INTENSIVE FOOD SEARCHING IN HUMID PATCHES: ADAPTATION OF A MYRMICINE ANT TO ENVIRONMENTAL CONSTRAINTS

Behaviour ◽  
2001 ◽  
Vol 138 (2) ◽  
pp. 251-259 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
Leaf Litter ◽  
Prey Density ◽  
Experimental Situation ◽  
Dry Season ◽  
Environmental Constraints ◽  
Wet Season ◽  
Significant Difference ◽  
Intensive Search ◽  
Active Searching

AbstractWe tested if foragers of the ant Decamorium decem control the sinuosity of their food searching paths and their speed in order to concentrate their activity in areas of high prey density, humid patches of leaf-litter, during the dry season. In experimental situation I simulating the wet season (uniformly humid arenas) food searching paths were erratic and homing paths direct. In situation II simulating the dry season (dry arenas with a humidified disk) the sinuosity of the searching paths increased and the speed decreased when workers moved from the dry arenas to the humidified disks; homing paths were again direct. Thanks to comparisons with situation I, we argue that in situation II workers first oriented themselves toward the humidified disks (sinuosity significantly lower on the dry than on the wet arenas; non-significant difference for speed). Otherwise, we show that the intensive search on the humidified disks depends only on a decrease in speed (significantly lower on the humidified disks than on the wet arenas of situation I; non-significant difference for sinuosity), with workers switching from active searching to ambush when prey are absent.

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

2013 ◽  
Vol 13 (1) ◽  
pp. 70-73 ◽  
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.

Phenological changes in a Sumatran rain forest

1986 ◽  
Vol 2 (4) ◽  
pp. 327-347 ◽  
Author(s):  
C. P. Van Schaik
Keyword(s):  
Leaf Litter ◽  
Rain Forest ◽  
Seasonal Pattern ◽  
Dry Season ◽  
Wet Season ◽  
Phenological Changes ◽  
Young Leaves ◽  
Fig Trees ◽  
One Year ◽  
Made In

ABSTRACTPhenological observations were made in a Sumatran rain forest during three years (1980–1982). Phenological changes followed a consistent seasonal pattern. The abundance of young leaves and the fall of leaf litter peaked between December and February (first dry season); flowers were most abundant between January and April (first dry and first wet sea son), and ripe fruits in July-August (the second dry season). The fruit of strangling fig trees showed peaks in April and October, both wet season months. Within the study area there was variation in both the phase and the amplitude of the phenological cycles. One year, 1981, displayed mast flowering and fruiting. The observations indicate that the conditions for production were better during the mast year, a finding that facilitates our understanding of the evolution of mast fruiting.

scholarly journals THE EFFECT OF SEASONAL VARIATION ON PERFORMANCE OF EGG TYPE POULTRY: A Case Study of Mitchell Farms, Mosogar, Delta State, Nigeria

2021 ◽  
Vol 24 (2) ◽  
pp. 101-105
Author(s):  
E. E. Guobadia
Keyword(s):  
Seasonal Variation ◽  
Feed Intake ◽  
Egg Production ◽  
Management Practices ◽  
Secondary Data ◽  
Dry Season ◽  
Wet Season ◽  
Egg Hatchability ◽  
Significant Difference

The study was designed to find out the effect of seasonal variation on poultry in Delta State of Nigeria. The variables considered were mortality rate, feed intake, egg production and egg hatchability in the wet and dry seasons of the year. Secondary data were also collected from records kept in the farm. Sites 4AHI-BLK,5AKI-BLK, 9H/BF and 10H/BF were used for the study with each having an average of 2,500-3,500 birds of the same breed and sex aged 1-9 weeks and 21-52weeks. The records were grouped into dry season (October-March) and wet season (April-September) covering three years, 1991-1994. The analysis of the result showed that seasonal variation does not have any significant effect (P < 0.05) on mortality and feed intake in the two seasons. However percentage egg production and egg hatchability revealed a significant difference (P < 0.05) between the two seasons, with a mean % egg production and hatchability of 74±.03 and 80.6 in the wet season and 53.67±0.01 and 55.9 respectively in the dry season. Recommendation is therefore made for proper planning which ensures the utilization of wet and dry season management practices to reduce the effect of high humidity and embient temperature on production.

Home-range and den use of the mahogany glider, Petaurus gracilis

2000 ◽  
Vol 27 (1) ◽  
pp. 49 ◽  
Author(s):  
Stephen M. Jackson
Keyword(s):  
Home Range ◽  
Dry Season ◽  
Home Ranges ◽  
Adjacent Area ◽  
Wet Season ◽  
Male And Female ◽  
Fragmented Habitat ◽  
Significant Difference ◽  
Socially Monogamous ◽  
Males And Females

The home-range of the mahogany glider was estimated, and its social behaviour examined, by following radio-collared animals over a two-year period within an area of continuous habitat and an adjacent area of fragmented habitat. The average home range within the continuous habitat was 19.25 ha for males and 20.34 ha for females, with male and female pairs occupying a combined area of 23.15 ha. In contrast, the average home range in the fragmented habitat was 11.05 ha for males and 6.80 ha for females, with a combined home-range of male and female pairs being 11.60 ha. The average overlap of the home ranges of paired males and females was 85.9%, compared with approximately 11% for non-paired individuals, which suggests that mahogany gliders are socially monogamous. For a total of 46 nights on which gliders were considered to behave normally for the entire night, the average foraging distance was 1506 m (range 590–3420 m) with no significant difference between males and females in either the continuous or fragmented habitat. There was, however, a significant difference in the distance individuals travelled during different times of the year, with longer distances being travelled during late dry season/wet season and shorter distances during the early to mid dry season. Mahogany gliders also travelled further when there was a high availability of nectar and pollen than when there was lower availability. A total of 83 dens (tree hollows) were recorded for the mahogany glider, with the poplar gum, Eucalyptus platyphylla, forest red gum, Eucalyptus tereticornis, and Clarkson's bloodwood, Corymbia clarksoniana, being most used.

Population density, development and behaviour of Diopsis longicornis and D. apicalis (Diptera: Diopsidae) on rice in the Republic of Guinée

1993 ◽  
Vol 83 (1) ◽  
pp. 5-13 ◽  
Author(s):  
H. Chiasson ◽  
S.B. Hill
Keyword(s):  
Dry Season ◽  
Wet Season ◽  
African Countries ◽  
Planting Dates ◽  
Transplanted Rice ◽  
Significant Difference ◽  
Important Pest ◽  
Direct Seeded ◽  
The Republic ◽  
Diopsis Longicornis

AbstractThe behaviour and pest status of the rice stem borers Diopsis longicornis Macquart and D. apicalis Dalman were investigated in the Republic of Guinée, particularly during the dry season. The variables were direct seeded and transplanted rice, and three (1988, 1989) and four (1987) planting dates. Transplanted rice was damaged nearly three times more than direct seeded rice in the dry season, but no significant difference was detected during the wet season. As previously observed in other West African countries, D.apicalis only occasionally damages rice in Guinée. Contrary to findings elsewhere, D. longicornis was not an important pest of Guinean rice, infesting only 5% and 3% of stems over the three dry and the two wet seasons, respectively. However, year round rice production could promote build up of the diopsid population if dry season planting is not sufficiently delayed (45 days) after the last rains of the wet season.

Ground Surface Features Attributable to Feral Buffalo, Bubalus bubalis I. Their Distribution relative to Vegetation Structure and Plant Lifeform

1984 ◽  
Vol 11 (2) ◽  
pp. 303 ◽  
Author(s):  
JA Taylor ◽  
GR Friend
Keyword(s):  
Leaf Litter ◽  
Vegetation Structure ◽  
Ground Surface ◽  
Bubalus Bubalis ◽  
Dry Season ◽  
Northern Australia ◽  
Wet Season ◽  
Surface Features ◽  
Dense Vegetation ◽  
Lower Elevation

Relationships among ground surface features attributable to feral buffalo (viz. wallows, trails, pug marks and dung pats), vegetation structure, and lifeform spectrum were examined in both dry and wet seasons in a tropical monsoonal area of northern Australia. In the dry season, the frequency of pug marks was negatively correlated with the number of trails and dung pats, and positively correlated with the number of wallows. In the wet season only dung pats and wallows were significantly correlated. In the dry season, wallows were not associated with any vegetation structure or lifeform attribute, but in the wet season they were associated with dense foliage <1 m high. Trails occurred in areas of low dense vegetation (<0.5 m) in the dry season, but in the wet were uncommon and positively associated with lianas. Pug marks occurred mainly in the lower-elevation, treeless areas dominated by forbs. Whereas the nature and strength of the relationships of pug marks to plant lifeform or vegetation structure remained constant from season to season, those involving dung pats changed seasonally. In the dry season, dung pats were associated with the higher-elevation areas where trees, lianas, dense mid-level foliage (1.5-2.5 m) and leaf-litter were common. In the wet, they were associated with low vegetation (<1 m) dominated by forbs, and were negatively correlated with the factors important in the dry.

Effect of the red land crab (Gecarcinus lateralis) on leaf litter in a tropical dry forest in Veracruz, Mexico

1993 ◽  
Vol 9 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Martin Kellman ◽  
Bianca Delfosse
Keyword(s):  
Leaf Litter ◽  
Seasonal Pattern ◽  
Coastal Dunes ◽  
Dry Season ◽  
Dry Forest ◽  
Wet Season ◽  
Nutrient Pools ◽  
Land Crab ◽  
Litter Biomass ◽  
Gecarcinus Lateralis

ABSTRACTThe effect of the red land crab (Gecarcinus lateralis) on leaf litter biomass and nutrient transformation was investigated in a semi-deciduous tropical forest on coastal dunes using access and exclusion plots observed for six months. Crabs were in burrows during drought, but began foraging immediately after rainfall. Crabs accelerated litter disappearance significantly during the wet season at one site located beneath Brosimum alicastrum, but had no effect beneath a nearby Enterolobium cyclocarpum. The difference is tentatively attributed to small leaflet size in the latter species which crabs were unable to handle and consume. At both sites, litter in exdosures had approximately doubled by the end of the ensuing dry season. At the Brosimum site it is attributed to sporadic crab detritivory occurring after dry seasonal rains. At the Enterolobium site it is attributed to preferential retention of litter in the cxclosures during strong dry season winds. The nutrient content of litter exposed to, or protected from, crabs was not significantly different at either site and differences in litter nutrient pools reflected differences in litter biomass. Accelerated nutrient mineralization due to crab detritivory was concentrated early in the wet season before leaching began from the soils, and it is suggested that this altered seasonal pattern of mineralization may reduce the loss of nutrients from the site in percolating water.

Trypanosome infection rates inGlossina morsitans submorsitansNewst. in Northern Nigeria

1964 ◽  
Vol 55 (2) ◽  
pp. 219-231 ◽  
Author(s):  
A. M. Jordan
Keyword(s):  
Infection Rate ◽  
Dry Season ◽  
Tsetse Fly ◽  
Effect Of Temperature ◽  
General Effect ◽  
Northern Nigeria ◽  
Trypanosome Infection ◽  
Infection Rates ◽  
Wet Season ◽  
Significant Difference

Previous records and new data on trypanosome infection rates inGlossina morsitans submorsitansNewst. in Northern Nigeria are presented, and discussed in relation to the hosts fed on by this tsetse fly. The new observations were carried out in three areas: at Mando and Gamagira, both lying in a fly-belt north of Kaduna, and in the Yankari Game Reserve in Bauchi Province.Infection rates were obtained by dissection of flies, and the trypanosomes were identified by their locus; the validity of this method of identification is discussed. All infections withTrypanosomaspp. were attributable either to thevivaxgroup or to theconrgolensegroup; nobrucen-group trypanosomes were identified. More than 260 flies from each area were examined during March 1962, at the end of the dry season, and similar numbers during October 1962, at the end of the wet season.There was no significant difference between dry-season and wet-season infection rates in any area. Taking the two seasons together, the rate at Yankari (12%) was significantly higher than the rates at Mando (5%) and Gamagira (3%), which did not differ significantly. These contrasting infection rates could be related to the host species principally fed on by flies in the different areas as shown by blood-meal determinations. The lowest infection rates occurred where Suidae furnished a high proportion of meals (Mando, 51%; Gamagira, 67%) and Bovidae a small proportion (Mando, 16%; Gamagira, 9%). The high infection rate at Yankari was associated with a high proportion of Bovid meals (53%), especially from buffalo (Syncerus nanus) and bushbuck (Tragelaphus scriptus), and a lower proportion of Suid meals (33%). For the three areas the relationship between infection rate and percentage of Bovid meals was statistically significant.The species groups of infecting trypanosomes showed further contrasts between the three areas which were unrelated to the total infection rates. At Gamagira, 81 per cent, of infections werecongolensegroup, and this proportion was significantly higher than that at Mando (45%) or Yankari (37%). The differences could be related to the types of host from which blood-meals were principally derived. The highest proportion ofcongolense-group infections occurred where the highest percentage of meals came from Suidae (Gamagira, 67%), and lower proportions occurred at Mando and Yankari where Suid feeds were relatively fewer (51% and 33%, respectively).These findings are discussed in the light of existing evidence on the factors governing infection rates inGlossina. It is concluded that, within the over-riding influence exerted by temperature through geographical latitude, infection rates are determined by the type of host that forms the principal source of food. In some populations of Glossina the influence of the nature of the main food source can be sufficient to obscure the general effect of temperature in determining the level of infection. Some of the reasons for these relationships are discussed.

scholarly journals The effect of different pasture management strategies in north-west Queensland on liveweight gain and wool growth rate of several groups of young sheep.

1985 ◽  
Vol 7 (2) ◽  
pp. 75 ◽  
Author(s):  
RGA Stephenson ◽  
DA Pritchard ◽  
PM Pepper ◽  
PT Connelly
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Management Strategies ◽  
Live Weight ◽  
Dry Season ◽  
Wet Season ◽  
Pasture Management ◽  
North West ◽  
Wool Growth ◽  
Significant Difference

The effect of three different pasture management strategies on liveweight gain and wool growth rate of young(weaner) sheep was examined immediately after weaning on Mitchell grass-Flinders grass pastures during the dry season of north-west Queensland. The pasture management strategies were designed to mimic various industry situations, while the performance of four different progeny groups was compared and used to provide an overall assessment of pasture quality. Pasture treatments (experiment 1) consisted of three paddocks, a harvested (c. 8% of pasture harvested and baled) and spelled, a spelled, and a continuously grazed paddock. Spelled paddocks were not grazed during and after the wet season for a period of six months while the continuously grazed paddock was continuously stocked before the experiment. Experiment 2 consisted of spelled and continuously grazed paddocks. Pastures were evaluated by measuring the changes in composition and quality (experiment 1) and the responses in liveweight gain (experiments 1 and 2) and wool growth of the weaners (experiment 1). Marked improvements (c. 100%) in weaner growth rates occurred in the spelled paddocks. Greasy wool production by three groups of ewes in experiment I was about 14% greater in the harvested paddock than in the others. At the start of the trial there were no significant differences in dry matter yield but a significant difference in botanical composition occurred between paddocks. The changes in dry matter that occurred between the beginning and end of grazing were not significantly different between paddocks. Before gazing, forbs made up approximately 16%, 4% and 1% of pastures in harvested, spelled and continuously grazed paddocks respectively. The change in the percentage forbs that occurred between the beginning and end of the grazing period was significantly greater in the harvested paddock than in the other paddocks indicating preferential selection and intake by sheep. The differences in weaner live weight and wool growth between paddocks suggest that paddock management can improve weaner productivity. The study also indicates that paddock management could be successfully used to increase the percentage of forbs and quality of the pasture during the dry season. The superior wool growth of two progeny groups also suggests that improved productivity of breeding flocks in the tropics is possible if superior sheep can be identified. The results highlight the importance of preferential management of pasture for weaners so that productivity advantages can be exploited.

scholarly journals Aerobic Rice Production System(ARPS): Improving Productivity and Profitability in Water-Scarce Areas of Bulacan

2015 ◽  
pp. 44-53 ◽  
Author(s):  
Dinah Marie Dayag ◽  
Junel Soriano ◽  
Josie Valdez ◽  
Gregory Moses Villacorta
Keyword(s):  
Production System ◽  
Yield Components ◽  
Cropping System ◽  
Dry Season ◽  
Rice Production ◽  
Aerobic Rice ◽  
Wet Season ◽  
Significant Difference ◽  
Rainfed Lowland ◽  
Yield And Yield Components

On-farm study on rice-based cropping system following recent water-saving technologies for rice production such as ARPS-ARPS, ARPS-alternate wetting and drying (AWD) and existing or Farmers’ Practice (FP) was conducted in a rainfed lowland area in Brgy. Mataas na Parang, San Ildefonso, Bulacan. Field experiments were conducted from June to November 2011 for the wet season and December 2011 to March 2012 for the dry season. Variety used for the ARPS and AWD was NSIc Rc192 and PSB Rc18 for FP. Yield and yield components of the three treatments showed no significant difference during WS. Significant higher number of tillers hill was observed for ARPS-ARPS and -1 ARPS-AWD compared to FP. No significant difference was observed for the yield and yield components during the dry season (DS) for ARPS-ARPS and ARPS-AWD. FP was not established during the DS because of the unavailability of water during the time. During WS, ARPS was the most appropriate cropping system since this intervention obtained higher water productivity and ROI when compared with the FP. During the dry season, AWD and ARPS were suitable to the rainfed lowland areas of Bulacan. Results of this study showed that aerobic rice production system for the rainfed lowland areas improved water and land productivity as well as increased annual rice production and farmers’ income most particularly in ARPS-AWD which consistently gave the highest net income of PhP36,896.20, PhP14,417.50 and PhP51,313.70 during the Wet Season, Dry Season and for the total two cropping seasons, respectively

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