Effects of temperature and food on the fecundity and egg development rates of Boeckella symmetrica Sars (Copepoda : Calanoida)

1981 ◽  
Vol 32 (6) ◽  
pp. 997 ◽  
Author(s):  
IO Woodward ◽  
RWG White
Keyword(s):  
Lower Limit ◽  
Clutch Size ◽  
Food Availability ◽  
Food Supply ◽  
Egg Size ◽  
Food Regime ◽  
Egg Development ◽  
Thermal Range ◽  
Effects Of Temperature ◽  
Increasing Temperature

The effects of temperature and food regime on the fecundity and egg development of B. symmetrica are presented. Clutch size decreases with increasing temperature and decreased food availability. At low food levels; there is increased variability in clutch size; this increase is less marked at lower temperatures. Duration of egg development decreases hyperbolically with increasing temperature; there may be a slight increase with increased food availability. Egg size decreases linearly with increasing temperature: food supply may have some effect. Variability of egg size decreases with decreasing temperature. Egg mortality is highest towards the lower limit of the natural thermal range of B. symmetrica and lowest near the middle.

Effects of temperature and food on instar development rates of Boeckella symmetrica Sars (Copepoda : Calanoida)

1983 ◽  
Vol 34 (6) ◽  
pp. 927 ◽  
Author(s):  
IO Woodward ◽  
RWG White
Keyword(s):  
Food Availability ◽  
Food Supply ◽  
Development Time ◽  
Development Rates ◽  
Effects Of Temperature ◽  
Increasing Temperature

The effects of temperature and food availability on rates of instar development of B. symmetrica are described. Increasing temperature decreased total development time. There may be evidence of a compensatory plateau for development rates between 15 and 20�C. A reduced food supply reduced development rates of the instars. Females generally developed more slowly than males.

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.

scholarly journals Food Supply and the Consequences of Egg Size in the Thick-Billed Murre

The Condor ◽  
2001 ◽  
Vol 103 (2) ◽  
pp. 240-247 ◽  
Author(s):  
J. Mark Hipfner ◽  
Anthony J. Gaston ◽  
Anne E. Storey
Keyword(s):  
Food Availability ◽  
Food Supply ◽  
Egg Size ◽  
Uria Lomvia ◽  
Female Age ◽  
Trade Off ◽  
Wing Feather ◽  
Phenotypic Correlations ◽  
Parental Quality ◽  
Feather Growth

Abstract We examined the effect of egg size on post-hatching development in the Thick-billed Murre (Uria lomvia), an Arctic seabird that lays a one-egg clutch, at a colony where food availability during chick-rearing was low (Digges Island, Nunavut, Canada). We compared our results to those of a previous study conducted at a colony where food availability was higher (Coats Island, Nunavut). To control for underlying phenotypic correlations between egg size and parental quality, we switched eggs at random among pairs. Egg size positively affected the rate of early wing-feather growth, but contrary to prediction, the advantage enjoyed by chicks from large eggs over those from small eggs at Digges Island (1.6 days' feather growth on average) was no greater than at Coats Island (2.0 days). Egg size had no effect on the rate at which chicks gained mass at Digges Island, but young from large eggs tended to remain heavier than those from small eggs. At Coats Island, this occurred only in a year in which chicks grew relatively slowly, offering some support for the hypothesis that a large egg confers greater advantage when feeding conditions are unfavorable. Adults at Digges Island invested heavily in provisioning their chicks, but there was no evidence of a trade-off between egg size and provisioning. As costs associated with large eggs have not been detected in Thick-billed Murres, the existence of considerable variation in egg size, beyond that associated with female age or experience, remains unexplained.

Proximate determination of clutch size in lesser black-backed gulls: the roles of food supply and body condition

1993 ◽  
Vol 71 (2) ◽  
pp. 273-279 ◽  
Author(s):  
Mark Bolton ◽  
Pat Monaghan ◽  
David C. Houston
Keyword(s):  
Clutch Size ◽  
Body Condition ◽  
Food Supply ◽  
Egg Size ◽  
Flight Muscle ◽  
Muscle Protein ◽  
Pectoral Muscle ◽  
Territory Quality ◽  
Additional Energy ◽  
Protein Levels

Though many authors have demonstrated an adaptive relationship between food supply or territory quality and clutch size, the proximate mechanism by which clutch size is determined remains largely unknown. A series of supplementary feeding experiments on lesser black-backed gulls (Larus fuscus) is used in conjunction with a new technique to measure pectoral muscle protein levels in live birds to investigate the relationships between food supply, body condition, and clutch size. Comparisons across treatments revealed a positive relationship between the level of flight muscle protein at the start of laying and clutch size, but not egg size. In a year when the clutch sizes of unfed birds were reduced, suggesting low food availability, gulls provided with a protein supplement had higher levels of flight muscle protein at the start of laying and laid larger clutches than birds that received no food supplement. In contrast, gulls provided with an additional energy source (fat) did not attain higher protein levels or lay larger clutches than unfed gulls. In a second year, when unfed gulls laid larger clutches, which were typical for the species, supplements of two different protein types (fish and egg) had no effect on clutch size, though egg-fed females laid considerably (10%) larger eggs. However, there were no detectable differences in condition between treatments at the start of laying, suggesting that though flight muscle protein levels may be of importance in determining clutch size, they may be of lesser significance for egg size, which may be largely influenced by dietary intake.

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

VARIATIONS IN CLUTCH-SIZE IN DUCKS IN RELATION TO THE FOOD SUPPLY

Ibis ◽  
2008 ◽  
Vol 113 (4) ◽  
pp. 523-526 ◽  
Author(s):  
S.-A. Bengtson
Keyword(s):  
Clutch Size ◽  
Food Supply

Survival of Endocronartium harknessii teliospores in a simulated airborne state

1989 ◽  
Vol 67 (3) ◽  
pp. 928-932 ◽  
Author(s):  
Kan-Fa Chang ◽  
P. V. Blenis
Keyword(s):  
Relative Humidity ◽  
Liquid Nitrogen ◽  
Long Distance ◽  
Spider Webs ◽  
Considerable Potential ◽  
Good Ability ◽  
Endocronartium Harknessii ◽  
Spore Longevity ◽  
Effects Of Temperature ◽  
Increasing Temperature

The effects of temperature and relative humidity (RH) on the survival of Endocronartium harknessii teliospores and the longevity of these spores out of doors during daylight hours were studied. In one experiment, fresh and liquid-nitrogen-stored spores of E. harknessii were impacted onto spider webs or plastic threads and incubated in darkness at temperatures of 6, 15, and 24 °C and RHs of 39 and 98%. Survival was measured after 1, 2, 4, 8, and 16 days. Spore longevity decreased with increasing temperature and was lower at 98 than at 39% RH. In a second experiment, spores were impacted onto spider webs and placed out of doors on clear days. Viability decreased linearly with time and averaged 33% after 12 h. The data suggest that E. harknessii has relatively good ability to survive in an airborne state and thus would have considerable potential for long distance spread.

Effects of Temperature on Leaf Expansion in Sunflower

1982 ◽  
Vol 9 (2) ◽  
pp. 209 ◽  
Author(s):  
HM Rawson ◽  
JH Hindmarsh
Keyword(s):  
Field Studies ◽  
Leaf Expansion ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Leaf Position ◽  
Leaf Emergence ◽  
Temperature Regimes ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Relative Change

Five commercial cultivars of sunflower were grown in cabinets at three temperature regimes, 32/22, 27/17 and 22/12°C, and with 15-h and 11-h photoperiods, and expansion of leaves 5-15 was followed. Leaves appeared faster with increasing temperature (0.022 leaves day-1 °C-1) and with increasing daylength. Areas of individual leaves increased linearly up the plant profile and, although final area per leaf (Amax) decreased with increasing temperature, the relative change was similar for each leaf position. Cultivars maintained their ranking for Amax across temperatures, and these rankings agreed with those in previous field studies. Within each temperature regime, both the expansion rate of leaves and the duration of expansion increased with leaf position. As temperature increased, leaves grew for shorter periods with a change of 1.04 days °C-1, but under the photon flux density used (500 �mol m-2 s-1, or about 25% full sunlight) expansion rates were greatest at the lowest temperature. Expansion rates were only one-third of those in field studies at comparable temperatures, but durations were similar. Cultivars that achieved the largest Amax did so via faster rates of expansion and not via longer durations: only one cultivar differed from the mean (20 days) duration of leaf expansion. All cultivars reached floral initiation progressively earlier with extension of photoperiod from 10 to 15 h, with the change for the most sensitive cultivars being 8 days and for the least sensitive 5 days. Rates of leaf emergence were linked with this sensitivity.

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