scholarly journals What makes Hemidactylus invasions successful? A case study on the island of Curaçao

2020 ◽  
Author(s):  
April D. Lamb ◽  
Catherine A. Lippi ◽  
Gregory J. Watkins-Colwell ◽  
Andrew Jones ◽  
Dan Warren ◽  
...  
Keyword(s):  
Urban Areas ◽  
Resource Competition ◽  
Food Resource ◽  
Stomach Contents ◽  
Western Hemisphere ◽  
Morphometric Analyses ◽  
Close Proximity ◽  
Reptile Species ◽  
Prey Resources ◽  
Hemidactylus Mabouia

AbstractHemidactylus spp. (House geckos) rank among the most successful invasive reptile species worldwide. Hemidactylus mabouia in particular has become ubiquitous across tropical urban settings in the Western Hemisphere. H. mabouia’s ability to thrive in close proximity to humans has led to the rapid displacement of native geckos in urban areas, however the mechanisms driving this displacement remain understudied. Here we combine data from nitrogen and carbon stable isotopes, stomach contents, and morphometric analyses of traits associated with feeding and locomotion to test alternate hypotheses of displacement between H. mabouia and a native gecko, Phyllodactylus martini, on the island of Curaçao. Consistent with expectations of direct food resource competition, we demonstrate substantial overlap of invertebrate prey resources between the species. Additionally, we found strong evidence from both diet content and stable isotope analyses that H. mabouia acts as a vertebrate predator, preying upon P. martini as well as other native and non-native reptiles. Finally, we show that H. mabouia possesses several morphological advantages, including larger sizes in feeding-associated traits and limb proportions that could offer a propulsive locomotor advantage on vertical surfaces. Together, these findings suggest the successful establishment of H. mabouia likely involves a combination of both exploitative interspecific competition and predation. Given the ubiquity of H. mabouia, illuminating the role of this species as both a competitor and a predator casts new concerns on the ecological and demographic impacts of this widespread urban invader.

scholarly journals Herpetofauna from an urban Pampa fragment in southern Brazil: composition, structure and conservation

Check List ◽  
2016 ◽  
Vol 12 (5) ◽  
pp. 1964
Author(s):  
Omar Machado Entiauspe-Neto ◽  
Tângela Denise Perleberg ◽  
Marco Antonio de Freitas
Keyword(s):  
Natural History ◽  
Urban Areas ◽  
Rio Grande ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Faunal Composition ◽  
Diversity Patterns ◽  
Reptile Species ◽  
History Of ◽  
Composition Structure

Faunistic inventories regarding natural history of amphibians and reptiles are considered scarce and very little is known about their assemblages in urban areas; the Pampas morphoclimatic domain, also known as Uruguayan Savannah or Southern Grasslands, is also poorly known regarding their faunal composition.  Herein, we present a checklist of 16 amphibian and 20 reptile species recorded over a course of four years in the Instituto Federal de Educação, Ciências e Tecnologia, Câmpus Pelotas-Visconde da Graça, in Pelotas, Rio Grande do Sul, Brazil. We also present data on natural history and discuss conservation efforts to be undertaken in the area, in one of the least preserved and known Brazilian morphoclimatic domains, providing insights into urban herpetofaunal diversity patterns and showing the importance of modified areas in its conservation.

scholarly journals Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

2009 ◽  
Vol 7 (4) ◽  
pp. 701-708 ◽  
Author(s):  
Ana Paula Vidotto-Magnoni ◽  
Edmir Daniel Carvalho
Keyword(s):  
Aquatic Insects ◽  
Food Resource ◽  
Gravimetric Method ◽  
Stomach Contents ◽  
Food Resources ◽  
Food Category ◽  
Main Food ◽  
Tietê River ◽  
Two Samples ◽  
Terrestrial Insects

We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples) and Bonito (two samples) between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI). The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera) were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped) indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%), followed by crustaceans (AI = 7.1%). Four trophic guilds were identified according a cluster analysis (Pearson distance): insectivorous (10 species), omnivorous (4 species), detritivorous (3 species) and piscivorous/carcinophagous (3 species). Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb). The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

scholarly journals Mobulid rays feed on euphausiids in the Bohol Sea

2017 ◽  
Vol 4 (5) ◽  
pp. 161060 ◽  
Author(s):  
Christoph A. Rohner ◽  
Katherine B. Burgess ◽  
Joshua M. Rambahiniarison ◽  
Joshua D. Stewart ◽  
Alessandro Ponzo ◽  
...  
Keyword(s):  
Life History ◽  
Food Resource ◽  
Stomach Contents ◽  
Fishing Effort ◽  
Fishing Activity ◽  
Prey Preferences ◽  
Manta Birostris ◽  
History Of ◽  
By Catch ◽  
Mobula Japanica

Mobulid rays have a conservative life history and are caught in direct fisheries and as by-catch. Their subsequent vulnerability to overexploitation has recently been recognized, but fisheries management can be ineffective if it ignores habitat and prey preferences and other trophic interactions of the target species. Here, we assessed the feeding ecology of four mobulids ( Manta birostris , Mobula tarapacana , M. japanica , M. thurstoni ) in the Bohol Sea, Philippines, using stomach contents analysis of fisheries specimens landed between November and May in 2013–2015. We show that the mobulids feed heavily on euphausiid krill while they are in the area for approximately six months of the year. We found almost no trophic separation among the mobulid species, with Euphausia diomedeae as the major prey item for all species, recorded in 81 of 89 total stomachs (91%). Mobula japanica and M. thurstoni almost exclusively had this krill in their stomach, while M. tarapacana had a squid and fish, and Ma. birostris had myctophid fishes and copepods in their stomachs in addition to E. diomedeae . This krill was larger than prey for other planktivorous elasmobranchs elsewhere and contributed a mean of 61 364 kcal per stomach (±105 032 kcal s.e., range = 0–631 167 kcal). Our results show that vertically migrating mesopelagic species can be an important food resource for large filter feeders living in tropical seas with oligotrophic surface waters. Given the conservative life history of mobulid rays, the identification of common foraging grounds that overlap with fishing activity could be used to inform future fishing effort.

CFD Investigation of the Multiple Rotors Darrieus Type Turbine Performance

2019 ◽  
Author(s):  
Omar Sherif Mohamed ◽  
Ahmed Ibrahim ◽  
Ahmed M. R. El Baz
Keyword(s):  
Urban Areas ◽  
Low Cost ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Cfd Simulations ◽  
Close Proximity ◽  
Horizontal Axis Wind Turbines ◽  
Computational Fluid Dynamics Cfd ◽  
Overall Performance

Abstract The last few years have witnessed researches concerned by vertical axis wind turbine (VAWT) performance considering its advantages compared to the horizontal axis wind turbines, as it can be operated in urban areas without producing noise, ease of maintenance and simple construction, in addition to its low cost. More interest is growing in developing efficient clusters of VAWT in order to increase power generation at specific sites by using multiple turbines. In the present work, the performance of various configurations of Darrieus type VAWT clusters is examined using computational fluid dynamics (CFD) simulations. The objective of this work is to increase the overall power coefficient of the turbines cluster compared to single rotor performance. This objective shall be achieved by examining mutual interactions between rotors arranged in close proximity and examining the effect of oblique angle between rotors on overall performance of the cluster of rotors. The performance is assessed by observing the overall power coefficient of the cluster. Also, the velocity wake of the simulated three rotors turbine cases was analyzed and compared to the that of the single rotor.

Breeding habitat selection in an obligate beach bird: a test of the food resource hypothesis

2015 ◽  
Vol 66 (9) ◽  
pp. 841 ◽  
Author(s):  
Anna Cuttriss ◽  
Grainne S. Maguire ◽  
Glenn Ehmke ◽  
Michael A. Weston
Keyword(s):  
Habitat Selection ◽  
Marine Pollution ◽  
Food Resource ◽  
Breeding Habitat ◽  
Breeding Sites ◽  
Kelp Harvesting ◽  
Bird Breeding ◽  
Prey Resources ◽  
Resource Hypothesis ◽  
A Site

The food resource hypothesis of breeding habitat selection in beach-nesting birds suggests that birds breed at sites with more prey to meet the increased energetic requirements associated with breeding. We compare prey resources using pitfall traps and core samples at breeding sites and absence sites of the eastern population of hooded plover, Thinornis rubricollis rubricollis, which, in this part of its range, is a threatened obligate beach bird. Breeding sites had higher abundances, equivalent species richness, and different assemblages of invertebrate prey compared with absence sites. Assemblages at breeding sites were characterised by more isopods, and fewer beetles of the family Phycosecidae. Breeding habitat selection by plovers appears to be associated with selection for sites with more food, and any process that degrades food resources at a site (e.g. kelp harvesting or marine pollution events) may reduce the likelihood of occupancy of that site by breeding birds.

scholarly journals Food Resource Utilization by Five Species of Benthic Feeding Fish in Passamaquoddy Bay, New Brunswick

1986 ◽  
Vol 43 (8) ◽  
pp. 1534-1546 ◽  
Author(s):  
J. Stevenson Macdonald ◽  
Roger H. Green
Keyword(s):  
Fish Species ◽  
Gadus Morhua ◽  
Function Analysis ◽  
Food Resource ◽  
Stomach Contents ◽  
Diet Overlap ◽  
Data Matrix ◽  
Pseudopleuronectes Americanus ◽  
Predator Species ◽  
Benthic Composition

Feeding relationships of various fish species, and their relationship to the composition of the surrounding sediments, were observed for 1 yr at two sites in the lower Bay of Fundy region. The fishes were the ocean pout (Macrozoarces americanus, Zoarcidae), winter flounder (Pseudopleuronectes americanus, Pleuronectidae), plaice (Hippoglossoides platessoides, Pleuronectidae), cod (Gadus morhua, Gadidae), and witch flounder (Glyptocephalus cynoglossus, Pleuronectidae). After reducing the size of the data matrix by removing redundant variables, we used discriminant function analysis to assess interspecific diet overlap and the degree to which stomach contents reflect benthic composition. Variables were ranked by their power to discriminate in pairwise comparisons among fish species and between a given fish species and benthic grab samples. Many amphipods are utilized to an equal or greater extent than their abundances in the sediments would suggest. Many annelids are underutilized. Predation by each fish species was a selective process, and interspecific diet differences are related to the morphology of the predator and the behavior and microhabitat of the prey. The fishes diets, however, are also correlated with spatial and temporal changes in the benthic composition. Specific examples are presented. As benthic food abundance increased in the surrounding sediments all predator species increased their food consumption and interspecific diet overlap declined. In some cases the degree of exploitation depended upon the size rather than the abundance of the prey item.

scholarly journals Changing Food Consumption and Nutrition Intake in Kazakhstan

Nutrients ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 326
Author(s):  
Mengmeng Jia ◽  
Lin Zhen ◽  
Yu Xiao
Keyword(s):  
Energy Intake ◽  
Food Consumption ◽  
Rural Areas ◽  
Urban Areas ◽  
Food Resource ◽  
Human Beings ◽  
Temporal Perspective ◽  
Nutrition Intake ◽  
Per Capita ◽  
Urban And Rural Areas

Food resource is an important bond that connects human beings and nature. In this study, we investigated the changes in food consumption and nutrition intake in Kazakhstan from a spatial and temporal perspective, from 2001 to 2018. The data were obtained from the Bureau of Statistics, international organizations and our social interview work. After the start of the 21st century, it was found that per capita food consumption significantly increased; however, the consumption of crop, vegetables and milk decreased. Per capita meat consumption was similar in both urban and rural areas. However, some food consumption showed differences between urban and rural areas. Changes of food consumption quantity and structure also had some effects on nutrient intake and the proportion of nutrients. Per capita energy intake in the national, urban and rural areas all increased remarkably. The energy intake changes in eastern states increased much more than that in western states. Protein intake in rural and urban areas was similar; however, the gap between carbohydrates and fat intake in urban and rural areas increased. The intake of protein, carbohydrates and fat in different states showed the same trend. Food consumption and nutrition intake are affected by economic, social and ecological factors.

scholarly journals The new cases of thelaziosis on the Balkan Peninsula

2020 ◽  
Vol 74 (2) ◽  
pp. 154-163
Author(s):  
Suzana Tasic-Otasevic ◽  
Sara Savic ◽  
Stefan Momcilovic ◽  
Marija Trenkic ◽  
Anastasia Diakou
Keyword(s):  
Urban Areas ◽  
Clinical Manifestations ◽  
Epidemiological Data ◽  
Balkan Peninsula ◽  
Thelazia Callipaeda ◽  
Cotton Swab ◽  
Mechanical Removal ◽  
Close Proximity ◽  
Antiparasitic Drugs ◽  
Human Infections

Thelazia callipaeda (Spirurida, Thelaziidae), known as oriental eyeworm, is a parasite infesting the eyes of many domestic and wild carnivores which can also cause human infections. Due to the fact that infections by T. callipaeda have been recently spreading through the Balkan Peninsula, the main aims of this mini review are to give a clear and concise overview of the clinical manifestations, diagnosis and treatment of thelasiosis in animals and humans as well as to update epidemiological data about thelaziosis in this area. Clinical manifestations of thelaziosis can vary from subclinical to severe. In both animals and humans, treatment of thelaziosis can be effectively achieved with the removal of the nematodes from the eye under local anesthesia using a cotton swab or fine forceps. In the treatment of animals, antiparasitic drugs should be used supplementarily to the mechanical removal of parasites, while in humans, the topical use of antibiotics is desirable in order to prevent secondary bacterial infection. The growing number of diagnosed thelasiosis cases in dogs in the Balkan Peninsula, and particularly among owned pets in urban areas of Serbia previously considered free of infection, indicates the spread of zoonotic T. callipaeda in the area and in close proximity to humans. Finally, cooperation between veterinarians and physicians is strongly advocated in favour of the development of effective preventive measures and strategies.

scholarly journals Response of Framed Building Models Near Underground Excavation Due to Artificial Excitation using Shake Table Test

2019 ◽  
Vol 9 (2) ◽  
pp. 1009-1015
Keyword(s):  
Urban Areas ◽  
Embedment Depth ◽  
Shake Table ◽  
Underground Excavation ◽  
Shake Table Tests ◽  
Building Frame ◽  
Building Models ◽  
Offset Distance ◽  
Close Proximity ◽  
Different Types

In urban areas where land is limited and buildings are closely spaced, deep excavations are necessary for the construction of surface and sub-surface facilities. Therefore, there is a concern that soil excavations resulting in a ditch or a trench adjacent to a building may adversely affect the response of nearby buildings when earthquakes occur. In this paper, the results of experimental study of building frame models in close proximity of excavations and subjected to artificial excitations are presented through a series of shake table tests. The study has been conducted to investigate the effects of the size and offset distances of excavations on the response of the building frame models founded on different types of foundation systems. It is observed that the width, depth and offset distance of the trench has a significant influence on the response of the building frame. It is seen that pile foundation with sufficient embedment depth produces less displacement at the top of the building as compared to other foundation systems.

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