Physiological Zoology

Next article No AccessThe Ecological Determinants of Population Growth in a Drosophila Culture. III. Larval and Pupal SurvivalJames Henderson SangJames Henderson SangPDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 22, Number 3Jul., 1949 Article DOIhttps://doi.org/10.1086/physzool.22.3.30152044 Views: 10Total views on this site Citations: 59Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). PDF download Crossref reports the following articles citing this article:Quentin Corbel, Pau Carazo Perception of dead conspecifics increases reproductive investment in fruit flies, Functional Ecology 36, no.88 (Jul 2022): 1834–1844.https://doi.org/10.1111/1365-2435.14108Srikant Venkitachalam, Srijan Das, Auroni Deep, Amitabh Joshi Density-dependent selection in Drosophila: evolution of egg size and hatching time, Journal of Genetics 101, no.11 (Jan 2022).https://doi.org/10.1007/s12041-021-01355-6Tadeusz J. Kawecki Sexual selection reveals a cost of pathogen resistance undetected in life‐history assays, Evolution 74, no.22 (Dec 2019): 338–348.https://doi.org/10.1111/evo.13895Lucas Khodaei, Tristan A. F. Long Kin recognition and co‐operative foraging in Drosophila melanogaster larvae, Journal of Evolutionary Biology 32, no.1212 (Oct 2019): 1352–1361.https://doi.org/10.1111/jeb.13531Peter Klepsatel, Emanuel Procházka, Martina Gáliková Crowding of Drosophila larvae affects lifespan and other life-history traits via reduced availability of dietary yeast, Experimental Gerontology 110 (Sep 2018): 298–308.https://doi.org/10.1016/j.exger.2018.06.016John Ringo Foraging by Drosophila melanogaster Larvae in a Patchy Environment, Journal of Insect Behavior 31, no.22 (Feb 2018): 176–185.https://doi.org/10.1007/s10905-018-9661-5Gustavo S. Betini, Aaron Pardy, Cortland K. Griswold, D. Ryan Norris The role of seasonality and non-lethal carry-over effects on density-dependent dispersal, Ecosphere 6, no.1212 (Dec 2015): art272.https://doi.org/10.1890/ES15-00257.1M S Przybylska, F Roque, R Tidon Drosophilid Species (Diptera) in the Brazilian Savanna are Larger in the Dry Season, Annals of the Entomological Society of America 107, no.55 (Sep 2014): 994–999.https://doi.org/10.1603/AN14011Zachary Durisko, Blake Anderson, Reuven Dukas Adult fruit fly attraction to larvae biases experience and mediates social learning, Journal of Experimental Biology 217, no.77 (Apr 2014): 1193–1197.https://doi.org/10.1242/jeb.097683Gustavo S. Betini, Cortland K. Griswold, D. Ryan Norris Density-mediated carry-over effects explain variation in breeding output across time in a seasonal population, Biology Letters 9, no.55 (Oct 2013): 20130582.https://doi.org/10.1098/rsbl.2013.0582Zachary Durisko, Reuven Dukas Attraction to and learning from social cues in fruitfly larvae, Proceedings of the Royal Society B: Biological Sciences 280, no.17671767 (Sep 2013): 20131398.https://doi.org/10.1098/rspb.2013.1398Mads Fristrup Schou Fast egg collection method greatly improves randomness of egg sampling in Drosophila melanogaster, Fly 7, no.11 (Oct 2014): 44–46.https://doi.org/10.4161/fly.22758 David Houle and Locke Rowe Natural Selection in a Bottle. D. Houle and L. Rowe, The American Naturalist 161, no.11 (Jul 2015): 50–67.https://doi.org/10.1086/345480 Avis C. James and Linda Partridge Geographic Variation in Competitive Ability in Drosophila melanogaster James, Partridge, The American Naturalist 151, no.66 (Jul 2015): 530–537.https://doi.org/10.1086/286138Jesús Fernández, Carlos López-Fanjul SPONTANEOUS MUTATIONAL GENOTYPE-ENVIRONMENT INTERACTION FOR FITNESS-RELATED TRAITS IN DROSOPHILA MELANOGASTER, Evolution 51, no.33 (May 2017): 856–864.https://doi.org/10.1111/j.1558-5646.1997.tb03667.xJeff P. Reeve, Daphne J. Fairbairn SEXUAL SIZE DIMORPHISM AS A CORRELATED RESPONSE TO SELECTION ON BODY SIZE: AN EMPIRICAL TEST OF THE QUANTITATIVE GENETIC MODEL, Evolution 50, no.55 (May 2017): 1927–1938.https://doi.org/10.1111/j.1558-5646.1996.tb03580.xGladys Ruiz-Dubreuil, Barrie Burnet, Kevin Connolly, Peter Furness Larval foraging behaviour and competition in Drosophila melanogaster, Heredity 76, no.11 (Jan 1996): 55–64.https://doi.org/10.1038/hdy.1996.7Gladys Ruiz-Dubreuil, Barrie Burnet, Kevin Connolly Behavioural correlates of selection for oviposition by Drosophila melanogaster females in a patchy environment, Heredity 73, no.11 (Jul 1994): 103–110.https://doi.org/10.1038/hdy.1994.105Mauro Santos, Kevin Fowler, Linda Partridge Gene–environment interaction for body size and larval density in Drosophila melanogaster: an investigation of effects on development time, thorax length and adult sex ratio, Heredity 72, no.55 (May 1994): 515–521.https://doi.org/10.1038/hdy.1994.69Russell L. Burke, Lance E. Little Drosophila do not skew offspring sex ratio as predicted by trivers and willard (Diptera: Drosophilidae), Journal of Insect Behavior 8, no.22 (Mar 1994): 231–239.https://doi.org/10.1007/BF01988907J R de Miranda, M Hemmat, Paul Eggleston The competition diallel and the exploitation and interference components of larval competition in Drosophila melanogaster, Heredity 66, no.33 (Jun 1991): 333–342.https://doi.org/10.1038/hdy.1991.42Eric Wajnberg, Michel Boulétreau, Geneviève Prévost, Pierre Fouillet Developmental relationships between Drosophila larvae and their endoparasitoid Leptopilina (Hymenoptera: Cynipidae) as affected by crowding, Archives of Insect Biochemistry and Physiology 13, no.3-43-4 (Feb 2005): 239–245.https://doi.org/10.1002/arch.940130310G Ribó, J Ocaña, A Prevosti Effect of larval crowding on adult mating behaviour in Drosophila melanogaster, Heredity 63, no.22 (Oct 1989): 195–202.https://doi.org/10.1038/hdy.1989.92Mortaza Hemmat, Paul Eggleston Competitive interactions in Drosophila melanogaster: genetic variation for interference through media conditioning, Heredity 61, no.33 (Dec 1988): 347–354.https://doi.org/10.1038/hdy.1988.125C.A. Parkin, B. Burnet Growth arrest of Drosophila melanogaster on erg-2 and erg-6 sterol mutant strains of Saccharomyces cerevisiae, Journal of Insect Physiology 32, no.55 (Jan 1986): 463–471.https://doi.org/10.1016/0022-1910(86)90007-7A. Moya, L. M. Botella Larva-to-adult and pupa-to-adult mortality dynamics in crowded cultures ofDrosophila melanogaster, Genetica 67, no.33 (Oct 1985): 201–207.https://doi.org/10.1007/BF02424491Laurence D. Mueller The Evolutionary Ecology of Drosophila, (Jan 1985): 37–98.https://doi.org/10.1007/978-1-4615-6980-0_2J. N. KEARNEY SELECTION AND UTILIZATION OF NATURAL SUBSTRATES AS BREEDING SITES BY WOODLAND DROSOPHILA SPP, Entomologia Experimentalis et Applicata 33, no.11 (Apr 2011): 63–70.https://doi.org/10.1111/j.1570-7458.1983.tb03234.xJ. N. KEARNEY, B. SHORROCKS The utilization of naturally occurring yeasts by Drosophila species, using chemically defined substrates, Biological Journal of the Linnean Society 15, no.11 (Jan 2008): 39–56.https://doi.org/10.1111/j.1095-8312.1981.tb00747.x Bibliography, (Jan 1981): 779–999.https://doi.org/10.1016/B978-1-4832-8401-9.50035-0Gonzalo Alvarez, Jos� Fari�a, Antonio Fontdevila Density and frequency-dependent selection on the singed locus of Drosophila melanogaster, Genetica 50, no.33 (Oct 1979): 161–166.https://doi.org/10.1007/BF00122040Ronald B. Aiken, David L. Gibo Changes in fecundity of Drosophila melanogaster and D. simulans in response to selection for competitive ability, Oecologia 43, no.11 (Jan 1979): 63–77.https://doi.org/10.1007/BF00346673Ramon M. Nogués POPULATION SIZE FLUCTUATIONS IN THE EVOLUTION OF EXPERIMENTAL CULTURES OF DROSOPHILA SUBOBSCURA, Evolution 31, no.11 (May 2017): 200–213.https://doi.org/10.1111/j.1558-5646.1977.tb00996.xS. Alahiotis GENETIC VARIATION AND THE ECOLOGICAL PARAMETER "FOOD MEDIUM" IN CAGE POPULATIONS OF DROSOPHILA MELANOGASTER, Canadian Journal of Genetics and Cytology 18, no.22 (Jun 1976): 379–383.https://doi.org/10.1139/g76-046Rosemary Dolan, Alan Robertson The Effect of conditioning the medium in drosophila, in relation to frequency-dependent selection, Heredity 35, no.33 (Dec 1975): 311–316.https://doi.org/10.1038/hdy.1975.102Ralph Hillman Genetic and environmental control of a continuous trait, Abnormal abdomen , in Drosophila melanogaster, Genetical Research 22, no.11 (Apr 2009): 37–50.https://doi.org/10.1017/S0016672300012829Ken-ichi Kojima, Shiu Lan Huang EFFECTS OF POPULATION DENSITY ON THE FREQUENCY-DEPENDENT SELECTION IN THE ESTERASE-6 LOCUS OF DROSOPHILA MELANOGASTER, Evolution 26, no.33 (May 2017): 313–321.https://doi.org/10.1111/j.1558-5646.1972.tb01935.xF.A. Lints, G. Gruwez What determines the duration of development in drosphila melanogaster?, Mechanisms of Ageing and Development 1 (Jan 1972): 285–297.https://doi.org/10.1016/0047-6374(72)90074-7M. R. El-Helw, A. M. M. Ali COMPETITION BETWEEN DROSOPHILA MELANOGASTER AND D. SIMULANS ON MEDIA SUPPLEMENTED WITH SACCHAROMYCES AND SCHIZOSACCHAROMYCES, Evolution 24, no.33 (May 2017): 531–537.https://doi.org/10.1111/j.1558-5646.1970.tb01788.xF.A. Lints, C.V. Lints Influence of preimaginal environment on fecundity and ageing in Drosophila melanogaster hybrids I. Preimaginal population density, Experimental Gerontology 4, no.44 (Dec 1969): 231–244.https://doi.org/10.1016/0531-5565(69)90011-4J. S. F. Barker THE FITNESS OF SINGLE-SPECIES POPULATIONS OF DROSOPHILA, Evolution 21, no.33 (May 2017): 606–619.https://doi.org/10.1111/j.1558-5646.1967.tb03415.xM. Bouletreau, J. David Influence de la densité de population larvaire sur la taille des adultes, la durée de développement et la fréquence de la diapause chezPteromalus puparum L. [Hym., Chalcidien], Entomophaga 12, no.22 (Jun 1967): 187–197.https://doi.org/10.1007/BF02370616Richard S. Miller Pattern and Process in Competition, (Jan 1967): 1–74.https://doi.org/10.1016/S0065-2504(08)60319-0Grace B. Cannon INTRASPECIES COMPETITION, VIABILITY, AND LONGEVITY IN EXPERIMENTAL POPULATIONS, Evolution 20, no.11 (May 2017): 117–131.https://doi.org/10.1111/j.1558-5646.1966.tb03348.xAlexander Sokoloff MORPHOLOGICAL VARIATION IN NATURAL AND EXPERIMENTAL POPULATIONS OF DROSOPHILA PSEUDOOBSCURA AND DROSOPHILA PERSIMILIS, Evolution 20, no.11 (May 2017): 49–71.https://doi.org/10.1111/j.1558-5646.1966.tb03342.xJiro Mishima The competition amongDrosophila larvae in different growth stages, Researches on Population Ecology 6, no.11 (Jun 1964): 22–27.https://doi.org/10.1007/BF02524941K. BAKKER, F. X. NELISSEN ON THE RELATIONS BETWEEN THE DURATION OF THE LARVAL AND PUPAL PERIOD, WEIGHT AND DIURNAL RHYTHM IN EMERGENCE IN DROSOPHILA MELANOGASTER, Entomologia Experimentalis et Applicata 6, no.11 (Apr 2011): 37–52.https://doi.org/10.1111/j.1570-7458.1963.tb00601.xJ. S. F. Barker The estimation of generation interval in experimental populations of Drosophila, Genetical Research 3, no.0303 (Apr 2009): 388.https://doi.org/10.1017/S0016672300003232James H. Sang CIRCUMSTANCES AFFECTING THE NUTRITIONAL REQUIREMENTS OF DROSOPHILA MELANOGASTER, Annals of the New York Academy of Sciences 77, no.22 (Dec 2006): 352–365.https://doi.org/10.1111/j.1749-6632.1959.tb36911.x John F. Ellis Reversal of an Adenine and a Cytidine Requirement in Axenic Drosophila Culture, Physiological Zoology 32, no.11 (Sep 2015): 29–39.https://doi.org/10.1086/physzool.32.1.30152289Eliot B. Spiess CHROMOSOMAL ADAPTIVE POLYMORPHISM IN DROSOPHILA PERSIMILIS II. EFFECTS OF POPULATION CAGE CONDITIONS ON LIFE CYCLE COMPONENTS, Evolution 12, no.22 (May 2017): 234–245.https://doi.org/10.1111/j.1558-5646.1958.tb02950.xF. S. Bodenheimer Approach to an Analysis of Some Animal Populations, (Jan 1958): 67–111.https://doi.org/10.1007/978-94-017-6310-3_4Peter Buri GENE FREQUENCY IN SMALL POPULATIONS OF MUTANT DROSOPHILA, Evolution 10, no.44 (May 2017): 367–402.https://doi.org/10.1111/j.1558-5646.1956.tb02864.xR. W. Kerr Rearing Drosophila melanogaster Mg. for Insecticide Investigations, Bulletin of Entomological Research 45, no.22 (Jul 2009): 313–316.https://doi.org/10.1017/S0007485300027127Robert C. King Studies with radiophosphorus in Drosophila. I. The mutagenic effectiveness of radioactive phosphorus in adult male Drosophila melanogaster, Journal of Experimental Zoology 122, no.33 (Apr 1953): 541–575.https://doi.org/10.1002/jez.1401220310Forbes W. Robertson, Eric Reeve Studies in quantitative inheritance, Journal of Genetics 50, no.33 (Feb 1952): 414–448.https://doi.org/10.1007/BF02986839JAMES HENDERSON SANG POPULATION GROWTH IN DROSOPHILA CULTURES, Biological Reviews 25, no.22 (Apr 1950): 188–219.https://doi.org/10.1111/j.1469-185X.1950.tb00590.x James Henderson Sang The Ecological Determinants of Population Growth in a Drosophila Culture. IV. The Significance of Successive Batches of Larvae, Physiological Zoology 22, no.33 (Sep 2015): 202–210.https://doi.org/10.1086/physzool.22.3.30152045 James Henderson Sang The Ecological Determinants of Population Growth in a Drosophila Culture. V. The Adult Population Count, Physiological Zoology 22, no.33 (Sep 2015): 210–223.https://doi.org/10.1086/physzool.22.3.30152046

James Henderson Sang

The Ecological Determinants of Population Growth in a Drosophila Culture. III. Larval and Pupal Survival

果蝇培养中种群增长的生态决定因素。III. 幼虫和蛹的存活

Energy allocation for maternal maintenance and milk production was examined in lactating hispid cotton rats (Sigmodon hispidus) supporting three to seven offspring at 10° or 24°C. Lactating mothers obtained most of their energy from dietary intake (ca. 90%), and the remainder was withdrawn from maternal stores. There was no indication that a central limit to maternal energy assimilation constrained lactational performance. Maternal energy assimilation increased with a larger litter size (a higher production cost) and a decline in ambient temperature (a higher thermoregulatory cost) during lactation, without reaching an apparent limit. Further, there was no evidence of competitive energy allocation, which might occur if maternal energy assimilation were limited. Hence, increases in maternal thermoregulatory expenditure during lactation did not decrease the energy allocation for milk production. Lactating mothers had a capacity to increase milk production. Nonetheless, the milk flow did not fully satisfy the energy requirements of dependent offspring in larger litters or at the lower ambient temperature (growth rates of offspring declined in both cases). Local physiological constraints and behavioral effects appear to limit maternal allocation during lactation. Constraints to allocation may be favored by selection because they reduce maternal risk or reproductive cost.

Gordon L. Rogowitz

Limits to Milk Flow and Energy Allocation during Lactation of the Hispid Cotton Rat (Sigmodon hispidus)

须毛棉鼠（Sigmodon hispidus）哺乳期乳汁流量与能量分配的限制

This study examined daily and seasonal activity and thermoregu‐latory behaviour of the sleepy lizard, Tiliqua rugosa, a large, diurnally active temperate‐dwelling Australian lizard, in the field and laboratory. Activity temperatures in the field were compared with those selected by lizards in laboratory thermal gradients in order to assess the extent to which endogenous versus exogenous factors contribute to seasonal variations in thermoregulatory behaviour. In the field, lizards are most active in late winter–spring (August –November), during which their activity varies from mostly unimodal on days of mild temperature to bimodal on hot days. In late spring–summer (November–January), activity is largely restricted to early morning, and at all other seasons sleepy lizards are rarely active. The winter–spring activity of sleepy lizards is constrained by low environmental temperatures, as lizards at these seasons have low body temperatures in the field but higher temperatures in laboratory thermal gradients. The lower temperatures selected in the laboratory in the summer–autumn months suggest the avoidance of high ambient temperatures and general inactivity in the field at these times. Thermal selection in the laboratory at the eight times of year tested showed that the phase of the minimum and maximum temperature selected and the amplitude of the rhythm of temperature selected varied continuously with the time of year. These daily and seasonal shifts in thermoregulatory behaviour may be regulated by endogenous physiological mechanisms coupled with seasonal ecological constraints such as food availability.

Bruce T. Firth

Ingrid Belan

Daily and Seasonal Rhythms in Selected Body Temperatures in the Australian LizardTiliqua rugosa(Scincidae): Field and Laboratory Observations

澳大利亚蜥蜴Tiliqua rugosa(石龙子科)选定体温的日变化和季节性节律：野外与实验室观察

This study aimed to describe the effects of change in environmental temperature, hypoxia, and hypercapnia on the breathing pattern of Crocodylus porosus. Increased environmental temperature, hypoxia, and hypercapnia each caused an increase in minute ventilation and changes in breathing pattern. Breathing frequency increased and the duration of the nonventilatory period decreased in response to all three conditions. Under hypercapnia tidal volume also increased, with no change in rate of inspiration. The number of breaths per breathing burst decreased with increased temperature but remained unaltered under hypoxia. Hypercapnia reduced the number of breaths per burst at 20 degrees C, but the number did not decrease further at 30 degrees C. The results support the idea that the responses to increased temperature, hypoxia, and hypercapnia are under separate control but that some effects of hypercapnia and temperature may involve a common regulatory pathway.

Suzanne L. Munns

Peter B. Frappell

Barbara K. Evans

The Effects of Environmental Temperature, Hypoxia, and Hypercapnia on the Breathing Pattern of Saltwater Crocodiles (Crocodylus porosus)

环境温度、低氧和高碳酸血症对咸水鳄鱼（Crocodylus porosus）呼吸模式的影响

In order to evaluate the normal (fed conditions) substrate utilization rates of rainbow trout (Oncorhynchus mykiss) brain, CO2production from glucose, lactate, and b‐hydroxybutyrate was tested in pooled brains. Oxidation rates, as well as the capacity for metabolism of carbohydrate and ketone bodies, were also evaluated in brain of rainbow trout that were food‐deprived for 14 d. Under normal (fed) conditions, rainbow trout brain oxidized glucose and lactate at rates higher than those described for mammals; oxidation rates of b‐hydroxybutyrate were lower in rainbow trout brain than those observed for lactate and glucose, and also lower than those described for mammals. Under food‐deprivation conditions, glucose and lactate oxidation rates decreased in brains, suggesting the existence of brain metabolic depression, and b‐hydroxybutyrate oxidation rates sharply increased, suggesting increased utilization of ketone bodies.

José L. Soengas

Elaine F. Strong

M. Dolores Andrés

Glucose, Lactate, and b‐Hydroxybutyrate Utilization by Rainbow Trout Brain: Changes during Food Deprivation

葡萄糖、乳酸和β-羟基丁酸在大西洋鲑鱼脑中的利用：禁食期间的变化

The apneas of many torpid mammals can persist longer than estimated O2 stores allow. This suggests that some O2 is acquired during these apneas by either cutaneous uptake or by a nonventilatory flux down an open airway (tracheal flux). Previous experiments confirmed apneic O2 uptake in the bat Eptesicus fuscus with the conclusion that the uptake most likely occurred by tracheal flux. However, the bat's large cutaneous wing area remained a potential source of cutaneous O2 uptake, leaving uncertainty regarding the mechanism of O2 uptake, particularly in regard to some evidence suggesting that small mammals might be obligated to maintain a closed glottis during apnea. This study sought experimental confirmation of passive O2 uptake in the pocket mouse Perognathus parvus, torpid at a body temperature of 10°C, body mass 16.0 ± 0.6 g (N = 9). Ventilation bouts lasted 1.49 ± 0.06 min, whereas apneas lasted 4.51 ± 0.14 min, despite estimated O2 stores able to support apneas of only 1.0 min. The maximum predicted cutaneous O2 uptake was 0.67 μmol O2/h, whereas the theoretically calculated tracheal flux was 20.2 μmol O2/h. This theoretical rate of tracheal flux compared favorably to the measured plateau apneic O2 uptake rate of 16.7 μmol O2/h. However, the diffusional component of tracheal flux was 3.6 times greater than predicted, indicating an important contribution from cardiogenic mixing. Overall, apneic O2 uptake provided 10.2% of the mouse's total O2 uptake. We conclude that passive tracheal flux is the most likely mechanism by which this animal acquires O2 during apnea.

Sean G. Sullivan

Joseph M. Szewczak

Apneic Oxygen Uptake in the Torpid Pocket MousePerognathus parvus

迟钝小囊鼠（Perognathus parvus）中的窒息氧气摄取

Wintering in a temperate climate with low water temperatures is energetically expensive for diving ducks. The energy costs associated with body cooling due to diving and ingesting large amounts of cold food were measured in tufted ducks (Aythya fuligula) feeding on zebra mussels (Dreissena polymorpha), using implanted heart rate and body temperature transmitters. The effects of diving depth and food ingestion were measured in two sets of experiments: we measured body cooling and energy costs of six tufted ducks diving to different depths in a 6‐m‐deep indoor tank; the costs for food ingestion and crushing mussel shells were assessed under seminatural winter conditions with the same ducks feeding on mussels in a 1.5‐m‐deep outdoor pond. Body temperature dropped during feeding bouts and increased gradually during intermittent resting periods. The temperature drop increased linearly with dive duration. The rate of body cooling increased with feeding depth, but it was lower again at depths below 4 m. Half of the increment in energy costs of diving can be attributed to thermoregulatory heat production, of which approximately 50% is generated after diving to warm up the body. The excess costs for ducks feeding on large‐sized mussels could be entirely explained by the estimated energy cost necessary to compensate the heat loss following food ingestion, suggesting that the heat production from shell crushing substituted for thermoregulation. Recovery from heat loss is probably a major component of the activity budget of wintering diving ducks.

Joep J. de Leeuw

Patrick J. Butler

Anthony J. Woakes

Fulco Zegwaard

Body Cooling and Its Energetic Implications for Feeding and Diving of Tufted Ducks

簇羽鸭的体表冷却及其对觅食和潜水的能量影响

When exposed to high ambient temperatures, birds defend body temperature by increasing evaporative water loss, via either respiratory or cutaneous water loss. Water deprivation can lead to changes in thermal responses and lower levels of water use for thermoregulation. We have studied the effect of 2–3 wk of water deprivation on the physiological responses of emus during exposure to an ambient temperature of 45°C. Water deprivation led to a delay in the onset of panting (54 vs. 24 min after start of exposure) and to higher body temperatures (38.7° vs. 38.3°C) at the end of exposure to 45°C. After panting was initiated and body temperature stabilised, the water‐deprived emus had a lower total evaporative water loss (77 vs. 101 g/h), the same respiratory water loss (70 vs. 72 g/h), and a lower cutaneous water loss (7 vs. 29 g/h) than they did when hydrated. The factor contributing most to the lower total evaporative water loss in the dehydrated emus was a 47% reduction in dry thermal conductance, which led to a decrease in the exogenous environmental heat load and therefore the level of evaporation needed to defend body temperature. We suggest that the decrease in dry thermal conductance follows from the lower level of cutaneous water loss.

Shane K. Maloney

Terence J. Dawson

Changes in Pattern of Heat Loss at High Ambient Temperature Caused by Water Deprivation in a Large Flightless Bird, the Emu

大型无飞行能力鸟类鸸鹋在高环境温度下因脱水导致的热量散失模式变化

To assess how the high‐sugar/low‐protein content of fruit diets affects digestive function and nutrition of frugivorous birds, I compared intake, passage rate, sugar utilization, protein requirements, and mass changes of cedar waxwings (Bombycilla ce‐drorum), American robins (Turdus migratorius), and wood thrushes (Hylocichla mustelina) fed synthetic diets simulating the range of sugar (6.6%, 12.4%, and 22.0% solutes) and protein (4.5%, 3.0%, and 1.5% of dry matter) content of bird‐dispersed fruits. The dietary emphasis on sugary fruits by cedar waxwings suggests the potential for digestive and physiological specializations to this food type. All birds increased volumetric food intake and passage rates as sugar concentration declined. Birds completely (22.0%–12.4% sugar solute concentration) or incompletely (12.4%–6.6% sugar solute concentration) compensated for dietary dilution. Cedar waxwings consumed each diet at higher rates than did thrushes, as they do when eating sugary fruits, demonstrating that interspecific differences in ingestion rates of sugary fruits are a consequence of nutrient composition, rather than seed bulk or secondary compounds of fruits. Passage rate was not responsible for interspecific differences in short‐term food intake rate, implicating gut morphology as the key functional feature limiting intake. Most sugary fruits are nutritionally deficient in apparent protein for thrushes but are nutritionally adequate in protein for cedar waxwings because of this species' relatively high intake rates and low protein requirements. The digestive systems of frugivorous birds respond flexibly to dietary sugar concentration, but protein content of fruits can present a nutritional limitation, potentially influencing the proportions of fruit and animal foods in birds' diets.

Mark C. Witmer

Ecological and Evolutionary Implications of Energy and Protein Requirements of Avian Frugivores Eating Sugary Diets

食糖饮食鸟类食果动物的能量和蛋白质需求对生态和进化的影响

Relative to small embryos, large embryos may have longer developmental periods and, subsequently, relatively greater maintenance budgets. Because of the potentially increased metabolic costs of maintaining large embryos for long embryonic periods, Salthe and Mecham (1974) suggested that as ovum size increases among amphibians, ovum lipids (the primary stored metabolic energy reserves) should increase at a proportionally greater rate. To test Salthe and Mecham's hypothesis, we quantified egg lipids for 13 amphibian species from the southeastern United States. As ovum size increased among species, total, nonpolar, and polar lipids increased at rates uniform with or relatively lower than rates of increase in ovum size, in contrast to the hypothesis of Salthe and Mecham. However, variation in ovum lipids among species may be related to differences in breeding biology. Our results indicate that the amount of lipids allocated to ova do not merely depend on ovum size, but rather on the selective environments of the embryo and neonate.

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Basic data	Year of publication: 1989，Proportion of original research papers: ，Self Citation Rate:， Gold OA Rate:

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