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1.
We describe the activity patterns and time budgets of white-headed langurs that were confined to about 4 km2 of Longlin habitat in Fusui County, Guangxi Province, China. Between February and December 1996, we observed 6 langur groups monthly via group focal sampling and continuously recording the behavior of a focal group. Our results indicate that the langur groups selected stone caves on cliffs as sleeping sites. The daily activity pattern outside caves had 8 stages: (1) leaving the cave in the early morning; (2) moving and resting; (3) morning feeding; (4) moving a long distance; (5) resting at noon; (6) afternoon feeding; (7) moving back to the cave, and (8) entering the cave. Over the year, langurs spent a daily average of about 11.5 h outside caves and about 12.5 h inside caves. Moving accounted for 7% (spring), 7% (summer-autumn) and 13% (winter) of the time budget, and langurs spent 9% (summer-autumn) and 14% (spring) to 20% (winter) of their time feeding. Resting accounted for 79% of the time budget in spring, 84% in summer-autumn, and 57% in winter. Sunbathing only occurred in winter and accounted for about 10% of the time budget. One-way ANOVA and multiple range tests demonstrated that time budgets differed significantly among seasons. Langurs spent significantly more time feeding and moving in winter than in spring and summer-autumn, but significantly less time resting in winter than in spring and summer-autumn.  相似文献   

2.
Serum values of retinol, carotenoids, tocopherol and ascorbic acid were assayed in healthy adult females (Group A: 20 cases) and in subjects with fibrocistic mastopathy (Group B: 20 cases), benign breast neoplasms, as fibroadenomas and intraductal papillomas (Group C: 18 cases), and breast carcinoma in situ (Group D: 36 cases). Retinol and carotenoids were evaluated by spectrophotometry using trifluoroacetic acid. Tocopherol was determined by a colorimetric method involving the reduction of Fe to Fe++ by tocopherol with the formation of a red complex of the Fe++ with alpha, alpha'-dipirydyl. Ascorbic acid was estimated by a colorimetric method after derivatization with 2,4-dinitrophenylhydrazine. Our results point out that there is a highly significant decrease (p less than 0.001) of average retinol serum levels in all three patient groups as compared with group A, whereas carotenoids resulted decreased but not significantly. Tocopherol was found to be significantly lower only in groups B (p less than 0.05) and D (p less than 0.01), ascorbic acid in groups B (p less than 0.01) C (p less than 0.05) and D (p less than 0.001).  相似文献   

3.
The immunobiochemical studies were conducted in a group of 98 production workers engaged in polyvinyl chloride manufacture from ethylene (group A workers) and in a group of 59 vinyl chloride workers from a chemical plant employing classic production technology from acetylene (group B workers). Both groups of workers were matched by age (group A workers: 37.7 +/- 8.66 years; group B workers: 34.9 +/- 11.2 years) and average exposure length (group A workers: 8.6 +/- 3.0 years; group B workers: 10.7 +/- 8.4 years). All workers were examined for the serum concentrations of immunoglobulins IgG, IgA and IgM and acute reactants lysozyme (LYS), transferrin (TRF), ceruloplasmin (CPL), alpha-l-antitrypsin (AlAT), alpha-2-macroglobulin (A2M) and orosomucoid (ORO). The statistical analysis included calculations of means, standard deviations and 95% confidence intervals. Differences in means were evaluated by t-test, differences in the distribution pattern of values by F-test. Abnormality of values was assessed by comparisons to normal values valid in Czechoslovakia. Group A worked in conditions meeting the MAC 10 mg VC.m-3 comparing with group B workers had elevated levels of IgG (P less than 0.005), IgA and IgM (P less than 0.001 both). Group B workers differed from group A workers by exhibiting significantly elevated levels of AlAT, and CPL. (P less than 0.001). The differences in the frequency of abnormal values between group A and group B worked in substantially less favourable hygienic conditions were significant for immunoglobulins elevated in group A and for ORO (P less than 0.01) and CPL (P less than 0.001) elevated in group B. The possible relationship of these immunobiochemical findings with the degree of vinyl chloride exposure are critically analyzed.  相似文献   

4.
2008 年6 月至2009 年5 月,在白马雪山国家级自然保护区南端的响古箐(北纬27°37′,东经99°22′),采用瞬时扫描取样法对一群数量约480 只的滇金丝猴群的活动时间分配进行了研究。研究期间共观察取样1 609 h,扫描个体数为260 546。研究表明,响古箐滇金丝猴用38.8% 的时间取食、27. 4% 的时间移动、20. 9%的时间休息、12.9% 的时间从事其他类型活动。滇金丝猴活动时间分配季节性差异明显。冬季,滇金丝猴的取食时间长于其他季节,达到41. 5% ;秋季,取食时间在全年最短(36.5% )。夏季的高温没有影响滇金丝猴的移动,它们移动的时间达到32.8% ,高于其他3 个季节。寒冷的冬季,响古箐滇金丝猴为了减少能量损失,用于休息的时间达到24.4% 。秋季,滇金丝猴从事其他类型活动的时间(15.7% )多于另外3 个季节。研究发现,
绝对移动时间与昼长和月平均温度呈明显正相关(P < 0. 01),绝对休息时间与月平均温度呈负相关(r =- 0. 585,P = 0.046),但降水量的多少与猴群各种活动时间分配之间没有明显的相关性(P > 0.05)。食物贡献率与滇金丝猴日活动时间分配也存在相关性。取食松萝比例与猴群移动时间呈负相关(r = - 0.902,P <0.001),与休息时间呈正相关(r = 0.860,P < 0.001)。猴群取食树叶比例增加时,它们移动时间也随之增加(r = 0.832,P = 0.001)。夏季,滇金丝猴取食竹笋的比例增加时,猴群移动时间也明显增多。以上结果表明,滇金丝猴活动时间分配受食物资源状况、昼长季节性变化和气候条件的影响。  相似文献   

5.
OBJECTIVE--To test whether a fat reduced diet rich in soluble dietary fibre, antioxidant vitamins, and minerals reduces complications and mortality after acute myocardial infarction. DESIGN--Randomised, single blind, controlled trial. SETTING--Primary and secondary care research centre for patients with myocardial infarction. SUBJECTS--505 patients with suspected acute myocardial infarction. Those with definite or possible acute myocardial infarction and unstable angina based on World Health Organisation criteria were assigned to diet A (n = 204) or diet B (n = 202) within 24-48 hours of infarction. INTERVENTIONS--Both groups were advised to follow a fat reduced diet. Group A was also advised to eat more fruit, vegetables, nuts, and grain products. MAIN OUTCOME MEASURES--Mortality from cardiac disease and other causes. Serum lipid concentrations and compliance with diet. RESULTS--Blood lipoprotein concentrations and body weight fell significantly in patients in group A compared with those in group B (cholesterol fell by 0.74 mmol/l in group A v 0.32 mmol/l in group B, 95% confidence interval of difference 0.14 to 0.70, and weight by 7.1 v 3.0 kg, 0.52 to 7.68). The incidence of cardiac events was significantly lower in group A than group B (50 v 82 patients, p less than 0.001). Group A also had lower total mortality (21 v 38 died, p less than 0.01) than group B. CONCLUSIONS--Comprehensive dietary changes in conjunction with weight loss immediately after acute myocardial infarction may modulate blood lipoproteins and significantly reduce complications and mortality after one year.  相似文献   

6.
This is a prospective study of 182 women (38 yrs or younger) undergoing IVF-ET. Endometrial thickness, echo pattern and blood flow on transvaginal ultrasonography were recorded eight hours prior to hCG administration. The patients were divided into three groups: A (n = 10) with undetectable endometrial blood flow; B (n = 82) with sub-endometrial blood flow; C (n = 90) with both endometrial and sub-endometrial blood flow. According to IVF-ET outcomes, all patients were re-divided into three groups: 1 non-pregnancy (n = 92); 2 intrauterine pregnancy with live fetus (n = 70); 3 others (n = 20 including biochemical pregnancy, embryonic diapause, ectopic pregnancy and miscarriage). Intrauterine pregnancy with live fetus in Group C (62.2%) was much higher than that in Group A and B (0% and 17.1%, p less than or equal to 0.001). The implantation rate (33.2%) was much higher than that in Group A and B (0% and 19.90%, p less than or equal to 0.001). The pulsatility index, resistance index, and S/D of endometrial spiral arteries were 0.1 +/- 0.2, 0.6 +/- 0.1 and 2.5 +/- 0.4 in Group 2, which were much lower than those in Group 1 and Group 3 (p1-2 less than 0.001, p2-3 less than 0.05). The patients with detectable endometrial blood flow had higher clinical pregnancy rates and implantation rates.  相似文献   

7.
Forty male patients: group A-autooxygenation and group B-bubble oxygenator used in extracorporeal circulation (ECC) were studied to evaluate the haemocompatibility of 2 types of ECC. The Plt count dropped significantly in group B patients: -73% of initial value vs only -27% in group A, (p less than 0.001). In both groups a rise in BTG was shown, but higher in group B, p less than 0.001. At the end of CPB aggregation decreased only slightly in group A after epinephrine and 4-ADP, and decreased hardly in group B with the significant difference between two groups (p less than 0.02 and p less than 0.001, respectively). In group A the mean blood loss was 278 +/- 49 ml/m2 and 483 +/- 67 ml/m2 in group B, p less than 0.001. The mean blood transfusion in group A and B was 198 +/- 82 ml/m2 and 427 +/- 85 ml/m2, respectively (p less than 0.001). We are positive that the elimination of artificial oxygenator from the ECC diminished markedly the decline in Plt count and Plt activation during CPB.  相似文献   

8.
Seasonality of feeding activity in Antarctic suspension feeders   总被引:3,自引:0,他引:3  
The feeding activity of four benthic suspension-feeding groups (bryozoans, hydroids, polychaetes and holothurians) was monitored in situ every month for a 2-year period at Signy Island in the maritime Antarctic. The bryozoans were monitored at species level, whereas the other taxa could be differentiated only to genus. A marked seasonal variation in feeding activity was observed in most taxa. Although environmental parameters such as sea water temperature, fastice duration and water column chlorophyll concentrations suggested that winter in the maritime Antarctic lasts for about 6 months, many animals ceased feeding only for a short period of 2 or 3 months around the middle of the austral winter (June/July). These suspension feeders must therefore be efficient at utilising the low concentration of the microplankton existing in the water column for much of the year. Comparison with environmental variables suggested several possible cues for changes in feeding activity, but these cues may differ between taxa. Photoperiod and changes in disturbance by water movement (both mediated by ice), and food concentration are likely to be important environmental cues for polar suspension feeders.  相似文献   

9.
Summary Amos Lake is a shallow, permanently cold, maritime Antarctic lake which is almost totally anoxic for much of the 9 month period of winter ice cover each year. The lake catchment is a source of considerable nutrient enrichment for the lake due to the presence, in summer, of large numbers of seals and seabirds. A dense growth of phytoplankton was supported by this enrichment and, in turn, was a source of nutrients for the diverse microflora of the lake. The phytoplankton had a very high assimilation efficiency and an apparent high tolerance of anoxia. Bacterioplankton numbers and activity were closely linked to algal activity and both groups showed a strong seasonality typical of polar systems. Anaerobic bacteria (notably sulphate reducers and methanogens) were not as significant as anticipated, being largely restricted to the deeper lake trough region and possibly subject to substrate limitation later in the anoxic period. The results are discussed in the context of previous findings for other maritime Antarctic lakes.  相似文献   

10.
Serum somatomedin-C (SM-C) and somatomedin (SM) concentrations were measured by, respectively, radioimmuno (SM-C RIA) and radioreceptor assays (SM RRA) in 3 groups of children with short stature. The patient population was different from previously reported series in that it was urban Brazilian, low income, and significantly older. Group A consisted of 6 male and 3 female children, aged 7.7-16.0 years, whose average peak plasma immunoreactive growth hormone (GH) was above 10 ng/ml. Group B contained 8 male and 5 female untreated GH-deficient patients, ranging in age from 9.5 to 21.0 years. In Group C there were 4 male and 1 female GH-deficient subjects treated with I.M. injections of GH (0.1 U/kg) from 1 month to 7 years. The mean +/- SE basal RIA SM-C (ng/ml) concentrations were significantly lower in groups B (34.2 +/- 8.8) and C (43.8 +/- 13.7) than A (214.3 +/- 42.7): A X B, P less than 0.001 and A X C, P less than 0.02. Likewise the mean +/- SE basal RRA SM (ng/ml) concentrations were significantly lower in groups B (78.9 +/- 17.6) and C (90.8 +/- 19.3) than group A (316.3 +/- 43.0): A X B, P less than 0.001 and A X C, P less than 0.002. A significant linear correlation was observed between RIA and RRA in group B (r = 0.84; P less than 0.001) and C (r = 0.96; P less than 0.01), but not for A (r = 0.61; P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
Subantarctic fur seal Arctocephalus tropicalis and Antarctic fur seal A. gazella pups at Marion Island were weighed frequently until weaning, which occurs earlier in A. gazella (112 days) than in A. tropicalis (± 300 days). The mean birth weight of both species was the same (4·2 kg) and males grew faster than females. Arctocephalus gazella growth was linear to weaning and faster than A. tropicalis growth, which was linear to 120 days of age, slowing until 203 days of age, and thereafter losing weight but recovering perceptibly prior to weaning. Tagging had no apparent effect on pup growth. Faster growth in males than in females is part of the differential growth patterns which lead to adult sexual dimorphism. Arctocephalus gazella pup growth at Marion Island is faster than at South Georgia, indicating that conditions at this, their most northerly breeding locality, are not limiting for pup growth. The decrease in A. tropicalis pup body weight in July/August may result from either a scarcity of food in winter or weaning having been initiated. The two groups (polar and non-polar) of fur seals exhibit two strategies, which include differences in pup growth and suckling period; the polar species have a short suckling period and rapid pup growth and are predominantly pelagic over winter, while the more temperate species have a longer suckling period and slower pup growth and are less pelagic over winter.  相似文献   

12.
Understanding the degree of genetic exchange between subspecies and populations is vital for the appropriate management of endangered species. Blue whales (Balaenoptera musculus) have two recognized Southern Hemisphere subspecies that show differences in geographic distribution, morphology, vocalizations and genetics. During the austral summer feeding season, the Antarctic blue whale (B. m. intermedia) is found in polar waters and the pygmy blue whale (B. m. brevicauda) in temperate waters. Here, we genetically analyzed samples collected during the feeding season to report on several cases of hybridization between the two recognized blue whale Southern Hemisphere subspecies in a previously unconfirmed sympatric area off Antarctica. This means the pygmy blue whales using waters off Antarctica may migrate and then breed during the austral winter with the Antarctic subspecies. Alternatively, the subspecies may interbreed off Antarctica outside the expected austral winter breeding season. The genetically estimated recent migration rates from the pygmy to Antarctic subspecies were greater than estimates of evolutionary migration rates and previous estimates based on morphology of whaling catches. This discrepancy may be due to differences in the methods or an increase in the proportion of pygmy blue whales off Antarctica within the last four decades. Potential causes for the latter are whaling, anthropogenic climate change or a combination of these and may have led to hybridization between the subspecies. Our findings challenge the current knowledge about the breeding behaviour of the world's largest animal and provide key information that can be incorporated into management and conservation practices for this endangered species.  相似文献   

13.
Acute, short term cooling of North Sea eelpout Zoarces viviparus is associated with a reduction of tissue redox state and activation of hypoxia inducible factor (HIF-1) in the liver. The present study explores the response of HIF-1 to seasonal cold in Zoarces viviparus, and to latitudinal cold by comparing the eurythermal North Sea fish to stenothermal Antarctic eelpout (Pachycara brachycephalum). Hypoxic signalling (HIF-1 DNA binding activity) was studied in liver of summer and winter North Sea eelpout as well as of Antarctic eelpout at habitat temperature of 0°C and after long-term warming to 5°C. Biochemical parameters like tissue iron content, glutathione redox ratio, and oxidative stress indicators were analyzed to see whether the cellular redox state or reactive oxygen species formation and HIF activation in the fish correlate. HIF-1 DNA binding activity was significantly higher at cold temperature, both in the interspecific comparison, polar vs. temperate species, and when comparing winter and summer North Sea eelpout. Compared at the low acclimation temperatures (0°C for the polar and 6°C for the temperate eelpout) the polar fish showed lower levels of lipid peroxidation although the liver microsomal fraction turned out to be more susceptible to lipid radical formation. The level of radical scavenger, glutathione, was twofold higher in polar than in North Sea eelpout and also oxidised to over 50%. Under both conditions of cold exposure, latitudinal cold in the Antarctic and seasonal cold in the North Sea eelpout, the glutathione redox ratio was more oxidised when compared to the warmer condition. However, oxidative damage parameters (protein carbonyls and thiobarbituric acid reactive substances (TBARS) were elevated only during seasonal cold exposure in Z. viviparus. Obviously, Antarctic eelpout are keeping oxidative defence mechanisms high enough to avoid accumulation of oxidative damage products at low habitat temperature. The paper discusses how HIF could be instrumental in cold adaptation in fish.  相似文献   

14.
Freshly caught samples of slugs were maintained at constant temperature and humidity but at day lengths (from 5 h 50 min to 16 h darkness) appropriate to the time of year at which they were collected. The duration of their feeding and crawling activities as well the total time spent active was recorded by time-lapse cinematography.
Total activity was significantly higher in autumn and spring than in summer and winter. The activity period was symmetrically disposed about the midpoint of the dark period except for two samples in autumn. At scotoperiods longer than about 12 h, activity onset was delayed relative to the start of the dark period and activity cessation was advanced relative to the end of the period, resulting in the short duration of activity seen in winter. At scotoperiods of less than 12 h the duration of activity was relatively independent of scotoperiod.
In spring the total time spent crawling was composed of relatively few bouts of long duration whereas in the autumn the number of bouts was greater and their duration shorter. The winter was characterized by slugs making single journeys to and from the food. While emerged these slugs stayed in close association with the food but not necessarily feeding on it.
These data are discussed in terms of comparisons with homoiothermic nocturnal animals. It is concluded that seasonal responses in poikilothermic animals are likely to be limited by the hazards of winter even when such animals are maintained in apparently non-limiting conditions.  相似文献   

15.
Maximum oxygen uptake (VO2max) was measured directly and predicted from cardiac frequency measurements in 54 healthy Chilean industrial workers aged 20 to 55 years, together with assessment of their dietary intake, body composition and blood chemistry. Measurement of VO2 was performed on a motor-driven treadmill. The predicted VO2max was obtained using a cycle ergometer by two methods: 1) the Astrand-Ryhming nomogram and 2) the linear relationship between "steady state" heart rate (HR) and submaximum work, with subsequent extrapolation to "maximum" heart rate. Extrapolation of the HR/load regression line to 170 bpm permitted determination of the physical working capacity at 170 bpm (W170). VO2max for the 20-29 year group (Group I) averaged 3624 ml.min-1 and decreased to 3066 ml.min-1 in the 50-55 year group (Group IV). Lower values were obtained using the Astrand-Ryhming nomogram and HR/load regression (-15% and -9% respectively). W170 was also affected by age (Group I: 190.6 W and Group IV: 158.5 W). No significant correlation were found between VO2max and plasma variables, with the exception of cholesterol (r = 0.59). On the contrary, anthropometric variables showed significant correlations with VO2max, which permitted the prediction of VO2max using multiple regression equations. The two best correlations were: 1. VO2max = 0.800 - 0.0225.(A) +0.0189.(W)+1.26.(H) (r = 0.87; p less than 0.001) 2. VO2max = 0.996 - 0.0176.(A) + 0.025.(W) + 0.838.(H) + 0.0255.(LBM) (r = 0.88; p less than 0.001) where A = years of age; W = body weight in kg; H = height in m and LBM = lean body mass in kg.  相似文献   

16.
Time budgets of Nuthatches Sitta europaea with supplementary food   总被引:4,自引:0,他引:4  
BODIL ENOKSSON 《Ibis》1990,132(4):575-583
Individual time budgets during winter and spring were studied in a population of Nuthatches Sitta europaea in south-central Sweden. In late winter birds spent about 90% of daytime foraging, males feeding somewhat less than females, possibly due to male dominance. In early spring, foraging time decreased to about 65% of daytime activity, and sex-related differences became more pronounced. Males then increased time spent resting and singing. Females were nestbuilding, spent less time resting and also devoted more time to foraging than did males. Prior to the observation periods, food density for part of the population was experimentally increased by supplying sunflower seed. In spite of this, time budgets in the experimental group were similar to those of the control group. It is possible that the intensity of foraging, rather than actual time devoted to it, was influenced by food density and that, as a result, birds in the experimental group were able to maintain a higher level of vigilance. Also, an increase in food supply may be less important to a hoarding bird such as the Nuthatch. However, the result remains that Nuthatch time budgets in winter and spring are not readily influenced by an increase in food density.  相似文献   

17.
The foraging distribution of marine predator populations is important for effective modelling and management of pelagic marine systems. We tracked 31 juvenile southern elephant seals from Macquarie Island (158°57E, 54°30S) over their annual post-moult and mid-year trips to sea. We calculated the amount of time spent in regional fisheries management areas and within bounded oceanographic regions. During the austral summer, juvenile seals spent over 90% of their time south of the Antarctic Polar Front and ~80% within fisheries management regions [Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and exclusive economic zones]. In winter, seals spent ~75% of their time in the region bounded by the Antarctic Polar Front and the southern boundary of the Antarctic Circumpolar Current, and ~60% within fisheries management regions. The time spent per region differed significantly between summer and winter. Our results demonstrate that juvenile southern elephant seals from Macquarie Island spent more time south of the Antarctic Polar Front and within fisheries management areas than previously suspected.  相似文献   

18.
We conducted a double-blind, retrospective comparison between low-bleed and non-low-bleed (conventional) mammary implants because no controlled study has shown a difference in the degree of capsular contracture between the two types of implants. Twenty-five patients had conventional implants and form group A; twenty-eight patients had low-bleed implants and form group B. All patients had submuscular augmentation. The mean Baker score was 1.51 for group A and 1.04 for group B for the entire patient population and 1.65 for group A and 1.07 for group B for patients with more than 1 year of follow-up. For the entire population, 34 percent of group A and 3.6 percent of group B had a Baker score of 2 or greater. For the population with more than 1 year of follow-up, 42 percent of group A and 7 percent of group B had a Baker score of 2 or greater. There was significantly (p less than 0.007) less contracture with the low-bleed implants for the entire population as well as for those patients with greater than 1 year of follow-up (p less than 0.015).  相似文献   

19.
One hundred twenty eight women underwent midtrimester induced abortion with: 1) combined regimen of intramniotic prostaglandin (PG) F2a injection and intracervical laminaria tents (group A, 50 women), 2) intramniotic PGF2a injection only (group B, 51 women) and 3) laminaria tents followed by intracervical PGF2a tablets insertion (group C, 27 women). The mean induction-abortion time (+/- SE) was 24.9 +/- 1.7 hours for group A, 28.2 +/- 2.2 hours for group B (p greater than 0.05) and 42.1 +/- 3.4 hours for group C, significantly longer than goup A and B (p less than 0.001 and p less than 0.01 respectively). In 48 hours 98% of the patients of group A, 90% of group B (p less than 0.05) and 59% of group C (p less than 0.001) completed the abortion procedure. Parous women of group A and B presented similar induction - abortion time, while in nulliparous the use of laminaria shortened the abortion procedure significantly (p less than 0.05). The complications rate was low. In conclusion, the intracervical PGF2a insertion is a simple but very slow abortion procedure with high failure rates. The intramniotic PGF2a injection is a successful method for late midtrimester medical pregnancy termination and the concurrent use of laminaria tents shortens the abortion procedure, particularly in nulliparous, reduces the number of prostaglandins' reinjections and increases the incidence of successful abortion within 48 hours.  相似文献   

20.
Most cooperative breeding bird species live in family groups that are formed through the prolonged association of offspring with their parents. Research into cooperative families has in particular investigated the balance between cooperation and conflict over reproductive decisions. As a consequence of this research focus, social interactions among group members outside the breeding season are rarely studied, despite the fact that they are likely to be crucial for social decisions. We investigated the social dynamics and ranging behaviour of the family group living cooperatively breeding apostlebird ( Struthidea cinerea ) outside the breeding season. Group size changed between, but not within, the seasons, being smaller during the breeding season than in the winter season. This change in group size was a consequence of breeding groups merging after breeding, then splitting again before the next breeding season. While breeding groups used small, non-overlapping home ranges (      = 113 ha) around the nesting site, during winter groups moved up to 1200 ha (      = 598 ha), and interacted frequently with up to four other winter groups. In particular large groups often joined together during winter and spent up to 50% of their time associating with other large winter groups. This apparent fission-fusion system facilitated the exchange of group members, offering the possibility to form new breeding coalitions and new groups. The results of this study suggest that behaviour outside the breeding season can be of considerable importance to the social dynamics of both families and cooperative breeding in such systems.  相似文献   

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