Effects of variation in egg size and hatching date on survival of Lesser ScaupAythya affinisducklings

Ibis ◽  
1996 ◽  
Vol 138 (4) ◽  
pp. 693-699 ◽  
Author(s):  
Russell D. Dawson ◽  
Robert G. Clark
Keyword(s):  
Egg Size ◽  
Hatching Date

scholarly journals Consequences of Egg Size for Offspring Survival: A Cross-Fostering Experiment in Ruddy Ducks (Oxyura Jamaicensis)

The Auk ◽  
2003 ◽  
Vol 120 (2) ◽  
pp. 384-393
Author(s):  
Jeffrey T. Pelayo ◽  
Robert G. Clark
Keyword(s):  
Egg Size ◽  
Hatching Date ◽  
Offspring Survival ◽  
Maternal Influences ◽  
Size Dependent ◽  
Duck Species ◽  
In The Wild ◽  
Ruddy Ducks ◽  
Cross Fostering ◽  
Oxyura Jamaicensis

Abstract In birds, large egg size often enhances subsequent offspring survival, but most previous studies have been unable to separate effects of egg size from other maternal influences. Therefore, we first evaluated variance components of egg size both within and among individual female Ruddy Ducks (Oxyura jamaicensis), and then tested for egg-size-dependent survival of ducklings in the wild by switching complete broods among females. Forty broods consisting of 244 individually color-marked, day-old ducklings of known egg size were given to foster mothers, and survival was monitored to one month. Analysis of mark–resighting data showed that offspring survival was best modeled to include effects of egg size and hatching date; survival probability increased with egg size, but declined with advancing hatching date. Duckling body mass, body size, and body condition measured at hatching were positively correlated with egg size. Unlike most other duck species, and for reasons that are speculative, egg sizes varied within clutches nearly as much as they did among clutches. Selective mortality of small egg phenotypes during the first weeks after hatching likely is the result of smaller duckling size and reduced energy reserves, characteristics that must be particularly unfavorable in adverse environments.

Effects of Predation and Trophic Conditions on the Reproduction of Tylototriton verrucosus (Caudata: Salamandridae) in Darjeeling

2011 ◽  
Vol 4 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Ritwik Dasgupta
Keyword(s):  
Frequency Distribution ◽  
Primary Productivity ◽  
Egg Size ◽  
Zooplankton Abundance ◽  
Trophic Conditions ◽  
Size Frequency Distribution ◽  
Size Frequency ◽  
High Predation ◽  
Hatchling Size ◽  
Predation Rates

The facts that small hatchlings emerged from small eggs laid under high predation levels prevailing at the lower altitudes of distribution of this species in Darjeeling while larger hatchlings emerged from larger eggs laid under lower levels of predation at higher altitudes, show that predation is not selected for large egg and initial hatchling size in this salamandrid species. Metamorphic size was small under high predation rates because this species relied on crypsis for evading predators. Egg and hatchling size are related inversely to levels of primary productivity and zooplankton abundance in lentic habitats. Hatchling sizes are related positively to egg size and size frequency distribution of zooplankton. Small egg and small hatchling size have been selected for at the lower altitudes of distribution of this salamandrid in Darjeeling because predation rates increased in step with improvement in trophic conditions at the lower altitudes.

scholarly journals Latitudinal Variation in Ayu Egg Size

1993 ◽  
Vol 59 (12) ◽  
pp. 2087-2087 ◽  
Author(s):  
Kei'ichiroh Iguchi
Keyword(s):  
Egg Size ◽  
Latitudinal Variation

scholarly journals Hurry-up and hatch: selective filial cannibalism of slower developing eggs

2008 ◽  
Vol 4 (2) ◽  
pp. 160-162 ◽  
Author(s):  
Hope Klug ◽  
Kai Lindström
Keyword(s):  
Egg Size ◽  
Adaptive Strategy ◽  
Filial Cannibalism ◽  
Sand Goby ◽  
Pomatoschistus Minutus ◽  
Fitness Consequences

Filial cannibalism (the consumption of one's own offspring) is thought to represent an adaptive strategy in many animals. However, little is known about the details of which offspring are consumed when a parent cannibalizes. Here, we examined patterns of within-brood filial cannibalism in the sand goby ( Pomatoschistus minutus ). Males spawned sequentially with two females, and we asked whether males cannibalized selectively with regard to egg size or the order in which eggs were received. Males preferentially consumed the larger eggs of the second female they spawned with. Because larger eggs took longer to hatch, and because female 2's eggs were up to 1 day behind those of female 1, such preferential cannibalism might allow males to decrease the time spent caring for the current brood and re-enter the mating pool sooner. More work is needed to understand the fitness consequences of such selective cannibalism.

scholarly journals Adult body growth and reproductive investment vary markedly within and across Atlantic and Pacific herring: a meta-analysis and review of 26 stocks

2021 ◽  
Author(s):  
Thassya C. dos Santos Schmidt ◽  
Doug E. Hay ◽  
Svein Sundby ◽  
Jennifer A. Devine ◽  
Guðmundur J. Óskarsson ◽  
...  
Keyword(s):  
Egg Size ◽  
Meta Analysis ◽  
Reproductive Investment ◽  
Body Growth ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Atlantic Herring ◽  
Additional Information ◽  
Trade Offs ◽  
Investment In Reproduction

AbstractLife-history traits of Pacific (Clupea pallasii) and Atlantic (Clupea harengus) herring, comprising both local and oceanic stocks subdivided into summer-autumn and spring spawners, were extensively reviewed. The main parameters investigated were body growth, condition, and reproductive investment. Body size of Pacific herring increased with increasing latitude. This pattern was inconsistent for Atlantic herring. Pacific and local Norwegian herring showed comparable body conditions, whereas oceanic Atlantic herring generally appeared stouter. Among Atlantic herring, summer and autumn spawners produced many small eggs compared to spring spawners, which had fewer but larger eggs—findings agreeing with statements given several decades ago. The 26 herring stocks we analysed, when combined across distant waters, showed clear evidence of a trade-off between fecundity and egg size. The size-specific individual variation, often ignored, was substantial. Additional information on biometrics clarified that oceanic stocks were generally larger and had longer life spans than local herring stocks, probably related to their longer feeding migrations. Body condition was only weakly, positively related to assumingly in situ annual temperatures (0–30 m depth). Contrarily, body growth (cm × y−1), taken as an integrator of ambient environmental conditions, closely reflected the extent of investment in reproduction. Overall, Pacific and local Norwegian herring tended to cluster based on morphometric and reproductive features, whereas oceanic Atlantic herring clustered separately. Our work underlines that herring stocks are uniquely adapted to their habitats in terms of trade-offs between fecundity and egg size whereas reproductive investment mimics the productivity of the water in question.

Shell Resistance and Evaporative Water Loss from Bird Eggs: Effects of Wind Speed and Egg Size

1981 ◽  
Vol 54 (2) ◽  
pp. 195-202 ◽  
Author(s):  
James R. Spotila ◽  
Christina J. Weinheimer ◽  
Charles V. Paganelli
Keyword(s):  
Wind Speed ◽  
Water Loss ◽  
Egg Size ◽  
Evaporative Water Loss ◽  
Evaporative Water ◽  
Bird Eggs

scholarly journals Proximate Factors Determining Age and Mass at Fledging in Rhinoceros Auklets (Cerorhinca Monocerata): Intra- and Interyear Variations

The Auk ◽  
2004 ◽  
Vol 121 (2) ◽  
pp. 452-462 ◽  
Author(s):  
Tomohiro Deguchi ◽  
Akinori Takahashi ◽  
Yutaka Watanuki
Keyword(s):  
Growth Rate ◽  
Wing Length ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Major Effect ◽  
Timing Of Breeding ◽  
Hatching Date ◽  
Cerorhinca Monocerata ◽  
Parental Provisioning ◽  
Underlying Mechanisms

Abstract In alcids, growth rate and hatching date of chicks appear to affect fledging age and mass. Underlying mechanisms are hypothesized to be (1) critical wing length at fledging for postfledging survival, (2) synchronization of fledging to dilute predation risk, and (3) variable parental provisioning according to timing of breeding. To elucidate the effects of growth rate and hatching date on fledging age and mass, and to test those mechanistic hypotheses, we measured chick growth and fledging periods in Rhinoceros Auklets (Cerorhinca monocerata) at Teuri Island from 1995 to 2000. The multiple-linear regression analysis showed that intrayear variations of fledging age and mass were explained by growth rate or hatching date in five out of six years. Faster-growing chicks fledged younger and heavier, and earlier-hatched chicks fledged older and heavier. Consequently, no apparent correlation between fledging age and mass was observed in five out of six years. Analysis of interyear variation showed a negative correlation between fledging age and mass, which indicates that growth rates rather than hatching dates had a major effect. Wing length at fledging was independent of growth in mass. More than 80% of chicks fledged when they attained a narrow range of wing length (130–150 mm), presumably because they remained in their nests until they attained the critical wing length. In five out of six years, the chicks did not synchronize timing of fledging relative to timing of hatching. Later-hatched chicks attained lighter peak masses and at younger ages, which may indicate that their parents decreased provisioning rates when the chicks were still young. We suggest that (1) critical wing length at fledging and (2) variable parental provisioning according to timing of breeding could be underlying mechanisms determining these relationships between fledging age and mass.

Parental Investment in Clutch Size and Egg Size in the Ural Owl Strix uralensis

1986 ◽  
Vol 17 (4) ◽  
pp. 309 ◽  
Author(s):  
Hannu Pietiainen ◽  
Pertti Saurola ◽  
Risto A. Vaisanen
Keyword(s):  
Clutch Size ◽  
Parental Investment ◽  
Egg Size ◽  
Ural Owl

Bénéfices à court terme des mouvements anadromes saisonniers pour une population d'omble de fontaine (Salvelinus fontinalis) du Nouveau Québec

1991 ◽  
Vol 48 (11) ◽  
pp. 2212-2222 ◽  
Author(s):  
Jean-François Doyon ◽  
Christiane Hudon ◽  
Roderick Morin ◽  
F. G. Whoriskey Jr.
Keyword(s):  
Water Level ◽  
Egg Size ◽  
Salvelinus Fontinalis ◽  
Condition Factor ◽  
Size At Maturity ◽  
Brook Charr ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Single Population ◽  
Energetic Reserves

This study characterizes the seasonal anadromous movements of a brook charr population and compares its biological and energetic characteristics with charr spending summer in freshwaters. Downstream movements monitored at a counting fence over 3 yr were most intense in spring but occurred until fall and were positively correlated with rapid increases of water level. The timing of movements varied from year to year. Smaller charr were most subject to being swept downstream compared with freshwater residents, and most trout were concentrated near the mouth of the river. These patterns suggest that the downstream movements of charr in this system are passive. Upstream migrants had a higher condition factor and a lower tissue water content than freshwater residents, indicating that downstream movements result in a faster accumulation of energetic reserves during summer. However, the fortuitous character of anadromous migrations as well as the absence of differences in the biological characteristics (growth, size at maturity, fecundity, egg size) suggests that anadromous and resident fish belong to a single population whose yearly migrant component could be randomly determined.

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