Factors affecting egg viability and incubation time in prairie dabbling ducks

1993 ◽  
Vol 71 (6) ◽  
pp. 1146-1152 ◽  
Author(s):  
Todd W. Arnold
Keyword(s):  
Clutch Size ◽  
Incubation Time ◽  
Egg Size ◽  
Hatching Success ◽  
Size Variation ◽  
Negative Effects ◽  
Factors Affecting ◽  
Ambient Temperatures ◽  
Weak Support ◽  
Anas Clypeata

I determined hatching success for 328 dabbling duck (Anas spp.) eggs that were experimentally subjected to varying lengths of preincubation delay and then artificially incubated. Hatchability declined as unincubated eggs were exposed to longer preincubation delays. This effect was more pronounced at higher ambient temperatures and later in the nesting season, but did not vary with egg size or among duck species. These results are largely consistent with observed patterns of clutch-size variation among prairie-nesting waterfowl. Clutch size may be smaller later in the year and at lower latitudes owing to the negative effects of date and temperature on the ability of eggs to withstand preincubation delay. The timing of embryo mortality was bimodal, with peaks occurring during early development (<6 d) and just before hatching (>22 d); however, only early mortality was affected by preincubation delay. Eggs lost up to 2.6% of their initial mass as water vapor during preincubation delay, but the amount of water loss did not affect hatching success. Eggs subjected to preincubation delay required about 1 additional day to hatch. Incubation time was related to egg size in northern shovelers (Anas clypeata) and in all species combined, but not in blue-winged teal (Anas discors) or mallards (Anasplatyrhynchos). These data provide only weak support for the hypothesis that large eggs are costly because they take longer to hatch.

Annual variation in common eider egg size: effects of temperature, clutch size, laying date, and laying sequence

1995 ◽  
Vol 73 (9) ◽  
pp. 1579-1587 ◽  
Author(s):  
Gregory J. Robertson
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Annual Variation ◽  
Size Variation ◽  
Egg Laying ◽  
Laying Date ◽  
Somateria Mollissima ◽  
Ambient Temperatures ◽  
Common Eiders ◽  
N 93

Annual variation in volumes of eggs laid by common eiders (Somateria mollissima sedentaria) nesting at La Pérouse Bay, Manitoba (58°43′N, 93°27′W), was studied over 3 years (1991–1993). Temperatures during the egg-laying period were higher in 1991 than in 1992 and 1993. However, the eiders began nesting in 1993 at the same time as in 1991, whereas in 1992 the eiders began laying approximately 2 weeks later. Eiders laid significantly smaller clutches in 1992 than in the other 2 years. Egg size did not correlate with clutch size or laying date in any year. However, eiders laid smaller eggs in 1992 and 1993 than in 1991. In five egg clutches, the pattern of intraclutch egg-size variation was different among years. The last laid eggs of five egg clutches were disproportionately smaller in 1992 and 1993 (cold years) than those laid in 1991. Minimum daily temperatures before the egg-laying period (during rapid yolk development) were positively correlated with egg size. However, this effect was not significant when year and egg sequence were controlled for. Egg-size variation was correlated with the overall ambient temperatures during the laying period, whereas annual clutch-size variation was correlated with laying date, suggesting that the proximate mechanisms affecting clutch and egg size are different.

Egg size and clutch size in three species of Nihonotrypaea (Decapoda: Thalassinidea: Callianassidae) from western Kyushu, Japan

2006 ◽  
Vol 86 (1) ◽  
pp. 103-111 ◽  
Author(s):  
K. Kubo ◽  
K. Shimoda ◽  
A. Tamaki
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Relative Size ◽  
Size Variation ◽  
Middle Part ◽  
Reproductive Period ◽  
Late Winter ◽  
Estuarine System ◽  
Ariake Sound ◽  
Interspecific Comparisons

Three species of the callianassid genus Nihonotrypaea occur in the Ariake Sound estuarine system, southern Japan; they consist of two tidal-flat species (N. harmandi; N. japonica) and one boulder-beach species (N. petalura), with maximum population densities of 1440, 343, and 12 ind m−2, respectively. Nihonotrypaea harmandi and N. petalura are distributed along the coastline from the outermost part of the sound to the open sea, while N. japonica occurs in the middle part of the sound. Nihonotrypaea japonica has an extended reproductive period from late winter to autumn, while those of the other species are from late spring or summer to autumn. Interspecific comparisons were made for recently laid egg size (as volume) and clutch size (as number of eggs per female). Only in N. japonica was a seasonal egg size variation observed, being significantly larger in winter to spring (mean=0.106 mm3) than in summer (0.080 mm3). By contrast, clutch size was significantly smaller in winter to spring, resulting in nearly the same clutch volume per female (product of the mean egg volume and clutch size) between the seasons. Among the three species, the egg size was ordered as N. japonica (overall mean volume through the seasons=0.092 mm3)>>N. petalura (0.057 mm3)>N. harmandi (0.054 mm3). The clutch size was ordered as N. harmandi>N. petalura≈N. japonica. The clutch volume was ordered as N. japonica≈N. harmandi>N. petalura. The smallest clutch volume value for N. petalura female showed an opposite trend to the relative size of the major cheliped found in a previous study.

Within-clutch egg-size variation in a subsocial bug: the positional effect hypothesis

2006 ◽  
Vol 84 (11) ◽  
pp. 1540-1544 ◽  
Author(s):  
Shin-ichi Kudo
Keyword(s):  
Predation Risk ◽  
Clutch Size ◽  
Egg Size ◽  
Size Variation ◽  
Instar Nymph ◽  
Offspring Size ◽  
Egg Mass ◽  
Female Body Size ◽  
Positional Effect ◽  
Effect Hypothesis

If there are differences in predation risk among the offspring within a clutch, parents should allocate less resources to the offspring facing higher risk. Predation risk, and thus offspring size, may depend on the spatial position of individual offspring within a clutch. To test this positional effect hypothesis, I examined egg-size (egg-mass) variation in the subsocial bug Elasmucha signoreti Scott, 1874 (Hemiptera: Acanthosomatidae). In subsocial insects, including Elasmucha , in which females guard their clutches against predators by covering the clutch with their bodies, there are large differences in survival between offspring at the centre and at the periphery of the clutch. There was considerable variation in reproductive output among females; female body size was positively correlated with egg mass but not with clutch size. Females laid significantly lighter eggs in the peripheral, and thus more vulnerable, part of the clutch. No phenotypic trade-off between egg mass and clutch size was detected. Egg mass was positively correlated with hatched first-instar nymph mass. Thus, E. signoreti females seem to allocate their resources according to the different predation risks faced by the offspring within a clutch. I suggest that the positional effect hypothesis can generally be applicable to species whose females lay eggs in clutches and that the eggs suffer different mortality rates which depend on their spatial positions within the clutch.

Egg size, contents, and quality: maternal-age and -size effects on house fly eggs

2000 ◽  
Vol 78 (9) ◽  
pp. 1544-1551 ◽  
Author(s):  
G S McIntyre ◽  
R H Gooding
Keyword(s):  
Clutch Size ◽  
Size Effects ◽  
Maternal Age ◽  
Egg Size ◽  
Egg Quality ◽  
Size Variation ◽  
House Fly ◽  
Egg Volume ◽  
Hatch Rate ◽  
Maternal Size

Egg size is generally regarded as a good predictor of egg quality. However, in phenotypic studies it is difficult to separate the effects of egg-size variation from the effects of the underlying cause of the differences in egg size. We examined the relationships between the size, shape, hatch rate, and biochemical and energy contents of house fly (Musca domestica L.) eggs using two distinct sources of egg-size variation: maternal age and maternal size. By comparing relationships among egg parameters between manipulations we were able to distinguish some maternal effects from pure egg-size effects. Maternal age was negatively correlated with clutch size, egg volume, hatch rate, and lipid content, but was not correlated with protein, carbohydrate, or energy content. Female size did not affect hatch rate or biochemical and energy contents, but was positively correlated with clutch size and egg volume. Partial correlation analyses revealed that egg-size variation due to maternal-age effects was unrelated to hatch rate, but that egg-size variation due to maternal-size effects was weakly negatively correlated with hatch rate. The results suggest that large and small house fly eggs differ primarily in size and that within size classes there is significant variation in other egg parameters. Size is not a useful predictor of egg quality in this system.

scholarly journals Reproductive biology of Cabot's Terns on Cardos Island, Santa Catarina, Brazil

2011 ◽  
Vol 11 (3) ◽  
pp. 75-81 ◽  
Author(s):  
Hélio Augusto Alves Fracasso ◽  
Joaquim Olinto Branco ◽  
Edison Barbieri
Keyword(s):  
South America ◽  
Reproductive Biology ◽  
Incubation Time ◽  
Egg Size ◽  
Hatching Success ◽  
Atlantic Coast ◽  
Nesting Success ◽  
Santa Catarina ◽  
Caribbean Islands ◽  
The Caribbean

Cabot's Terns Thalasseus acuflavidus (Latham, 1737) are widely distributed along the Atlantic coast of South America from the Caribbean Islands (12º S) to the region of Porto Deseado, Argentina (46º S). Daily observations were conducted on the Cardos Island during 2003, 2005 and 2006 to determine timing and nesting success, and the reproductive biology of the Cabot's Terns nesting there. The first adults arrived at the colony from 22 April to 15 May during the three years recorded; a total of 144 nests were recorded in 2003, 174 in 2005 and 50 in 2006. Observed incubation time was 24.1 ± 0.35 days, and mean egg size was 5.15 ± 0.02 cm in length and 34.30 ± 0.25 g in weight. Hatching success was lowest in 2003 and highest in 2006, with natural causes (such as nest abandonment, flooding, inter and intra-specific fight) being the main cause of loss. The first eggs hatched in July in 2003, and in June in 2005 and 2006. Overall nesting success was lowest (4.00%) in 2006 and much higher (36.1% and 27.01%, respectively) in 2003 and 2005.

scholarly journals Clutch and egg size variation in the Marsh Harrier Circus aeruginosus in eastern Poland

Ornis Svecica ◽  
2010 ◽  
Vol 20 (2) ◽  
Author(s):  
Marcin Polak
Keyword(s):  
Clutch Size ◽  
Strong Correlation ◽  
Egg Size ◽  
Size Variation ◽  
Fish Ponds ◽  
Egg Volume ◽  
Mean Values ◽  
Marsh Harrier ◽  
Circus Aeruginosus

The main aim of this study was to examine how clutch size and season influenced egg size in a population of Marsh Harriers Circus aeruginosus in eastern Poland. The Marsh Harriers nested in small, isolated patches of reed belts surrounding fish ponds. A total of 328 eggs from 70 clutches were measured during four nesting seasons (2005–2008). Average clutch size was 4.69 ± 0.71 eggs and did not vary between years; the modal clutch size was 5 eggs. Mean values of the egg dimensions were: egg length = 48.60 ± 1.78 mm; egg breadth = 38.36 ± 1.13 mm; egg volume = 36.53 ± 2.99 cm3. There was a strong correlation between egg length and egg breadth. The number of eggs in a clutch had no effect on the egg size.

Contrasting reproductive strategies in a narrow latitude range: the case of D’Orbigny’s slider

2017 ◽  
Vol 38 (4) ◽  
pp. 425-434
Author(s):  
Priscila Silva Lucas ◽  
Alex Bager
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Evolutionary Biology ◽  
Egg Size ◽  
Life History Theory ◽  
Geographical Area ◽  
Size Variation ◽  
Reproductive Traits ◽  
Maternal Body ◽  
Trade Offs

Reproductive traits and the level of parental investment in offspring varies between individuals and species. These are central issues in life history theory and evolutionary biology. Maternal body size plays an important role in reproduction, and we usually observe variable investment in offspring by females. Thus, optimal egg size may not be reached in some populations or species. In this study, we tested if reproductive traits differed between populations of D’Orbigny’s slider in a specific geographical area in Brazil. We evaluated the relationship between reproductive traits to maternal body size and clutch size to egg size to determine possible trade-offs across populations. At the population level, maternal body size and reproductive traits of D’Orbigny’s slider were different even in geographically nearby areas. Maternal body size had a positive effect on clutch size, but not on egg size, except in the Arroio Grande population. Nevertheless, we did not observe a negative correlation between clutch and egg size in any population. Although maternal body size had effects in the different populations explaining most of the variation of clutch size, variation in egg size may be the result of decreased survival chances in unpredictable environments and possibly morphological constraints. The trade-off between egg size and number was not observed and this could be expected if resource availability and reproductive allocation by females vary greatly among individuals.

Intraclutch egg-size variation and hatching success in the common eider

1993 ◽  
Vol 71 (3) ◽  
pp. 544-549 ◽  
Author(s):  
Gregory J. Robertson ◽  
Fred Cooke
Keyword(s):  
Egg Size ◽  
Hatching Success ◽  
Size Variation ◽  
Hudson Bay ◽  
Somateria Mollissima ◽  
Physiological Mechanisms ◽  
Common Eiders ◽  
Laying Sequence ◽  
The Common ◽  
Nutrient Reserves

Intraclutch egg-size variation and hatching success were studied in a population of Hudson Bay common eiders (Somateria mollissima sedentaria) at La Pérouse Bay, Manitoba (58°24′N, 94°24′W), to test the hypothesis that females allocate more nutrient reserves to eggs that are more likely to hatch. Egg volumes were calculated for 575 known-sequence eggs in 134 complete clutches of 3–6 eggs. In general, the length of eggs decreased linearly with position in the laying sequence, whereas the breadth of eggs followed a curvilinear pattern, the second or third egg being the widest. For all clutch sizes, the last-laid egg was the smallest and the second- or third-laid egg the largest. Hatching success also varied with position in the laying sequence. Pre-incubation failure declined over the laying sequence, whereas hatching failure (dead, infertile, or rotten eggs) increased. In all cases pre-incubation failure was the major cause of egg loss (84% of total loss). Overall, third and fourth eggs were the most successful and first eggs were the least successful. With one exception, successful and unsuccessful eggs were the same size within a laying sequence. We conclude that there is no clear relationship between egg size and hatching success, and that laying sequence per se has a greater effect on hatching success. Female eiders do not appear to allocate more reserves to eggs that are most likely to hatch, and we consider other proximate, physiological mechanisms to explain the observed pattern of intraclutch egg-size variation.

scholarly journals On clutch size and hatching success of the South American turtles Podocnemis expansa (Schweigger, 1812) and P. unifilis Troschel, 1848 (Testudines, Podocnemididae)

2003 ◽  
Vol 75 (4) ◽  
pp. 415-430 ◽  
Author(s):  
Paulo Emilio Vanzolini
Keyword(s):  
Regression Analysis ◽  
Geographic Variation ◽  
Clutch Size ◽  
Egg Size ◽  
Hatching Success ◽  
South American ◽  
Geographic Differentiation ◽  
Egg Volume ◽  
The South ◽  
Podocnemis Expansa

Data on clutch size and hatching success of P. expansa were gathered for seven beaches traditionally used by the species and re-analyzed statistically by means of regression analysis, of the number of eggs on the number of females (or nests) and of the number of young on the number of eggs. All regressions were linear, passed through the origin and had excellent fits. Average clutch size varied from 75 to 123, and presented geographic differentiation: (i) Rio Orinoco, (ii) Rio Trombetas + Rio Branco and (iii) Rio Juruá + Rio Purus. Average hatching success was ca. 83%. In P. unifilis there was also geographic variation in clutch size, the Iquitos area showing the highest values. Hatching success of P. unifilis was uniformly high: only one sample, from Iquitos, had less than 90% success. The outstanding fit of the clutch size regressions leads one to consider egg volume variability, which was found to be high in both species, in contradiction with current optimal egg size theory.

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