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1.
Consistency of animal personality traits is expected. Mounting evidence suggests that animal personalities will change with time and major life events. Research into this phenomenon is often limited to span only short periods of time in the animals’ life or have few measures across their life. We measured Exploration, Activity and Boldness of litters of meadow voles, Microtus pennsylvanicus, in a pair of novel object tests six times over a year, representing a large proportion of the lifespan of the vole. Our null hypothesis was that the personality traits would not change, and our first alternative hypothesis was that personality traits would change equally for all individuals as they aged. Neither was supported. The data support our third hypothesis that traits would change and change unequally. Activity and Boldness were consistent across time. However, Exploratory behaviour increased with the vole's age. The supported models show that personality traits change consistently for related individuals, but the litters differ in their change with age. This suggests that meadow vole life history affects how personality traits develop, but not necessarily their magnitudes. We also tested the repeatability of traits across the testing intervals. We discovered that the repeatability of these three personality traits varied across time, depending on the trait. Activity was repeatable equally across ages. Exploration became more repeatable and Boldness became less so. Thus, personality traits may be more malleable than supposed, especially over long periods of time.  相似文献   

2.
This paper describes observations on body size, growth, and the timing of births in an individually identified population of oribi (Ourebia ourebi, Zimmermann 1783) in the Serengeti National Park, Tanzania. Females tended to be larger and approximately 2 kg heavier than males. Young oribi grew rapidly, attaining near-adult size in about 7 months. Horns appeared in male oribi at about 4½ months of age and grew rapidly up to 20 months of age. Births occurred in all months of the year but were most common between March and June. The results provide an observational means of estimating the age of sub-adult oribi by body size, and the age of adult male oribi, up to 20 months of age, by horn length.  相似文献   

3.
Song repertoires are often important determining factors in sexual selection. In several species, older males have larger repertoires than 1-year-old males. The development of large song repertoires by an individual is, however, poorly understood. We studied song element repertoire changes in five individual male Whitethroats Sylvia communis sampled as 1- and 2-year olds. These males increased the size of their element repertoire between their first and second year, but song length and number of different elements per song did not change. On average, 44.3% of the song elements in the first-year repertoire were also found in the second-year repertoire. Elements shared between years were found earlier in the songs and tended to occur in sequences. Sequences of shared elements also seemed to be conserved between years. The study suggests that the song element repertoire of the second year is partly based on the first-year repertoire, which may explain why large song repertoires are mainly expressed by males at least 2 years of age. It would appear, therefore, that song element repertoire size could be a reliable signal of male age.  相似文献   

4.
于1997年10月到1999年10月在泰国KhaoYai国家公园对两种同域分布的物种(即豹猫和云豹)进行了研究。使用带诱饵的陷阱捕捉了这些动物,进行麻醉,确定了性别、年龄,并戴上了无线电项圈,对6只雌性豹猫和4只雄性豹猫进行了1—18个月的无线电追踪。豹猫在干旱季节的利用区域大于雨季,雄性利用的区域大于雌性。在夜间和晨昏时节,豹猫活动增加,但是并没有节律性活动。所有豹猫个体在旱季和雨季的活动都相似,但雄性个体的白天活动多于雌性。豹猫的行走距离有性别差异但是没有季节差异;其食物以鼠类为主。分别对1只雌性云豹和1只雄性云豹进行了17个月和7个月的无线电追踪,雌性个体的活动面积为39.4km^2,而雄性个体活动面积为42.2km^2,核心区都是2.9km2。云豹对半绿林的使用大于其它类型的植被,在晨昏和夜间的活动增加,其活动无节律。  相似文献   

5.
《Animal behaviour》1988,36(4):1016-1024
Young male and female zebra finches, Taeniopygia guttata, were tested for their ability to discriminate between the song of their father or tutor and that of another male in two types of preference test, one with a male whose song was dissimilar to that of the father or tutor and one with a male who sang a similar song, on removal from the father, at 4 months and at 6 months of age. Birds that were isolated from their father at 25 days (group A) did not show a preference for their father's song whereas those isolated from the father at 35 days (groups B and C) learnt to prefer their father's song. In addition, group C, which were housed with tutor 1 from 35 to 70 days and with tutor 2 from 4 to 6 months of age, preferred their tutors' songs to those of other males. If one compares the strength of preference in the two types of test, group B showed a weaker preference for the father in tests with the father and a similar male. Further, group C showed a weaker preference in the test with tutor 1 versus a similar male. The possible influence of tutor, sibling and own song on the discrimination of the father's song is discussed, and the results are compared with those for song performance learning. Finally, the mother birds preferred their mate's song.  相似文献   

6.
A conventional cat breeding colony with 70 queens (female cats) was studied during a 4 year period 1979-1982. During that time the fat content in the diet was increased from 15% to 27% of dry matter. An increase in the number of kittens per litter (from 4.5 to 5.5) and in the annual number of litters per queen (from 1.4 to 2.3) was found. In addition, the mortality decreased from over 20% to 9%. Bodyweight gain under the new diet was such that the males reached 2500 g in 4 months while the females showed this same weight at 5 months of age. Litter size and sex distribution as a function of queen age, litter interval and time of year are presented. It is concluded that husbandry and diet are factors which are of great importance in a cat breeding unit. It is shown that under our conditions it is possible to breed conventional cats with good results.  相似文献   

7.
The renal metabolism of the tripeptide, gamma-glutamylfelinylglycine, which our group recently identified in the blood of domestic cats (Felis catus), was investigated. To test our hypothesis that this unique tripeptide is metabolised by the kidney in a similar manner to glutathione-S-conjugates in other animal species, [(35)S]cysteine was administered intraperitoneally to an entire male cat, and urine collected at 1, 4 and 8 h post-injection. Radiolabelled fractions were isolated from the urine following reversed-phase (RP) HPLC. Four [(35)S]radiolabelled fractions were identified and characterised by amino acid analysis, mass spectrometry and comparison of retention times with synthetic compounds (felinine, N-acetyl felinine, felinylglycine, gamma-glutamylfelinylglycine). In addition to the previously described presence of free felinine, we showed the presence of several felinine-containing metabolites, including N-acetyl felinine, felinylglycine and unaltered gamma-glutamylfelinylglycine in cat urine. The results show that renal metabolism of gamma-glutamylfelinylglycine in cats, generally occurs in a similar manner to glutathione S-conjugates in other animal species, although the detection of felinylglycine indicates that subtle differences may exist. Additionally, our research indicates that previously reported estimates of felinine excretion in male cats need to be increased by as much as 54% to account for other felinine containing metabolites in the urine.  相似文献   

8.
In male Tokara (Japanese native) goats, testis development and the onset of puberty were studied histologically and observing sexual behaviour. Testes weight increased from 36+/-5.4 (S.E.) g (n=5) at 3 months of age to 126+/-6.3 g (n=6) at 12 months. The degree of the testis development differed among kids at 3 months of age and only one of four had produced spermatozoa in the testis. Large number of spermatozoa were always present in seminiferous tubules and epididymal ducts from 4 months of age. The diameter of seminiferous tubules increased from 133+/-9.9 microm (n=4) at 3 months to 198+/-1.0 microm (n=3) at 6 months with little increase thereafter. Mounting and pelvic thrusts onto a teaser doe started at from 9 to 14 weeks of age. Ejaculated semen contained sperm with good motility for the first time from 17 weeks. The male Tokara goat reaches puberty at around 4 months of age but testis development continues to 12 months.  相似文献   

9.
The onset and pattern of the clinical signs of feline corona virus (FCoV) infection in cats were studied in a setting behind an isolation barrier. Two FCoV-seropositive cats were the source of the infection, and 3 barrier reared cats–initially FCoV-seronegative–were the recipients. The first clinical sign in the recipients appeared 11 days after contact with the source of infection. After 2 years 1 male and 1 female of the recipients started to breed. Their offspring developed clinical signs of disease at an age of 4-5 weeks. A pattern of recurring upper respiratory tract signs and conjunctivitis at intervals of about 4 months was observed in both the recipients and their offspring, while CNS dependent signs and wasting remained or got worse, once developed. Once demonstrated, FCoV antigen persisted in membrana nictitans throughout the investigation, and was found in all cats but 4 (90%). The offspring died during 2 periods, around the first week of life (9/37), and at 3-5 months of age (5/25). For comparison 3 offspring were euthanised at an age of 1 day and 16 offspring at an age of 3-6 months. FCoV antigen was demonstrated in all organs investigated (100%) from offspring dying during the first period, and in 97% from those dying during the second period. For the offspring euthanised during the same 2 periods the corresponding findings were 95% and 85%. Offspring euthanized between 9 and 17 months (4 kittens) had antigen in 67% of all investigated organs. The incidence of FCoV antigen in almost every organ in the investigated newborn kittens suggests an intrauterine infection. The demonstration of FCoV antigen in all euthanised cats, suggests a persistant infection. Virus was cultivated from membrana nictitans, that was FCoV antigen positive in the M3 test.  相似文献   

10.
Testicular growth and maturation of the hypothalamic-pituitary-testicular axis were assessed in male tammars from 12 to 25 months of age to establish the time of sexual maturity. The testicular dimensions and body weights of 20 male tammars, approximately 12 months of age at the beginning of the study, were measured monthly for 1 year. Groups of 3 animals were castrated at 13, 19 and 25 months of age and their testes sectioned for histological examination. Testicular volume increased between 12 and 24 months of age and was highly correlated with body weight (r = 0.91). In the 13-month group the seminiferous tubules were closed with few mitotic figures. Spermatogenesis had begun in 2 of the 19-month animals. All stages of spermatogenesis were present in the other 19-month male, and in all of the 25-month males. Basal FSH concentrations increased with the age of the animal (21.0 +/- 32.48, 94.40 +/- 55.18 and 193.05 +/- 40.21 ng/ml (mean +/- s.d.) at 19, 20 and 25 months respectively) while basal LH concentrations were similar at 20 months and 25 months (0.43 +/- 0.18 and 0.58 +/- 0.25 ng/ml respectively). Basal testosterone concentrations were also similar 0.11 +/- 0.04, 0.35 +/- 0.16 and 0.22 +/- 0.10 ng/ml in 13-, 19- and 25-month-old animals. LHRH injection in tammars at 13, 19 and 25 months of age induced release of both LH and testosterone 10-30 min after injection. The hormone concentrations increased in both magnitude and duration with increasing age.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
Pituitary dwarfism (hGHD) is known to be associated with trace element deficiency, which causes improper functioning of the involved endocrine system. Previously, we reported on the head hair concentrations of zinc, copper, manganese, and iron from a total of 418 normal subjects (154 male and 264 female). In this report, we analyzed the head hair concentrations of the same four trace metals of 103 hGHD children (60 male and 43 female) under treatment with human growth hormone (hGH). These subjects ranged in age from 5 to 18 yr. The results were compared with 338 agematched normal subjects (120 male and 218 female). Both male and female hGHD showed approx 1.7 times higher zinc concentrations than normal subjects. Cheruvanky et al. reported a similar trend but with a slightly lower difference between hGHD and normal subjects. The average copper content in the hair of both male and female subjects also showed higher values for the hGHD than for the normal subjects, a trend similar to the values reported by Teraoka et al. In the case of manganese, the concentrations in hair of the hGHD were approx 50% of the values in the normal subjects. Head hair concentrations of iron in the hGHD were commensurate with the normal subjects. Because the content of trace elements in hair varies with the age of subjects, as a control, we investigated the head hair concentration of zinc from 20 healthy girls ranging in age from 10 to 18 yr. The average zinc concentration decreased from 10 to 12 yr, but no clear relation to age was observed from 13 yr and older. These trends were similar to our previous report. The zinc concentration in hair and body weight gain over a year was negatively correlated. The age variation in the content of zinc, copper, manganese, and iron in hair was measured comparing hGHD with the normal subjects in various ages. Concerning the zinc-level variation of hGHD and normal subjects, there were conspicuous differences between hGHD and normal subjects. For copper, the variations in concentration with age were similar to zinc. Regarding the age variations for manganese, hGHD had lower concentrations in hair compared to the normal subjects throughout adolescence (11–18 yr). We have studied the effects between the hair and these trace element concentrations in hGHD before and after hGH administration. These results suggest that hGH affects the metabolism of these trace elements.  相似文献   

12.
This study was designed to investigate the reproductive fertility by the natural breeding of cloned male cats with domestic female cats, and to measure endocrine hormone concentration related to male reproduction such as testosterone, leutinizing hormone (LH), and follicle stimulating hormone (FSH). Cloned A, B, C, and D cats produced three, two, four, and five kittens after natural mating with four domestic female cats, respectively, despite later puberty of the cloned D cat than those of the other cloned male cats. Three of the 14 kittens expressed an odd eye color, which was produced by 1 and 2 from cloned A and B cats. The eye color of the other F1 kittens varied from nine brown to two blue. Body weight at birth ranged from 72.9 to 134.0 g. Although clone D had a poorer libido and entered puberty later than those of the other cloned male cats, he produced gonadal hormones within the average range. Four of the cloned male cats had normal fertility. The concentration of gonadal hormones in cloned male cats was similar to two control and donor cats. The concentration of testosterone was not significantly different among clones A, B, C, D, and control cats (5.99 +/- 5.68; 3.46 +/- 2.81; 6.41 +/- 2.17; 3.75 +/- 0.34; 4.0 +/- 3.63 ng/mL, p < 0.05). The concentrations of LH and FSH were not significantly different among the cloned cats (p < 0.05). Seven male and seven female (in total 14) kittens were produced by the natural breeding with four domestic female cats. These results indicated that cloned male cats have normal reproductive fertility and lie within the normal range of gonadal hormone production. All F1 kittens were produced by natural breeding and delivery, and are still alive and have normal growth health (27 months age).  相似文献   

13.
In an isolated population of Drosophila melanogaster on Ishigaki Island the chromosomal distribution of several retrotransposons, including copia, 412, 297, 17.6, I, and jockey elements, was examined by in situ hybridization. In this population the cosmopolitan inversion, In(2L)t, is known to exist in high frequency. One major haplotype concerning the occupied sites of the transposable elements was identified in the In(2L)t-carrying chromosomes. This haplotype is suggested to be the ancestral one. The age of the inversion in this local population was estimated to be 1,400 generations. The transposition rates of these elements were estimated based on the age of the inversion and the number of the elements lost and gained. The excision rates were in the range from 9.13 x 10(-5) to 2.25 x 10(-4) per site per generation. They were similar each other in the copia-like elements as well as in the LINE-like elements. The rate was higher in the copia-like elements than in the LINE-like elements. Insertions occurred in the range from 6.79 x 10(-4) to 9.05 x 10(-4) per element per generation. It is herein shown that both insertions and excisions occurred at a significantly higher rate in this population than in the laboratory.   相似文献   

14.
Predation by domestic cats in an English village   总被引:8,自引:0,他引:8  
We studied predation by approximately 70 domestic cats ( Felis catus L.) in the Bedfordshire village of Felmersham over a one-year period. All the prey items brought home by virtually all the cats in the village were recorded and, where possible, identified. A total of 1090 prey items (535 mammals, 297 birds and 258 unidentified animals) were taken, an average of about 14 per cat per year. Twenty two species of birds and 15 species of mammals were identified. The most important items were woodmice (17%), house sparrows (16%) and bank voles (14%).
Old cats of both sexes caught fewer prey over the year than young cats. Female cats on the edge of the village also caught more prey than female cats in intermediate or central areas of the village; male cats showed no such effect. The type of prey caught also varied with position in the village; 'core' cats caught proportionately more birds than 'edge' cats. There was some indication in the data that cats caught fewer prey in areas where cat density was highest, but this effect was impossible to disentangle from position in the village. Weather apparently influenced hunting success. Temperature had no direct influence, but fewer prey were caught in winter; cats also caught less on wet days and windy days.
Estimates of the number of house sparrows in the village at the start of the breeding season, and the number of sparrows known to have been caught by the cats, suggest that at least 30% of the sparrow deaths in the village were due to cats. Domestic cats would appear to be major predators in this typical English village.  相似文献   

15.
Determination of amino acid requirements by the factorial method requires an estimate of the amount of amino acids required for the replacement of hair. Hair growth rates in a total of 39 adult male and female domestic short-haired cats were determined throughout the year using the mid-side patch technique. The ratio of hair on the mid-side area to total hair on the body was also determined to allow conversion of mid-side hair growth rates to hair growth rates over the entire body. The mid-side hair growth rate showed a sinusoidal pattern throughout the year, similar to that found for day length and daily mean air temperature, with a maximum hair growth rate of 289 μg/cm2/day in summer and a minimum hair growth rate of 62 μg/cm2/day in winter. The peak hair growth rate for the female cats was reached earlier than that for the male cats. Sine-functions describing day length, minimum and maximum daily air temperatures and daily hair growth rates are presented. Adult domestic short-haired cats were found to grow 32.7 g of hair per kg body weight per year. Monthly amounts of hair growth per unit of body weight and body surface area are calculated.  相似文献   

16.
Wyttenbach  A.  Schleppi  P.  Tobler  L.  Bajo  S.  Bucher  J. 《Plant and Soil》1995,(1):305-312
The endogenous concentrations of the essential elements Ca, Cl, Cu, Fe, K, Mg, Mn, N, P and Zn, and of the nonessential elements Al, As, Ba, Br, Co, Cr, Cs, Hg, I, La, Na, Rb, Sb, Sc, Si and Sr were determined in 5 successive needle age classes. 40 mature spruce trees from 6 different sites were investigated individually. A given element usually shows smooth changes with the needle age class t. Trees on a given site usually have a similar dynamic behaviour. The same holds for the different site means. The concentrations can be approximated by functions c=f(t). Three different types of functions are required to describe the dynamic behaviour of 3 groups of elements that increase with t, and one for the elements that decrease with t. A given element usually can be described by the same type of function at all sites, even if its concentration differs widely. Exceptions are Mn, Co and Zn, which change from a decreasing function at low concentrations to an increasing function at high concentrations. Further irregulatities are found at some sites with Ca, Sr and Ba. These findings are corroborated by a multivariate statistical analysis.  相似文献   

17.
The mating behaviour of a quasi‐gregarious egg parasitoid Telenomus triptus Nixon (Hymenoptera: Platygastridae), which exploits egg masses of a stink bug Piezodorus hybneri (Heteroptera: Pentatomidae), is examined in the laboratory. In this parasitoid wasp, male adults that emerge earlier stay at the natal egg mass and mate with subsequently emerging females. In the present study, a male adult that encounters the emergence of another male always waits for it to egress, and then mounts the newly emerging male. To examine why males of T. triptus show same‐sex sexual behaviour, male adults are presented with a parasitized host egg mass or a freshly killed wasp. Male adults are observed to remain at host egg masses from which only male wasp(s) had emerged. In addition, male adults attempt to copulate with freshly killed young male wasps. It is suggested that newly emerging male wasps are targets of same‐sex sexual behaviour because they possess cues for male sexual behaviour similar to the cues of females. Both the sex and age of freshly killed wasps affect the frequency of the sexual behaviour of male adults: females are more attractive than males, although their attractiveness declines with age. When the mating opportunity is restricted to the natal egg mass, the costs of failing to notice newly emerging female adults should be extremely high. Therefore, males are forced not to discriminate the sex, resulting in same‐sex sexual behaviour.  相似文献   

18.
Several recent studies show that animal friendships, like human friendships, are durable and have fitness benefits by increasing survival, infant survival, or reproductive success. However, the determinants of especially non-kin friendships are unclear. Human non-kin friendships are partly determined by similarity in personality. We investigated personality similarity of friends in 38 captive chimpanzees. Within-subject comparisons revealed that friends are more similar than non-friends in their Sociability and Boldness. Subsequent analyses, including both kin- and non-kin dyads, revealed higher similarity in Sociability among all individuals who sat in contact more often, while in Boldness and Grooming Equity the positive effect of similarity was only found in non-kin individuals’ contact-sitting. Our results show that similar to humans, chimpanzees’ friendships are related to homophily in certain personality characteristics, particularly those relevant for socio-positive and cooperative behaviour. We suggest that having friends similar to self in personality decreases uncertainty in interactions by promoting reliability especially in cooperative contexts, and is consequently adaptive. Further, we suggest that homophily in human friendships dates back at least to our last common ancestor with chimpanzees.  相似文献   

19.
Attraction to sexually mature males and the immobilization response were evaluated after postpubertal estrogen treatment of ovariectomized females and of males castrated within 48 hr after birth or at 4 or 8 months of age. The time spent in the end of an evaluation pen which housed a mature intact male, the proportion of animals that showed the immobilization response, and the latency to onset and the duration of this response were similar in ovariectomized females and males castrated within 48 hr after birth. These two groups spent more time in the male end of the evaluation pen as opposed to the opposite end which housed an ovariectomized female, showed a shorter latency to the onset of the immobilization response, and expressed this response for a greater number of days than males castrated either at 4 or 8 months of age. Males castrated at 4 or 8 months did not show a strong preference for either a mature male or an ovariectomized female. The immobilization response in estrogen-treated males castrated at 4 or 8 months of age diminished as these animals became older. On the basis of the observations made in this study, attraction to a mature, intact male is a sexually dimorphic behavioral trait in pigs, and defeminization of this trait in male pigs is associated with the pubertal increase in testicular steroid secretion. Presently, pigs are the only mammalian species in which a role has been identified for pubertal, testicular steroid secretion in the defeminization process.  相似文献   

20.

Background

Leiomyosarcoma of the inferior vena cava is a rare tumor that presents in an insidious manner with non-specific symptoms. Given its rarity, there are no consensus guidelines to its management. The aim of this study was to report the clinical experience in the management of patients presenting to our institution during a 12 year period.

Patients and Methods

Four patients with leiomyosarcomas of the inferior vena cava were managed at our institution during the period reviewed. Patient details were identified through a search of the pathology department computerized database, and case notes were retrospectively reviewed to obtain details of presentation and management.

Results

There were 3 females and 1 male with a mean age of 59 years. All tumors were identified within 2 months of first symptoms. Three of the 4 had localized tumors whilst 1 patient had lung metastases at presentation. The three patients with resectable tumors underwent radical surgical excision of the tumor, and two patients had postoperative radiotherapy. One patient died of recurrence at 7 months, and another at 30 months. The third patient is currently well and disease free at 16 months. The fourth patient with metastatic disease was treated with chemotherapy alone and survived 36 months.

Conclusion

Leiomyosarcoma of the inferior vena cava is an uncommon tumor that presents with non-specific symptoms. At the time of presentation, tumors are usually large and resection is challenging but probably offers the best opportunity for long-term survival.  相似文献   

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