黑线仓鼠繁殖输出与基础代谢率的关系

为了解黑线仓鼠繁殖输出与基础代谢率(BMR)的关系,阐明最大持续能量收支(SusMR)的限制水平, 揭示哺乳期能量收支对策,本文测定了哺乳期黑线仓鼠的体重、摄食量、BMR 和身体组成,以及哺乳期的胎仔数、胎仔重和泌乳能量支出(MEO)。结果显示,黑线仓鼠哺乳期体重降低了15.0 ± 0.8% , 摄食量显著增加, 哺乳高峰期平均摄食量为13.9 ± 0.3 g /d, 摄入能为222.1 ± 5.3 kJ/ d, 比哺乳初期增加121% , 比对照组高288% ;哺乳高峰期MEO 为62.4 ± 2.3 kJ/ d, 哺乳末期BMR 为49.7 ± 1.1 kJ/ d; 断乳时平均胎仔数4.7 ± 0.2、窝胎仔重50.5 ±1.6 g; 哺乳末期BMR 比对照组增加48% ,BMR 与消化系统各器官的相关性高于对照组; BMR 与胎仔数、胎仔重、乳腺重量和MEO 显著正相关。结果表明:初次繁殖的黑线仓鼠哺乳期SusMR 限制为4.47 ×BMR, 在自身维持和繁殖输出之间采取了“权衡分配”的原则,通过体重降低以减少BMR 的增加幅度, 从而有利于繁殖输出。     

北京大兴地区黑线仓鼠种群繁殖生态研究

黑线仓鼠(Cricetulus barabensis)是我国华北地区广泛分布的农田主要害鼠之一。1982年9月到1985年3月,作者在北京、天津及河北省一些地区,调查了它的分布和群落结构并研究其种群生态,本文仅就北京郊区大兴县黑线仓鼠的种群繁殖问题进行讨论。     

A breeding colony of cotton-top tamarins (Saguinus oedipus)

A breeding colony of cotton-top tamarins is described where 91% of the breeding females are from the first and second laboratory-born generations, and whose infants have a one year survival rate of 62%. Mortality is greatest in the first week of life, and mortality rate is greater for a female's first litter than for subsequent litters. Females without early experience in caring for other infants have a higher infant mortality rate than females with such experience. No seasonal birth patterns have been observed. Large complex cages with food, water and runways located in the upper half of the cage, high protein diets and reduced handling of animals are suggested as additional variables affecting breeding success.     

臭鼩的繁殖和种群年龄结构

对浙江萧山瓜沥区农田臭鼩的研究,发现种群性比不等,存在明显的两性异型。分析了雄体的性成熟率和雌体的怀孕率及性活动率的变化规律。一年中存在两个繁殖高峰期。以齿长指数为指标．臭鼩种群可划分为4个年龄组。探讨了种群年龄结构的季节变化及其自然寿命。     

青海海北地区艾虎的某些生态学特征及种群能量动态资料

艾虎,又名艾鼬(Mvstela eversmanni Lesson)在生态系统的牧食食物链(grazingfood chain)结构上,属二级消费者。其在能流和物质循环中起着重要作用。 有关艾虎生态学研究,报道甚少。Ванников(1954)和Новиков(1956)仅作过一般简单的综述,嗣后,Сысоев(1966),лалваниявов(1968)。Попов等(1968),Маръпп(1974)Bednarz(1964),Bardu(1971)亦均系简报之类。至于其能量的研究,涉及者甚少。国内有关艾虎生态学研究,尚乏报道。     

Feeding and breeding aspects of Stomoxys calcitrans (Diptera: Muscidae) under laboratory conditions

Bionomic aspects of Stomoxys calcitrans (Linnaeus, 1758) (Diptera: Muscidae) were studied under laboratory conditions. For this reason, laboratory-rearing techniques were optimized at the National Veterinary School of Toulouse. The colony was maintained at 25 ± 2 °C, 50 ± 10% RH under a 12-hour light cycle and observed daily. The size of each adult cage is 30 x 30 x 30 cm and designed to house about 500-1,000 flies. The average cycle from egg to adult was 19.2 ± 1.7 days. The mean longevity of imagos was 9.3 ± 5.8 days and not significantly different between sexes. Stable flies were split into two groups; the first was fed with blood, honey and water, and the second was fed only with honey and water. The mean weight of a blood meal was 11.1 ± 3.8 mg with no significant differences between males and females. The mean longevity of non-blood fed flies was found to be significantly higher (10.4 ± 3.9 days) than those fed with blood. The maximum lifespan was shorter for non-blood fed males (17 days) and females (18 days) than for those fed with blood (females: 24 days, males: 23 days). Under these laboratory conditions, S. calcitrans rearing was successfully established. In the end, the number of expected generations of S. calcitrans and the net reproduction rate were estimated to be 11.8 generations/year and 16.2 living females per female respectively.     

Social Behaviour and Cooperative Breeding in Arctic Foxes,Alopex lagopus (L.), in a Semi-natural Environment

Most canid species show cooperative breeding at least occasionally. The helper-at-the-den system, when extra adults serve as helpers by feeding and guarding the cubs of an alpha pair, has been observed but not studied in any detail in wild Arctic foxes (Alopex lagopus). During a 3-months study of arctic foxes in two enclosures of 4 ha each, we measured the social behaviour during the reproductive season. Older foxes dominated younger ones and males dominated females of the same age. A litter with one surviving cub was born in one enclosure. The alpha male increased his rate of urine marking and barking and fed the alpha female both before and after the birth of the litter. However, about 10 days after the birth, the alpha female died. The cub was fed by his putative father, his sister and his brother (both one year old). The one year old female increased her rate of territorial defence, measured as urine marking and barking, when the mother died. The subordinate females were probably suppressed from breeding by the high aggression levels and territorial defence of the dominant females in each enclosure. The dominant female in the second enclosure came into heat after the death of the alpha female (her mother) in the first enclosure. These changes in behaviour can probably be explained by sexual inhibition by the alpha female while she was present. The significance of territorial defence and dominance, inbreeding avoidance, sexual suppression and evolution of helping behaviour are discussed.     

Feeding behaviour of cod (Gadus morhua) in relation to spawning

The food consumption and egg production of 26 adult (13 female and 13 male) Atlantic cod ( Gadus morhua ) were monitored during prespawning, spawning and postspawning periods. Females spawned from late January to mid-April. Feeding activity occurred from December to early January and ceased for females, on average, 36 days (15–54 days) before the onset of spawning. The duration of spawning by females was, on average, 42 days (10–61 days) and feeding was suppressed by both sexes during the first three-quarters of each female's spawning period. Mature females went, on average, 70 days or 19% of the year without eating. An abrupt increase in feeding activity, particularly by females, occurred during the last quarter of spawning or shortly after the release of the last egg batch (on average, feeding started again after 91% of a female's eggs had been released or 82% of egg batches). Females consumed greater quantities of food than males during both winter and postspawning feeding periods. During spawning, females lost, on average, 29% of their body weight and males 14%. Fecundity ranged from 0.75 to 3.97 million eggs per female. The volume of eggs produced by four individual females (range = 1285–5995 ml in four to 11 batches) ranged from 99 to 195% (mean 150%) of a female's postspawning body volume. Six immature cod fed throughout the experimental period and gained, on average, 8% of initial body weight. Laboratory results were supported by stomach fullness index values of Georges Bank cod exhibiting different maturity states.     

Maternal provisioning and possible joint breeding in the burrower bug Adomerus triguttulus (Heteroptera: Cydnidae)

Subsocial burrower bugs (Heteroptera: Cydnidae) provide unique opportunities to investigate evolutionary ecological questions regarding parental provisioning and family dynamics. Observations and marked nutlet‐setting experiments in the field showed that Adomerus triguttulus females progressively delivered mint nutlets into nests harbouring nymphs under the litter. More than one female often attended nymphs, but not eggs, in a nest in the field. The number of nymphs aggregating in a nest with a single female was usually smaller than that in a nest with two females, suggesting the joining of different families and facultative joint parental care. There was a positive correlation between the number of nutlets delivered and the number of nymphs in a nest. The number of attendant females also affected the amount of provisioning; more nutlets were found for second‐instar broods with more females. The effect of brood size on provisioning was confirmed for families under laboratory rearing. Maternal provisioning also varied with the developmental stage of offspring; second‐instar broods received more nutlets than first‐instar broods, with a temporal decrease in provisioning during the moulting of nymphs. Considering the growing evidence of food solicitation signals of young in subsocial insects, the observed finely tuned supply of food by the female could be induced by begging signals from the nymphs.     

Maintenance and breeding of Thrichomys (Trouessart, 1880) (Rodentia: Echimyidae) in captivity

South American histricognath rodents Thrichomys apereoides laurentius and Thrichomys pachyurus are natural hosts of Trypanosoma cruzi, agent of Chagas disease. We established breeding colonies of these species to serve as experimental models in various parasitological studies. Both species of Thrichomys have all the requirements necessary to become excellent laboratory models: they can be easily maintained in the standard laboratory conditions and breed throughout the year and they do not have any special dietary demands and can be fed by standard food pellets designed for laboratory mice. Both species produce precocious offspring that have their eyes and ears open, teeth erupted, fur well developed, and can eat solid food in the first week of life. T. a. laurentius has larger litter sizes and lower body masses at birth and weaning than T. pachyurus. Moreover, females of T. a. laurentius reach puberty earlier and with lower body mass than T. pachyurus.     

Role of benthic insect feces in a Rocky Mountain stream: fecal production and support of consumer growth

The feces of stream insects may be a major component of fine particulate organic matter (FPOM) available to collector organisms. In Mink Creek, Idaho, winter defecation rates for 9 species ranged from 86 mg dry feces (g dry body wt)⁻¹ d⁻¹ (Ephemerella spinifera) to 154 mg g⁻¹ d⁻¹ (Paraleptophlebia heteronea) . Detailed studies of 3 species in summer revealed that rates were much greater than in winter and exhibited high between-individual variation (e.g., 695 ± 184.8 mg (g body wt)⁻¹ d⁻¹ for Baetis tricaudatus ). By combining measured and literature values, it is estimated that the benthic insect community egests approximately 3.4 kg feces m⁻² yr⁻¹. This value lies within the range of FPOM estimated to be derived from degradation of leaf litter input (0.7–9.9 kg m⁻² yr⁻¹, depending upon assimilation efficiency of the organisms).
Short-term winter growth experiments showed that, with two exceptions, collectors fed on fecal detritus will grow as well as on other food resources; relative growth rates depend upon the species. Because fecal detritus is abundant throughout the year, and is treated by many species as a source of food, it could be a major mechanism by which seasonal fluctuation in availability of allochthonous litter input is minimized and homeostasis of structure and function maintained.     

Experimental manipulation of breeding density and litter size: effects on reproductive success in the bank vole

1. Reproductive success of individual females may be determined by density-dependent effects, especially in species where territory provides the resources for a reproducing female and territory size is inversely density-dependent.
2. We manipulated simultaneously the reproductive effort (litter size manipulation: ± 0 and + 2 pups) and breeding density (low and high) of nursing female bank voles Clethrionomys glareolus in outdoor enclosures. We studied whether the reproductive success (number and quality of offspring) of individual females is density-dependent, and whether females can compensate for increased reproductive effort when not limited by saturated breeding density.
3. The females nursing their young in the low density weaned significantly more offspring than females in the high density, independent of litter manipulation.
4. Litter enlargements did not increase the number of weanlings per female, but offspring from enlarged litters had lower weight than control litters.
5. In the reduced density females increased the size of their home range, but litter manipulation had no significant effect on spacing behaviour of females. Increased home range size did not result in heavier weanlings.
6. Mother's failure to successfully wean any offspring was more common in the high density treatment, whereas litter manipulation or mother's weight did not affect weaning success.
7. We conclude that reproductive success of bank vole females is negatively density-dependent in terms of number, but not in the quality of weanlings.
8. The nursing effort of females (i.e. the ability to provide enough food for pups) seems not to be limited by density-dependent factors.     

Food quality affects wing-form,demographic traits and number of yeast-like symbionts (YLS) in the planthopper vector,Delphacodes kuscheli (Hemiptera: Delphacidae)

Delphacodes kuscheli, the main vector of maize Mal de Río Cuarto disease in Argentina, was used to analyze the effect of food quality on wing-form, demographic traits and number of yeast-like symbionts (YLS). First instar nymphs were caged on the leaf apex or on the ligular zone of oat plants, characterized by having low and high nutritional value respectively, and followed in their development to adulthood. Food quality affected the proportion of wing morphs, with an increased number of brachypterous individuals on the higher food quality zone. Macropterous and brachypterous females from the ligular zone had higher survivorship, shorter development time and higher number of YLS. For males, development time and number of YLS did not differ significantly in individuals fed from both zones, while body and wing length were superior in individuals fed on the ligular zone. Results suggest that females allocate the resources from feeding on a richer zone to reduce the pre-reproductive period and to increase the number of YLS, and males acquire a larger size while maintaining development time and YLS number. This is the first study quantifying the variation of number of YLS according to food quality in a Neotropical planthopper pest.     

Effects of feeding endophyte infected tall fescue seed on reproductive performance of female CD-1 mice via competitive breeding

This study was conducted to determine the effects of feeding endophyte-infected (Acremonium coenophialum ) tall fescue (Festuca arundinacea ) seed on the growth and reproductive performance of female CD-1 mice via competitive breeding. One hundred sixty female mice were randomly allocated to groups of ten and fed one of two diets. Diet 1 consisted of 50% mouse chow and 50% noninfected Ky-31 tall fescue seed (w/w). Diet 2 contained 50% chow and 50% tall fescue seed that was 80% infected with A. coenophialum . After 50 d of preconditioning on their respective diets, a single male was introduced into each group of 10 females and allowed to cohabitate for 96 h. The males were removed after the cohabitation period and the females continued through gestation on their respective diets. Body weight of dams and litter weights were recorded at parturition. There were no differences (P>0.05) in pregnancy rates between dietary Treatments 1 and 2 (50% vs 48.8%, respectively). However, the average number of pups born per litter (11.10 pups) and average total litter weight (17.21 g) was greater for those females consuming Diet 1 than for females consuming Diet 2 (9.33 pups per litter and 13.97 g total litter weight). The incidence of dead and cannibalized pups was more frequent with Diet 2 than Diet 1 (0.13 vs 0.0 dead; 0.21 vs 0.03 cannibalized, respectively). The obtained data suggest that although the pregnancy rate was similar between the two dietary treatments, the reproductive capacity (litter size and litter weight) of female CD-1 mice was affected by the consumption of endophyte infected fescue seed.     

黑线仓鼠自身生存和繁殖输出间的权衡不受温度影响

  为阐明野生小型哺乳动物哺乳期能量收支对策,深入理解最大持续能量摄入（SusEI）限制的因素和机理,测定了不同环境温度下（21℃、30℃和5℃）与哺育不同胎仔数（自然胎仔数Con、减少Minus和增加胎仔数Plus）的黑线仓鼠哺乳期体重、摄食量、基础代谢率（BMR）、非颤抖性产热（NST）,以及褐色脂肪组织（BAT）细胞色素C氧化酶（COX）活性、血清T₃、T₄和催乳素水平。结果显示,哺乳期体重显著降低,摄食量显著增加,21℃和30℃组间差异不显著。最大持续摄食量约为14g/d,Minus组比Con和Plus组低20.3%和18.6%。温度对摄食量的影响显著,5℃下摄食量达16g/d,比21℃和30℃组高14%（P<0.05）。Con和Minus组胎仔数维持稳定,而Plus组胎仔数显著降低,断乳时Con和Plus组胎仔数差异不显著。Minus组胎仔重显著低于Con和Plus组。断乳时Minus组平均幼体体重比Con和Plus组分别高17.9%和24.9%（P<0.05）。5℃下BMR、NST、COX活性、血清T₃、T₄和催乳素水平显著高于21℃和30℃,而21℃和30℃组间差异不显著。结果表明：黑线仓鼠SusEI水平为5×BMR,低温下可通过增加能量摄入应对代谢产热的能量支出,在自身维持和繁殖输出之间采取了“权衡分配”的能量学策略,研究结果支持热耗散限制假说,也符合外周限制假说的预测。     

Ecological correlates of lion social organization (Panthers, leo)

Data on lion home range size, pride size, density, group size, cub survival, litter size and adult sex ratio were extracted from studies carried out in 10 habitats. The data were compared with five measures of food supply: mean prey biomass, prey biomass during the season of greatest abundance, prey biomass during the season of least abundance, biomass of middle-sized prey species (i.e. those with mean adult live-weights between 50 and 250 kg), and the mean size of carcasses fed on by lions. The results indicated that range size is inversely correlated with the abundance of prey during the period of least abundance, but not with overall prey abundance. Range size showed no consistent variation with pride size or with minimum metabolic requirements. Pride size (measured in terms of average number of animals per pride and average number of adult females) and cub survival strongly correlated with lean season food abundance. No relationship was found between group size or litter size and any of the measures of food supply Adult sex ratio did not vary consistently with food supply or lion density, although the data did suggest that prides inhabiting small, circumscribed reserves may experience less inter-male competition and this, in turn, may affect the adult sex ratio.     

Foraging behaviour of Brachionus calyciflorus (Pallas): variations in the swimming path according to presence or absence of algal food (Chlorella)

Both swimming and attachment behaviour of immature female Brachionus calyciflorus (Pallas) from a young orthoclone were analyzed under four experimental conditions: with and without algae (Chlorella), and with fed and starved individuals. Eighteen hours before the recording, two random groups were formed. To the first group, Chlorella was added. The second was placed in pure water. Both were filmed in red light to avoid a phototactic effect. Video-recorded swimming behaviour of B. calyciflorus was analyzed by automatic tracking. Each B. calyciflorus was filmed alternately in the presence or absence of Chlorella for five periods of 15 min. Under indentical light and temperature conditions the number of animals attached to the culture dish was measured with both starved and fed females. We observed a significant difference in swimming paths depending on the presence or absence of food, and the physiological state of the individuals. In the presence of Chlorella the linear speed was lower and the angular speed was greater. This increase in angular speed was more pronounced when females were subjected to a period of starvation before the experimentation. The attachment behaviour increased in the algal environment. This modification of swimming behaviour enables females to increase the time spent in a favorable food environment.     

Annual production of young in European hares (Lepus europaeus) in the Netherlands

In the Netherlands, hares have a period of sexual inactivity in autumn. Even though a reactivation of spermatogenesis was found from the second half of November onwards, first conceptions did not occur until the last week of December. Throughout January, the proportion of pregnant females increased to 80% in February in healthy adults, but only to 8% in diseased ones. Due to the spread in the start of the breeding season caused by variations in health and age, no synchronization in birth was found. Consequently, in order to be able to determine the annual production of young, the gradual change in pregnancy rate and mean litter size over the year had to be taken into account. Taking mean monthly values for healthy adult females, an average annual production of nearly 11 young was found. Compared with other European countries, annual production in the Netherlands is relatively high which is probably due to a comparatively long breeding season.     

Long-term effects of accelerated or delayed sexual maturation on reproductive output in wild female house mice (Mus musculus)

The effects of acceleration and delay of puberty in female house mice on survival and reproduction were tested using 6 experimental groups: (1) control females mated at the time of first oestrus, (2) females mated at weaning, (3) females treated with male urine starting at weaning and mated at first oestrus, (4) females housed in groups and mated at first oestrus, (5) females housed alone, treated with urine from grouped females and mated at first oestrus, and (6) females housed alone and mated at 68 days of age. Females caged with males at weaning or treated with male urine and mated at puberty had lower rates of survival to 180 days of age, but did not differ in rates of fertility from mice in the other four treatments. Those females that were housed with males from weaning or treated with male urine also had smaller total numbers of litters, fewer total young, and smaller average litter sizes than did females for which the age of mating was delayed, by grouping or treatment with urine from grouped females, or by being held until age 68 days before mating. Control females mated at first oestrus generally were intermediate or did not differ from the male treatments on these dependent variables. There were no differences in the average number of female young/litter across the 6 treatments. However, females that were delayed in age of first mating had significantly more male young/litter than did females that were accelerated in their sexual development or control females.(ABSTRACT TRUNCATED AT 250 WORDS)     

高体重布氏田鼠产仔数较多但繁殖输出及氧化损伤不受影响

体重可影响动物几乎所有的生物学变量。高体重双亲通常产生较大胎仔数。繁殖过程代价很高,可能伴随着氧化损伤。为比较双亲体重对繁殖期能量学特征、繁殖输出和氧化损伤的影响,检测了高体重组(雌性:51. 5 g ± 1. 6 g;雄性:60. 4 g ±2. 5 g)和低体重组(雌性:35. 5 g ± 1. 2 g;雄性:49. 6 g ± 2. 8 g)布氏田鼠繁殖过程中母体的体重和摄食量,分娩时的胎仔数和胎仔总重,及后代断乳时母体的身体成分、激素含量(血清瘦素和催乳素)和氧化损伤(血清丙二醛、蛋白质羰基和肝脏丙二醛含量)。结果显示:(1)高体重组妊娠末期的母体体重增量显著高于低体重组;(2)高体重组母体的出生胎仔数显著高于低体重组,但出生及断乳时的平均胎仔重、胎仔总重和母体繁殖期间的能量摄入无显著差异; (3)血清激素含量、身体成分、身体脂肪重量及氧化损伤指标均无组间差异。结果表明,高体重布氏田鼠可产生较多的出生胎仔数,但母体并不通过摄入更多的能量来保证其繁殖输出,对氧化损伤也没有影响。这些结果对于理解不同体重的动物在繁殖期间的能量策略以及繁殖与生存之间的权衡等生活史理论具有重要意义。