中国怒江片马地区怒江金丝猴种群动态及社会组织初探

2011 年10 月至2013 年10 月在云南高黎贡山自然保护区泸水县片马镇地区对一群怒江金丝猴的社会组织进行研究,基于野外实地记录与获得的视频资料统计猴群的个体数量,研究群数量初步估计为100 只。根据体型、毛色及是否携带婴猴等特征来划分所有个体的性别年龄组,依据单元内个体通过林窗时移动的时间间隔比单元间短的原则来划分不同繁殖单元及全雄群。所有视频中共发现22 个一雄多雌单元(OMU) 和1 个全雄群(AMU),因此怒江金丝猴的社会组织与其他金丝猴物种相似,由多个一雄多雌及其后代组成繁殖单元(OMUs)与雄性个体组成全雄群(AMU)组成重层社(Modular society);另外基于GPS 位点初步确定猴群活动的海拔范围为1 900 - 3 700 m,猴群生境面积约为12 km² ,初步获得猴群的密度为8 只/ km² ,比缅甸的种群密度(1 只/ km² )大得多。基于种群性别年龄计算种群动态参数,雄雌比为1∶ 2.1, 婴雌比为1∶ 4. 7,成幼比为2.5∶ 1。与滇金丝猴种群相比,该种群有很低的婴雌比和很高的成幼比。     

Population structure,demography, and dynamics of mountain baboons: An interim report

Counts of 61 baboon troops (Papio cynocephalus ursinus) at four localities in the Drakensberg mountains confirmed earlier reports of a small mean troop size. This troop size of 22.49 animals changed neither with latitude nor elevation. Data from two of the sites suggested that population density increases from south to north, while a working assumption of 2.5 animals/ km² allowed us to set the population size at 7,540 animals, living in 335 troops. Both the adult sex ratio of 2.07 females/male and the immature/ adult female ratio of 1.17 were unaffected by troop size. Repeated counts from nine known troops revealed that the population is at equilibrium. © 1995 Wiley-Liss, Inc.     

Abundance, use of space, and activity patterns of white-faced sakis (Pithecia pithecia) in French Guiana.

White-faced sakis (Pithecia pithecia) are among the least studied neotropical primates. The combination of shy and quiet behavior, their ability to move silently, and the extreme difficulty of capturing them may explain why very few field studies have been undertaken in undisturbed habitats. During the course of a wildlife rescue in French Guiana, six individuals were captured and translocated to a safe area of primary rainforest. In this area, based on the observation of 35 groups, the average group size was 2.3 animals (SD = 1.2) and a density of 0.28 group/km(2) (0.64 individuals/km(2)) was estimated from transect censuses. Our study focused successively on three radio-collared animals (two males and one female) over a 287-day period, starting from release to the loss of the animal. From the study start, the triangulation method was used prior to habitutation to human presence, followed thereafter by 1,327 hr of visual monitoring. The translocated animals settled down, and two of them had a stable and compact home range. Two of them merged in association with members of the resident population. A resident group had a much larger home range than previously reported: 148 and 287 ha, using grid cells and 100% minimum convex polygon techniques, respectively. A group composed of two translocated individuals (one male and one female) had a home range of 68 and 135 ha using the same techniques. Additionally, two solitary animals used 152 and 162 1-ha quadrats. We observed animals (translocated and residents) moving quickly in one direction up to 11.5 km. The mean daily path length of resident animals was 1,880 m. Sakis used the lower strata of the forest more when in group, and the intermediate strata more when solitary. Allogrooming is fairly common in social groups. On average, the activity period ranged from 7:17 to 15:59 hr.     

Population and group structure of western lowland gorillas (Gorilla gorilla gorilla) at Lokoué, Republic of Congo

During a 17-month study at the Lokoué clearing in Odzala National Park, Republic of Congo, we identified 377 western lowland gorillas. This population included 31 solitary males, 37 breeding groups, and eight nonbreeding groups. Its age- and sex-class structure was similar to those observed at two other clearings in the same forest block. However, the size of breeding groups varied with site (either clearing or forest sites). At Lokoué, breeding groups (mean size: 8.2 gorillas; range: 3-15) included a single silverback male and, on average, 3.2 adult females. Nonbreeding groups (mean size: 5.5; range: 2-15) were devoid of adult females. Five of the nonbreeding groups were composed predominantly of blackbacks, subadult males, and juveniles, and thus fit the definition of all-male groups previously observed in mountain gorillas. Our study confirms that 1) one-male breeding groups are the norm in western gorillas, and 2) all-male groups occur in this species. Despite frequent changes in members due to migrations of the males, the persistence of these all-male groups indicates that they may play an important role in the life of migrating males. Variations in population structure, and group composition and type among gorilla populations are discussed. However, a further understanding of the evolution of group-living in gorillas requires detailed ecological studies conducted in parallel with studies of the population structure and dynamics of these groups.     

Population status of Andean Condors in central and southern Bolivia

Andean Condors (Vultur gryphus) are a Near Threatened species that was formerly distributed along the entire length of the Andes from western Venezuela to Tierra del Fuego. Populations have been severely reduced north of Peru, but several thousand Andean Condors still exist in the southern portion of their range in Argentina and Chile. Little is known, however, about the size of the Andean Condor population in the central part of their range in Peru and Bolivia. From June to September 2012, we used feeding stations to attract Andean Condors and estimate the size and structure of the population in the eastern Andes of central and southern Bolivia. We estimated a minimum population of 253 condors, an adult male‐to‐female ratio of 1:0.6, an immature male‐to‐female ratio of 1:0.9, and an adult‐to‐immature ratio of 1:1.1. At our five survey areas, estimated abundance ranged from 15 to 100 condors per area. Males outnumbered females in three areas and the opposite was true in two areas. Our estimated adult‐to‐immature ratio, overall and in each area, suggests that the populations could be reproducing at a high rate. As previously observed in other Andean Condor populations, skewed sex ratios could be associated with differences between sexes and age classes in habitat selection. Although our results suggest that Bolivian populations of Andean Condors are still reasonably large, population monitoring is urgently needed, including use of feeding stations throughout the entire Bolivian range of the species and intensive searches for roosting and nesting sites.     

Population dynamics of Macaca sylvanus in Algeria: An 8-year study

The demography and dynamics of two groups, one living in an evergreen cedar-oak forest (Tigounatine) and the other, in a deciduous oak forest (Akfadou) in Algeria, were studied from 1982 to 1990. Group size fell within the range of other wild groups except for the Tigounatine group when it reached 88 individuals before splitting into three new independent groups. The structure of the studied groups, except one which was temporarily “one male,” was comparable to that of other groups of Barbary macaques. There were 43–50% of immatures on average depending on the group. The sex ratio (M:F) of the sexually mature animals was relatively balanced (1:0.9–1.2). The mean age of primiparous females was 5.5 years in Tigounatine and 5.3 in Akfadou; the rate of reproduction of sexually mature females was 0.56 and 0.63, respectively, while the infant mortality rate was 0.23 and 0.38, respectively. Great interannual variations occurred at both sites. The differences between natality and mortality induced a higher intrinsic mean annual increase for the Tigounatine group (14.6%) than for the Akfadou group (4.8%). The rate of intergroup transfers was not correlated with the increase in group size. Integration of male immigrants did not lead to the departure of resident males. Conversely, fission process promoted a substantial increase in the number of transfers in Tigounatine. The period presenting the greatest risk of infant mortality was the summer dry period, in both habitats. Wide interannual variations occurred in the availability of two staple foods for monkeys: caterpillars and acorns. The cumulative effects of a low acorn supply during the gestation period (autumn) and a low caterpillar supply during the beginning of the following nursing period (spring) led to a temporary increase in infant mortality. © 1993 Wiley-Liss, Inc.     

Progeny of somatic cell nuclear transfer (SCNT) pig clones are phenotypically similar to non-cloned pigs

Systematic studies of cloned animals generated from adult somatic cell nuclei are critical in assessing the utility of somatic cell cloning in various applications, including the safety of food products from cloned animals and their offspring. Previously, we compared somatic cell derived cloned pigs with naturally bred control pigs on a series of physiological and genetic parameters. We have extended our studies to the F1 progeny of these clones to see whether these phenotypic differences are transmitted to the next generation. There were no differences in the average litter size between litters from cloned gilts and naturally bred controls (7.78 +/- 2.6 and 7.40 +/- 3.0, respectively; mean +/- SD) or in the degree of litter size variation (coefficients of variation of 33.4% and 40.5% for litters of clones and controls, respectively). Similarly there were no statistical differences between sex ratios of cloned litters (51-49%, M:F) and control litters (59-41%, M:F). Blood profiles between cloned pigs, control pigs, and their progeny were compared at two time points (i.e., 15 and 27 weeks) to quantify the effect of cloning on various blood parameters and their transmission to the next generation. Although the range of values for all traits overlapped between different classes, the variability between all the traits in F1 progeny of clones and the control pigs was similar at 15 and 27 weeks, with one exception. Combined, our data and previous results in mice strongly support the hypothesis that offspring of clones are similar to offspring of naturally bred animals, and as such there should not be any increased risks associated with consumption of products from these animals.     

Natal emigration by both sexes in the La Pacifica population of mantled howlers: when do some stay?

We have reported previously that all male and female mantled howlers emigrate from natal groups at Hacienda La Pacifica, Costa Rica. In the years since that report, a small number of juveniles have stayed in the natal group without experiencing a solitary phase. Here, we present a post hoc analysis on juvenile emigration in six groups of howlers under observation for varying amounts of time between 1972 and 2005. Our records revealed 139 juveniles for whom emigration status was certain, and 125 of these did emigrate. There was a significant association between presence of mother and emigration: juveniles without mothers were more likely to remain in their natal group (chi(1)(2) = 53.1, P<.0001). The mean age of emigration for all juveniles (n = 125) was 2.47 years (SD = 0.9, range = 1.5-6.5). There was no difference in age of emigration by adult male composition (one-male, multi-male, both), but juveniles of unknown sex emigrated younger than either known males or females (F(2,116) = 4.4, P<.02). For emigrating juveniles of known sex (n = 99), both males and females without mothers left at a later age than those with mothers (F(1,95) = 6.5, P<.02). Although philopatry or delayed emigration occurs in a few motherless animals, most males and females do emigrate from their natal groups at ages consistent with those reported for other species of howlers.     

Anatomic capillarization is maintained in relative excess of fiber oxidative capacity in some skeletal muscles of late middle-aged rats.

The anatomic size of the capillary-to-fiber (C/F) interface plays an important role in O(2) flux from blood to tissue by determining the surface area available for diffusion and is maintained in relative proportion to fiber mitochondrial volume across a wide range of muscle aerobic capacity. In the present study, we examined an estimate of the anatomic size of the C/F interface [the quotient of the individual C/F ratio and fiber perimeter, C/F perimeter exchange (CFPE) index] and fiber oxidative capacity in different skeletal muscles, or muscle regions, to test the hypothesis that capillarization would be maintained in relative excess of reduced fiber oxidative capacity in aged muscles. The right gastrocnemius, plantaris, and soleus muscles from young adult (8 mo old) and late middle-aged (28-30 mo old) Fischer 344 x Brown Norway F1 hybrid rats were excised for evaluation of flux through electron transport chain complexes I-III and/or morphometric estimation of capillarization. Muscle mass was lower in the gastrocnemius muscles of the older animals (2,076 +/- 32 vs. 1,825 +/- 47 mg in young adult vs. late middle-aged, respectively; mean +/- SE) but not the plantaris or soleus muscles. Fibers were smaller in the white region of gastrocnemius muscles but larger in the red region of gastrocnemius muscles of the older animals. There was no difference in the number of capillaries around a fiber, the individual C/F ratio, or the CFPE index between groups for any muscle/region, whereas flux through complexes I-III was reduced by 29-43% in late middle-aged animals. Thus the greater quotient of indexes of anatomic capillarity (individual C/F ratio or CFPE index) and fiber oxidative capacity in soleus and the white region of gastrocnemius muscles, but not in the red region of gastrocnemius muscles of the older animals, shows that anatomic capillarity is maintained in relative excess of oxidative capacity in some muscle regions in late middle-aged rats.     

棕榈蓟马在茄子上的种群增长、分布和抽样技术研究

棕榈蓟马在茄子上的种群增长,用种群增长模型来分析,露地栽培的成虫、若虫种群增长率ｒ分别为０．０６３０和０．０８０１,设施栽培分别为０．０９８３和０．１０３６。设施栽培的逻辑斯蒂曲线的Ｋ值为３３．９０,明显大于露地栽培的Ｋ值２３．５０。棕榈蓟马种群在茄子上空间分布调查结果,成、若虫的Ｍ＾＊－Ｍ回归式分别为Ｍ＝０．６０１１＋１．４６８Ｍ和Ｍ＾＊＝７．２５１５＋２．０６４０Ｍ。成虫＋若虫的Ｍ－Ｍ回归式为     

Home Range and Population Density of Fishers in Eastern Ontario

Abstract: Fishers (Martes pennanti) were almost extirpated in Ontario, Canada, south of the French and Mattawa rivers by the 1940s but have recolonized much of their former range over the past several decades. We assessed the effect of the current harvest quota on a fisher population in eastern Ontario by estimating home range size and population density from a sample of radiocollared animals. Mean (± SD) adult home ranges (based on annual 95% min. convex polygons) were consistently smaller than those reported in the literature (M: 11 ± 4.4 km²; F: 2.1 ± 0.8 km²), with up to 71% overlap of adjacent intrasexual home ranges. This yielded an estimated adult fisher population density of 32.7/100 km² of suitable habitat, as defined by the habitat composition within observed home ranges. We further estimated that between 2003 and 2005, trappers harvested 17.8-42.3% of the pretrapping population. These results suggest that although current fisher population density is high in our study area compared to reported densities in other areas, harvest rate is also high and an increase in quota is unwarranted.     

A note on group sizes of oribi (Ourebia ourebi, Zimmermann, 1783) from two contrasting sites in Zambia, with and without predation

The oribi (Ourebia ourebi, Zimmermann, 1783) is a small species of antelope widely represented across open grasslands of sub‐Saharan Africa. Although largely territorial, differences in group size and mating systems (monogamy/polygamy), have been linked to habitat conditions and population density. At high population densities, additional males are recruited to assist in territorial defence. Other factors which might impact on group size, include predation threat, especially at low population densities. In this study (1995–98), we recorded group sizes of oribi across two contrasting areas (c. 300 km² each) of Zambia with (Kafue), and without (Bangweulu), large vertebrate predators. A total of 412 groups was recorded across the two sites, with mean sizes of 2.31 (n = 217) at Bangweulu and 2.33 (n = 195) at Kafue. The modal group size was two throughout (range 1–6). Groups were more variable in size and sex composition at Kafue than at Bangweulu, but there was no significant difference in estimates of population density between sites. Mean estimates were 2.02 and 1.90 km^?2 for Bangweulu and Kafue, respectively. Sex ratios (males : females) were biased towards females (1 : 1.72 and 1 : 3.55, respectively) at both sites. Adult males were particularly scarce at Kafue. However, values of density and group size, were both unexceptional for the species. Whilst a modal group size of two is consistent with a monogamous mating system, variations in group composition and size were more difficult to explain. Adult females appeared to retain or recruit additional animals to groups, irrespective of the needs of territorial defence. This suggests that vigilance is an important function of groups on large open plains, especially in the presence of predators. By extension, reversed sexual dimorphism in oribi could reflect increased selection for vigilance duties in females. Predators had no apparent effect on population density, but oribi groups were more variable in size and sex composition in their presence. Adult males may be particularly vulnerable to predation when defending territorial borders at low population densities. However, further work is needed to define group dynamics in this species and to identify causes of mortality amongst adult males.     

SEXUAL DIMORPHISM AND SEX RATIO IN THE YELLOWSHOULDERED WIDOWBIRD EUPLECTES MACROURUS SOROR

Savalli, U.M. 1994. Sexual dimorphism and sex ratio in the Yellowshouldered Widowbird Euplectes macrourus soror. Ostrich. 65: 297–301.

Yellowshouldered (Yellowbacked) Widowbirds Euplectes macrourus soror are sexually dimorphic in plumage and size. At Kakamega, western Kenya, adult males were all black except for the yellow shoulders, contrary to previous reports that yellow-mantled individuals were predominant in this area. Males were larger than females, with wing length the best single measure to distinguish sex (since immature males are streaky brown, like females). Immature males had shorter wings and tails than did adult males, but did not differ in other measures of size. The sex ratio of netted birds was near 1:1, but nearly half of the males were immature. The breeding sex ratio was nearly even in one year but heavily male biased the second, suggesting that not all females may breed.     

Group dynamics of the Nubian ibex (Capra ibex nubiana) in the Tuwayiq Canyons, Saudi Arabia

Group dynamics of the Nubian ibex ( Capra ibex nubiana ), a sub-species adapted to arid environments, were studied at the Ibex Reserve, Saudi Arabia. Most of the animals (83%) were seen in mixed herds during the rut and post-rut. Mean group size of all sex-age categories was 7.2, with the majority of the ibex seen in groups of < 10. The sex ratio of adult animals was equal but that of juveniles, older than six months, was skewed towards females. Habitat structure, sparse vegetation cover and a small population size are factors that favour small group size. An equal adult sex ratio and a high number of juveniles indicate that the population has a high reproductive potential.     

Group size,composition, and reproductive success in wild common marmosets (Callithrix jacchus)

Data from published sources about size and composition of wild common marmoset groups (Callithrix jacchus) were analyzed to see if the number of juveniles in a group is closely related to the number of other group members. Mean group size was 8.7 members including 4.4 adults (1.8 females, 2.5 males), 2.9 subadults, and 1.4 juveniles. The number of juveniles was significantly positively correlated to the number of adult males. Groups with one or two adult males had significantly fewer juveniles (mean: 1:1 juveniles) than groups containing more than two adult males (mean: 2.0 juveniles). Apart from a different number of subadults, results showed obvious similarities between common marmosets and tamarins of the genus Saguinus in size and composition of subgroups of adults as well as the key role of adult males in mediating the reproductive success of a breeding female. Common marmoset females seem to gain direct fitness benefits in increased reproductive success from the presence of a larger number of adult males. Whether or not other group members get fitness benefits depends on the reproductive strategy of adult males (monogamy vs. polyandry), their kinship, and on the genetic relationship of nonbreeders to the offspring of the breeding female. © 1995 Wiley-Liss, Inc.     

Spatial organization in the Ethiopian wolf Canis simensis: large packs and small stable home ranges

The spatial organization of the rare Ethiopian wolf ( Canis simensis ) was studied in the Afroalpine heathlands of Bale Mountains National Park, southern Ethiopia, between 1988 and 1992. Nineteen animals were radio-tracked, 48 ear-tagged and 64 others recognized by coat patterns and observed directly. Dry season (October—March) home ranges of resident wolves covered between 2 and 15 km². The ranges of adult males were slightly larger than those of females, and subadults' home ranges were slightly smaller than those of adults. The population density of the wolves was correlated with prey biomass. In optimal habitat, wolves lived in packs of 3—13 adults (mean 5.9 wolves > 1year old) containing several close-kin males; adult sex ratio favoured males 1.88: 1 and combined pack home ranges averaged 6.0km². In an area of lower prey productivity, wolves lived in pairs or small groups (mean 2.7), adult sex ratio was 1:1 and home ranges averaged 13.4 km².
Home ranges overlapped extensively (mean 85%) between members of the same pack. Four to seven percent of the population was additionally composed of non-resident females, inhabiting larger ranges (mean 11.1 km²). Home ranges of neighbouring packs were largely discrete, forming a tessellating mosaic of packs occupying all available habitat. Pack home ranges were stable in time, drifting only during major pack readjustment after the disappearance of a pack or significant demographic changes. Ethiopian wolf home ranges were smaller than would be expected for a carnivore of its size and sociality, presumably as a result of the high rodent productivity of the Afroalpine ecosystem.     

Population ecology of the white-nosed coati (Nasua narica) on Barro Colorado Island, Panama

The white-nosed coati, Nasua narica , is a common Neotropical carnivore with a social structure of band-living adult females and solitary adult males. A coati population on Barro Colorado Island, Panama, was studied over a four-year period by mark-recapture, radiotelemetry. and direct observation of habituated individuals. The population density was approximately 51.5 individuals/km² and the sex ratio was 1:1. Band size varied from six to 26 individuals (mean = 15.3) with extensive fluctuation within and between years. Mean foraging group size was smaller (7.2 individuals) than population group size, and fluctuated with food availability, synchronous parturition, and the emigration of mature males. Mean home-range size of six bands was 0.33 km², and ranges of adjacent bands overlapped from 0–66%. One band fissioned during the study; however, the resulting bands did not disperse from the original home range. Seven adult males had a mean home-range size of 0.37 km², each extensively overlapping the home ranges of several other males. Observations of 10 adult males whose natal bands were known indicate that when males disperse they do not simultaneously leave the band's home range. Rather, their home ranges remain within or broadly overlapping those of their natal bands. This dispersal pattern is unusual within the order Carnivora.     

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.     

Chinko/Mbari drainage basin represents a conservation hotspot for Eastern Derby eland in Central Africa

One of the largest of antelopes, Derby eland (Taurotragus derbianus), is an important ecosystem component of African savannah. While the western subspecies is Critically Endangered, the eastern subspecies is classified as least concern. Our study presents the first investigation of population dynamics of the Derby eland in the Chinko/Mbari Drainage Basin, Central African Republic, and assesses the conservation role of this population. We analysed data from 63 camera traps installed in 2012. The number of individuals captured within a single camera event ranged from one to 41. Herds were mostly mixed by age and sex, mean group size was 5.61, larger during the dry season. Adult (AD) males constituted only 20% of solitary individuals. The overall sex ratio (M:F) was 1:1.33, while the AD sex ratio shifted to 1:1.52, reflecting selective hunting pressure. Mean density ranged from 0.04 to 0.16 individuals/km², giving an estimated population size of 445–1,760 individuals. Chinko harbours one of the largest documented populations of Derby eland in Central Africa, making Chinko one of its potential conservation hotspots.     

Influence of age on saline hypertension in subtotal nephrectomized rats

In uninephrectomised immature and adult male rats 34% renal tissue was removed from the remaining kidney and after 60-days exposure to saline treatment (0.17 mol/l NaCl solution as only drinking fluid) the mean arterial blood pressure, plasma urea concentration, plasma and extracellular fluid volumes were estimated. In comparison with water drinking uninephrectomised age-matched controls it has been found that: in both age groups, the loss of tissue from the remaining kidney was fully replaced by compensatory growth of the renal stump, plasma urea concentration remained unchanged in animals operated on when adult, but increased in animals operated on when immature, the interstitial fluid volume increased in both age groups--the plasma volume as well as blood pressure remained unchanged in animals treated when adult, but increased in animals treated when immature. It is concluded that under conditions of elevated salt intake the loss of renal mass in immature rats was compensated by growth of tissue with a lower excretory ability than in adult ones, this being responsible for the development of hypertension in the younger group.