Environmental, ontogenetic, and genetic variation in egg size of Pied Flycatchers

1993 ◽  
Vol 71 (8) ◽  
pp. 1534-1542 ◽  
Author(s):  
Jaime Potti
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Relative Volume ◽  
Laying Date ◽  
Territory Quality ◽  
Trade Off ◽  
Nest Boxes ◽  
Female Condition ◽  
Almost All ◽  
Breeding Seasons

Ontogenetic, genetic, and environmental variation in egg length, breadth, and volume were investigated in the Pied Flycatcher across four breeding seasons in central Spain. Egg length and breadth were poorly correlated and did not vary with laying date. There was an indication of decreasing egg breadth with increasing clutch size that may indicate a trade-off between both variables. Egg size increased with female condition and, independently, with territory quality. Mean egg size decreased with advancing female age, which is perhaps related to the increase of clutch size with age in this species. There were high, significant repeatabilities of almost all egg dimensions, including relative volumes of first and last eggs, among females, both within and between years. Also, nest boxes were repeatable in the relative volume of the last eggs of (different) females laying in them, suggesting an influence of territory quality on relative egg size. Territory quality also had positive influences on some egg measurements that were independent of female condition. Heritability, estimated by mother–daughter regression, was significant only for egg length. These results are discussed in relation to proximate constraints on egg formation, predictions from the brood-survival hypothesis, and a possible trade-off between clutch and egg sizes.

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.

Clutch and egg size of the tropical lizard Tropidurus torquatus (Tropiduridae) along its geographic range in coastal eastern Brazil

2008 ◽  
Vol 86 (12) ◽  
pp. 1376-1388 ◽  
Author(s):  
M. C. Kiefer ◽  
M. Van Sluys ◽  
C. F.D. Rocha
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Female Body ◽  
Egg Size ◽  
Reproductive Investment ◽  
Geographic Range ◽  
Minimum Size ◽  
Brazilian Coast ◽  
Female Body Size ◽  
Almost All

The tropidurid lizard Tropidurus torquatus (Wied, 1820) has a set of populations inhabiting coastal sand dune habitats (“restinga”) along the eastern Brazilian coast. Despite its wide geographic range, there is no information about geographic variation in reproductive features among its populations. In the present study we compared some reproductive aspects of females in 10 coastal populations of T. torquatus, aiming to evaluate to what extension they vary geographically. The minimum size at maturity was relatively similar to most populations, but mean female body size had a considerable variation. Clutch size of almost all coastal populations of T. torquatus had little variation and was composed predominantly of two eggs. Interpopulational variation in the mean egg volume was relatively wide and strongly influenced by the variation in mean female body size. The data of the present study indicated that females of almost all coastal populations of T. torquatus produce, predominantly, clutches with two eggs and invest more energy in egg size instead of clutch size, probably as a consequence of morphological and environmental factors. The increased reproductive investment in egg size was confirmed by the values obtained for the relative clutch mass, which remained relatively constant along the coastal geographic distribution of T. torquatus.

Female reproductive characteristics of the Balkan wall lizard (Podarcis taurica) in the northwestern periphery of its range

2010 ◽  
Vol 5 (3) ◽  
pp. 391-395 ◽  
Author(s):  
Katarina Ljubisavljević ◽  
Georg Džukić ◽  
Miloš Kalezić
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Breeding Season ◽  
Egg Size ◽  
Reproductive Traits ◽  
Species Range ◽  
Trade Off ◽  
Female Body Size ◽  
Female Reproductive Traits ◽  
Gravid Females

AbstractWe present data on the female reproductive traits of the Balkan wall lizard in the Deliblato Sand, a large continental sandland in the Pannonian area in the northwestern periphery of the species range. The clutch and egg characteristics of the population were investigated on the basis of clutches laid in laboratory conditions by gravid females captured in one locality. Balkan wall lizards produced at least two clutches in a breeding season. Individual females laid clutches of commonly two (range 1–4) eggs. The female body size had no effect on clutch and egg size. There was no trade-off between egg size and clutch size.

scholarly journals Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

2012 ◽  
Vol 58 (6) ◽  
pp. 820-827 ◽  
Author(s):  
Long-Hui Lin ◽  
Fei Mao ◽  
Ce Chen ◽  
Xiang Ji
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Traits ◽  
Egg Laying ◽  
Laying Date ◽  
Egg Mass ◽  
Size Number ◽  
Female Reproductive Traits ◽  
Clutch Mass

Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou (CZ), Jiangshan (JS) and Dinghai (DH), to study geographical variation in female reproductive traits. Egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern lati-tutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity (clutch size), greater reproductive output (clutch mass) and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population.

scholarly journals Age and Reproduction in Lesser Spotted Woodpeckers (Dendrocopos Minor)

The Auk ◽  
2001 ◽  
Vol 118 (3) ◽  
pp. 624-635 ◽  
Author(s):  
Ulf Wiktander ◽  
Ola Olsson ◽  
Sven G. Nilsson
Keyword(s):  
Clutch Size ◽  
Pair Bond ◽  
Egg Laying ◽  
Laying Date ◽  
Territory Quality ◽  
Differential Survival ◽  
Positive Effects ◽  
Pair Bonds ◽  
Term Pair ◽  
Dendrocopos Minor

Abstract We examined the influence of female age, male age, and pair-bond duration on start of egg-laying, clutch size, and number of young fledged in the Lesser Spotted Woodpecker (Dendrocopos minor). We also attempted to disentangle the relative influence of individual age and pair-bond duration on reproduction, because the effect of those factors may be confounded. Breeding performance improved with age in that old females started egg-laying earlier and old males raised more young than yearlings, and old pairs both started egg-laying earlier and raised more young than new pairs. Clutch size was not affected by age, but showed a strong negative relation with laying date. Late-laying yearling females experienced a lower survival, and the survival of yearling males showed a positive relation with fledgling production. That differential survival was a likely mechanism explaining the differences in reproductive performance between yearling and old birds. Several analyses suggested that pair-bond duration had independent positive effects on reproduction. Benefit of long-term pair-bonds appeared to depend upon repeated breeding with a particular partner. The mechanisms behind the benefit of remating with a particular partner remain unclear, however. We postulate that much of the patterns of age effects on reproduction in the Lesser Spotted Woodpecker may be caused by constraints posed by the territorial system and effects of territory quality, although effects of individual quality can not be excluded.

Breeding biology of the red-capped robin

2003 ◽  
Vol 51 (6) ◽  
pp. 533 ◽  
Author(s):  
Damian K. Dowling
Keyword(s):  
National Park ◽  
Predation Rate ◽  
Nesting Success ◽  
Breeding Biology ◽  
Laying Date ◽  
Breeding Ecology ◽  
Incubation Periods ◽  
Almost All ◽  
Breeding Seasons ◽  
Semi Arid

The breeding biology of the red-capped robin (Petroica goodenovii) (Petroicidae) was studied over two breeding seasons (2000–02) in Terrick Terrick National Park, Victoria. Breeding commenced in August and the last offspring fledged in January. Only females developed brood patches, built nests and incubated. However, both sexes fed the young. Clutch size ranged from one to three eggs, with a mean of 2.1, with clutches of three occurring relatively early in the season. For clutches of two, the period from laying of the first egg to hatching was 14 or 15 days, with a mean of 14.2. The time from hatching to fledging was 13–15 days, with a mean of 14. In all, 34% of nesting attempts successfully fledged offspring. On average, 0.62 fledglings were produced per nesting attempt, whilst 0.57 offspring reached independence. Nesting success peaked in October. Predation appears to be responsible for almost all nest failure, and predation rate varied over the season. Breeding pairs produced 0–3 broods per season (0–5 independent fledglings) and pairs that began nesting early in the season produced a greater number of independent offspring. Nestling weight was affected by both laying date and brood size. A comparative analysis within the Petroicidae, controlled for body size, revealed that species endemic to Australia have shorter incubation periods, and species from semi-arid and dry woodlands have longer incubation periods than other species. Findings from this study are discussed in relation to the breeding ecology of other members of the Petroicidae.

Egg and clutch size in the mallard as related to food quality

1991 ◽  
Vol 69 (1) ◽  
pp. 156-162 ◽  
Author(s):  
Olof Pehrsson
Keyword(s):  
Clutch Size ◽  
Food Quality ◽  
Negative Correlation ◽  
Egg Size ◽  
Common Factor ◽  
Wild Strain ◽  
Laying Date ◽  
Protein Food ◽  
In Captivity ◽  
In The Wild

The effect of food quality on egg and clutch size was studied in captive wild-strain and game-farm mallards, Anas platyrhynchos, and comparisons were made with various wild Swedish populations from different habitat types. Captive mallards laid larger eggs than wild birds. In captivity, game-farm ducks laid larger eggs than wild-strain birds, but when they were exposed to wild conditions the size was reduced. Captive ducks supplied with high-protein food laid larger eggs than ducks fed low-protein food. In the wild, there was a negative correlation between egg size and population density. Various wild Swedish populations showed similar egg-size variations among years, indicating some common factor operating outside the breeding season. In the food quality experiments, clutch size was positively correlated with egg size, but no correlation was found in wild populations. A negative correlation between clutch size and laying date, obtained in the wild, was not found in captivity. Egg and clutch sizes were both significantly smaller in a lake with food competition from fish than in an area rich in lakes empty of fish. When comparing egg characteristics of mallard populations it is important to distinguish between wild, captive wild-strain, and captive game-farm birds.

Inter and Intraspecific Relationships between Egg Size and Clutch Size in Waterfowl

The Auk ◽  
1988 ◽  
Vol 105 (1) ◽  
pp. 161-176 ◽  
Author(s):  
Frank C. Rohwer
Keyword(s):  
Clutch Size ◽  
Egg Production ◽  
Egg Size ◽  
Inverse Relationship ◽  
Oceanic Islands ◽  
Trade Off ◽  
Anas Discors ◽  
Intraspecific Relationships ◽  
Strong Inverse Relationship

Abstract Lack (1967, 1968a) proposed that clutch size of waterfowl and other birds with self-feeding young was limited by females' ability to produce eggs. Lack supported this egg-production hypothesis by showing a strong inverse relationship between egg size and clutch size within and among species of waterfowl. A reanalysis using updated data and more appropriate statistics failed to confirm Lack's results. Grouping all the waterfowl produced a weak (r2 = 0.13 inverse relationship between relative egg size and relative clutch size. This relationship was due mainly to a handful of ducks that nest on oceanic islands. Analyses by tribes showed that relative egg size and relative clutch size were inversely related in only 2 of the 8 major tribes of waterfowl. Finally, intraspecific analyses failed to reveal a trade-off between egg size and clutch size in Blue-winged Teal (Anas discors) and Northern Shovelers (A. clypeata). Similar intraspecific analyses for 12 other waterfowl have failed to show the predicted inverse relationship between egg size and clutch size. These results suggest that the widely accepted egg-production hypothesis may be considerably overemphasized.

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