scholarly journals Shift in feather mite distribution during the molt of passerines: the case of barn swallows (Hirundo rustica)

2006 ◽  
Vol 84 (5) ◽  
pp. 729-735 ◽  
Author(s):  
R. Jovani ◽  
D. Serrano ◽  
Ó. Frías ◽  
G. Blanco
Keyword(s):  
Distribution Patterns ◽  
Hirundo Rustica ◽  
Feather Mites ◽  
Feather Mite ◽  
Stages Of Growth ◽  
Early Stages ◽  
Air Turbulence ◽  
Barn Swallows ◽  
High Diversity

Feather mites show a high diversity of distribution patterns on the wings of birds, but we are currently unable to make precise predictions about the distribution of mites on a given bird at a given time. This is especially intriguing because factors such as air turbulence, humidity, or temperature are already recognized as shaping feather mite distribution. We hypothesize that feather mites, rather than responding to single factors, respond at the same time to different constraints when deciding where to live. To test this hypothesis, we studied the distribution of mites along the wings of barn swallows ( Hirundo rustica L., 1758) in Europe before molting and in Africa during and after molt. Feather mite preferences shifted according to the stage of molt of the bird, with a pattern suggesting a clear compromise between being as close as possible to the non-molting distribution while avoiding the molt of the occupied feather and the early stages of growth of new feathers. Thus, we suggest that interacting factors, rather than single variables, must be studied to further advance the understanding of the distribution of feather mites on the wings of birds.

scholarly journals Population trends of passage and wintering barn swallows (Hirundo Rustica) in Peninsular Malaysia

2021 ◽  
Vol 880 (1) ◽  
pp. 012055
Author(s):  
N A Ismail ◽  
U N S Daud ◽  
S M Nor ◽  
M S Mansor
Keyword(s):  
Species Distribution Model ◽  
Land Use Changes ◽  
Geographical Area ◽  
Distribution Patterns ◽  
Peninsular Malaysia ◽  
Hirundo Rustica ◽  
Distribution Model ◽  
Barn Swallow ◽  
Barn Swallows ◽  
Using Data

Abstract In Peninsular Malaysia, passage and wintering Barn Swallows (Hirundo rustica) often congregate at nocturnal roosts in towns. As a Holarctic migratory species, it is at risk of population collapse. Despite extensive research, little is known about this species in its wintering grounds, especially in the tropics. This study aimed to determine how climate change influences the population growth of this species across a geographical area over a decade, from 2009 to 2019. A species distribution model was constructed using data obtained from the eBird database – a citizen science project – of records from diverse locations. We used the Kernel Density tool in ArcGIS to describe Barn Swallow density and expansion pattern across Peninsular Malaysia. We demonstrate that the Barn Swallow’s population has fallen by about 27.1% over the last decade. In 2009, the species was dispersed in two distinct areas: Perlis to Pulau Pinang; and the Pahang region bordering Selangor and Negeri Sembilan; in addition, some individuals chose to winter in south-eastern Johor. Within ten years, the flock has descended from Perlis to the northwest corner of Perak, while the vast wintering area in Pahang has decreased and stretched down to Melaka and Johor. The differences in Barn Swallow numbers and distribution patterns observed in this study could be a result of climate and land use changes which have caused this species to spread to parts of other wintering regions, altering the arrival and departure times of migration, thereby interfering with its breeding season.

Host–symbiont relationship and abundance of feather mites in relation to age and body condition of the barn swallow (Hirundo rustica): an experimental study

2005 ◽  
Vol 83 (8) ◽  
pp. 1059-1066 ◽  
Author(s):  
Péter László Pap ◽  
Jácint Tökölyi ◽  
Tibor Szép
Keyword(s):  
Reproductive Potential ◽  
Breeding Population ◽  
Hirundo Rustica ◽  
Laying Date ◽  
Tail Feather ◽  
Feather Mites ◽  
Second Year Of Life ◽  
Barn Swallows ◽  
Second Year ◽  
The Difference

We analyzed the host–symbiont relationship and factors determining the abundance of feather mites among individual barn swallows (Hirundo rustica L., 1758) in two different host populations during the breeding season and postbreeding period. By experimentally removing the feather mites from the flight feathers of the birds with an insecticide, we showed that these symbiotic organisms have neither harmful nor beneficial effects on the fitness of the host, supporting the view that mites are commensals. This was indicated by the lack of any difference in the change in wing-feather length, tail-feather length, fluctuating asymmetry in tail-feather length, breeding performance, and survival of the birds between the fumigated and control groups 1 year after the experiment. During the postbreeding period juveniles harbored fewer mites than adults and the difference was also significant between the 1-year-old birds and those over 1 year old in the breeding population. The number of mites did not change after the second year of life of the birds. We hypothesize that the difference in abundance of mites between the age classes can be explained by the low reproductive potential of the mites, which are not able to populate the exploitable space until the second year of life of the host. Alternatively, young birds might provide fewer resources than old birds. The significant negative association between the number of mites and the laying date of female barn swallows seems to support the conclusion that the abundance of mites is condition-dependent. Because there was no relationship between other condition indices for males and females and number of mites, further research is needed to confirm this conclusion.

Spherulitic crystal growth in the prodissoconch larval of Crassostrea virginica

1983 ◽  
Vol 41 ◽  
pp. 518-519
Author(s):  
George G. Cocks ◽  
Louis Leibovitz ◽  
DoSuk D. Lee
Keyword(s):  
Crystal Structure ◽  
Crassostrea Virginica ◽  
Crystal Orientation ◽  
Developmental Changes ◽  
Gastrula Stage ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Stages Of Growth ◽  
Early Stages ◽  
Initial Deposition

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.

Flight speed, foraging efficiency, and daily energy budget of the Barn Swallow, Hirundo rustica

1997 ◽  
Vol 75 (7) ◽  
pp. 1176-1183 ◽  
Author(s):  
Horacio de la Cueva ◽  
Robert W. Blake
Keyword(s):  
Doppler Radar ◽  
Flight Speed ◽  
Hirundo Rustica ◽  
Foraging Efficiency ◽  
Barn Swallow ◽  
Aerodynamic Model ◽  
Daily Energy ◽  
Energy Store ◽  
The Mean ◽  
Barn Swallows

Aerodynamic power equations predict optimal speeds at which birds ought to fly if they are to maximize time spent in the air on a given energy store (minimum power speed, Vmp), distance covered using a given amount of fuel (maximum range speed, Vmr), and rate of delivering food to the chicks in the nest (Vnest), or maximize the daily energy balance (VDBAL). With the aerodynamic model employed, these speeds are 5.3, 7.0, 7.9, and 8.9 m∙s−1, respectively, for the Barn Swallow, Hirundo rustica. A comparison of the predicted flight speed with both the mean and median flight speeds (8 m∙s−1 in both cases; n = 821) recorded with Doppler radar indicates that Barn Swallows fly at speeds not significantly different from Vnest. The true sample size was unknown, and realistic sample sizes are drawn with bootstrap procedures and compared with those given by the number of measurements (821); no significant differences were found. To test the model, energy requirements for growth, prey density, and time spent foraging were varied independently in a sensitivity analysis. Large but realistic changes in these three variables do not contradict the model and predict speeds within the range measured in the field.

scholarly journals Effects of different types of shelter on physiology and growth of Sangiovese vines during the first year after planting

2019 ◽  
Vol 13 ◽  
pp. 04020
Author(s):  
Giovan Battista Mattii ◽  
Eleonora Cataldo ◽  
Linda Salvi ◽  
Sofia Sbraci ◽  
Francesca Paoli ◽  
...  
Keyword(s):  
Water Potential ◽  
First Year ◽  
Gas Exchanges ◽  
Circular Section ◽  
Stages Of Growth ◽  
Early Stages ◽  
Single Leaf ◽  
Leaf Gas Exchanges ◽  
Different Types ◽  
Sprout Growth

In the early stages of planting, the shelter can provide for young vines protection against damage of various kinds. Despite their widespread use, few surveys have been devoted to the study of innovative shelter types and the possible influence of these protections on the physiology and development of plants. In the present experiment, which took place in 2017 in a Tuscan winery, the effects of vine protections by the company OSO (Prato) on single leaf gas exchanges and on the shoot growth in the first year of planting were studied. Three types of shelters with a circular section (completely perforated, partially perforated and closed) have been compared with the traditional full-wall shelters with square section. During the growing season, sprout growth measures, leaf area, leaf gas exchanges and water potential were carried out on the young vines. At the end of the season, shoots were sampled to measure the dry matter accumulated during the season. Among the shelters taken into consideration, it emerges that the completely perforated type guarantees the best development, with differences that are almost always significant for most of the measured parameters with traditional shelters. On the contrary, the closed typology has led to a reduction in growth, in gas exchanges and in water potential. In conclusion, the type completely perforated could constitute a valid alternative to the traditional one because, besides being a useful means for the protection of the vine, it could benefit the development of the root system in the early stages of growth.

Seed priming with cysteine modulates the growth and metabolic activity of wheat plants under salinity and osmotic stresses at early stages of growth

2016 ◽  
Vol 21 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Fatemeh Nasibi ◽  
Khosrow Manouchehri Kalantari ◽  
Roya Zanganeh ◽  
Ghasem Mohammadinejad ◽  
Hakimeh Oloumi
Keyword(s):  
Metabolic Activity ◽  
Seed Priming ◽  
Stages Of Growth ◽  
Early Stages

2D versus 3D competition at the early stages of growth for Ge on Si(001) by molecular dynamics

2002 ◽  
Vol 89 (1-3) ◽  
pp. 157-159 ◽  
Author(s):  
P Raiteri ◽  
M Celino ◽  
F Valentinotti ◽  
L Miglio
Keyword(s):  
Molecular Dynamics ◽  
Stages Of Growth ◽  
Early Stages
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