scholarly journals Behavior, ecology and territory of the chestnut-bellied hummingbird, Saucerottia castaneiventris, in the xerophytic vegetation of the Chicamocha canyon of Colombia

2021 ◽  
Vol 16 (4) ◽  
pp. 501-520
Author(s):  
Gerson Marcel Peñuela Díaz ◽  
Ludy Archila-Durán ◽  
Jorge Parra ◽  
Juan E. Carvajal‑Cogollo

The Chestnut-bellied Hummingbird Saucerottia castaneiventris is an endemic hummingbird of Colombia, currently categorized as Near Threatened (NT) globally and as Vulnerable (VU) in Colombia. We characterize the territorial defense and foraging behaviors of S. castaneiventris hummingbird during different seasons of the year, and we determined the size of the S. castaneiventris territory and its relationship with floral abundance at different times of the year. We made four field trips between 2008 and 2009 and registered 19 individuals from S. castaneiventris. Of these, 10 were in the rainy periods, distributed in five territories (one male and one female for each). Eight were in the dry period (July), distributed in four territories. And one individual was in the dry period of February, which did not settle in any of the identified territories. Territorial defense occupied a large part of species’ time. The nectar drinking, and insect hunting were the most frequent activities. The most common floral resources were Opuntia dillenii, Tillandsia sp. and Aloe vera. The hummingbirds Chlorostilbon gibsoni and Doryfera ludoviciae shared habitats with S. castaneiventris and there were fluctuations in encounter rates between the seasons (C. gibsoni ER: 20–7.5 and D. ludoviciae and ER: 0.0–2.5). Territories ranged between 1800 and 3800 m2 for the dry season and between 1500 and 6500 m2 for the rainy season. Our results provided primary information on the ecology of S. castaneiventris and form the basis for the formulation of conservation strategies for the species and for its habitats..

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 240
Author(s):  
Rayonil Carneiro ◽  
Gilberto Fisch ◽  
Theomar Neves ◽  
Rosa Santos ◽  
Carlos Santos ◽  
...  

This study investigated the erosion of the nocturnal boundary layer (NBL) over the central Amazon using a high-resolution model of large-eddy simulation (LES) named PArallel Les Model (PALM) and observational data from Green Ocean Amazon (GoAmazon) project 2014/5. This data set was collected during four intense observation periods (IOPs) in the dry and rainy seasons in the years 2014 (considered a typical year) and 2015, during which an El Niño–Southern Oscillation (ENSO) event predominated and provoked an intense dry season. The outputs from the PALM simulations represented reasonably well the NBL erosion, and the results showed that it has different characteristics between the seasons. During the rainy season, the IOPs exhibited slow surface heating and less intense convection, which resulted in a longer erosion period, typically about 3 h after sunrise (that occurs at 06:00 local time). In contrast, dry IOPs showed more intensive surface warming with stronger convection, resulting in faster NBL erosion, about 2 h after sunrise. A conceptual model was derived to investigate the complete erosion during sunrise hours when there is a very shallow mixed layer formed close to the surface and a stable layer above. The kinematic heat flux for heating this layer during the erosion period showed that for the rainy season, the energy emitted from the surface and the entrainment was not enough to fully heat the NBL layer and erode it. Approximately 30% of additional energy was used in the system, which could come from the release of energy from biomass. The dry period of 2014 showed stronger heating, but it was also not enough, requiring approximately 6% of additional energy. However, for the 2015 dry period, which was under the influence of the ENSO event, it was shown that the released surface fluxes were sufficient to fully heat the layer. The erosion time of the NBL probably influenced the development of the convective boundary layer (CBL), wherein greater vertical development was observed in the dry season IOPs (~1500 m), while the rainy season IOPs had a shallower layer (~1200 m).


2021 ◽  
Vol 20 (1) ◽  
pp. 65-77
Author(s):  
O. A. OKUKENU ◽  
B. T. AKINYEMI ◽  
P. A. DELE ◽  
A. A. OLAJIDE ◽  
A.O. JOLAOSHO ◽  
...  

The research was carried was carried out to evaluate the chemical composition of the dominant grasses harvested from the natural pasture in selected villages in Ogun State, South-western Nigeria at different seasons. The study was carried out using a 4 × 6 factorial arrangement comprising four seasons (early rain, late rain, early dry and late dry) at six locations (Afami, Atokun, Ibooro, Ileniku, Ipaaya, and Okerori). Results showed that the crude protein (CP) content significantly (p<0.05) varied from 5.56 % for Okerori to 7.34 % for Ibooro and the grasses harvested at Afami had the highest (72.75 %) neutral detergent fibre (NDF) values with the least (68.75 %) value recorded for Okerori, while the acid detergent fibre (ADF) values ranged from 41.00 % for Atokun to 48.25 % for Okerori. Also, CP value as affected by the season ranged from 4.23 % for late rainy to 9.44 % for the early rainy season and NDF values from 67.33% for late dry to 72.33 % for late rainy season while the early dry season had the highest value (48.00 %) for ADF with the least value (40.33 %) was recorded for the early rainy season. The phosphorus (P) value was highest at Ipaaya (2.99 g/kg) with the least value observed at Okerori (1.62 g/kg). The value for calcium ranged from 2.55 g/kg at Afami to 6.59 g/kg at Okerori. The P value of grasses as affected by seasons ranged from 1.46 g/kg for early dry to 2.66 g/kg for early rainy seasons.


2001 ◽  
Vol 61 (3) ◽  
pp. 397-404 ◽  
Author(s):  
G. H. B. de MIRANDA ◽  
D. S. de FARIA

Ecological data about three free-ranging groups of C. penicillata (black-pincelled marmoset) were observed between March and December 1996, in one cerradão patch (in the Ecological Reserve of Brazilian Institute of Geography and Statistics, RECOR) and two patches of dense cerrado (one in the Recor and another in the Botanical Garden of Brasília, JBB), situated in the APA (area of environmental protection) of the Gama/Cabeça-de-Veado, Distrito Federal. Each area was visited weekly during three periods of two months -- end of the rainy season (01/04 to 31/05), dry season (16/06 to 15/08) and beginning of the rainy season (14/10 to 15/12) -- and instantaneous scan records at fifteen minute intervals were made for the vertical and horizontal position of each visible individual of the target group. The group size ranged between 4 and 11 elements. In September, the birth of twins in both groups of the Recor was observed. Home-range varied from 8.25 to 18.5 hectares, while density ranged from 0.4 to 0.82 ind/ha. Twenty two species of nine tree families were identified as exudate sources. Qualea grandiflora (Vochysiaceae), Vochysia thyrsoidea (Vochysiaceae), Scheflera macrocarpum (Araliaceae) and Qualea parviflora (Vochysiaceae) were more explored. Fruits (14 species, two of which were exotics), nectar, honey, arthropods (mainly orthopterans) and bird eggs complete their diet. The main sleep-tree species was Emmotum nitens (Icacinaceae). Data from different seasons and studied groups/areas were compared along previous data from this primate species in gallery forests. In the cerradão and dense cerrado areas C. penicillata had a similar group size, however a larger home-range and smaller density than in gallery forests were observed in this study.


2009 ◽  
Vol 69 (1) ◽  
pp. 75-85 ◽  
Author(s):  
LM. Rangel ◽  
LHS. Silva ◽  
MS. Arcifa ◽  
A. Perticarrari

Phytoplankton vertical and diel dynamics in a small shallow lake (Lake Monte Alegre, Ribeirão Preto, state of São Paulo) were investigated in two climatological periods: July 2001 (cool-dry season) and March 2002 (warm-rainy season). Monte Alegre is a eutrophic reservoir, with a warm polymictic discontinuous circulation pattern. The lake was thermally stratified in both periods, although dissolved oxygen varied less in the cool-dry period. Phytoplankton biomass was higher in the warm-rainy season and the vertical distribution was stratified in both seasons. Flagellate groups (Lm, Y, W1 and W2) and functional groups typical of shallow eutrophic environments (J, X1 and Sn) were important throughout the study period. The lake's thermal pattern strongly influenced the vertical distribution of the phytoplankton community in both periods. Biomass, functional groups and size classes of phytoplankton also were determined by the presence of more efficient herbivores in the lake, especially during the cool-dry period when phytoplankton biomass decreased.


2009 ◽  
Vol 69 (2) ◽  
pp. 231-240 ◽  
Author(s):  
MV. Cianciaruso ◽  
MA. Batalha

In South America, the largest seasonal savanna region is the Brazilian cerrado. Our aim was to study temporal changes in some community descriptors, such as floristic composition, richness, species density, plant density, and cylindrical volume, in a seasonal cerrado, comparing it to a nearby hyperseasonal cerrado. In four different seasons, we placed randomly ten 1 m² quadrats in each vegetation form and sampled all the vascular plants. Seasonal changes in floristic composition, species density, and plant density were less pronounced in the seasonal than in the hyperseasonal cerrado. Floristic similarity between the vegetation forms was lower when the hyperseasonal cerrado was waterlogged. Richness and species density were higher in the seasonal cerrado, which reached its biomass peak at mid rainy season. The hyperseasonal cerrado, in turn, reached its biomass peak at early rainy season and, despite the waterlogging, maintained it until late rainy season. In the hyperseasonal cerrado, waterlogging acts as an environmental filter restricting the number of cerrado species able to withstand it. The seasonal cerrado community was more stable than the hyperseasonal one. Our results corroborated the idea that changes in the environmental filters will affect floristic composition and community structure in savannas.


2014 ◽  
Vol 1010-1012 ◽  
pp. 1059-1063
Author(s):  
Wei Guan ◽  
Tao Fan ◽  
Xiu Qin Zhu

To elucidate the relationship between stable isotopes of precipitation (SIP) and the extreme drought in Kunming area, based on the stable isotopes data of the GNIP in Kunming site from 1986 to 2003, the precipitation line equation is brought forward and the seasonal change rule of stable isotopes are discussed. The stable isotopic compositions of precipitation exhibit great diversities in different seasons during to influences of multiple factors, such as monsoon, rainfall amount moisture source and others. The δ18O values in rainwater exhibit significant seasonal variations, the average of-10.12‰ in rainy season, the dry season is-4.5‰, having lower values in the rainy season and higher one in the dry season. The amount effect of precipitation is very distinct, that concealed the temperature effect. Got the special geographical position,dvalues present unique characteristics, the average ofdvalues is 10.78‰ in rainy season, and is 4.86‰ in dry season, the mean value is generally lower than most parts of the world.


2018 ◽  
Vol 2 (3) ◽  
Author(s):  
Ade Arinda ◽  
Eka Wardhani

 ABSTRAKAir Waduk Saguling saat ini menunjukkan penurunan, baik secara kualitas maupun kuantitas akibat aktivitas manusia yang menghasilkan limbah rumah tangga, industri, pertanian, peternakan, perikanan dan pertambangan. Salah satu pencemar di Waduk Saguling adalah logam berat. Penelitian ini bertujuan menganalisis konsentrasi Pb di perairan Waduk Saguling pada musim yang berbeda. Penelitian ini menggunakan data sekunder yang diperoleh dari PT Indonesia Power tahun 2008-2017. Data berasal dari tiga kedalaman yaitu kedalaman permukaan, tengah, dan dekat dasar perairan. Berdasarkan hasil penelitian menunjukkan konsentrasi Pb di musim kemarau lebih tinggi daripada musim hujan dan sebagian sudah melebihi baku mutu yang mengacu pada Peraturan Pemerintah No. 82 Tahun 2001 tentang Pengelolaan Kualitas Air dan Pengendalian Pencemaran Air untuk logam Pb sebesar 0,03 mg/L. Parameter pendukung yang di analisis yaitu parameter DO, pH, TDS, suhu, kekeruhan, dan kesadahan. Berdasarkan hasil analisis statistik menggunakan PCA, parameter yang paling mempengaruhi konsentrasi Pb di musim kemarau adalah kekeruhan dan suhu sedangkan musim hujan adalah TDS.Kata kunci: Musim, Pb, PCA, Waduk SagulingABSTRACTSaguling Water Reservoir currently shows a decline, both in quality and quantity due to human activities that produce domestic waste, industry, agriculture, livestock, fishery and mining. One of the pollutants in Saguling Reservoir is heavy metal. The research aims to analyze the concentration of Pb in the waters of Saguling Reservoir in different seasons. This research uses secondary data which is obtained from PT Indonesia Power in 2008-2017. The data comes from three depths: surface depth, center, and near bottom of water. Based on the results of the research shows that the concentration of Pb in the dry season is higher than the rainy season and some have exceeded the quality standard which refers to Government Regulation no. 82 of 2001 on the Management of Water Quality and Control of Water Pollution for Pb metal by 0.03 mg/L. The supporting parameters in the analysis are DO, pH, TDS, temperature, turbidity, and hardness parameters. Based on the results of statistical analysis using PCA, the parameters that most influence the concentration of Pb heavy metals in the dry season are turbidity and temperature and rainy season is TDS.Keywords: Season, pb, pca, saguling reservoi


2020 ◽  
Vol 32 ◽  
Author(s):  
Tatiane Araujo Santos ◽  
Thamires Souza Gonçalves ◽  
Patricia Silva do Nascimento ◽  
Cézar Augusto Freire Fernandes ◽  
Francisca Edna de Andrade Cunha

Abstract: Aim Identify seasonal variations in the diet of juvenile living in the estuary of the Parnaíba River Delta. Methods Food items were identified through analysis of stomach contents, and later submitted to analysis by regular methods for Frequency of Occurrence (FO), Frequency Numerical (FN), Gravimetric Frequency (FW) and Relative Importance Index (IRI). Results Juvenile diet of Elops saurus that inhabit the lagoons in the Parnaíba delta was composed in order decreasing of importance by Osteichthyes (Teleostei), Insecta and Crustacea in addition to Polychaeta and Nematoda. It was also observed a high frequency of occurrence of fragments of plastics in the diet. In the rainy season, 17 items were recorded in the diet, whereas in the dry season only 7 items were present. Relative Importance Index showed high presence of the Teleostei fish (69.93%) on diet of E. saurus during the rainy season, whereas during the dry period the insects of the families Corixidae (43.25%) and Dysticidae (39.16%). Conclusions With the study it was possible to identify that juvenile are piscivorous in the rainy season when there is a higher availability of prey in the environment and insectivores in the dry season when it reduces the supply of food, indicating feeding flexibility to environmental alterations.


Author(s):  
Berenice Aranda-Cuevas ◽  
Jorge Tamayo- Cortez ◽  
Lourdes Vargas y Vargas ◽  
Ignacio Islas- Flores ◽  
Víctor Arana- Argáez ◽  
...  

The present study evaluates the immunomodulatory effect of high molecular weight fractions of Aloe vera polysaccharides harvested during the dry season (March-April) and the rainy season (August-September). Peritoneal macrophages (MΦs) secluded from Balb/c mice underwent treatment with A. vera leaves extract and acemannan standard (the major component found in A. vera) and stimulated with lipopolysaccharides (LPS). Macrophage cell viability was assessed by the 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. Phagocytic activity was also evaluated in peritoneal macrophages, such as the production of nitric oxide and interleukin 6 (IL-6). In the results, found that the A. vera polysaccharides harvested during the rainy season stimulated the phagocytic activity with greater intensity than dry season and improvement NO and IL-6 production. No cytotoxic effect was found on cell viability and they cause a significant proliferative effect on macrophages in a concentration-dependent manner. It can be concluded that the A. vera polysaccharides harvested during the rainy season possessed a stronger immunostimulatory effect compared to the extracts from leaves obtained during dry seasons in a concentration-dependent manner without aff at the cell viability of macrophages.


Our Nature ◽  
2017 ◽  
Vol 15 (1-2) ◽  
pp. 44-54
Author(s):  
Govinda Shrestha ◽  
Shiva Kumar Rai

In this paper, a total 46 algae belonging to 34 genera and 3 classes (Chlorophyceae 54%, Bacillariophyceae 28%, Cyanophyceae 18%) have been reported from Rajarani Lake, Dhankuta, Nepal. Among these, 13 algae were reported as new to the country. Genera Ankistrodesmus, Closterium, and Desmodesmus had maximum number of species whereas 25 genera were represented by single species. Seasonal variation of algae showed that there was changing number and type of algae with physicochemical parameters in different seasons. Cyanophycean algae Microcystis flos-aque was dominant and observed in all sites in every collection of winter, summer and rainy seasons, and followed by bacillariophyceaean algae i.e., Aulacoseira granulata var. angustissima. The maximum number of algae was found in summer (59%) followed by winter (50%) and rainy (31%) seasons. There were 6 common algae found in all season’s viz. Ankistrodesmus falcatus, Aulacoseira granulata var. angustissima, Flagilaria tenera, Microcystis flos-aquae, Navicula radiosa and Oedogonium sp. Algae viz., Anabaena affinis, Cyclotella meneghiana, Pinnularia divergens, Pinnularia interrupta, Tetrastrum heteracanthum, and Ulothrix subtilissima were found only in winter season whereas, Aulacoseirsa granulata var. muzzanensis, Bolbochaete sp, Closterium striolatum, Cylindrospermum muscicola, Desmodesmus abundans, Desmodesmous quadricauda var.bicaudatus, Eunotia bilunaris, Gomphonema lacusrankaloides and Gomphonema pseudoaugur were observed only in summer. Similarly, Aphanocapsa pulchra, Oscillatoria sancta and Pediastrum duplex var. gracillimum were reported only in rainy season.


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