Chaco Chachalaca (Ortalis canicollis, Wagler, 1830) feeding ecology in a gallery forest in the South Pantanal (Brazil)

Cracids are generalist frugivores, which often exploit plant food resources such as flowers and leaves, mainly when fruit production declines. The Chaco chachalaca (Ortalis canicollis) is the most abundant cracid in the Pantanal (Brazil), and particularly common in the gallery forests. However, the factors related to their occurrence in this habitat type are unclear. In this study I describe the feeding habits and feeding niche breadth fluctuations of the Chaco chachalaca in relation to food resources abundance and diversity at the Miranda river gallery forest (Southern Pantanal). I also analyzed the relationships between Chaco chachalacas feeding activity and food resources abundance. This parameter (flowers and fruits) exhibited significant seasonal differences of abundance in which flowers were plentiful at the end of the dry, while fruits were abundant during the early wet season. However, food resources diversity to Chaco chachalacas exhibited no seasonal difference. Their feeding activity paralleled the availability of food resources, so that when some items were massively available an enhanced number of Chaco chachalacas foraged in the gallery forest, particularly during the prolonged dry season when they extensively used flowers and Genipa americana fruits. In fact, the Chaco chachalaca feeding niche breadth value presented low values in this period, while high values were common in the rest of the year. The flexible diet of this cracid, potentially favors their year round presence in the gallery forest, mainly during the prolonged dry season when the propensity for famine might be high. Since the Chaco chachalaca is among the largest and most abundant canopy frugivores in the gallery forest, it may contribute to forest regeneration, an underscored role due to the impact of annual floods and meandering dynamics on tree loss.

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Plant food resources exploited by Blue-and-Yellow Macaws (Ara ararauna, Linnaeus 1758) at an urban area in Central Brazil

Brazilian Journal of Biology ◽

10.1590/1519-6984.27312 ◽

2014 ◽

Vol 74 (2) ◽

pp. 429-437 ◽

Cited By ~ 8

Author(s):

AA. Santos ◽

J. Ragusa-Netto

Keyword(s):

Urban Areas ◽

Feeding Habits ◽

Feeding Activity ◽

Food Resources ◽

Food Plants ◽

Plant Food ◽

Native Plant ◽

Wet Season ◽

Mato Grosso ◽

Feeding Niche

In this study, we described the food plants available to Blue-and-Yellow Macaws (Ara ararauna), its feeding habits and the relationship between these parameters with feeding niche breadth. We established four transects, each one 12 km long, to sample fruiting plants and the feeding habits of this macaw (monthly 40 h, of observations), at the urban areas of Três Lagoas (Mato Grosso do Sul, Brazil). During all studied months, macaws foraged for palm fruits, mainly Syagrus oleracea and Acrocomia aculeata fruit pulp, both available all year, as well as Caryocar brasiliense and Anacardium occidentale seeds, in the wet season. The year-round feeding activity of macaws suggests Três Lagoas city as an adequate feeding area. The permanent availability of plant food resources, potentially, resulted from the diverse fruiting patterns of exotic and, mainly, native plant species, which provided a variety of suitable fruit patches.

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Seasonal changes in water quality and macrophytes and the impact of cattle on tropical floodplain waterholes

Marine and Freshwater Research ◽

10.1071/mf12114 ◽

2012 ◽

Vol 63 (9) ◽

pp. 788 ◽

Cited By ~ 17

Author(s):

N. E. Pettit ◽

T. D. Jardine ◽

S. K. Hamilton ◽

V. Sinnamon ◽

D. Valdez ◽

...

Keyword(s):

Water Quality ◽

Seasonal Changes ◽

Aquatic Macrophyte ◽

Plant Cover ◽

Critical Role ◽

Dry Season ◽

Nutrient Concentrations ◽

Wet Season ◽

Dry Tropics ◽

The Impact

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.

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Feeding habits and microhabitat utilization by two syntopic Brazilian Amazonian frogs (Hyla minuta and Pseudopaludicula sp. (gr. falcipes)

Revista Brasileira de Biologia ◽

10.1590/s0034-71081998000400003 ◽

1998 ◽

Vol 58 (4) ◽

pp. 559-562 ◽

Cited By ~ 19

Author(s):

M. VAN SLUYS ◽

C. F. D. ROCHA

Keyword(s):

Diet Composition ◽

Niche Breadth ◽

Feeding Habits ◽

Niche Overlap ◽

Microhabitat Use ◽

Feeding Niche ◽

Frog Species

We studied the feeding habits and microhabitat use of the Amazonian frogs Hyla minuta and Pseudopaludicula sp. at Serra Norte, Carajás, Brazil. Although living syntopically, the two species differed markedly in both prey types and sizes. Standardized feeding niche breadth of H. minuta (Bst = 0.572) was larger than that of Pseudopaludicula sp. (Bst = 0.149) and their feeding niche overlap was considerably low (10.5%). The two frog species also differed in microhabitat use. When active, Pseudopaludicula sp. were found partially submerged at the lake border whereas H. minuta were found predominantly on Nymphaea sp. leaves. Although we have not evaluated taxonomic effects on diet composition, differences in diet may be partially explained by differences in microhabitat use and frogs' size.

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Ecology of the Asian elephant in southern India. II. Feeding habits and crop raiding patterns

Journal of Tropical Ecology ◽

10.1017/s0266467400004004 ◽

1990 ◽

Vol 6 (1) ◽

pp. 33-53 ◽

Cited By ~ 111

Author(s):

R. Sukumar

Keyword(s):

Feeding Habits ◽

Natural Habitat ◽

Foraging Strategy ◽

Dry Season ◽

Southern India ◽

Crop Raiding ◽

Wet Season ◽

Seasonal Movement ◽

Food Requirement ◽

Optimal Foraging Strategy

ABSTRACTThe Asian elephant's foraging strategy in its natural habitat and in cultivation was studied in southern India during 1981–83. Though elephants consumed at least 112 plant species in the study area, about 85% of their diet consisted of only 25 species from the order Malvales and the families Leguminosae, Palmae, Cyperaceae and Gramineae. Alteration between a predominantly browse diet during the dry season with a grass diet during the early wet season was related to the seasonally changing protein content of grasses.Crop raiding, which was sporadic during the dry season, gradually increased with more area being cultivated with the onset of rains. Raiding frequency reached a peak during October-December, with some villages being raided almost every night, when finger millet (Eleusine coracana) was cultivated by most farmers. The monthly frequency of raiding was related to the seasonal movement of elephant herds and to the size of the enclave. Of their total annual food requirement, adult bull elephants derived an estimated 9.3% and family herds 1.7% in quantity from cultivated land. Cultivated cereal and millet crops provided significantly more protein, calcium and sodium than the wild grasses. Ultimately, crop raiding can be thought of as an extension of the elephant's optimal foraging strategy.

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A Comparative Frequency Analysis of Maximum Daily Rainfall for a SE Asian Region under Current and Future Climate Conditions

Advances in Meteorology ◽

10.1155/2017/2620798 ◽

2017 ◽

Vol 2017 ◽

pp. 1-16 ◽

Cited By ~ 7

Author(s):

Velautham Daksiya ◽

Pradeep Mandapaka ◽

Edmond Y. M. Lo

Keyword(s):

General Circulation ◽

Daily Rainfall ◽

Circulation Model ◽

Dry Season ◽

Wet Season ◽

Climate Conditions ◽

Rainfall Extremes ◽

Annual Maximum Daily Rainfall ◽

The Impact ◽

Maximum Daily Rainfall

The impact of changing climate on the frequency of daily rainfall extremes in Jakarta, Indonesia, is analysed and quantified. The study used three different models to assess the changes in rainfall characteristics. The first method involves the use of the weather generator LARS-WG to quantify changes between historical and future daily rainfall maxima. The second approach consists of statistically downscaling general circulation model (GCM) output based on historical empirical relationships between GCM output and station rainfall. Lastly, the study employed recent statistically downscaled global gridded rainfall projections to characterize climate change impact rainfall structure. Both annual and seasonal rainfall extremes are studied. The results show significant changes in annual maximum daily rainfall, with an average increase as high as 20% in the 100-year return period daily rainfall. The uncertainty arising from the use of different GCMs was found to be much larger than the uncertainty from the emission scenarios. Furthermore, the annual and wet seasonal analyses exhibit similar behaviors with increased future rainfall, but the dry season is not consistent across the models. The GCM uncertainty is larger in the dry season compared to annual and wet season.

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Seasonal Variation of Phthalate Esters in Urban River Sediments: A Case Study of Fengshan River System in Taiwan

Sustainability ◽

10.3390/su14010347 ◽

2021 ◽

Vol 14 (1) ◽

pp. 347

Author(s):

Kuan-Nan Lin ◽

Chiu-Wen Chen ◽

Chih-Feng Chen ◽

Yee Cheng Lim ◽

Chih-Ming Kao ◽

...

Keyword(s):

Phthalate Esters ◽

River Sediments ◽

Aquatic Organisms ◽

River System ◽

Dry Season ◽

Ecological Risks ◽

Total Risk ◽

Wet Season ◽

Potential Risks ◽

The Impact

The Fengshan River system is one of the major rivers in Kaohsiung City, Taiwan. This study investigated the concentration of eight phthalate esters (PAEs) in sediments of the river and the impact of potential ecological risks during the dry and wet seasons. The potential risk assessment of sediment PAEs was evaluated by adopting the total risk quotient (TRQ) method. The total PAEs concentrations (∑PAEs) in the sediments of the Fengshan River system are between 490–40,190 ng/g dw, with an average of 8418 ± 11,812 ng/g dw. Diisononyl phthalate (38.1%), bis(2-ethylhexyl) phthalate (36.9%) and di-isodecyl phthalate (24.3%) accounted for more than 99.3% of ∑PAEs. The concentration of ∑PAEs in sediments at the river channel stations is higher during the wet season (616–15,281 ng/g dw) than that during the dry season (490–1535 ng/g dw). However, in the downstream and estuary stations, the wet season (3975–6768 ng/g dw) is lower than the dry season (20,216–40,190 ng/g dw). The PAEs in sediments of the Fengshan River may have low to moderate potential risks to aquatic organisms. The TQR of PAEs in sediments at the downstream and estuary (TQR = 0.13) is higher than that in the upstream (TQR = 0.04). In addition, during the wet season, rainfall transported a large amount of land-sourced PAEs to rivers, leading to increased PAEs concentration and potential ecological risks in the upper reaches of the river.

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IMPACT OF COVID-19 EVENT ON AIR POLLUTANTS OF PM2.5 AND PM10 IN JAKARTA, INDONESIA

Journal of Southwest Jiaotong University ◽

10.35741/issn.0258-2724.56.4.12 ◽

2021 ◽

Vol 56 (4) ◽

pp. 117-140

Author(s):

Nora Idiawati ◽

Sepridawati Siregar

Keyword(s):

Air Quality ◽

Control Strategies ◽

Dry Season ◽

Capital City ◽

Future Research ◽

Air Pollution Control ◽

Wet Season ◽

Two Cities ◽

Pm2.5 And Pm10 ◽

The Impact

As the capital city of Indonesia, the Province of Jakarta encounter a problem seriously of decreasing air quality. This study analyzes the air quality of two cities in Jakarta Province, Central Jakarta and South Jakarta, from March to June 2016–2020, and the impact of COVID-19 epidemic prevention and control actions on air quality. The combined air quality index (AQI) for two cities from 2016–2019, in the wet season, indicated that it has the lowest AQI with an average of 79, and the highest AQI occurred in the dry season with averaged 118. The distribution of the six AQI classes for two cities in dry season were 2%, 24%, 63%, 11%, 0%, and 0%, and in wet season, they were 10%, 48%, 39%, 3%, 0%, and 0%, respectively. The concentrations for PM2.5 and PM10 in March, April, May, and June 2016–2019 and those for 2020 were also analyzed in this study. Based on the data from the two cities, during March, April, May, and June 2020, the average PM2.5 decreased by 23.6%, 39.5%, 41.5%, and 13.3%, respectively, and the average PM10 decreased by 22.2%, 29.9%, 36.9%, and 29.8%, respectively, compared with that in March, April, May, and June 2016–2019. It is obvious that air quality greatly improved during the COVID-19 epidemic. This study presents beneficial information to policymakers for developing scientific air pollution control strategies and is a useful reference for future research in improving urban air quality.

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Patterns of Fish Assemblage, Growth, and Diet Composition in a Tropical River between Two Cascading Hydropower Dams

International Journal of Ecology ◽

10.1155/2021/6652782 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Lee Nyanti ◽

Chen-Lin Soo ◽

Afina-Yian Chundi ◽

Elsa-Cordelia-Durie Lambat ◽

Alvinna Tram ◽

...

Keyword(s):

Fish Species ◽

Diet Composition ◽

Fish Assemblages ◽

Condition Factor ◽

Dry Season ◽

Growth Patterns ◽

Native Fish ◽

Wet Season ◽

Fish Samples ◽

The Impact

Construction of cascade dams has been shown to have impacts on fish assemblages and biodiversity. Yet, there is no literature on fish assemblages in the Murum River that connects the cascading Bakun and Murum dams in Sarawak, Malaysia. Hence, study on this modified ecosystem is necessitated to better understand the effects of the cascade dam construction on fish fauna. For this, fish samples were caught at five stations located along the river during both dry and wet seasons. Environmental parameters were taken concurrently with fish sampling. Length-weight relationship, condition factors, and diet composition of selected fish species in the river were also determined. The present study demonstrated that there are indications of the impact of cascading dams on the formation of a complex ecosystem in the Murum River, that is, changing from the shallow downstream of the Murum Dam to the deep transitional and inundated zone of the Bakun reservoir. The transitional zone in the Murum River exhibited the lowest fish species diversity, richness, and evenness during the dry season due to low pH and DO coupled with high turbidity. The biological indices improved when the water quality improved during the wet season. On the contrary, the diversity and evenness indices at the inundated tributary station decreased remarkably during the wet season, likely due to the migration of fish during the onset of the rainy season. This study showed that Barbonymus schwanenfeldii has a wider feeding habit which contributes to its higher distribution and abundance in the Murum River. The growth patterns of B. schwanenfeldii, Cyclocheilichthys apogon, Hampala macrolepidota, Lobocheilos ovalis, and Osteochilus enneaporos were better during wet than dry season. Overall, the condition factor of all native fish species in the Murum River was in poor to fair condition, whereas the exotic species, Oreochromis mossambicus, exhibited excellent condition (K value > 2) for both seasons. The increase in the number of O. mossambicus coupled with its high condition factor indicates biological intrusion and a potential threat to the native fish species in the Murum River. Continuous monitoring is essential to detect in-time risk issues associated with environmental degradation and biological invasion in this regulated and inundated river ecosystem.

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Trophic ecology of two piranha species, Pygocentrus nattereri and Serrasalmus marginatus (Characiformes, Characidae), in the floodplain of the Negro River, Pantanal

Acta Limnologica Brasiliensia ◽

10.1590/s2179-975x2014000400006 ◽

2014 ◽

Vol 26 (4) ◽

pp. 381-391 ◽

Cited By ~ 9

Author(s):

Fabiane Silva Ferreira ◽

Wagner Vicentin ◽

Fábio Edir dos Santos Costa ◽

Yzel Rondon Súarez

Keyword(s):

Trophic Ecology ◽

Niche Breadth ◽

Feeding Activity ◽

Interspecific Variation ◽

Dry Season ◽

Ontogenetic Changes ◽

Flood Season ◽

Negro River ◽

Main River ◽

Main River Channel

AIM: This study aimed to evaluate influence of hydrological variation, ontogeny and interspecific variation in the feeding activity and diet composition for P. nattereri and S. marginatus in floodplain of Negro River, South Pantanal. METHODS: The samples were taken with the use of gillnets and cast nets of different sizes, from October/2005 to August/2008. RESULTS: We sampled 748 specimens, 442 of P. nattereri and 306 of S. marginatus. We identified 31 items in the dry and 14 in the flood season for P. nattereri, and 29 items in the dry and eight in the flood season for S. marginatus. For both species, fish was the predominant food item in both seasons. The PERMANOVA results showed that the diet varied significantly between the two species (p<0.001), during ontogenetic development (p<0.001) and seasonally (p=0.024). The ancova results suggests that the intensity of food intake was higher in the dry season (p<0.001) for both species. The niche breadth varied only between studied species with S. marginatus presenting higher niche breadth than P. nattereri. CONCLUSION: Piranhas feed more during dry season, probably because in this period food is more varied and abundant, due to the concentration of fish in the main river channel. There were ontogenetic changes in the diet, with no feeding overlap between the two species, probably because of differences in preference for some items and differences in feeding behavior displayed during hunting attacks.

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Amplification of black carbon light absorption induced by atmospheric aging: temporal variation at seasonal and diel scales in urban Guangzhou

10.5194/acp-2019-654 ◽

2019 ◽

Author(s):

Jia Yin Sun ◽

Cheng Wu ◽

Dui Wu ◽

Chunlei Cheng ◽

Mei Li ◽

...

Keyword(s):

Optical Properties ◽

Organic Carbon ◽

Black Carbon ◽

Light Absorption ◽

Dry Season ◽

Diurnal Fluctuation ◽

Absorption Enhancement ◽

Wet Season ◽

Diurnal Variability ◽

The Impact

Abstract. Black carbon (BC) is an important climate forcer in the atmosphere. Amplification of light absorption can occur by coatings on BC aerosols, an effect that remains one of the major sources of uncertainties for accessing the radiative forcing of BC. In this study, the absorption enhancement factor (Eabs) was quantified by the minimum R squared (MRS) method using elemental carbon (EC) as the tracer. Two field campaigns were conducted in urban Guangzhou at the Jinan university super site during both wet season (July 31–September 10, 2017) and dry season (November 15, 2017–January 15, 2018) to explore the temporal dynamics of BC optical properties. The average concentration of EC was 1.94 ± 0.93 and 2.81 ± 2.01 μgC m−3 in the wet and dry seasons, respectively. Mass absorption efficiency at 520 nm by primary aerosols (MAEp520) determined by MRS exhibit a strong seasonality (8.6 m2g−1 in the wet season and 16.8 m2g−1 in the dry season). Eabs520 was higher in the wet season (1.51 ± 0.50) and lower in the dry season (1.29 ± 0.28). Absorption Ångström exponent (AAE470-660) in the dry season (1.46 ± 0.12) were higher than that in the wet season (1.37 ± 0.10). Collective evidence showed that the active biomass burning (BB) in dry season effectively altered optical properties of BC, leading to elevated MAE, MAEp and AAE in dry season comparing to those in wet season. Diurnal Eabs520 was positively correlated with AAE470-660 (R2 = 0.71) and negatively correlated with the AE33 aerosol loading compensation parameter (k) (R2 = 0.74) in the wet season, but these correlations were significantly weaker in the dry season, which may be related to the impact of BB. This result suggests that lensing effect was dominating the AAE diurnal variability during the wet season. The effect of secondary processing on Eabs diurnal dynamic were also investigated. The Eabs520 exhibit a clear dependency on secondary organic carbon to organic carbon ratio (SOC/OC). Eabs520 correlated well with nitrate, implying that gas-particle partitioning of semi-volatile compounds may potentially play an important role in steering the diurnal fluctuation of Eabs520. In dry season, the diurnal variability of Eabs520 was associated with photochemical aging as evidenced by the good correlation (R2 = 0.69) between oxidant concentrations (Ox=O3+NO2) and Eabs520.

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