Patterns of parasitism by Amblyomma rotundatum (Ixodidae) on Rhinella schneideri (Bufonidae) in islands of São Francisco River, Minas Gerais, Brazil

Abstract: We sampled ticks from specimens of the rococo toad Rhinella schneideriby flannel dragging on two Islands located in the São Francisco River near the Três Marias hydroelectric dam, southeastern Brazil. A total of 120 toads was examined, of which 63 (52.5%) were parasitized only by Amblyomma rotundatumtotaling 96 larvae, 163 nymphs and 134 females. The burden of parasitism ranged from one to 43 ticks, with a mean intensity of infestation of 6.2±5.5 ticks per host. The tick A. rotundatumexhibited highly aggregated distribution. Peak abundance of larvae and nymphs occurred in the dry season (May to September), whereas peak abundance of females occurred in the wet season (October to April). We collected most ticks near the head and hind limbs of R. schneideri. The finding of two engorged A. rotundatumnymphs in the same resting places of two toads and the absence of this species in the dragged areas suggest a nidicolous behavior at the studied site.

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Agricultural crops in the diet of bearded capuchin monkeys, Cebus libidinosus Spix (Primates: Cebidae), in forest fragments in southeast Brazil

Revista Brasileira de Zoologia ◽

10.1590/s0101-81752008000100006 ◽

2008 ◽

Vol 25 (1) ◽

pp. 32-39 ◽

Cited By ~ 38

Author(s):

Carlos Henrique de Freitas ◽

Eleonore Z. F. Setz ◽

Alba R. B. Araújo ◽

Nivar Gobbi

Keyword(s):

Fruit Production ◽

Dry Season ◽

Southeastern Brazil ◽

Capuchin Monkeys ◽

Home Ranges ◽

Forest Fragments ◽

Wet Season ◽

Plant Matter ◽

Wide Range ◽

Cebus Libidinosus

Capuchin monkeys occupy a wide range of habitats where they feed on fruits, arthropods, and vertebrates. Their large home ranges (80-900 ha) suggest that living in forest fragments may challenge their adaptability. We identified and quantified the main food items of Cebus libidinosus Spix, 1823 in forests fragments (100 ha) in southeastern Brazil. We recorded the feeding activities of two groups using scan sampling over a 13-month period. The diet was composed of fruits, crops, animal prey, seeds, plant matter and undetermined. Fruit was eaten more in the wet season than in the dry season, and maize and sugar cane consumption peaked in the early dry season. The proportion of fruit in the diet was positively correlated with fruiting intensity of zoochorous trees. The plant diet included 54 species, with maize, Rhamnidium elaeocarpus, Acrocomia aculeata, Guazuma ulmifolia and Cariniana, being most important. Although dietary composition and diversity were similar to capuchins in larger forest fragments, feeding on crops attained higher percentages at times when zoochorous fruit production was low in fragments.

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Effects of extended absence of flooding on the fish assemblages of three floodplain lagoons in the middle São Francisco River, Brazil

Neotropical Ichthyology ◽

10.1590/s1679-62252006000400006 ◽

2006 ◽

Vol 4 (4) ◽

pp. 427-433 ◽

Cited By ~ 26

Author(s):

Paulo dos Santos Pompeu ◽

Hugo Pereira Godinho

Keyword(s):

Fish Species ◽

Fish Assemblages ◽

Local Extinction ◽

Management Tool ◽

Southeastern Brazil ◽

Water Volume ◽

Sao Francisco River ◽

São Francisco River ◽

Large Water ◽

To Receive

In the Neotropics, a large proportion of fish communities of large rivers use floodplain as habitats for feeding, reproduction, and refuge. An evaluation was made of the effects of extended dry periods on the species richness, abundance and local extinction of fish species in three marginal lagoons in the middle São Francisco River, southeastern Brazil. The studied lagoons fail to receive river floods during the study period (1994-1996). A gradual reduction in richness and abundance was observed in all lagoons. Migratory fish species had the highest probability to become extinct in the two lagoons that remained with large water volume. Species tolerant to low levels of dissolved oxygen had the lowest probability of local extinction in the lagoon showing an abrupt reduction in water volume. Similar changes to those observed in the current study are likely to occur in the floodplains if dams would be constructed in this segment of the river. Adequate water releases from Três Marias reservoir, located upstream, should be considered as a management tool for producing episodic flooding on the marginal lagoons of the region.

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Seasonality of Mansonia titillans during dam construction, Biritiba-Mirim, São Paulo State, Brazil

Biota Neotropica ◽

10.1590/s1676-06032013000100007 ◽

2013 ◽

Vol 13 (1) ◽

pp. 70-73 ◽

Cited By ~ 2

Author(s):

Frederico Alves D'Avila ◽

Almério de Castro Gomes

Keyword(s):

Early Spring ◽

Dry Season ◽

Southeastern Brazil ◽

Rank Test ◽

Late Winter ◽

Dam Construction ◽

Wet Season ◽

Paulo State ◽

Significant Difference ◽

Wilcoxon Rank Test

A two and a half year survey was conducted at a dam in southeastern Brazil. Shannon Traps were used for sampling. Kruskal-Wallis test showed little relation between rainfall and abundance. The data clearly show three abundance peaks, all of them in the end of the dry season, in consonance with the scarce literature existent. Although Kruskal-Wallis Test did not find a clear preference for the dry season, Pairwise Wilcoxon Rank Test revealed a significant difference between Fall and Spring samples. Ma. titillans population had a peak on late winter/early spring, close to the begin of wet season.

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Seasonal Variation in Bee-Plant Interactions in an Inselberg in the Atlantic Forest in Southeastern Brazil

Sociobiology ◽

10.13102/sociobiology.v65i4.3473 ◽

2018 ◽

Vol 65 (4) ◽

pp. 612 ◽

Cited By ~ 1

Author(s):

Marcelita França Marques ◽

Mariana Scaramussa Deprá ◽

Maria Cristina Gaglianone

Keyword(s):

Plant Species ◽

Atlantic Forest ◽

Temporal Dynamics ◽

Interaction Network ◽

Dry Season ◽

Floral Resources ◽

Southeastern Brazil ◽

Plant Interactions ◽

Wet Season ◽

Bee Plant

Studies on bee-plant interactions are relevant to the understanding of temporal patterns in neotropical communities. In isolated habitats such as inselbergs little is yet known about the temporal dynamics in the availability of fl oral resources and interacting bee. In the present study, the objective is to verify the eff ect of seasonality on the bee-plant interaction in an Atlantic Forest inselberg in southeastern Brazil. The bees were sampled monthly in the dry (April/2008-September/2008) and wet seasons (October/2008-March/2009) using an entomological net. A total of 322 bees of 33 species were captured on fl owers of 34 species of plants during the year. Bees richness was similar between seasons (22 species in the wet season and 21 in the dry season), but abundance was higher in the wet season (60% of individuals) and higher diversity occurred in the dry season. Augochloropsis sp1 were the most abundant species and visited the largest number of plant species at each season. In the interaction network, plants with the highest degree were distinct between the seasons. The number of possible interactions was higher in the dry season compared to the wet season and connectance was similar; nestedness however varied between the seasons. The composition of plant and bees species was distinct between the seasons, as well as the interactions between them, mainly due to the alteration in the composition of the plant species and the change in the choice of the bees for the floral resources between the seasons.

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Occurrence of the grasshopper pest Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae) in south-western Nigeria in relation to the wet and dry seasons

Bulletin of Entomological Research ◽

10.1017/s0007485300007914 ◽

1980 ◽

Vol 70 (4) ◽

pp. 621-633 ◽

Cited By ~ 5

Author(s):

W. W. Page

Keyword(s):

Dry Season ◽

Seasonal Abundance ◽

Secondary Peak ◽

Rapid Decline ◽

Arid Zones ◽

Zonocerus Variegatus ◽

Wet Season ◽

The North ◽

Dry Seasons ◽

Peak Abundance

AbstractAn investigation into the seasonal abundance of Zonocerus variegatus (L.) around Ibadan, Nigeria, showed that hatching occurs between October and March and peak abundance is in late November. Adults occur almost throughout the year. Oviposition takes place between March and October or possibly November, with a peak in April. Eggs laid in March and April hatch in October and November after a diapause, while those laid from June onwards do not appear to enter diapause. Thus eggs laid in June and July hatch at the same time as those laid in March and April. Parasitism by the sargophagid fly Blaesoxipha filipjevi (Rod.) during March and April results in a rapid decline in adult numbers which may be followed by a secondary peak in adult numbers when nymphs, which are present at the same time and are rarely parasitised, reach adult stage. Oviposition resulting from such a peak does not produce a secondary peak in hatching as this coincides with hatching from earlier layings. The fungus Entomophthora grylli plays an important role in controlling the abundance of nymphs and adults during the dry season despite the intermittent nature of the attacks. During the wet season, the fungus is able to germinate and disperse more readily, thus keeping the numbers of the insects low. It is concluded that there is one generation of Z. variegatus a year, with a peak in population coinciding with the dry season (November-March). It is suggested from the results that the grasshopper may have originated in the semi-arid zones of the north.

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Influence of the Abaeté River on the reproductive success of the neotropical migratory teleostProchilodus argenteus in the São Francisco River, downstream from the Três Marias Dam, southeastern Brazil

River Research and Applications ◽

10.1002/rra.859 ◽

2005 ◽

Vol 21 (8) ◽

pp. 939-950 ◽

Cited By ~ 50

Author(s):

Yoshimi Sato ◽

Nilo Bazzoli ◽

Elizete Rizzo ◽

Maria Beatriz Boschi ◽

Mario O. T. Miranda

Keyword(s):

Reproductive Success ◽

Southeastern Brazil ◽

Sao Francisco River ◽

São Francisco River

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Hydrogeological, hydrochemical, and natural isotopes evaluation of groundwater and surface water interactions in the alluvial plain, tropical region of southeastern Brazil

10.22541/au.163534840.02185492/v1 ◽

2021 ◽

Author(s):

Waldilene Correa ◽

Sueli Pereira ◽

Joaquim Ernesto Bernardes ◽

Paulo Ricardo Pereira

Keyword(s):

Surface Water ◽

Groundwater Flow ◽

Rainy Season ◽

Dry Season ◽

Alluvial Plain ◽

Morphological Features ◽

Southeastern Brazil ◽

Wet Season ◽

Natural Isotopes ◽

Abandoned Meanders

Groundwater-Surface water interactions in alluvial plains facing morphological features are the subject of the study. Considered transitions zones, alluvial plains have different morphological features interfering with groundwater flow and hydrochemistry. The alluvial plain of Mogi Guaçu river (southeastern Brazil) presented topography-controlled groundwater flow, nevertheless, natural levees, wet fields, oxbow lakes, and abandoned meanders can control local flow and interfere in discharges points of the main river. Two sampling water campaigns were done in the dry and wet season for physicochemical and natural isotopes analysis, collecting in total 44 groundwaters samples from monitoring wells and eight water samples from the river, creek, and lake. The groundwaters in wet fields and terraces, and surface waters from creek and lake presented low mineralization (EC from 8 to 37 μS.cm), pH acidic (4.98 to 5.8), and essentially Ca and Na-HCO composition. River waters samples presented pH between 5.92 e 7.69 (acidic in the rainy season and basic in the dry season), and EC from 24.2 and 181.1 μS/cm (lower values in the wet season), Na-HCO and Na-HCO-SO (dry season) and Ca-HCO and Na-HCO (rainy season) compositions. In dry season groundwaters composition showed evolution from sodium mixed (SO – HCO) to bicarbonate waters and higher mineralization; in wet season waters varied from Ca to Na-HCO composition and low mineralization, denoting dilution due to rainwater infiltration. Closer to the river margins, in abandoned meanders and oxbows, the groundwaters have increased values of EC and major ions indicating GW-SW mixtures, and effluent-influent changes (descendent and ascendent flux) in wet and dry seasons, respectively. Natural isotopes in groundwaters imply meteoric origin, without evaporation during recharge and high d-excess can be influenced by continental air masses and Amazonia Basin low-level jet. Shallow water table, permeable silty-sand material of vadose zone, flat terrain, and pristine conditions can contribute to direct infiltration of rainwaters, recharging the shallow aquifer.

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Seed-dispersing bird assemblages in riparian environments of a partially urbanized river basin, Southeastern Brazil

Brazilian Journal of Biology ◽

10.1590/1519-6984.230785 ◽

2020 ◽

Author(s):

B. F. Lessi ◽

M. G. Reis ◽

C. Z. Fieker ◽

M. M. Dias

Keyword(s):

Ecosystem Services ◽

Seed Dispersal ◽

Bird Species ◽

Dry Season ◽

Ecosystem Dynamics ◽

Southeastern Brazil ◽

Wet Season ◽

Frugivorous Birds ◽

Entire Area ◽

Number Of Individuals

Abstract Birds play a key role in ecosystem dynamics, including urban and rural areas, bringing environmental quality improvements and ecological stability. Species contribute directly to natural regeneration of vegetation and succession processes, by offering ecosystem services as seed dispersal, an important role in human-modified areas. We studied the assemblages of fruit-eating birds in riparian environments of Monjolinho basin, central São Paulo state, southeastern Brazil. Birds were recorded in 41 points distributed in riparian ecosystems alongside waterbodies, in landscapes with five types of surrounding matrices: urban, periurban, farmland, and native vegetation. We described how assemblages are structured aiming to evaluate the possible influence of seasonality and landscape type. We recorded 39 bird species that can play a role as seed-dispersers, 32 in wet season and 32 in dry season. There were no significant differences in the diversity and dominance of species between seasons considering the entire area, indicating stability of basic assemblage structure. However, total number of individuals of all species recorded in different landscapes were influenced by seasonality. Also, the composition and abundance of species significantly changed between seasons, leading to a high dissimilarity with almost 50% of the species contributing with almost 90% of the observed variation. A higher taxonomic diversity and distinctness pointed to a wider array of possible seed dispersal services in natural areas, while the lowest values of indexes were found in human-modified areas. The higher number of non-related bird species during dry season contrasted with the higher number of individuals during wet season, indicating that there is more possible ecosystem services offered by frugivorous birds in driest period of the year, while in the rainy period the carrying capacity of the riparian environments was increased.

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Temporal and spatial variation of fine roots in a northern Australian Eucalyptus tetrodonta savanna

Journal of Tropical Ecology ◽

10.1017/s0266467408004860 ◽

2008 ◽

Vol 24 (2) ◽

pp. 177-188 ◽

Cited By ~ 17

Author(s):

David P. Janos ◽

John Scott ◽

David M. J. S. Bowman

Keyword(s):

Fine Roots ◽

Soil Surface ◽

Dry Season ◽

Annual Rainfall ◽

Tropical Savannas ◽

Wet Season ◽

Temporal And Spatial Variation ◽

Deep Roots ◽

Temporal And Spatial ◽

Peak Abundance

Abstract:Six rhizotrons in an Eucalyptus tetrodonta savanna revealed seasonal changes in the abundance of fine roots (≤ 5 mm diameter). Fine roots were almost completely absent from the upper 1 m of soil during the dry season, but proliferated after the onset of wet-season rains. At peak abundance of 3.9 kg m−2 soil surface, fine roots were distributed relatively uniformly throughout 1 m depth, in contrast with many tropical savannas and tropical dry forests in which fine roots are most abundant near the soil surface. After 98% of cumulative annual rainfall had been received, fine roots began to disappear rapidly, such that 76 d later, less than 5.8% of peak abundance remained. The scarcity of fine roots in the upper 1 m of soil early in the dry season suggests that evergreen trees may be able to extract water from below 1 m throughout the dry season. Persistent deep roots together with abundant fine roots in the upper 1 m of soil during the wet season constitute a ‘dual’ root system. Deep roots might buffer atmospheric CO2 against increase by sequestering carbon at depth in the soil.

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