Clutch Initiation Dates, Clutch Size, and Egg Size of the American Oystercatcher in Virginia

The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 855-867 ◽  
Author(s):  
Erica Nol ◽  
Allan J. Baker ◽  
Michael D. Cadman
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Egg Laying ◽  
American Oystercatcher ◽  
Mode 2 ◽  
Haematopus Palliatus ◽  
Clutch Initiation ◽  
Mode 3 ◽  
One Year ◽  
Breeding Seasons

AbstractThe timing of egg laying, clutch size, and egg size of the American Oystercatcher (Haematopus palliatus) were studied over six consecutive breeding seasons in Virginia. Synchrony of laying dates occurred in each of five localities of the study area in at least one year. Mean clutch size was 2.8 eggs (mode = 3) in first clutches and 2.4 eggs (mode = 2) in replacement clutches. Individual females laid replacement clutches of the same size and laid eggs of similar average volume in all years. A change in mate had little effect on the date on which females initiated their first clutches in successive years. The average egg size in a clutch was correlated with the size of the laying female. Egg-size ordering occurred within clutches, the first-laid egg being smaller than the second egg and about equal in volume to the third. We propose that the second egg is largest because it has the highest probability of hatching, and the resulting sibling hierarchy reduces the frequency of sibling competition.

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.

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.

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.

Clutch size and egg size of spruce grouse in relation to spring diet, food supply, and endogenous reserves

1989 ◽  
Vol 67 (4) ◽  
pp. 969-980 ◽  
Author(s):  
Brian J. Naylor ◽  
James F. Bendell
Keyword(s):  
Body Weight ◽  
Clutch Size ◽  
Food Supply ◽  
Crude Protein ◽  
Egg Size ◽  
Follicular Development ◽  
Egg Laying ◽  
High Rate ◽  
Large Clutch ◽  
Endogenous Reserves

We examined the hypothesis that female spruce grouse (Dendragapus canadensis) rely entirely on their spring diet or endogenous reserves for the nutrients required for clutch formation. Spring food habits of 40 radio-tagged hens were documented by direct observation (21 262 min) during the period encompassing oviducal recrudescence, follicular development, and egg laying (late April – late May 1984 – 1986) and compared with clutch size and mean egg weight. Hens consumed conifer foliage, flowers, fruits, and foliage of ground plants, grit, and arthropods. Compared with their prebreeding diet, foods preferred in spring were rich in protein and P, but not necessarily Ca. Large clutch size was associated with a high rate of intake of the two most preferred foods, flowers of trailing arbutus (Epigaea repens) and spore capsules of Polytrichum mosses, and crude protein, P, and Ca, but was not related to the size of hens (body weight) or the size of endogenous reserves (scaled body weight). Egg size was not associated with spring diet or the size of endogenous reserves, but appeared to be related to the size of hens. Rate of intake of arbutus flowers and moss capsules was correlated with their availability on territories, suggesting that clutch size might have been proximately limited by food supply. However, rough estimates of nutrient intake suggested that the spring diet provided only about 60% of the protein and 45% of the Ca needed for clutch formation. Consequently, hens appeared to rely on both their spring diet and stored reserves for the nutrients required for clutch formation.

Reproduction of Pied Flycatchers (Ficedula hypoleuca) in Good and Bad Breeding Seasons in a Northern Marginal Area

The Auk ◽  
1984 ◽  
Vol 101 (3) ◽  
pp. 439-450 ◽  
Author(s):  
Antero Järvinen ◽  
Risto A. Väisänen
Keyword(s):  
Breeding Success ◽  
Egg Size ◽  
Local Population ◽  
Ficedula Hypoleuca ◽  
Nesting Success ◽  
Egg Laying ◽  
Female Size ◽  
Finnish Lapland ◽  
Breeding Seasons ◽  
Better Than

Abstract We studied relationships between female size, date of egg laying, clutch size, egg size, and breeding success in Pied Flycatchers (Ficedula hypoleuca) in a marginal area in northwestern Finnish Lapland (69°N). Average June temperatures in 1975-1981 were used to classify years into "good" (warm) and "bad" (cold) breeding seasons. In general, early and warm springs were followed by "good" breeding seasons: females were heavier, laying was earlier, clutches were larger and contained larger eggs, and hatching and fledging success were better than in late and cold springs. Mainly due to low nesting success in "bad" breeding seasons, the local population could not maintain itself; immigration from the south was needed. We suggest that spring weather may provide information concerning the character of the coming breeding season, which may help birds to maximize their lifetime production of young.

Fecundity, egg size and the influence of rainfall in an isolated population of malleefowl (Leipoa ocellata)

2005 ◽  
Vol 32 (7) ◽  
pp. 639 ◽  
Author(s):  
David Priddel ◽  
Robert Wheeler
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
New South ◽  
Extended Period ◽  
Early Summer ◽  
Egg Laying ◽  
Daily Maximum ◽  
Isolated Population ◽  
South Wales ◽  
The Mean

An isolated population of malleefowl (Leipoa ocellata) at Yalgogrin in New South Wales, Australia, was studied intensively between 1986–87 and 1998–99. During this period the population produced 124 clutches, comprising a total of 1705 eggs. The number of clutches per annum varied between 5 and 15. Eggs were laid between mid-August and mid-February, with 90% laid between the last week of September and the first week of January. The mean date of laying of the first egg of each clutch (±s.d.) was 21 September ± 13 days and the mean date of the last egg was 23 December ± 19 days. The mean duration of egg laying varied significantly between years (range 70–117 days) and was negatively correlated with the daily maximum ambient temperature in December. Cool temperatures and rain in early summer prolonged the laying season. The mean interval between laying was 6.4 ± 1.1 days (range 3–12 days), with eggs laid at a faster rate during the first half of the laying period. Overall, mean clutch size was 14.1 ± 5.8 (range 1–28). Large clutches were the result of an extended period of laying rather than an increase in the rate of laying. Mean clutch size was greatest when laying extended into mid-February. The best predictor of clutch size was rainfall between May and December – the interval spanning both nest construction and egg laying. The mean volume of all measured eggs (n = 1362) was 162.1 ± 9.0 mL (range 99–200 mL). Egg volume varied during the laying period, with those eggs laid early or late in the breeding season being smaller. Eggs at Yalgogrin were, on average, 10.5% smaller than those recorded at nearby Pulletop.

scholarly journals Estimating Repeatability of Egg Size

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 500-503 ◽  
Author(s):  
Paul L. Flint ◽  
Robert F. Rockwell ◽  
James S. Sedinger
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Size Variation ◽  
Egg Laying ◽  
Nested Model ◽  
Sequence Number ◽  
Nested Design ◽  
Black Brant ◽  
Laying Sequence ◽  
Analytical Approaches

Abstract Measures of repeatability have long been used to assess patterns of variation in egg size within and among females. We compared different analytical approaches for estimating repeatability of egg size of Black Brant. Separate estimates of repeatability for eggs of each clutch size and laying sequence number varied from 0.49 to 0.64. We suggest that using the averaging egg size within clutches results in underestimation of variation within females and thereby overestimates repeatability. We recommend a nested design that partitions egg-size variation within clutches, among clutches within females, and among females. We demonstrate little variation in estimates of repeatability resulting from a nested model controlling for egg laying sequence and a nested model in which we assumed laying sequence was unknown.

scholarly journals Reproduction, development, asymmetry and late eye regression in the Brazilian cave catfish Ituglanis passensis (Siluriformes, Trichomycteridae): evidence contributing to the neutral mutation theory

2021 ◽  
Vol 38 ◽  
pp. 91-112
Author(s):  
Sandro Secutti ◽  
Eleonora Trajano
Keyword(s):  
Egg Size ◽  
Egg Laying ◽  
Karst Area ◽  
Source Population ◽  
Central Brazil ◽  
Neutral Mutation ◽  
Mutation Theory ◽  
Neutral Mutation Theory ◽  
One Year ◽  
Cave Habitat

The troglobitic (exclusively subterranean source population) catfish Ituglanis passensis (Siluriformes, Trichomycteridae) is endemic to the Passa Três Cave, São Domingos karst area, Rio Tocantins basin, Central Brazil. This unique population presents variably reduced eyes and melanic pigmentation. We describe reproduction and early development in this species based on a spontaneous (non-induced) reproductive-event that occurred in the laboratory in January–February, 2009, while simultaneously comparing with data from the cave-habitat and a previous reproductive event. Egg laying was parceled. Egg-size and number were within variations observed in epigean congeners. Larvae behavior and growth is described. A single surviving specimen was monitored over two years. Eye-regression started late, one year after birth, and followed a pattern of stasis phases intercalated with slow growth and fluctuating asymmetric rates. Late eye regression, associated with asymmetry in eye development and intra-population variability of troglomorphic traits, as shown by several Brazilian subterranean fishes, provide support for the Neutral Mutation Theory.

scholarly journals Nesting Effort of Northern Pintails in Alberta

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 619-628 ◽  
Author(s):  
Karla L. Guyn ◽  
Robert G. Clark
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Traits ◽  
Trade Off ◽  
Variable Environments ◽  
Southern Alberta ◽  
First Clutch ◽  
Northern Pintails ◽  
One Year

Abstract We studied nesting effort and success of Northern Pintails (Anas acuta) in southern Alberta. Annual nesting success estimates ranged from 6–18%. Clutch size averaged 7.2, and declined in a simple curvilinear fashion with nest initiation date. We found no relationship between egg size and clutch size or evidence from one year to the next of a trade-off between current and future investment in eggs. Within-year renesting rate ranged from 55%, based on a sample of 20 decoy-trapped females that lost their first nests to predators, to 85% based on a sample of 13 nest-trapped females forced to renest when we removed their clutches. Greater investment in initial clutches led to longer delays in laying replacement clutches. Because delays in renesting are costly (late-nesting females produce fewer offspring), females must contend with a trade-off between maximizing reproductive output in initial clutches versus the risk of delayed renesting if the first clutch should fail. We suggest that pintail reproductive traits have evolved primarily in response to short nesting seasons and variable environments.

Oviparous reproduction of Vestia ranojevici moravica confirms taxonomic value of life history characters in carpathian clausiliids (Gastropoda: Pulmonata)

Biologia ◽  
2013 ◽  
Vol 68 (4) ◽  
Author(s):  
Anna Sulikowska-Drozd ◽  
Tomasz Maltz
Keyword(s):  
Reproductive Strategies ◽  
Egg Size ◽  
Room Temperature ◽  
Reproductive Tract ◽  
Shell Growth ◽  
Egg Laying ◽  
Anatomical Studies ◽  
One Year ◽  
Previous Assumption ◽  
Actual Size

AbstractBased on five-year observation of 36 snails collected in the Čeladná valley (Moravia, Czech Republic) and their progeny reared in laboratory, it was found that Vestia ranojevici moravica (Brabenec, 1952) is oviparous. The oviparity in V. ranojevici is in line with the previous assumption of its reproductive strategy based on anatomical studies alone. It supports the separate position of the species in the genus Vestiaa (subgenus Brabenecia). V. ranojevici was kept at room temperature (18–25°C) between March and October; in winter snails were stored at 3°C. The egg-laying period started in late March, ca. 1 month after raising the temperature, and lasted till September, with one maximum in spring. In the laboratory the snails laid eggs in batches (usually 4–6 eggs, max 11) or singly. The number of batches per pair per season was 1–8; the corresponding number of eggs — 3–40. The eggs were gelatinous, with separate calcium carbonate crystals in the external envelope. The average egg size was 1.80 × 1.51 mm, but actual size and shape were highly variable: larger and more elongated eggs were produced mainly by laboratory reared animals. Freshly deposited eggs did not contain shelled embryos nor the reproductive tract of dissected individuals contained eggs. At room temperature the eggs hatched after ca. 14–16 days, then the shell growth lasted 20–29 weeks; the snails laid eggs 30 weeks after completion of shell growth indicating one-year life cycle under laboratory conditions. Adult individuals collected in the field reproduced during 4–5 consecutive years. Comparison of V. ranojevici reproduction to the results of breeding of other Carpathian clausiliids in the same laboratory shows that similar reproductive strategies may have evolved independently in different lineages of the group: both the oviparous and egg retaining species belong to the genera Vestia and Balea.

Sign in / Sign up

Export Citation Format

Share Document