The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Andrew E. Mckechnie - One of the best experts on this subject based on the ideXlab platform.
-
Environmental correlates of Freckled Nightjar (Caprimulgus tristigma) activity in a seasonal, subtropical habitat
Journal of Ornithology, 2008Co-Authors: Robert A. M. Ashdown, Andrew E. MckechnieAbstract:We examined environmental correlates of activity in the Freckled Nightjar ( Caprimulgus tristigma ), a nocturnal aerial insectivore that is resident year-round in the colder and drier parts of southern Africa. Specifically, we tested the prediction that air temperature ( T _a), in addition to light availability, is a significant correlate of Freckled Nightjar activity. We found that aerial insect density varied by over three orders of magnitude (from
-
environmental correlates of freckled nightjar caprimulgus tristigma activity in a seasonal subtropical habitat
Journal of Ornithology, 2008Co-Authors: Robert A. M. Ashdown, Andrew E. MckechnieAbstract:We examined environmental correlates of activity in the Freckled Nightjar (Caprimulgus tristigma), a nocturnal aerial insectivore that is resident year-round in the colder and drier parts of southern Africa. Specifically, we tested the prediction that air temperature (T a), in addition to light availability, is a significant correlate of Freckled Nightjar activity. We found that aerial insect density varied by over three orders of magnitude (from <1.0 to 117.1 insects 1,000 m−3) during the course of the study, and was strongly and positively related to T a. Nightjar activity was also significantly temperature-dependent, with a cessation of activity at T a < 12°C. Consistent with previous studies, we found that activity levels were strongly related to ambient light, with markedly reduced activity levels on dark nights. The average number of Freckled Nightjars encountered per 14.6-km transect was 1.95 ± 2.44 nightjars transect−1 during nights near full moon, but only 0.17 ± 0.61 nightjars transect−1 around new moon. Our study reveals that caprimulgid activity can be significantly influenced by temperature as well as ambient light.
-
torpor in an african caprimulgid the freckled nightjar caprimulgus tristigma
Journal of Avian Biology, 2007Co-Authors: Andrew E. Mckechnie, Robert A. M. Ashdown, Murray B Christian, Mark R BrighamAbstract:Recent data suggest that facultative hypothermic responses such as torpor are more important in the energy balance of birds from tropical and sub-tropical regions than previously thought. We used telemetric measurements of skin temperature (Tskin) for five individuals on 151 bird-nights to investigate the occurrence of torpor during winter in an 81 g African caprimulgid, the freckled nightjar Caprimulgus tristigma . We found that freckled nightjars have the capacity to enter torpor, with a minimum observed Tskin of 12.88C. During the torpor bouts we observed, complete rewarming typically occurred after sunrise, and coincided with the availability of solar radiation. There was considerable inter-individual variability in the frequency and depth of torpor bouts, with one female nightjar exhibiting particularly frequent and deep torpor. Our results confirm the ability to use torpor by a nocturnal aerial insectivore from the Afrotropics, and reiterate the variability in patterns of torpor that can exist within a population.
L. Van Elsacker - One of the best experts on this subject based on the ideXlab platform.
-
Insectivory by Gorilla gorilla gorilla in Southeast Cameroon
International Journal of Primatology, 2003Co-Authors: I. Deblauwe, J. Dupain, G. M. Nguenang, D. Werdenich, L. Van ElsackerAbstract:Our study extends quantitative analyses of insect-eating by gorillas ( Gorilla gorilla gorilla ) to Cameroon. During a 2-mo period (May–June 2001), we recorded and analyzed feeding traces on plants and insects and in gorilla feces. We found 180 feeding traces, 17% of which involved Insectivory. Seventy-eight percent of the fecal samples ( n = 36) contained insects. Ants were found in 61% of the samples, termites in 39%, while 56% of the samples contained remains of other insects. We added ≥14 new species to the known insect diet of western lowland gorillas. Overall, social insects are predominant. The choice of prey by the Ntonga gorillas gives new clues for the existence of cross-cultural differences among gorilla populations. A comparison of the overall frequency of Insectivory with those at other sites in Central Africa indicate a possible effect of forest disturbance on the insectivorous behavior of gorillas. The study suggests the existence of temporal variation in ant- and termite-eating by gorillas.
Rodrigo Martinezsastre - One of the best experts on this subject based on the ideXlab platform.
-
animal biodiversity in cider apple orchards simultaneous environmental drivers and effects on Insectivory and pollination
Agriculture Ecosystems & Environment, 2020Co-Authors: Rodrigo Martinezsastre, Marcos Minarro, Daniel F GarciaAbstract:Abstract Making agriculture more sustainable requires a greater understanding of animal-mediated ecosystem services. The beneficial effects of pest-control and pollination provided by, respectively, insectivorous birds and pollinator insects are essential for many crops. Improving these ecosystem services simultaneously in the same crop system means, first, identifying the drivers of animal biodiversity that operate in agricultural landscapes, and second, revealing the relationships between biodiversity and the two services. Here, for two years, we addressed how landscape and small-scale orchard features affected bird and insect biodiversity (abundance and species richness) in cider apple orchards in northern Spain. We examined the effects of bird and insect biodiversity on the magnitude of, respectively, Insectivory and pollination. Bird biodiversity was positively affected by the cover of apple canopy within orchards, whereas that of pollinators responded positively to the cover of semi-natural woody habitats and eucalyptus plantations in the surrounding landscape, and also on the level of bloom at the orchard scale. Insectivory, estimated from sentinel model and exclusion experiments, was positively affected by increased abundance and richness of birds across orchards. Similarly, fruit set responded positively to higher abundance and richness of wild bees, whereas seed set mostly depended on the abundance of wild pollinators. Our findings suggest simultaneous positive effects of animal biodiversity on pest-control and pollination in apple orchards, with no sign of trade-offs between biodiversity groups or between ecosystem functions. A multi-scaled management of orchard-level features (apple canopies and surrounding hedgerows for birds, and apple bloom and ground cover for pollinators) and landscape-level ones (surrounding cover of semi-natural woody habitats, moderate for birds, high for pollinators) is encouraged for the simultaneous enhancement of pest-control and pollination. Biodiversity-farming win-win scenarios are possible in cider apple orchards by simultaneously promoting multiple animal-mediated ecosystem services.
-
birds as suppliers of pest control in cider apple orchards avian biodiversity drivers and Insectivory effect
Agriculture Ecosystems & Environment, 2018Co-Authors: Daniel Garcia, Marcos Minarro, Rodrigo MartinezsastreAbstract:Abstract Making farming compatible with biodiversity conservation requires identifying the biodiversity drivers that operate in agricultural landscapes, while also addressing the role of biodiversity in ecosystem services. Such integrative information is, however, rare for specific biodiversity groups and services. Here, we focus on insectivorous birds in cider apple orchards in northern Spain, ascertaining the relationships between landscape- and orchard-scale features and bird biodiversity. We conducted field observations and experiments to estimate the potential of birds for controlling arthropod abundance and pest outbreaks in apple trees. Twenty-nine tree-dwelling, insectivorous bird species were observed during one year, inside and around cider apple orchards, with six abundant species representing a predictable core across sites and seasons. Bird abundance and richness increased with the availability of semi-natural woody habitats (hedgerows, remnant trees, and forest patches) both in the immediate neighborhood of the orchard and in the landscape within a 1-km radius of the orchard. Orchards with higher cover of apple tree canopy also harbored a greater abundance and richness of birds. Apple tree branches that were cage-excluded from birds and manually infested with aphids suffered increased shoot damage and aphid outbreak, compared to those that were aphid-infested but open to birds. Bird exclusion led to increased abundances of pest insects other than aphids, and also of other arthropods considered as natural enemies or mutualists of pests. Arthropod abundance was lower in those orchards showing higher abundances of insectivorous birds during spring and summer. Multi-scaled farming management, involving both within-field practices and regional land use schemes, should be considered in order to promote win–win scenarios in cider apple orchards, whereby species-rich assemblages of insectivorous birds provide effective pest control service.
Robert A. M. Ashdown - One of the best experts on this subject based on the ideXlab platform.
-
Environmental correlates of Freckled Nightjar (Caprimulgus tristigma) activity in a seasonal, subtropical habitat
Journal of Ornithology, 2008Co-Authors: Robert A. M. Ashdown, Andrew E. MckechnieAbstract:We examined environmental correlates of activity in the Freckled Nightjar ( Caprimulgus tristigma ), a nocturnal aerial insectivore that is resident year-round in the colder and drier parts of southern Africa. Specifically, we tested the prediction that air temperature ( T _a), in addition to light availability, is a significant correlate of Freckled Nightjar activity. We found that aerial insect density varied by over three orders of magnitude (from
-
environmental correlates of freckled nightjar caprimulgus tristigma activity in a seasonal subtropical habitat
Journal of Ornithology, 2008Co-Authors: Robert A. M. Ashdown, Andrew E. MckechnieAbstract:We examined environmental correlates of activity in the Freckled Nightjar (Caprimulgus tristigma), a nocturnal aerial insectivore that is resident year-round in the colder and drier parts of southern Africa. Specifically, we tested the prediction that air temperature (T a), in addition to light availability, is a significant correlate of Freckled Nightjar activity. We found that aerial insect density varied by over three orders of magnitude (from <1.0 to 117.1 insects 1,000 m−3) during the course of the study, and was strongly and positively related to T a. Nightjar activity was also significantly temperature-dependent, with a cessation of activity at T a < 12°C. Consistent with previous studies, we found that activity levels were strongly related to ambient light, with markedly reduced activity levels on dark nights. The average number of Freckled Nightjars encountered per 14.6-km transect was 1.95 ± 2.44 nightjars transect−1 during nights near full moon, but only 0.17 ± 0.61 nightjars transect−1 around new moon. Our study reveals that caprimulgid activity can be significantly influenced by temperature as well as ambient light.
-
torpor in an african caprimulgid the freckled nightjar caprimulgus tristigma
Journal of Avian Biology, 2007Co-Authors: Andrew E. Mckechnie, Robert A. M. Ashdown, Murray B Christian, Mark R BrighamAbstract:Recent data suggest that facultative hypothermic responses such as torpor are more important in the energy balance of birds from tropical and sub-tropical regions than previously thought. We used telemetric measurements of skin temperature (Tskin) for five individuals on 151 bird-nights to investigate the occurrence of torpor during winter in an 81 g African caprimulgid, the freckled nightjar Caprimulgus tristigma . We found that freckled nightjars have the capacity to enter torpor, with a minimum observed Tskin of 12.88C. During the torpor bouts we observed, complete rewarming typically occurred after sunrise, and coincided with the availability of solar radiation. There was considerable inter-individual variability in the frequency and depth of torpor bouts, with one female nightjar exhibiting particularly frequent and deep torpor. Our results confirm the ability to use torpor by a nocturnal aerial insectivore from the Afrotropics, and reiterate the variability in patterns of torpor that can exist within a population.
Adriana Coletto - One of the best experts on this subject based on the ideXlab platform.
-
ANALYSIS OF THE STOMACH CONTENTS OF Astyanax lineatus (Perugia, 1891) (CHARACIFORMES: CHARACIDAE) FROM THE REGION OF SERRA DA BODOQUENA, MATO GROSSO DO SUL STATE, CENTRAL BRAZIL
2009Co-Authors: Adriana ColettoAbstract:SUMMARY: The goal of this work was to study the diet of Astyanax lineatus from the Taquaracu Stream, in the region of Serra da Bodoquena, State of Mato Grosso do Sul, central Brazil. The fish were caught using a combination of electric fishing, seines and hoop nets. The stomach contents of 15 specimens was analyzed using the frequency of occurrence, in which the number of fish that contain certain item is expressed as percentage of total number of fish examined with the content. Our results indicate that A. lineatus is an euryphagic species, with a tendency to Insectivory, with a predominance of aquatic insects in its diet.
-
ANÁLISE DO CONTEÚDO ESTOMACAL DE Astyanax lineatus (Perugia, 1891) (CHARACIFORMES: CHARACIDAE), PROVENIENTES DA SERRA DA BODOQUENA, ESTADO DE MATO GROSSO DO SUL, BRASIL
2009Co-Authors: Adriana ColettoAbstract:SUMMARY: The goal of this work was to study the diet of Astyanax lineatus from the Taquaracu Stream, in the region of Serra da Bodoquena, State of Mato Grosso do Sul, central Brazil. The fish were caught using a combination of electric fishing, seines and hoop nets. The stomach contents of 15 specimens was analyzed using the frequency of occurrence, in which the number of fish that contain certain item is expressed as percentage of total number of fish examined with the content. Our results indicate that A. lineatus is an euryphagic species, with a tendency to Insectivory, with a predominance of aquatic insects in its diet.
-
ANÁLISE DO CONTEÚDO ESTOMACAL DE Moenkhausia intermedia (Eigenmann, 1908) (CHARACIFORMES: CHARACIDAE), PROVENIENTE DA LAGOA DO DIOGO, BACIA DO RIO MOGI- GUAÇU, LUÍS ANTÔNIO, ESTADO DE SÃO PAULO
2009Co-Authors: Clycie Aparecida Da Silva, Adriana ColettoAbstract:SUMMARY: The goal of this study was to analyze the diet of Moenkhausia intermedia (Eigenmann, 1908) from Diogo Lake, Rio Mogi-Guacu basin, municipality of Luis Antonio, State of Sao Paulo, southeastern Brazil. Sixteen stomachs were examined using the method of frequency of occurrence (%FO). According to our analysis 28.79% of the food items were autochthonous, 48.48% allochthonous and 22.73% from non identified origins. Our results indicate that M. intermedia belongs to the omnivorous food guild, with a tendency to Insectivory. The allochthonous items were the most frequent, with seeds showing a 100% frequency of occurrence and terrestrial insects 68.75%. Hence, an intact riparian vegetation is considered of great importance as a source of food for most aquatic invertebrates and fish.