scholarly journals Male-built nest volume varies with colony and the timing of the breeding season but not with the nesting-substrate quality and egg production in whiskered terns

2021 ◽  
Author(s):  
JEAN MARC PAILLISSON ◽  
Rémi Chambon
Keyword(s):  
Egg Production ◽  
Aquatic Vegetation ◽  
Selective Advantage ◽  
Laying Date ◽  
Species Variation ◽  
Substrate Quality ◽  
Whiskered Tern ◽  
Monogamous Species ◽  
Large Nest ◽  
Nesting Substrate

Nest building can represent an energetically-costly activity for a variety of animal taxa. Besides, the determinants of within-species variation in the design of nests, notably with respect to natural and sexual selection, are still poorly known although the situation has been partly remedied recently. Based on an observational study, we examined the influence of nesting conditions (nesting-substrate quality, colony, laying date, and year) on the volume of male-built nests and its potential role as a post-mating sexually-selected display in the whiskered tern Chlidonias hybrida, a monogamous species with obligate bi-parental care breeding on unstable aquatic vegetation beds. No relationship was found between the nest volume and the nesting-substrate quality (i.e. nest stability) indicating that the density of white waterlily leaves was large enough when whiskered terns breed. In contrast, building a large nest likely constitutes a selective advantage since nests were larger in less densely populated colonies and for early breeders whatever the year. Since being influenced by nesting conditions, the volume of male-built nests was unlikely to be a sexually selected trait in whiskered terns. The reproductive effort by females (the probability of laying one, two or three eggs, and variation in mean egg volume per clutch) was indeed not correlated with the volume of male-built nests. The fitness consequences of building a large nest are yet to be studied and additional investigations are recommended to better depict the participation of males early during breeding (including notably courtship feeding) and later to chick provisioning.

scholarly journals Natural Variation in Flight Performance is Related to Timing of Breeding in Tree Swallows (Tachycineta Bicolor) in New York

The Auk ◽  
2004 ◽  
Vol 121 (2) ◽  
pp. 345-353 ◽  
Author(s):  
Melissa S. Bowlin ◽  
David W. Winkler
Keyword(s):  
Egg Production ◽  
Natural Variation ◽  
Performance Test ◽  
Tachycineta Bicolor ◽  
Laying Date ◽  
Flight Performance ◽  
Individual Quality ◽  
Tree Swallows ◽  
Flight Ability ◽  
Clutch Initiation

Abstract In many avian species, including Tree Swallows (Tachycineta bicolor), females that lay eggs earlier in the season have higher fitness. It has been hypothesized that nonheritable variation in individual quality could explain how variation in laying date persists in the face of this apparently directional selection. Previous experimental work on Tree Swallows has suggested that natural variation in flight ability enables early-laying females to attain feeding rates high enough to support egg production on earlier, sparser food than later-laying females. We tested that hypothesis with standardized flights through a 9.75-m flight-performance test tunnel. One group of female swallows was tested at the height of the breeding season on 28 May regardless of their nesting phenology; another group was tested on the 11th day of incubation. Average acceleration in the tunnel was negatively correlated with clutch initiation date for the females tested on 28 May. Daily variation in ambient environmental conditions had strong effects on swallow flight performance in the tunnel, and no relationship was observed in the day-11 birds. Because natural variation in foraging performance is correlated with variation in female Tree Swallows' clutch initiation dates, flight ability appears to be a key element of individual quality in this species.

Variation in laying date, clutch size, egg size, and egg composition of yellow-headed blackbirds (Xanthocephalus xanthocephalus): a supplemental feeding experiment

1992 ◽  
Vol 70 (10) ◽  
pp. 1904-1911 ◽  
Author(s):  
Todd W. Arnold
Keyword(s):  
Food Availability ◽  
Egg Production ◽  
Egg Size ◽  
Energy Content ◽  
Laying Date ◽  
Food Supplementation ◽  
Supplemental Feeding ◽  
Xanthocephalus Xanthocephalus ◽  
Egg Composition ◽  
Nest Initiation

I studied the effects of food availability, habitat quality, and timing of breeding on egg production in yellow-headed blackbirds (Xanthocephalus xanthocephalus). Food availability was experimentally manipulated by providing females on six wetlands with supplemental food; six additional wetlands served as unsupplemented controls. Mean nest initiation dates varied by up to 6 d among wetlands, and supplementally fed blackbirds initiated nests 2 d earlier than controls, on average (although this latter difference was not quite significant; P = 0.07). Clutch size declined with laying date, but was unaffected by wetland location, food supplementation, or interactions between these two factors and laying date. Although egg size did not vary among wetlands or in relation to supplemental feeding, egg composition varied with both of these factors. All egg components except wet and dry shell and dry albumen varied among wetlands, whereas total water, wet yolk, and lean yolk were the only components that varied with food supplementation. Large blackbird eggs contained proportionately more water and albumen, but proportionately less yolk and shell. These patterns were somewhat compensatory, such that proportional protein and energy content did not vary with egg size; however, large eggs contained proportionately less fat than did small eggs. Proportional egg composition varied among wetlands (yolk and energy content), but was not affected by supplemental feeding. In general, egg production by yellow-headed blackbirds was not greatly affected by food availability. This may have been due to any of the following four factors: (1) inaccessibility of food supplements owing to competition between male and female blackbirds, (2) insufficient time for females to respond to food supplements, owing to rapid settlement and nest initiation, (3) a nutritionally inappropriate food supplement (i.e., protein availability may not have been enhanced among fed birds), or (4) superabundance of natural foods such that food availability was not limiting egg production.

scholarly journals Covariation of Clutch Size, Laying Date, and Incubation Tendency in the American Kestrel

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 570-578 ◽  
Author(s):  
Keith W. Sockman ◽  
Hubert Schwabl
Keyword(s):  
Environmental Factors ◽  
Clutch Size ◽  
Egg Production ◽  
Laying Date ◽  
Falco Sparverius ◽  
Free Living ◽  
American Kestrel ◽  
Proximate Mechanisms ◽  
American Kestrels ◽  
Seasonal Decline

Abstract Seasonal decline in clutch size is common in birds, but the proximate mechanisms for this phenomenon have not been elucidated. The most credible model to date posits that late-laying females lay fewer eggs due to a seasonal increase in the tendency to incubate during laying, which inhibits egg production. We tested this model with free-living and laboratory American Kestrels (Falco sparverius) by quantifying changes in clutch size and incubation tendency during laying over the course of the breeding phase. Consistent with the model, clutch size in free-living kestrels decreased while incubation increased with progress of the 74-day breeding phase. Inconsistent with the model, variation in incubation tendency during laying was not associated with clutch size in either the field or the laboratory. In the laboratory, incubation increased but clutch size did not decrease over the course of the 77-day breeding phase. In the laboratory, females that nested early in one breeding phase renested more quickly and nested in a second breeding phase more quickly than females nesting late in the first breeding phase. This indicates that timing of laying is, in part, a property of individual females, independent of environmental factors. Together, our findings suggest that both clutch size and timing of laying are inherent, correlated properties of particular females. Although incubation tendency may influence clutch size, other factors appear to override its influence. Covariación del Tamaño de la Nidada, la Fecha de Postura y la Tendencia de Incubación en Falco sparverius Resumen. Aunque la disminución estacional en el tamaño de la nidada es común entre las aves, los mecanismos proximales para este fenómeno no han sido elucidados. El modelo de mayor credibilidad propuesto hasta el momento sugiere que las hembras que ovipositan tarde ponen menos huevos debido a un aumento estacional en la tendencia a incubar durante la postura que inhibe la producción de huevos. Pusimos a prueba este modelo con individuos de Falco sparverius en condiciones naturales y en cautiverio, cuantificando los cambios en el tamaño de la nidada y la tendencia a incubar durante la postura a lo largo de la época reproductiva. Tal como el modelo plantea, el tamaño de la nidada en individuos silvestres de F. sparverius disminuyó mientras que la incubación aumentó a medida que transcurrían los 74 días de la época de reproducción. Mientras tanto, en contraste con el modelo, la variación en la tendencia a incubar durante la postura no estuvo asociada con el tamaño de la nidada ni en el campo ni en el laboratorio. En el laboratorio, la incubación aumentó pero el tamaño de la nidada no disminuyó en el transcurso de la época reproductiva (77 días). En condiciones de laboratorio, las hembras que anidaron temprano en una fase reproductiva volvieron a anidar más rápidamente en una segunda fase que las hembras que anidaron tarde en la primera. Esto indica que el tiempo en que se hace la postura es en parte una propiedad de cada hembra y es independiente de factores ambientales. En conjunto, nuestros hallazgos sugieren que tanto el tamaño de la nidada como el momento de la postura son propiedades correlacionadas de cada hembra en particular. Aunque la tendencia a incubar podría influenciar el tamaño de la nidada, otros factores parecen anular su influencia.

scholarly journals Recombination Rate Predicts Inversion Size in Diptera

Genetics ◽  
1999 ◽  
Vol 153 (1) ◽  
pp. 251-259 ◽  
Author(s):  
Mario Cáceres ◽  
Antonio Barbadilla ◽  
Alfredo Ruiz
Keyword(s):  
Recombination Rate ◽  
Selective Advantage ◽  
Species Variation ◽  
Physical Length ◽  
Adaptive Value ◽  
Intermediate Size ◽  
Common Observation ◽  
Recombination Length ◽  
Paracentric Inversions ◽  
Double Crossovers

Abstract Most species of the Drosophila genus and other Diptera are polymorphic for paracentric inversions. A common observation is that successful inversions are of intermediate size. We test here the hypothesis that the selected property is the recombination length of inversions, not their physical length. If so, physical length of successful inversions should be negatively correlated with recombination rate across species. This prediction was tested by a comprehensive statistical analysis of inversion size and recombination map length in 12 Diptera species for which appropriate data are available. We found that (1) there is a wide variation in recombination map length among species; (2) physical length of successful inversions varies greatly among species and is inversely correlated with the species recombination map length; and (3) neither the among-species variation in inversion length nor the correlation are observed in unsuccessful inversions. The clear differences between successful and unsuccessful inversions point to natural selection as the most likely explanation for our results. Presumably the selective advantage of an inversion increases with its length, but so does its detrimental effect on fertility due to double crossovers. Our analysis provides the strongest and most extensive evidence in favor of the notion that the adaptive value of inversions stems from their effect on recombination.

Impact of Wildfire on the Nesting behaviour of Birds in Heathland

1991 ◽  
Vol 18 (3) ◽  
pp. 249 ◽  
Author(s):  
MG Brooker ◽  
I Rowley
Keyword(s):  
Western Australia ◽  
Egg Production ◽  
Abundant Species ◽  
High Rate ◽  
First Year ◽  
Nest Sites ◽  
Adequate Food ◽  
Nesting Behaviour ◽  
The Mean ◽  
Nesting Substrate

This paper describes the effects of wildfire on the nesting behaviour of some species of birds in a heathland community at Gooseberry Hill, Western Australia. The most severe fire during the nine year (1981-89) study was a hot summer burn in January 1985, which destroyed 95% of the study area. In the spring following that fire, 81% of the species previously known to breed in the area were still able to nest. The nesting substrate, height, site and aspect for three of the most abundant species (splendid fairy-wrens, western thornbills and yellow-rumped thornbills) were examined in detail. In the immediate post-fire year, all three used as nest sites only those plant species which regenerate by sprouting. The mean height of splendid fairy-wren nests in shrubs was lower than in unburnt habitat, although the wrens also built some nests in unusually high sites in trees in the first two seasons after fire. The mean height of western thornbill nests did not change but nest placement in a favoured substrate, Xanthorrhoea preissii, varied according to time since fire. Yellow-rumped thornbill nests built in burnt habitat tended to be higher and in a more restricted range of substrates than previously. Breeding of splendid fairy-wrens was delayed by three to five weeks in the first year after fire and the number of nests built per group had almost doubled by the second season. Only 59% of adult female western thornbills attempted to nest in the season immediately following the 1985 fire and the onset of breeding in burnt habitat was up to five weeks later than in unburnt. The delay by splendid fairy-wrens and western thornbills was attributed to a shortage of nesting material and adequate food for egg production, respectively, whereas the increase in the number of nests built by splendid fairy-wrens was attributed to a high rate of nest failure. At least two species (white-browed scrubwren and white-cheeked honeyeater) did not nest for two years after the 1985 fire and Acanthiza apicalis has not nested up to the present time (five years). The fire-modified habitat appeared beneficial to little button-quail and elegant parrot, which nested on the study area only after fire. White-winged triller and dusky woodswallow were more numerous breeders after fire than previously. Our findings highlight the importance of detailed long-term studies for estimating adequate fire-free intervals necessary for the conservation of resident avian species. A minimum period of at least 10 years is suggested for heathlands of south-western Australia.

scholarly journals Temperature has a causal effect on avian timing of reproduction

2009 ◽  
Vol 276 (1665) ◽  
pp. 2323-2331 ◽  
Author(s):  
Marcel E. Visser ◽  
Leonard J.M. Holleman ◽  
Samuel P. Caro
Keyword(s):  
Climate Change ◽  
Direct Effect ◽  
Egg Production ◽  
Causal Effect ◽  
Cold Treatment ◽  
Bird Species ◽  
Parus Major ◽  
Effect Of Temperature ◽  
Laying Date ◽  
Timing Of Reproduction

Many bird species reproduce earlier in years with high spring temperatures, but little is known about the causal effect of temperature. Temperature may have a direct effect on timing of reproduction but the correlation may also be indirect, for instance via food phenology. As climate change has led to substantial shifts in timing, it is essential to understand this causal relationship to predict future impacts of climate change. We tested the direct effect of temperature on laying dates in great tits ( Parus major ) using climatized aviaries in a 6-year experiment. We mimicked the temperature patterns from two specific years in which our wild population laid either early (‘warm’ treatment) or late (‘cold’ treatment). Laying dates were affected by temperature directly. As the relevant temperature period started three weeks prior to the mean laying date, with a range of just 4°C between the warm and the cold treatments, and as the birds were fed ad libitum, it is likely that temperature acted as a cue rather than lifting an energetic constraint on the onset of egg production. We furthermore show a high correlation between the laying dates of individuals reproducing both in aviaries and in the wild, validating investigations of reproduction of wild birds in captivity. Our results demonstrate that temperature has a direct effect on timing of breeding, an important step towards assessing the implication of climate change on seasonal timing.

scholarly journals Egg Composition in Relation to Female Age and Relaying: Constraints on Egg Production in Thick-Billed Murres (Uria Lomvia)

The Auk ◽  
2003 ◽  
Vol 120 (3) ◽  
pp. 645-657 ◽  
Author(s):  
J. Mark Hipfner ◽  
Anthony J. Gaston ◽  
Gene R. Herzberg ◽  
John T. Brosnan ◽  
Anne E. Storey
Keyword(s):  
Amino Acid ◽  
Biochemical Composition ◽  
Egg Production ◽  
Adult Survival ◽  
Laying Date ◽  
Egg Mass ◽  
Uria Lomvia ◽  
Protein Amino Acid ◽  
Shell Mass ◽  
Young Females

Abstract There is growing awareness that costs associated with egg production play a significant role in shaping avian life histories. The life-history strategy of the Thick-billed Murre (Uria lomvia), a colonial, cliff-breeding seabird of Arctic waters, is characterized by a high annual adult survival rate, deferred breeding, and laying of a single-egg clutch. The single-egg clutch is a widespread phenomenon among seabirds and is generally thought to reflect demands of chick provisioning, rather than egg production. We compared composition of eggs laid by Thick-billed Murres most likely to be physiologically constrained in their capacity to produce eggs (young females with no prior experience, and females forming replacement eggs) to that of first eggs laid by early laying females (typically older, more experienced members of the population). Young, inexperienced females laid 4–18 days past the populationwide median laying date, and their eggs averaged 13% lighter in mass than those laid by early layers. Compared to early laid eggs, shell mass on young females’ eggs was similar to that predicted from egg mass, but their eggs had a lower yolk-to-albumen ratio. There was little difference between the two groups in relative protein content of albumen, relative protein or lipid content of yolk, or amino acid makeup of protein in yolk or albumen. Replacement eggs averaged 6% lighter in mass than first eggs laid by the same females earlier that season. As with young females’ eggs, replacement eggs had shells similar in mass to that predicted from egg mass, but lower yolk-to-albumen ratios, when compared to early laid eggs. Both protein and lipid concentrations in yolk were similar in first and replacement eggs, but replacements were deficient in albumen protein. Amino acid makeup of protein in yolk and albumen was similar in the two groups. Those results suggest that any limitations on egg production acting on young, inexperienced females are manifested in delayed laying and reductions in overall egg mass and proportional yolk content, but not in variation in biochemical composition of their eggs. Limitations on females forming replacement eggs are manifested not only in reduced egg mass and yolk content (as with young females), but also in changes in the biochemical composition of eggs; in particular, evidence suggests that relaying females may face a deficit of endogenous protein. The existence of such limitations suggests that demands of egg production can be significant even in a species that lays a single-egg clutch.

Variation in the stability of cockatiel (Nymphicus hollandicus) pair relationships: the roles of males, females, and mate compatibility

Behaviour ◽  
2004 ◽  
Vol 141 (10) ◽  
pp. 1211-1234 ◽  
Author(s):  
James Millam ◽  
Tracey Spoon ◽  
Donald Owings
Keyword(s):  
Social Interactions ◽  
Emergent Properties ◽  
Species Variation ◽  
Monogamous Species ◽  
The Social ◽  
Nymphicus Hollandicus ◽  
Opposite Sex ◽  
Males And Females ◽  
The Stability

AbstractPair relationships and their emergent properties represent potentially significant sources of proximate and ultimate influence on mating systems, but the study of such relational factors has been rare compared to the volume of literature dedicated to individual-level measures of mate quality. This study assessed variation in the stability of pair relationships in cockatiels (Nymphicus hollandicus) and sought sources for that variation in both the behavior of mated individuals and their compatibility. Pair relationships represent an especially salient aspect of the social system of cockatiels, a socially monogamous species with long-term pairing.In a semi-natural, captive setting, this study compared (1) the social interactions between cockatiel mates to those individuals' interactions with opposite-sex non-mates, (2) the roles of males and females in pair relationships, and (3) the various pairs in their displays of intrapair and extrapair interactions. We also assessed the behavioral features underlying pair relationships by examining the interrelationships among social behaviors within pairs and the degree to which emergent properties structure pair relationships. Interactions between mates, as compared to opposite-sex non-mates, were characterized by closer proximity, greater behavioral synchrony, less aggression, more allopreening, and greater sexual behavior. Males and females displayed little dimorphism in many intrapair and extrapair behaviors; however, males approached and courted their mates more than females did, and males but not females exhibited more intersexual aggression to non-mates than to their mates. Social interactions between mates varied significantly among pairs in ways that reflected variation in the degree of behavioral compatibility between mates. In other words, suites of highly correlated behaviors characterized the interactions between mates such that pairs exhibiting greater affiliative or accordant behaviors exhibited less aggressive or discordant behaviors and vice versa. Emergent properties appeared to play an especially important role in compatibility. By examining significant within-species variation in pair relationships, this study complements the increasing knowledge of mating relationships gained from comparative studies and illustrates the importance of emergent, pair-level behavior in the maintenance of long-term monogamous pair-bonds.

Effects of substrate quality and annealing on defect structures at GaAs/Si interfaces

1987 ◽  
Vol 45 ◽  
pp. 340-341
Author(s):  
H. L. Tsai ◽  
J. W. Lee
Keyword(s):  
Growth Process ◽  
Molecular Beam ◽  
Substrate Surface ◽  
Lattice Misfit ◽  
Device Fabrication ◽  
Silicon Substrates ◽  
Defect Structures ◽  
Gaas Film ◽  
Substrate Quality ◽  
Gaas On Si

Growth of GaAs on Si using epitaxial techniques has been receiving considerable attention for its potential application in device fabrication. However, because of the 4% lattice misfit between GaAs and Si, defect generation at the GaAs/Si interface and its propagation to the top portion of the GaAs film occur during the growth process. The performance of a device fabricated in the GaAs-on-Si film can be degraded because of the presence of these defects. This paper describes a HREM study of the effects of both the substrate surface quality and postannealing on the defect propagation and elimination.The silicon substrates used for this work were 3-4 degrees off [100] orientation. GaAs was grown on the silicon substrate by molecular beam epitaxy (MBE).

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