scholarly journals Sintopy of two Tropidurus lizard species (Squamata: Tropiduridae) in a rocky Cerrado habitat in Central Brazil

2004 ◽  
Vol 64 (4) ◽  
pp. 775-786 ◽  
Author(s):  
R. G. Faria ◽  
A. F. B. Araujo
Keyword(s):  
Sympatric Species ◽  
Microhabitat Use ◽  
Lizard Species ◽  
Cerrado Vegetation ◽  
Central Brazil ◽  
Heterogeneous Landscapes ◽  
Interspecific Territoriality ◽  
Morphological Differences ◽  
Rocky Habitats ◽  
Ecological Differences

We studied the ecology of Tropidurus itambere and T. oreadicus that occur syntopically in rocky habitats of Cerrado vegetation in central Brazil during the dry season (April to September 2000). The two species are ecologically similar, but somewhat differentiated in vertical microhabitat use. The two species preferred rocky surface microhabitat. Both species demonstrated a unimodal activity pattern, with a peak between 10 and 15 h. Their diets were similar in composition and prey size. The most frequent item used by both species was ants, whereas the most important preys volumetrically were termites and ants. Small morphological differences observed between the two Tropidurus species could explain minor microhabitat divergence: T. itambere is slightly smaller, heavier, and more robust, and uses lower perches. T. oreadicus is larger, lankier, with longer extremities (tail, fore- and hindlegs), and uses a larger vertical microhabitat range. These ecological differences are slight, when compared with those observed between sympatric species of Tropidurus in spatially more heterogeneous landscapes. Considering the slight ecomorphological divergence between the two Tropidurus species and their high abundance in outcrops, we suggest that interspecific territoriality is the mechanism of coexistence.

scholarly journals Evidence of character displacement in microhabitat use between two tropical sympatric Holcosus lizard species (Reptilia, Teiidae)

2019 ◽  
pp. 379-388
Author(s):  
F. Ruiz Real ◽  
J. Martín
Keyword(s):  
Interspecific Competition ◽  
Competitive Exclusion ◽  
Species Coexistence ◽  
Character Displacement ◽  
Sympatric Species ◽  
The Other ◽  
Microhabitat Use ◽  
Lizard Species ◽  
Species Shifts ◽  
Selection Of

Interspecific competition between sympatric related species leading to character displacement is critical for species coexistence, especially in tropical habitats. We examined microhabitat use of two sympatric species of tropical lizards of the genus Holcosus in relationship to the microhabitats available in two ecosystems. The species H. festivus lives exclusively in the forest and uses microhabitats in proportion to their availability; while the other, H. quadrilineatus, lives both in forest and on the beach and selects microhabitats with specific characteristics. In the ecosystem where these two lizards live in sympatry (forest), we observed a differential microhabitat use between the two species. However, these differences indicated changes in habitat use by H. quadrilineatus (the smaller species) concerning its patterns of habitat selection in the ecosystem (beach) where only this species occurs. The age of the lizards did not affect the patterns of selection of microhabitats of either species. Shifts in microhabitat use may allow coexistence in sympatry of both species, which might result from the competitive exclusion of the smaller species by the larger species. Key words: Interspecific competition, Holcosus, Lizards, Microhabitat use, Tropical habitats

scholarly journals Niche differences between two sympatric whiptail lizards (Cnemidophorus abaetensis and C. ocellifer, Teiidae) in the restinga habitat of northeastern Brazil

2007 ◽  
Vol 67 (1) ◽  
pp. 41-46 ◽  
Author(s):  
EJR. Dias ◽  
CFD. Rocha
Keyword(s):  
Niche Differentiation ◽  
Sympatric Species ◽  
Northeastern Brazil ◽  
Activity Period ◽  
Microhabitat Use ◽  
Lizard Species ◽  
Niche Differences ◽  
Niche Dimension ◽  
Food Niche ◽  
Prey Items

Differences among sympatric lizard species usually result from differences in the use of three resources: space, time and food or some combination of these three. However, differences in resource utilization among sympatric species may simply reflect their specific ecological needs rather than competitive pressures. In this study, we analyzed the temporal, spatial and food niche of two congeneric teiids (Cnemidophorus abaetensis and C. ocellifer) living sympatrically in the "restinga" habitat of Abaeté in the Salvador Municipality, Bahia State, Brazil to assess the degree of niche differentiation among them. The whiptail species overlapped considerably in an hourly activity (Ojk = 0.93), in microhabitat use (Ojk = 0.97) and in the prey items consumed (Ojk = 0.89). Differences in amount of vegetation in the microhabitats used by both lizard species may have contributed to differences in the activity period and in the distribution of the main prey eaten by these lizards which may, in turn, facilitate their coexistence in Abaeté. Although sympatric C. ocellifer and C. abaetensis in Abaeté differed only slightly in their use of microhabitats, period of activity and diet, the most important niche dimension segregating the two species seemed to be the food niche.

Quantitative Trait Loci Affecting Differences in Floral Morphology Between Two Species of Monkeyflower (Mimulus)

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 367-382 ◽  
Author(s):  
H D Bradshaw ◽  
Kevin G Otto ◽  
Barbara E Frewen ◽  
John K McKay ◽  
Douglas W Schemske
Keyword(s):  
Quantitative Trait Loci ◽  
Reproductive Isolation ◽  
Quantitative Trait ◽  
Floral Morphology ◽  
Cumulative Effect ◽  
Sympatric Species ◽  
Accurate Estimate ◽  
Phenotypic Variance ◽  
Trait Loci ◽  
Morphological Differences

Abstract Conspicuous differences in floral morphology are partly responsible for reproductive isolation between two sympatric species of monkeyflower because of their effect on visitation of the flowers by different pollinators. Mimulus lewisii flowers are visited primarily by bumblebees, whereas M. cardinalis flowers are visited mostly by hummingbirds. The genetic control of 12 morphological differences between the flowers of M. lewisii and M. cardinalis was explored in a large linkage mapping population of F2 plants (n = 465) to provide an accurate estimate of the number and magnitude of effect of quantitative trait loci (QTLs) governing each character. Between one and six QTLs were identified for each trait. Most (9/12) traits appear to be controlled in part by at least one major QTL explaining ≥25% of the total phenotypic variance. This implies that either single genes of individually large effect or linked clusters of genes with a large cumulative effect can play a role in the evolution of reproductive isolation and speciation.

Pollination ecology of Caryocar brasiliense (Caryocaraceae) in Central Brazil cerrado vegetation

1993 ◽  
Vol 9 (2) ◽  
pp. 199-211 ◽  
Author(s):  
Rogério Gribel ◽  
John D. Hay
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Seed Set ◽  
Floral Biology ◽  
Cerrado Vegetation ◽  
Central Brazil ◽  
Glossophaga Soricina ◽  
Caryocar Brasiliense ◽  
Anoura Geoffroyi ◽  
Phyllostomus Discolor

ABSTRACTThe floral biology, breeding system and pollination of Caryocar brasiliense were studied in the cerrado vegetation of Central Brazil. The large, yellowish-cream, brush-like flowers are pollinated mainly by glossophagine bats (Glossophaga soricina and Anoura geoffroyi). Three non-glossophagine bats (Phyllostomus discolor, Vampyrops lineatus and Carollia perspicillata) and two short probosisced hawk moths (Erinyis ello and Pseudosphinx tetrio) may also act as occasional pollinators. Caryocar brasiliense is self-compatible although it sets significantly more fruits when crossed than when selfed. The natural fruit set (fruit/flower ratio) and seed set (seed/ovule ratio) are 3.1% and 1.0% respectively. Most of the fruits and seeds are formed through the action of the flower visitors, despite the fact that about 20% of the non-visited flowers receive self pollen on at least one stigma.

scholarly journals The length of the dry season may be associated with leaf scleromorphism in cerrado plants

2015 ◽  
Vol 87 (3) ◽  
pp. 1691-1699 ◽  
Author(s):  
MARCELO C. SOUZA ◽  
AUGUSTO C. FRANCO ◽  
MUNDAYATAN HARIDASAN ◽  
DAVI R. ROSSATTO ◽  
JANAÍNA F. DE ARAÚJO ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Specific Leaf Area ◽  
Woody Species ◽  
Dry Season ◽  
Core Region ◽  
The Other ◽  
Low Fertility ◽  
Fertility Rates ◽  
Cerrado Vegetation ◽  
Central Brazil

Despite limitations of low fertility and high acidity of the soils, the cerrado flora is the richest amongst savannas. Many cerrado woody species show sclerophyllous leaves, which might be related to the availability of water and nutrients in the soil. To better understand the function and structure of cerrado vegetation within its own variations, we compared two cerrado communities: one in its core region in central Brazil (Brasília, DF) and the other on its southern periphery (Itirapina, SP). We contrasted the length of the dry season, soil fertility rates, leaf concentrations of N, P, K, Ca and Mg and the specific leaf area (SLA) between these communities. The dry season was shorter on the periphery, where the soil was more fertile although more acidic. Plants from the periphery showed higher SLA and higher leaf concentrations of N, P, Ca and Mg. We propose that the higher SLA of plants from the periphery is related to the shorter dry season, which allows better conditions for nutrient uptake.

scholarly journals The rediscovery of the Red-tailed Newtonia Newtonia fanovanae in south-eastern Madagascar with notes on the natural history of the genus Newtonia

1991 ◽  
Vol 1 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Steven M. Goodman ◽  
Thomas S. Schulenberg
Keyword(s):  
Natural History ◽  
Sympatric Species ◽  
The Other ◽  
Single Specimen ◽  
The South ◽  
Humid Forest ◽  
Ecological Relationships ◽  
South Eastern ◽  
History Of ◽  
Morphological Differences

SummaryThe Red-tailed Newtonia Newtonia fanovanae, previously known from a single specimen from the eastern rainforest of central Madagascar, was rediscovered in October 1989 in the Marosohy Forest in the south-east of the island. In the study area, N. fanovanae occurs in the middle and upper section of the canopy of humid forest between 300 and 1,300 m. Ecological relationships with the other two sympatric Newtonia, amphichroa and brunneicauda, are discussed. The main morphological differences between fanovanae and the other two sympatric species are that the former has relatively long wings and short tarsi. The song of fanovanae is described and compared to other members of the genus. Our observations on the morphology, behaviour and vocalisations of N. fanovanae confirm its validity as a species.Le Newtonie à queue rouge Newtonia fanovanae jusqu'à presént uniquement connu d'un seul spécimen provenant de la partie orientale de la forêt tropicale du Madagascar central, fût redécouvert en octobre 1989 dans la forêt de Marosohy au sud-est de l'île. N. fanovanae fût rencontré dans les parties moyennes et supérieures du feuillage de la forêt humide entre 300 et 1,300 m d'altitude. Les relations écologiques avec les deux espèces sympatriques de Newtonia, amphichroa et brunneicauda sont discutées. Les différences morphologiques principales entre fanovanae et les deux espéces sympatriques sont que celle-ci a des ailes relativement longues et des tarses courts. Le chant de fanovanae est decrit et comparé avec celui d'autres membres du genre. Nos observations sur la morphologie, le comportement et les vocalizations de N. fanovanae confirment sa validité comme bonne espéce.

Nest Density of some Social Wasp Species in Cerrado Vegetation of Central Brazil (Hymenoptera: Vespidae)

1992 ◽  
Vol 17 (4) ◽  
pp. 265-268 ◽  
Author(s):  
Raimundo P. Barros Henriques ◽  
Ivone R. Diniz Rocha ◽  
Kiniti Kitayama
Keyword(s):  
Social Wasp ◽  
Nest Density ◽  
Wasp Species ◽  
Cerrado Vegetation ◽  
Central Brazil

scholarly journals Changes in the structure of fish assemblages in streams along an undisturbed-impacted gradient, upper Paraná River basin, Central Brazil

2010 ◽  
Vol 8 (3) ◽  
pp. 587-598 ◽  
Author(s):  
Alesandra Martins Dias ◽  
Francisco Leonardo Tejerina-Garro
Keyword(s):  
Fish Assemblages ◽  
Anthropogenic Impacts ◽  
Similarity Index ◽  
Fish Assemblage Structure ◽  
Conservation Unit ◽  
Dry Period ◽  
Conservation Areas ◽  
Cerrado Vegetation ◽  
Central Brazil ◽  
Agricultural Areas

The João Leite River is located in the upper Paraná basin, Central Brazil. It drains areas covered by Cerrado vegetation interspersed with urban and agricultural areas. This study aims to asses changes of the fish assembleges structure along a undisturbed-impacted gradient in ten stream stretches using ecological descriptors, a similarity index and the abundance-biomass relationship (ABC curves). The fish were collected during the dry period using electrofishing gear in stretches of 50 m. Results show that the environmental variation observed along the undisturbed-impacted gradient considered influences on fish assemblage structure. Both richness and diversity differences between fish assemblages are partially influenced by stream stretch orthonian order and anthropogenic impacts. ABC curves classified six stream stretches located in preserved or impacted areas as undisturbed while four stretches were classified as disturbed. This is attributed to the influence of the undisturbed habitat within the conservation unit and the presence of K- or r- strategist species. This type of study contributes to an understanding of the effects of aquatic environment conservation on the Brazilian Cerrado core area, where the choice of conservation areas prioritizes terrestrial over aquatic aspects.

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