Egg-laying sequence influences egg mercury concentrations and egg size in three bird species: Implications for contaminant monitoring programs

2016 ◽  
Vol 35 (6) ◽  
pp. 1458-1469 ◽  
Author(s):  
Joshua T. Ackerman ◽  
Collin A. Eagles-Smith ◽  
Mark P. Herzog ◽  
Julie L. Yee ◽  
C. Alex Hartman
Keyword(s):  
Egg Size ◽  
Bird Species ◽  
Egg Laying ◽  
Contaminant Monitoring ◽  
Monitoring Programs ◽  
Laying Sequence

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.

Elevated nest predation risk promotes offspring size variation in birds with prolonged parental care.

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Predation Risk ◽  
Reproductive Cycle ◽  
Perceived Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Size Variation ◽  
Egg Laying ◽  
Offspring Size ◽  
Natural Predation ◽  
Risk Spreading

Predation of offspring is the main cause of reproductive failure in many species, and the mere fear of offspring predation shapes reproductive strategies. Yet, natural predation risk is ubiquitously variable and can be unpredictable. Consequently, the perceived prospect of predation early in a reproductive cycle may not reflect the actual risk to ensuing offspring. An increased variance in investment across offspring has been linked to breeding in unpredictable environments in several taxa, but has so far been overlooked as a maternal response to temporal variation in predation risk. Here, we experimentally increased the perceived risk of nest predation prior to egg-laying in seven bird species. Species with prolonged parent-offspring associations increased their intra-brood variation in egg, and subsequently offspring, size. High risk to offspring early in a reproductive cycle can favour a risk-spreading strategy particularly in species with the greatest opportunity to even out offspring quality after fledging.

Time-Energy Budgets During Reproduction and the Evolution of Single Parenting in the Superb Lyrebird

1986 ◽  
Vol 34 (3) ◽  
pp. 351 ◽  
Author(s):  
A Lill
Keyword(s):  
Growth Rate ◽  
Brood Size ◽  
Slow Growth ◽  
Bird Species ◽  
Egg Laying ◽  
Energy Budgets ◽  
Brood Care ◽  
Single Parenting ◽  
Slow Growth Rate ◽  
Small Brood

Estimated expenditures on brood-care by unassisted female superb lyrebirds, obtained through time-energy budgeting, were compared with published values for other bird species. With the exception of nestbuilding, estimated daily expenditures were relatively low, due mainly to the small brood size and low level of parental attentiveness. It is suggested that the traits which reduce daily brood-care expenditures, particularly the small brood size and extremely slow growth rate, may have evolved as adaptations which enabled deserted females operating close to maximal capacity to cope with single-parenting. Male parental involvement could probably increase the growth rate of the young, but not brood size; moreover, egg- laying was sufficiently asynchronous to afford multiple mating opportunities to parentally emancipated males. However, the slow growth rate of the young results in relatively large overall brood-care expenditures for females. Investments by males of up to 50% of daylight hours and 45% of BMR on singing at the height of the mating season were comparable with those of partially emancipated, polygynous males of other species. They probably reflect the high level of competition to control good display areas and to advertise status and quality to widely spaced females.

scholarly journals Duration of colonial bird species egg incubation

2018 ◽  
Vol 7 (1) ◽  
pp. 58-64
Author(s):  
Yuri Gennadievich Lamekhov
Keyword(s):  
Ordinal Number ◽  
Bird Species ◽  
Early Ontogeny ◽  
Egg Laying ◽  
Early Ontogenesis ◽  
Time Interval ◽  
Egg Incubation ◽  
Colonial Bird ◽  
Incubation Duration ◽  
Colonial Settlement

The paper deals with one of the aspects of bird early ontogenesis biology - egg incubation duration, which was defined as the time interval between egg laying and hatching from it. The oomorphological parameters are determined taking into account the ordinal number of the laid eggs. Parameters of early ontogeny of birds are studied on the example of colonially nesting species: blackberry toadstool ( Podiceps nigricollis C.L. Brehm.) and lake gull ( Larus ridibundus L.). Within the colonial settlement of these species, the biological center and the periphery of the colony were isolated. When studying the parameters of early ontogeny of birds and oomorphological characteristics, the same number of eggs was taken into account. During field and laboratory studies it was found that the incubation of eggs lasts longer in eggs from the nests of the biological center of the colony. The first eggs are incubated longer. These features clearly manifested in the early ontogeny of the gull. The increase in the egg incubation duration occurs against the background of an increase in their mass and a decrease in the concentration of lysozyme in the protein shell of the egg. Egg incubation duration is one of the results of embryonalization as a way of evolution of ontogeny. The manifestation of the results of embryogenesis was revealed for the first eggs in the nests of the biological center of the colony. Embryonalization leads to an increase in egg incubation duration as well as to a decrease in the intensity of elimination in early ontogenesis, which affects the number of individuals breeding in the colony and, accordingly, the structure of the colonial settlement of birds.

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.

Spawning Mode and Reproductive Output of the Tropical Cephalopod Idiosepius pygmaeus

1993 ◽  
Vol 50 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Andrew R. Lewis ◽  
J. Howard Choat
Keyword(s):  
Body Weight ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Potential ◽  
Adult Life ◽  
Somatic Growth ◽  
Egg Laying ◽  
Adult Life Span ◽  
Adult Weight ◽  
Food Stress

Reproductive biology of the tropical sepioid cephalopod Idiosepius pygmaeus was investigated in wild specimens and in individuals maintained in aquaria through the adult life span. This species produced multiple egg batches over 80% of the observable adult weight range, indicating a coordination of reproductive and somatic growth. Reproductive output was consistent within, but variable between, individuals. Oocyte synthesis and maturation occur continuously after sexual maturation has been reached. Senescence and death are not related to an exhaustion of reproductive potential. On average, captive female I. pygmaeus with access to unlimited food produced 640 eggs in 11 batches over 18 d. When reproductive output was expressed as a ratio of dry female body weight, on average, specimens had incorporated five times their body weight into eggs and egg coatings. Under food stress, captive specimens laid fewer eggs but maintained egg size and periodicity of egg laying. Food stress had no effect on either laying duration or weight at death. This study provides further evidence that terminal spawning modes are not ubiquitous amongst cephalopods.

UPTAKE OF [3H]PROGESTERONE BY THE ANTERIOR LOBE OF PITUITARY AND SOME OTHER TISSUES OF THE HEN DURING AN OVULATORY CYCLE

1976 ◽  
Vol 82 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Katuhide Tanaka ◽  
Michiharu Kamiyoshi ◽  
Mitsuo Kawashima
Keyword(s):  
Median Eminence ◽  
Pectoral Muscle ◽  
Anterior Lobe ◽  
Egg Laying ◽  
The Other ◽  
White Leghorn ◽  
Ovulatory Cycle ◽  
Laying Sequence

ABSTRACT [1,2-3H]progesterone was injected intravenously into White Leghorn hens at various times during the period between ovulations of the initial ovum and the second ovum (C2) of an egg-laying sequence, and the uptake of radioactivity was determined in tissues of the anterior lobe of pituitary, median eminence, telencephalon, liver, adrenal, magnum and pectoral muscle. The uptake by the anterior lobe of the pituitary changed during the ovulatory cycle showing a peak 8 h before C2 ovulation. Similar changes were also observed in the median eminence and in the magnum, but not in the other tissues examined.

Composition of Wood Duck Eggs in Relation to Egg Size, Laying Sequence, and Skipped Days of Laying

The Auk ◽  
1997 ◽  
Vol 114 (3) ◽  
pp. 479-487 ◽  
Author(s):  
Robert A. Kennamer ◽  
Sheila V. Colwell
Keyword(s):  
Egg Size ◽  
Laying Sequence ◽  
Wood Duck

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.

Sign in / Sign up

Export Citation Format

Share Document