Breeding ecology of the fairy martin

1999 ◽  
Vol 47 (5) ◽  
pp. 463 ◽  
Author(s):  
Michael J. L. Magrath
Keyword(s):  
Breeding Season ◽  
Weather Conditions ◽  
Adult Mortality ◽  
First Year ◽  
Breeding Ecology ◽  
Adult Males ◽  
Annual Productivity ◽  
Adverse Weather ◽  
Colony Site ◽  
The One

The breeding biology of the fairy martin, Hirundo ariel, was studied over three years (1992–95) in the Yarra Valley, Victoria. Adult males and females in this population were morphologically similar, though only females acquired a brood patch during the breeding season. Colonies ranged in size from 8 to 29 nests. Birds arrived in the study area in September and usually commenced laying in October, though nesting activities were generally asynchronous both between and within colonies. Most colonies contained active nests until February. At least 16% of adults and 5% of fledglings, on average, returned to the study area in the following year. Returning adults generally nested at the same colony site as the previous year, while most first-year birds nested at sites other than their natal colony. Adult males were more likely to return than adult females. Clutch size ranged from 2 to 5, with a mean of 3.5, and declined over the season. The incubation period varied from 12 to 18 days with a mean of 13.7. A mean of 1.8 chicks fledged per completed clutch, while 60% of clutches produced at least one chick. The period from hatching to fledging varied from 17 to 32 days, with a mean of 22.1, and increased with brood size. Fledging success was highest during the middle of the breeding season. Adverse weather conditions, resulting in the abandonment of clutch and brood, were the most common cause of nest failure, and on several occasions also resulted in adult mortality. Almost half the breeding females produced at least two clutches in the one season. Pairs produced from 0 to 8 fledglings per season, with those that commenced nesting earlier in the season having higher annual productivity. These results are discussed in relation to the breeding ecology of other members of the Hirundinidae.

B. M. Bhatia. Indian Agriculture: A Policy Perspective. New'Delhi: Sage Publications India Pvt. Ud., 1988.191 pp.Rupees (Indian) 140.00 (Hardbound Edition).

1989 ◽  
Vol 28 (2) ◽  
pp. 164-167
Author(s):  
Khwaja Sarmad
Keyword(s):  
Green Revolution ◽  
Weather Conditions ◽  
Total Output ◽  
North West ◽  
Agriculture Sector ◽  
Indian Agriculture ◽  
The North ◽  
Total Food ◽  
Adverse Weather ◽  
The One

India is self-sufficient in the production of foodgrains, and in good years has substantial exportable surpluses. This is no small achievement for a country which, in the late Sixties, had to import as much as 13 percent of its requirements of foodgrains. The turnaround came as a result of the distribution of high-yielding seeds, fertilizer, modern agricultural technology, and provision of extension services. But agricultural growth has remained concentrated in the north-west of the country, which is well-endowed with infrastructures like irrigation, rural electrification, roads, markets, etc. By one estimate, these areas, which account for less than 15 percent of the total area under foodgrains cultivation in the country, have contributed as much as 56 percent of the increase in foodgrain production in the post-green· revolution period. No doubt, this has led to an increase in the regional disparities as well. Another serious imbalance in Indian agriculture has arisen because of cropwise disparities in growth, between foodgrains and non-foodgrains on the one hand, and among different foodgrains on the other. About 70 percent of the total cultivated area in the country is rain-fed, which contributes a large proportion of the total output of important crops like cereals, pulses, oilseeds, and cotton; and over 40 percent of the total food grains production of the country. But productivity in these areas is low and fluctuates according to the amount of rainfall. Dr Bhatia shows that stagnation in the agriculture sector has coincided not only with adverse weather conditions but also with adverse inputoutput price ratios, particularly between fertilizer and procurement prices of cereals.

scholarly journals Effects of Weather Conditions on Motorway Lane Flow Distributions

2018 ◽  
Vol 30 (1) ◽  
pp. 83-92
Author(s):  
Robert Rijavec ◽  
Darja Šemrov
Keyword(s):  
Traffic Control ◽  
Flow Distribution ◽  
Weather Conditions ◽  
Flow Perturbation ◽  
Lane Changes ◽  
Traffic Characteristics ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Snow Conditions ◽  
The One

Several factors affect the lane choices made by motorway drivers. According to the driving rules, the nearside lane is the one that is primarily used. The main reasons for lane changes are overtaking, congestion, or restrictions on other lanes. The empirical research presented in this paper presents comprehensive traffic characteristics observed in different traffic lanes on four-lane motorways in Slovenia. The research was focused on the influence of adverse weather conditions on the lane flow distribution, and on the speed of vehicles in different lanes. The lane flow and speed distributions both directly affect road capacity and safety; therefore, estimating these characteristics could improve the reliability of active traffic control when traffic flow perturbation is detected. Field test results show that lane flow distributions and lane speed distributions at a particular site vary depending on weather conditions, namely, dry, wet (rain), low-visibility, and snow conditions.

scholarly journals Breeding Ecology and Nest-Site Selection of Song Wrens in Central Panama

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 345-354 ◽  
Author(s):  
Tara R. Robinson ◽  
W. Douglas Robinson ◽  
E. Ceinwen Edwards
Keyword(s):  
Breeding Season ◽  
Site Selection ◽  
Nest Predation ◽  
Nest Site ◽  
Nest Site Selection ◽  
Breeding Ecology ◽  
Annual Productivity ◽  
Daily Nest Survival ◽  
Central Panama ◽  
Selection Of

Abstract We describe nest-site selection and report measures of breeding productivity from a population of Song Wrens (Cyphorhinus phaeocephalus) in central Panama. We studied 31 pairs from 1995 to 1998 and collected data on nest predation from 1996 to 1998. Song Wrens are year-round residents that build breeding nests for reproduction and dormitory nests for roosting. Twenty-five of 50 Song Wren breeding nests produced fledglings (daily nest survival rate = 0.968). Song Wrens usually (78%) placed their breeding nests in ant-defended acacias (Acacia melanoceras). However, nests placed in acacias did not experience lower rates of nest predation than nests placed in sites not defended by ants. The population-wide breeding season was seven months long, but individual pairs often bred within a span of only 2.5 months. Modal clutch size was two (n = 42), but the frequency of three-egg clutches was high (≥27%). Pairs that lost eggs or chicks renested more quickly than pairs that fledged young and attempted a second brood. Observed annual production of young was 1.4 fledglings per pair. Compared with other wrens, Song Wrens had a much longer breeding season and longer intervals between broods. The annual productivity of Song Wrens was the lowest recorded for any wren, which may have been due to smaller clutch sizes, long intervals between broods, and the correspondingly low number of nesting attempts per pair per year.

scholarly journals Reproductive success of the threatened Reed Parrotbill Paradoxornis heudei in non-harvested and harvested reedbeds in the Yangtze River estuary, China

2011 ◽  
Vol 22 (3) ◽  
pp. 339-347 ◽  
Author(s):  
ANTHONY BOULORD ◽  
ZHANG MEI ◽  
WANG TIAN-HOU ◽  
WANG XIAO-MING ◽  
FRÉDÉRIC JIGUET
Keyword(s):  
Breeding Season ◽  
River Estuary ◽  
Weather Conditions ◽  
Nesting Success ◽  
Conservation Strategies ◽  
Yangtze River Estuary ◽  
Nest Failure ◽  
Adverse Weather ◽  
Daily Nest Survival ◽  
The Impact

SummaryUnderstanding the factors that affect the nesting success of threatened birds is essential in designing effective conservation strategies. Here we compare nesting success of the Reed Parrotbill Paradoxornis heudei in annually harvested and non-harvested reedbed habitats in the Chongming Dongtan Nature Reserve in China, by recording the number of nestlings produced per nest and the causes of nest failure. We modelled daily nest survival rate (DSR) by considering the effects of harvesting, vegetation characteristics, year, date, advancement within the breeding season, nest age and nearest-nest distance, using the program MARK. Nest densities, but not the number of fledglings per nest, were significantly lower in harvested than non-harvested reedbed habitats. The best-fit DSR model estimated constant survival; none of the tested co-variables had significant effects. Moreover, harvesting did not affect the date of breeding initiation, likelihood of nest failure, or causes of nest failure, as vegetation cover was not significantly different between harvested and non-harvested reedbeds during the whole breeding season. Nest failure following adverse weather conditions was unusually common in harvested and non-harvested reedbeds, accounting for as many nest failures as depredation. However, comparisons with other studies suggest that deriving a conclusion on the impact of harvesting on nesting success is not straightforward and is probably linked to environmental characteristics affecting reed growth.

scholarly journals Tri-axial accelerometry shows differences in energy expenditure and parental effort throughout the breeding season in long-lived raptors

2021 ◽  
Author(s):  
Pascual LÓPEZ-LÓPEZ ◽  
Arturo M PERONA ◽  
Olga EGEA-CASAS ◽  
Jon ETXEBARRIA MORANT ◽  
Vicente URIOS
Keyword(s):  
Energy Expenditure ◽  
Parental Care ◽  
Breeding Season ◽  
Video Recording ◽  
Experimental Manipulation ◽  
Biparental Care ◽  
Breeding Ecology ◽  
Parental Effort ◽  
Ecological Data ◽  
Movement Trajectories

Abstract Cutting-edge technologies are extremely useful to develop new workflows in studying ecological data, particularly to understand animal behaviour and movement trajectories at the individual level. Although parental care is a well-studied phenomenon, most studies have been focused on direct observational or video recording data, as well as experimental manipulation. Therefore, what happens out of our sight still remains unknown. Using high-frequency GPS/GSM dataloggers and tri-axial accelerometers we monitored 25 Bonelli’s eagles (Aquila fasciata) during the breeding season to understand parental activities from a broader perspective. We used recursive data, measured as number of visits and residence time, to reveal nest attendance patterns of biparental care with role specialization between sexes. Accelerometry data interpreted as the Overall Dynamic Body Acceleration, a proxy of energy expenditure, showed strong differences in parental effort throughout the breeding season and between sexes. Thereby, males increased substantially their energetic requirements, due to the increased workload, while females spent most of the time on the nest. Furthermore, during critical phases of the breeding season, a low percentage of suitable hunting spots in eagles’ territories led them to increase their ranging behaviour in order to find food, with important consequences in energy consumption and mortality risk. Our results highlight the crucial role of males in raptor species exhibiting biparental care. Finally, we exemplify how biologging technologies are an adequate and objective method to study parental care in raptors as well as to get deeper insight into breeding ecology of birds in general.

scholarly journals Ship Handling in Unprotected Waters: A Review of New Technologies in Escort Tugs to Improve Safety

2021 ◽  
Vol 2 (1) ◽  
pp. 46-62
Author(s):  
Santiago Iglesias-Baniela ◽  
Juan Vinagre-Ríos ◽  
José M. Pérez-Canosa
Keyword(s):  
High Performance ◽  
New Technologies ◽  
Weather Conditions ◽  
Hull Form ◽  
Best Available Technologies ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
New Type ◽  
Technological Challenge ◽  
And Performance

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.

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