Coccothraustes coccothraustes (L.), with 6.3% of prey items and 7.6% of the total biomass. Sparrowhawks also consumed significant numbers of thrush Turdus spp. that formed in total over 11% of the total consumed biomass. It would appear that the observed population growth was a result of prohibited persecution and the ban on DDT usage in agriculture.

scholarly journals Food Deliveries at Swallow-Tailed Kite Nests in Southern Florida

The Condor ◽  
2004 ◽  
Vol 106 (1) ◽  
pp. 171-176 ◽  
Author(s):  
Kenneth D. Meyer ◽  
Steven M. McGehee ◽  
Michael W. Collopy
Keyword(s):  
United States ◽  
The United States ◽  
Total Biomass ◽  
Incubation Stage ◽  
La Florida ◽  
Southern Florida ◽  
Insect Biomass ◽  
Prey Items

Abstract We studied the diets of nesting Swallow-tailed Kites (Elanoides forficatus) at eight nests in 1988–1989 in southern Florida, where the species reaches its greatest abundance in the United States. Males fed females during the incubation stage an average of 2.1 ± 0.8 times per day. The adults averaged 10.9 ± 4.5 deliveries daily during the nestling stage, and 10.3 ± 12.5 deliveries to young daily following nest departure. Vertebrates comprised 97% of the biomass for the 1092 identifiable prey items delivered to nests. Frogs accounted for 56%, birds 30%, and reptiles 11% of all prey. Numerically, frogs made up 83% of the reptile and amphibian prey. The relative proportions of prey types varied substantially among nests within years, and significantly more snakes and insects were delivered in 1989. Total biomass delivered in 1988 did not differ from that in 1989. Bird biomass, however, was greater in 1988 and insect biomass was greater in 1989. Anoles and snakes were brought to nests in larger numbers during the morning and evening hours; and birds were delivered mainly from midmorning to midafternoon. Entregas de Alimentos en Nidos de Elanoides forficatus en el Sur de Florida Resumen. Durante 1988 y 1989 estudiamos la dieta de los polluelos de Elanoides forficatus en ocho nidos localizados en el sur de la Florida, donde la especie alcanza su mayor abundancia de nidificacion dentro de los Estados Unidos. Durante la incubación, los machos alimentaron a las hembras un promedio de 2.1 ± 0.8 veces por día. Durante la etapa de polluelos, los adultos hicieron un promedio de 10.9 ± 4.5 entregas diarias y un promedio de 10.3 ± 12.5 entregas diarias después de abandonar el nido. Los vertebrados comprendieron el 97% de la biomasa de las 1092 presas identificables entregadas en los nidos. Las ranas constituyeron el 56%, las aves el 30% y los reptiles el 11% del total de las presas. Numéricamente, las ranas constituyeron el 83% de la herpetofauna depredada. Las proporciones relativas de los tipos de presa variaron substancialmente entre los nidos a través de los años, y considerablemente más serpientes e insectos fueron entregados en 1989. La biomasa total entregada durante 1988 no difirió de la observada en 1989. Sin embargo, la biomasa de las aves fue mayor en 1988, mientras que la de los insectos fue mayor en 1989. Las lagartijas y serpientes fueron entregadas a los nidos en mayor cantidad durante las horas de la mañana y de la tarde, mientras que las aves fueron entregadas principalmente desde la mitad de la mañana hasta la mitad de la tarde.

Trophic ecology of large pelagic fish in the Saint Peter and Saint Paul Archipelago, Brazil

2019 ◽  
Vol 70 (10) ◽  
pp. 1402 ◽  
Author(s):  
F. V. Albuquerque ◽  
A. F. Navia ◽  
T. Vaske ◽  
O. Crespo ◽  
F. H. V. Hazin
Keyword(s):  
Trophic Ecology ◽  
Feeding Habits ◽  
Saint Paul ◽  
Pelagic Fish ◽  
Trophic Niche ◽  
Trophic Relationships ◽  
Main Prey ◽  
Important Prey ◽  
Saint Peter ◽  
Prey Items

Trophic relationships of large pelagic predators can determine the structure and dynamics of oceanic food webs. The feeding habits and trophic ecology of five large pelagic fish (Acanthocybium solandri, Coryphaena hippurus, Elagatis bipinnulata, Thunnus albacares and Thunnus atlanticus) in the Saint Peter and Saint Paul Archipelago were evaluated to determine whether there is a trophic-niche overlap or resource partitioning among them. Eighty prey items found in 1528 stomachs were identified and grouped into Cephalopoda, Cnidaria, Crustacea, Gastropoda, Teleostei and Tunicata. Exocoetidae and Scombridae were the main prey in the diet of Acanthocybium solandri. In C. hippurus, Cheilopogon cyanopterus and Exocoetus volitans were the most important prey items, whereas C. cyanopterus was the main prey for T. albacares. Thunnus atlanticus consumed a great proportion of invertebrate species, with shrimps of Sergestidae family being particularly important. The gastropod Cavolinia sp. was the most important prey for E. bipinnulata. The five species had a high trophic specialisation and a high trophic level (>4.4), whereas most dietary overlaps were consistently low. The most important factor for diet dissimilarity was the consumption of Exocoetidade. All species were classified as top predators with varied diets, indicating their structural and functional importance in the food web of the Archipelago.

Population diet variation and individual specialization in the poison toad, Melanophryniscus rubriventris (Vellard, 1947)

2011 ◽  
Vol 32 (2) ◽  
pp. 261-265 ◽  
Author(s):  
María Fernanda Quiroga ◽  
Marcos Vaira ◽  
Maria Ines Bonansea
Keyword(s):  
Entire Range ◽  
Diet Composition ◽  
Foraging Strategies ◽  
Future Research ◽  
Individual Specialization ◽  
Generalist Species ◽  
Defensive Strategies ◽  
Important Prey ◽  
Diet Variation ◽  
Prey Items

AbstractFew studies have investigated the level of individual variation in diet composition of poisonous frogs and toads. We compare the diet composition of three populations of a poisonous toad, Melanophryniscus rubriventris, and predicted that toads within a population might be constrained to forage on particular types of alkaloid-containing prey and consequently diets among populations might not diverge from each other. Most important prey categories in the diets of the three populations consisted of the same ground-dwelling arthropods. We found evidence for individuals consuming different arrays of prey types in all populations implying that this “generalist” species is actually comprised of individuals eating different sets of the available range of prey. Formicidae, Acari, and Coleoptera were all important alkaloid-containing prey items in the diets of all populations and individuals, although there were differences in their order of importance among populations and individuals use different sets of the entire range of alkaloid-containing preys. Future research should evaluate individual diet variation in other poisonous anurans taxa given that shifts in diet composition might have important implications for understanding the consequences of alternate foraging strategies in the evolution of defensive strategies among species.

scholarly journals Trophic ecology and foraging behavior of Tropidurus hispidus and Tropidurus semitaeniatus (Squamata, Tropiduridae) in a caatinga area of northeastern Brazil

2011 ◽  
Vol 101 (3) ◽  
pp. 225-232 ◽  
Author(s):  
Leonardo B. Ribeiro ◽  
Eliza M. X. Freire
Keyword(s):  
Foraging Behavior ◽  
Diet Composition ◽  
Trophic Ecology ◽  
Dry Season ◽  
Northeastern Brazil ◽  
Wet Season ◽  
Lizard Species ◽  
Important Prey ◽  
Lepidopteran Larvae ◽  
Prey Items

This study aimed to analyze the seasonal variation in diet composition and foraging behavior of Tropidurus hispidus (Spix, 1825) and T. semitaeniatus (Spix, 1825), as well as measurement of the foraging intensity (number of moves, time spent stationary, distance traveled and number of attacks on prey items) in a caatinga patch on the state of Rio Grande do Norte, Brazil. Hymenoptera/Formicidae and Isoptera predominated in the diet of both species during the dry season. Opportunistic predation on lepidopteran larvae, coleopteran larvae and adults, and orthopteran nymphs and adults occurred in the wet season; however, hymenopterans/Formicidae were the most important prey items. The number of food items was similar between lizard species in both seasons; however the overlap for number of prey was smaller in the wet season. Preys ingested by T. hispidus during the wet season were also larger than those consumed by T. semitaeniatus. Seasonal comparisons of foraging intensity between the two species differed, mainly in the wet season, when T. hispidus exhibited less movement and fewer attacks on prey, and more time spent stationary if compared to T. semitaeniatus. Although both lizards are sit-and-wait foragers, T. semitaeniatus is more active than T. hispidus. The diet and foraging behavior of T. hispidus and T. semitaeniatus overlap under limiting conditions during the dry season, and are segregative factors that may contribute to the coexistence of these species in the wet season.

Feeding habits of the sandskate Psammobatis extenta (Garman, 1913): sources of variation in dietary composition

2005 ◽  
Vol 56 (4) ◽  
pp. 395 ◽  
Author(s):  
J. Matías Braccini ◽  
Jorge E. Perez
Keyword(s):  
Feeding Habits ◽  
Seasonal Pattern ◽  
Seasonal Patterns ◽  
Dietary Composition ◽  
Important Prey ◽  
Eastern Brazil ◽  
Prey Diversity ◽  
Sources Of Variation ◽  
Males And Females ◽  
Prey Items

Understanding the variation in the diet of skates is crucial for determining their roles in marine ecosystems. The diet of 458 sandskates, Psammobatis extenta, from Puerto Quequén, Argentina was quantified to determine whether there was geographical, sexual, ontogenetic, and/or seasonal variation in dietary composition. Cumulative prey-diversity curves reached a stable level at ~30 stomachs and thus the sample size was large enough to describe the overall diet of the sandskate. The diet comprised a variety of small invertebrates, suggesting that the sandskate is a secondary consumer (trophic level of 3.5). The most important prey items were gammarids, shrimps and, to a lesser extent, polychaete worms. A significant correlation was found between the diets of sandskates from south-eastern Brazil and Puerto Quequén, suggesting that in both locations they used similar resources and would have similar ecological roles. No difference was found between the diets of males and females, but ontogenetic and seasonal patterns were detected. Small sandskates preyed largely on gammarids and shrimps but consumed fewer polychaetes and brachyurans than larger individuals. In summer and winter, the most important prey item by number was gammarids, whereas the consumption of shrimps peaked in autumn. This ontogenetic and seasonal pattern indicates that large and small sandskates are versatile predators that can shift their diets in response to prey abundance.

scholarly journals Diet of Chiasmocleis cordeiroi Caramaschi and Pimenta, 2003 from the Atlantic Rainforest in southern Bahia, Brazil

2020 ◽  
Vol 30 (30) ◽  
pp. 52-56
Author(s):  
Indira Maria Castro ◽  
Caio Vinícius de Mira-Mendes ◽  
Mirco Solé
Keyword(s):  
Atlantic Forest ◽  
Stomach Contents ◽  
Foraging Strategy ◽  
The State ◽  
Atlantic Rainforest ◽  
Prey Category ◽  
Taxonomic Level ◽  
Important Prey ◽  
Southern Bahia ◽  
Prey Items

We studied the diet of a Chiasmocleis cordeiroi population in a fragment of the Atlantic Forest in the state of Bahia, Brazil. Frogs were collected at night after an explosive breeding event and were transferred to the lab where they were measured, weighed and had their stomach contents retrieved following a stomach flushing protocol. Individuals were later released back into the pond from which they had been collected. Stomach contents were measured and identified to the lowest possible taxonomic level. The most important prey category in the diet of C. cordeiroi was Hymenoptera (Formicidae), as has been already observed for other microhylids. The large number of prey items in the stomach and the low niche amplitude suggest that C. cordeiroi is a specialist using an active foraging strategy to detect its prey.

Striped marlin (Kajikia audax) diet variability off Cabo San Lucas, B.C.S., Mexico during El Niño–La Niña events

2017 ◽  
Vol 98 (6) ◽  
pp. 1513-1524 ◽  
Author(s):  
Sofía Ortega Garcia ◽  
Dana I. Arizmendi-Rodríguez ◽  
Marcela S. Zúñiga-Flores
Keyword(s):  
Annual Variation ◽  
Stomach Contents ◽  
Diet Breadth ◽  
Dosidicus Gigas ◽  
Important Prey ◽  
Jumbo Squid ◽  
Diet Variability ◽  
Analysis Of Similarity ◽  
Index Of Relative Importance ◽  
Prey Items

The stomach contents of 1261 striped marlins caught from 2007 to 2010 by the sport-fishing fleet of Cabo San Lucas, Baja California Sur, Mexico, were analysed, taking into account sea surface temperatures estimated using satellite images of the study area and the Oceanic Niño Index (ONI). The analysis allowed the identification of three anomalously cold periods during 2007, 2008 and 2010 and a warm period in 2009. The stomach content results showed 89 different prey items eaten during the study period. Of the specimens captured, 868 (69%) stomachs contained food items. The most important prey items were cephalopods (Dosidicus gigas and Argonauta spp.) and fish (Scomber japonicus, Selar crumenophthalmus and Sardinops caeruleus). Despite having a broad trophic spectrum, the striped marlin was classified as a specialist consumer, with Bi = 0.03. Based on the diet breadth value and the prey-specific index of relative importance (PSIRI), the jumbo squid, D. gigas, was the main prey species, coinciding with cold periods. On the other hand, the fishes S. caeruleus and S. japonicus showed the highest PSIRI values during the 2009 warm anomalies. Analysis of similarity showed the formation of four groups in relation to PSIRI values. According to a non-metric multidimensional scaling ordination, these groups were formed with a similarity of 30% and a stress of 0.17. These results demonstrate inter-annual variation in the diet as well as in the availability and abundance of prey items.

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