Diet and prey availability of terrestrial insectivorous birds prone to extinction in amazonian forest fragments

This study compared niche breath, prey size, and diet variability in two pairs of sympatric species of terrestrial insectivorous birds, each pair containing one species that can persist in small forest fragments and one that does not. The pairs were Myrmeciza ferruginea and Sclerurus rufigularis; and Formicarius colma and F. analis, respectively. The prey availability in forest fragments was also sampled and compared to the availability in continuous forests. Niche breath indices did not differ between pair members, but diet variability differed in the opposite direction from that hypothesized. Although the two bird species most vulnerable to fragmentation fed on larger prey than less vulnerable species, prey availability, including that based on prey size did not differ among fragmented versus continuous forest sites. Thus, diet per se appeared not to be an important cause of extinction-proneness in these species. The simplest explanation proposed, that vulnerability to fragmentation was directly related to territory size, requires testing. However, it was consistent with observations that the bird species feeding on larger prey also need larger territories.

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Structurally complex farms support high avian functional diversity in tropical montane Ethiopia

Journal of Tropical Ecology ◽

10.1017/s0266467413000023 ◽

2013 ◽

Vol 29 (2) ◽

pp. 87-97 ◽

Cited By ~ 11

Author(s):

Aaron D. Gove ◽

Kristoffer Hylander ◽

Sileshi Nemomissa ◽

Anteneh Shimelis ◽

Woldeyohannes Enkossa

Keyword(s):

Bird Species ◽

Feeding Guilds ◽

Forest Conversion ◽

Forest Fragments ◽

Feeding Guild ◽

Species Accumulation Curves ◽

Point Counts ◽

Forest Sites ◽

Agricultural Habitat ◽

Regional Species Pool

Abstract:Of all feeding guilds, understorey insectivores are thought to be most sensitive to disturbance and forest conversion. We compared the composition of bird feeding guilds in tropical forest fragments with adjacent agro-ecosystems in a montane region of south-west Ethiopia. We used a series of point counts to survey birds in 19 agriculture and 19 forest sites and recorded tree species within each farm across an area of 40 × 35 km. Insectivores (~17 spp. per plot), frugivores (~3 spp. per plot) and omnivores (~5 spp. per plot) maintained species density across habitats, while granivores and nectarivores increased in the agricultural sites by factors of 7 and 3 respectively. Species accumulation curves of each guild were equal or steeper in agriculture, suggesting that agricultural and forest landscapes were equally heterogeneous for all bird guilds. Counter to most published studies, we found no decline in insectivore species richness with forest conversion. However, species composition differed between the two habitats, with certain forest specialists replaced by other species within each feeding guild. We suggest that the lack of difference in insectivorous species numbers between forest and agriculture in this region is due to the benign nature of the agricultural habitat, but also due to a regional species pool which contains many bird species which are adapted to open habitats.

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Species-Area Relationships Induced by Forest Habitat Fragmentation Apply Even to Rarely Detected Organisms

Tropical Conservation Science ◽

10.1177/19400829211017366 ◽

2021 ◽

Vol 14 ◽

pp. 194008292110173

Author(s):

Ana Filipa Palmeirim ◽

Rafael de Fraga ◽

Marcus V. Vieira ◽

Carlos A. Peres

Keyword(s):

Biodiversity Loss ◽

Forest Fragments ◽

Detection Rates ◽

Conservation Policies ◽

Number Of Species ◽

Continuous Forest ◽

Forest Sites ◽

Species Area ◽

Riparian Habitats ◽

Forest Islands

Neotropical snakes have extremely low detection rates, hampering our understanding of their responses to habitat loss and fragmentation. We addressed this gap using a limited sample (50 individuals, 16 species) across 25 variable-size insular forest fragments within a hydroelectric lake and four adjacent mainland continuous forest sites, in Central Brazilian Amazonia. The number of species recorded on forest islands (1.55 [Formula: see text] 0.78) was much lower than that at continuous forest sites (5.0 [Formula: see text] 3.1), with no snakes being recorded at twelve islands smaller than 30 ha. As such, snake assemblages were positively affected by forest area, explaining 48% of the number of species, and negatively affected by island isolation. The markedly higher number of species recorded across continuous forest sites likely results from the availability of riparian habitats, which have virtually disappeared from the archipelagic landscape given the widespread inundation of lowland areas. To prevent further severe biodiversity loss, including those of poorly known rare taxa, conservation policies should avert the additional construction of mega-dams that create myriad of small islands, in addition to extensive reservoir lakes from which all riparian habitats are eliminated.

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Changes in aboveground locomotion of a scansorial opossum associated to habitat fragmentation

Journal of Mammalogy ◽

10.1093/jmammal/gyaa044 ◽

2020 ◽

Vol 101 (4) ◽

pp. 1097-1107

Author(s):

Ana Cláudia Delciellos ◽

Suzy Emidio Ribeiro ◽

Jayme Augusto Prevedello ◽

Marcus Vinícius Vieira

Keyword(s):

Habitat Fragmentation ◽

Animal Movement ◽

Interspecific Interactions ◽

Home Ranges ◽

Forest Fragments ◽

Active Selection ◽

Continuous Forest ◽

Forest Sites ◽

Males And Females ◽

Selection Of

Abstract Habitat fragmentation may affect animal movement patterns due to changes in intra- and interspecific interactions as well as in habitat quality and structure. Although the effects of habitat fragmentation on terrestrial movements are relatively well-known, it is unclear whether and how they affect aboveground locomotion of individuals. We compared aboveground locomotion of a Neotropical small mammal, the gray four-eyed opossum, Philander quica, between two forest fragments and two areas of continuous forest in the Brazilian Atlantic Forest. We 1) quantified support availability and tested for active selection of different support diameters and inclinations by individuals; and 2) compared support diameters and inclinations used (observed values) among areas and between males and females. Both males and females selected supports based on diameters and inclinations in forest fragments. In continuous forests sites, females selected supports based on diameters and inclinations, but males selected only support diameters. Frequency of support diameter use differed significantly between forest fragments and continuous forest sites and between males and females. Frequency of support inclination use differed significantly between areas only for females, and between sexes only in continuous forest sites. Sex-related differences in support selection and use are likely related to differences in body size and conflicting energetic and behavioral demands related to use of arboreal space. Site-related differences in aboveground movements likely reflect the effects of forest edges that result in increased use of thinner supports in forest fragments. These results complement our previous findings that habitat fragmentation reduces daily home ranges and increases the total amount of aboveground locomotion of P. quica, and provide a more thorough picture of how forest-dependent species are able to use and persist in small forest fragments.

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Fragmentation and elevation effects on bird–army ant interactions in neotropical montane forest of Costa Rica

Journal of Tropical Ecology ◽

10.1017/s0266467407004270 ◽

2007 ◽

Vol 23 (5) ◽

pp. 581-590 ◽

Cited By ~ 19

Author(s):

Anjali Kumar ◽

Sean O'Donnell

Keyword(s):

Costa Rica ◽

Body Mass ◽

Bird Species ◽

Forest Fragments ◽

Flock Size ◽

Army Ants ◽

Total Body Mass ◽

Army Ant ◽

Continuous Forest ◽

Total Body

Army ants (Formicidae: Ecitoninae) are top predators in neotropical forests. Army ant raids support a community of diverse organisms, including birds that attend the raids to collect prey. While elevation and forest fragmentation influence army ant and insectivorous bird communities, their effects on the interaction between army ants and bird species is unknown. We studied the size and species composition of bird flocks attending army ant swarms in forest fragments and continuous forest across an elevational gradient (1100–1680 m asl) in a neotropical montane region (Monteverde, Costa Rica). We observed a total of 41 bird species attending army ant swarms. Neither the number of birds, nor the total body mass of birds, nor the number of bird species in attending bird flocks was related to elevation. However, we found a higher bird species richness, larger flock size and greater total body mass of birds attending army ant swarms in continuous forest. Continuous and fragmented forest shared many attending bird species in common, but there was elevational segregation of attending bird species. Some montane endemic birds, and neotropical migrants, attend swarms regularly and use army ant raids as a food source.

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Bird species that occupy river edge in continuous forest tend to be less sensitive to forest fragmentation

Revista Brasileira de Ornitologia ◽

10.1007/bf03544468 ◽

2019 ◽

Vol 27 (3) ◽

pp. 172-186

Author(s):

Barbara Rocha Arakaki Lindsey ◽

Gabriela Menezes Bochio ◽

Luiz dos Anjos

Keyword(s):

Forest Fragmentation ◽

Bird Species ◽

Forest Edge ◽

Bird Communities ◽

Forest Fragments ◽

Small Stream ◽

Edge Habitat ◽

Forest Interior ◽

Continuous Forest ◽

Significant Difference

AbstractAlong a distance gradient from a given river, two types of habitat can be recognized: natural river edge and forest interior, each one with its own vegetation characteristics and dynamics. In a continuous area of the Brazilian Atlantic Forest, we investigated (1) if bird communities are different between a riverbank of a small stream and an inland forest habitat; (2) if the species of the river edge habitat are the ones that persist in the most in forest fragments after deforestation of a continuous forest; (3) if the river edge habitat species are those that are less sensitive to forest fragmentation. It is expected that there are differences in the bird communities and the occupancy of some species between the two habitats. We allocated 16 sampling points in each of the habitats and sampled the birds by point counts with a short radius of 30 m. Results suggest that there is a significant difference between the composition of the bird communities of the river edge and forest interior habitats, although the species richness is similar. Six species were more likely to occupy the river edge and 14 species had a greater probability of occupancy in the forest interior. Species associated with the river edge habitat (15 species) tend not to be sensitive to forest fragmentation (12 species). In this study, we demonstrated that river-border species of continuous forest areas form a significant part of the bird communities that persist in small forest fragments, with intense edge effect. This shows that not all forest edge species are the result of the colonization from open areas. Congruently, species that occupy the most distant areas from the river vegetation in a continuous forest are those more sensitive to forest fragmentation.

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Prey Size Decline as a Unifying Ecological Selecting Agent in Pleistocene Human Evolution

Quaternary ◽

10.3390/quat4010007 ◽

2021 ◽

Vol 4 (1) ◽

pp. 7

Author(s):

Miki Ben-Dor ◽

Ran Barkai

Keyword(s):

Prey Size ◽

Prey Availability ◽

Stone Tool ◽

Foraging Efficiency ◽

Energetic Cost ◽

Large Prey ◽

Biomass Density ◽

Cultural Changes ◽

Progressive Decline ◽

Brain Expansion

We hypothesize that megafauna extinctions throughout the Pleistocene, that led to a progressive decline in large prey availability, were a primary selecting agent in key evolutionary and cultural changes in human prehistory. The Pleistocene human past is characterized by a series of transformations that include the evolution of new physiological traits and the adoption, assimilation, and replacement of cultural and behavioral patterns. Some changes, such as brain expansion, use of fire, developments in stone-tool technologies, or the scale of resource intensification, were uncharacteristically progressive. We previously hypothesized that humans specialized in acquiring large prey because of their higher foraging efficiency, high biomass density, higher fat content, and the use of less complex tools for their acquisition. Here, we argue that the need to mitigate the additional energetic cost of acquiring progressively smaller prey may have been an ecological selecting agent in fundamental adaptive modes demonstrated in the Paleolithic archaeological record. We describe several potential associations between prey size decline and specific evolutionary and cultural changes that might have been driven by the need to adapt to increased energetic demands while hunting and processing smaller and smaller game.

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The persistence of ant-following birds in small amazonian forest fragments

Acta Amazonica ◽

10.1590/1809-43921989191263 ◽

1989 ◽

Vol 19 (0) ◽

pp. 249-263 ◽

Cited By ~ 41

Author(s):

Lee H. Harper

Keyword(s):

Forest Fragments ◽

Ant Colonies ◽

Amazonian Forest ◽

Army Ant ◽

Continuous Forest ◽

Introduced Birds ◽

Small Forest

SUMMARYMist-net captures of army ant-following bird were monitored during the isolation of central Amazonian forest fragments of 1 ha (n = 5), 10 ha (n = 4) and 100 ha (n = 1). Post-isolation captures of the three obligate ant-following birds Dendrocinela merula, Pithys albifrons, and Gymnopithys rufigula decreased significantly in all fragments. post-isolation captures of four facultative ant-following species were not significantly different in forest fragments of 1 ha and 10 ha, although two species decreased significantly in the 100 ha fragment. Experimental introductions of obligate species into small forest fragments in the absence and presence of introduced Eciton burchelli army ant colonies resulted in significantly greater recaptures of introduced birds when active army ant colonies were present. Of the 105 birds introduced, 58 ' 55%) crossed 100-320 m od dedorested area an were recaptured in continuous forest.

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Diet composition and feeding habits of the eyespot skate, Atlantoraja cyclophora (Elasmobranchii: Arhynchobatidae), off Uruguay and northern Argentina

Neotropical Ichthyology ◽

10.1590/1982-0224-20160032 ◽

2016 ◽

Vol 14 (3) ◽

Cited By ~ 5

Author(s):

Santiago A. Barbini ◽

Luis O. Lucifora

Keyword(s):

Body Size ◽

Diet Composition ◽

Prey Size ◽

Prey Availability ◽

Feeding Habits ◽

Warm Season ◽

Cold Season ◽

The North ◽

Multiple Hypothesis ◽

Modelling Approach

ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS) and crabs in the north region (38º - 41ºS). Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.

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Bird communities in three forest types in the Pernambuco Centre of Endemism, Alagoas, Brazil

Iheringia Série Zoologia ◽

10.1590/s0073-47212013000200002 ◽

2013 ◽

Vol 103 (2) ◽

pp. 85-96 ◽

Cited By ~ 5

Author(s):

Lahert W. Lobo-Araújo ◽

Mário T. F. Toledo ◽

Márcio A. Efe ◽

Ana C. M. Malhado ◽

Marcos V. C. Vital ◽

...

Keyword(s):

Species Richness ◽

Bird Species ◽

Bird Communities ◽

Northeastern Brazil ◽

Forest Fragments ◽

Forest Types ◽

Risk Of Extinction ◽

Bird Fauna ◽

Richness Patterns ◽

Ombrophilous Forest

The Pernambuco Center of Endemism (PCE) in northeastern Brazil is highly fragmented and degraded. Despite its potential conservation importance the bird fauna in this area is still relatively unknown and there are many remnant fragments that have not been systematically surveyed. Here, we report the results of bird surveys in five forest fragments (one pioneer, two ombrophilous and two seasonal). In total, 162 taxa were recorded, 12 of which are endemic to the PCE. The frequency of endangered species was lower than what has been reported in studies from the same area and most of the taxa considered to be at risk of extinction were sub-species of uncertain taxonomic validity. The comparatively low number of endemic/threatened species may be due to the small size of the fragments in the present study - a consequence of the high levels of habitat loss in this region. Analysis of species richness patterns indicates that ombrophilous forest fragments are acting as refuges for those bird species that are most sensitive to environmental degradation.

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