首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
M. E. BIRKHEAD 《Ibis》1981,123(1):75-84
Observations were carried out on a colour-ringed population of Dunnocks. During the winter, regular feeding groups formed at feeding sites, stable in composition, space and time. Dominance hierarchies formed and were weight related. Males were significantly heavier than females. The mean size of winter home-ranges was not significantly different from the mean size of breeding territories.
Three categories of breeding territory were established: solitary males, male-female pairs and pairs plus a male helper. There was one case of a bigamous male plus a helper. Pairs plus a helper had significantly larger territories than pairs alone; however, pairs raised significantly more fledglings. Five pairs produced a total of 23 fledglings, whereas four groups (pairs plus a helper) only produced seven fledglings.  相似文献   

2.
Abstract  The mating behavior of cat flea, Ctenocepholides felis (Bouche) was studied on an artificial feeding device. Male and female can mate repeatedly with same partner or Merent ones. In the situation of male: female ratio of 1 :5, each mating lasted an average of 6.6 min, with a mean interval between matings at 2.5 min., compared to 11. 1 min and 12.1 min respectively in a cell with 5 males and 1 female. As many as 48 mating events were observed for one male during an 8 h period. One female mated 27 times in 7 h with 5 males in the same cell. Newly emerged males and females can not mate before blood meal and about 24 h blood feeding is rewuired for successful mating. Newly emerged males can not mate with fed females (fed for 48 h), but fed males can mate with newly emerged females who are feeding the blood. Significantly more male contacts and male-male mating attempts were observed after the paper treated with female extract was introduced into the cell. The paper contacts and mating attempts were 16.75–32.25 times and 15.75–31.38 times, respectively, on average during a period of 20 min when different doses (FE) of extract were provided.  相似文献   

3.
在人工饲喂系统上研究了猫蚤的交配习性及雄蚤对雌蚤化学提取物的反应,结果表明,当5雌1雄在饲养盒内时,该雄虫可与其他雌虫进行多次交配,连续8小时内交配达48次,交配时间平均持续6.6分钟,两次交配的间隔时间平均为2.5分钟,当1雌5雄时,交配时间平均持续11.1分钟,交配间隔时间为12.1分钟,连续7小时内,该雌虫与雄虫交配27次,新羽化的雌雄虫吸血前不能交配,当把用雌虫提取物处理过的黑色滤纸片放进只有雄虫的饲养盒时,雄虫接触纸片的次数及雄-雄交配企图明显增加。  相似文献   

4.
W. R. Siegfried 《Ostrich》2013,84(4):216-218
Tarboton, W. R. 1981. Cooperative breeding and group territoriality in the Black Tit. Ostrich 52:216-225.

In a small, colour-ringed population of Black Tits Parus niger in central Transvaal, 11 of 19 observed breeding units comprised pairs with one to three helper-males. These pairs and groups defended permanent territories, the size of which correlated with the size of the group. There were significantly more territorial disputes during winter when less food was available than in summer. Breeding occurred in summer and the female alone built the nest, incubated the eggs and brooded the young while they were small. During this time she was fed by the alpha male and helper males, although before egg-laying the alpha male prevented helpers from courtship-feeding her. On average, unassisted pairs reared 0,88 young/season whereas pairs with helpers reared 1,55 young/season. However the feeding rate of nestlings of pairs with helpers was not higher than that of unassisted pairs and the number of young reared per group did not correlate with the number of helpers within the group.

The helper system in Black Tits was associated with a skewed sex-ratio (1,7:1 males: females) in the adult population and the data are consistent with the “hopeful reproductive” hypothesis for cooperative breeding.  相似文献   

5.
雌性动物多次交配行为的机制及进化   总被引:9,自引:2,他引:7  
刘晓明  李明  魏辅文 《兽类学报》2002,22(2):136-143
雌性动物的后代数量不可能超过她的卵子数。在理论上, 一个生殖季节内, 一次或几次交配就足够使雌性所有卵子受精, 最大化其生殖潜能。但与理论预测相反, 许多物种的雌性经常与同一个或多个雄性发生多次交配。交配通常要付出较高的代价, 所以很难理解为什么雌性动物要反复进行多次交配。本文综述了解释此行为的一些适应性和非适应性假说。从获得直接收益和间接收益二个角度介绍了适应性假说。直接收益主要包括求偶喂食和“彩礼”、受精保证、亲代抚育、生殖刺激和护卫交配权等5 个方面。还着重介绍了多次交配对雌性后代的间接遗传受益, 即获得优质基因、提高后代遗传多样性和遗传互补性3 个假说。非适应性假说包括了遗传相关假说和顺从雄性行为假说。  相似文献   

6.
Barbara K.  Snow 《Ibis》1972,114(2):139-162
The Calf bird Perissocephalus tricolor was studied in the Kanuku Mountains of southern Guyana for three months (January-April 1970), during which time almost daily visits were paid to a lek of four adult males. The adult males owned perches about 30 ft up in understorey trees, where they displayed and called throughout much of the day. Four immature males also visited the lek, particularly in the morning and evening. The immatures also wandered, feeding and occasionally calling together, over an area of forest of approximately 3 miles by half a mile. There was a hierarchy among the adult and immature males, the dominant males owning the most coveted perches at the lek. The male's most far-reaching call, the “moo call”, is a co-operative advertising call, in that birds calling together adjust the timing of their calls so as to follow each other and not overlap. The adult males perform a number of silent agonistic displays on their lek perches. Periodically, adult and immature males and sometimes a female invade the vicinity of a lek perch, usually that of the dominant male. Once a female was briefly mounted by the dominant male on his lek perch during an invasion. On other occasions females visited the lek but no mating occurred. The food of the males attending the lek was recorded by the daily collection of a total of 2,500 regurgitated fruit seeds (mostly drupes) from below the perches. Males also regularly take insects, but in smaller quantities. Three nests were found. The nest is an extremely light structure built entirely of fine twigs. A single egg was laid in each nest. All the nests (and two old ones) were within half a mile of the lek. Two of the nests were only 5 yards apart and the eggs were laid in them within 10 days of each other. The incubation period at one nest was 26–27 days and the fledging period approximately 27 days. The chick on hatching was covered in bright orange-chestnut down. It was fed mostly on insects (predominantly Orthoptera) brought by the female in her beak. There was no evidence of a male attending the nest. The Calfbird's nesting and lek behaviour is compared with that of other species of Cotingidae.  相似文献   

7.
C. B. Frith 《Ibis》1976,118(2):155-178
The Aldabran Fody Foudia eminentissima aldabrana was studied for 12 months on West Island, Aldabra atoll. A complete annual cycle was followed in detail in a small population of marked birds, and observations were made on feeding, courtship, breeding and other behaviour. The breeding season coincided closely with the wet season, when insect abundance was highest.
Although coconut palms and casuarina trees are both thought to have been introduced into Aldabra by man, the fodies preferred both of these trees as nest-sites to the native vegetation. It is suggested that this may be a recent preference, resulting from excessive predation by introduced rats Rattas rattus on nests in other sites.
In addition to insects and seeds, the Aldabran Fody feeds partly on nectar, and its tongue shows some degree of adaptation to a nectar diet. It is argued that the diversity in bill shape in Foudia cannot be interpreted simply in terms of adaptation for feeding on insects or seeds, but that all three elements in the diet must be considered, in conjunction with the presence or absence of possible competitors.
Adult males defend and maintain nesting territories for most of the year. After breeding, they undergo a full moult and assume an eclipse (female-type) plumage for a variable length of time, regaining the male breeding plumage after a partial prenuptial moult. A small number of males were found to be aberrant, the red in the plumage being replaced by golden yellow. One such bird showed defective territorial behaviour, and four that were dissected Jacked gonads.
In almost all ways the behaviour and reproductive patterns of the Aldabran Fody are very similar to those of the Madagascar Fody F. madagascariensis. The latter has been introduced onto many Indian Ocean islands, and in view of its similarities to the Aldabran Fody might well be a serious competitor if it were to be introduced onto Aldabra.  相似文献   

8.
以海洋青鳉(Oryzias melastigma)为试验动物,分析了铜和镉两种重金属离子胁迫对海洋青鳉摄食行为特征的影响,包括摄食响应时间、摄食量、摄食成功率和摄食效率等参数。结果显示,随着Cu2+浓度的升高,开始时,海洋青鳉的摄食量有所升高,当Cu2+浓度达到0.087 mg/L时有最大的摄食量和最短的摄食响应时间。随后,摄食量出现下降,在0.174 mg/L时达到最低。低浓度的Cu2+还能提高海洋青鳉的摄食成功率和摄食效率,而Cu2+的高浓度和长时间暴露则降低海洋青鳉的摄食成功率和摄食效率。Cd2+对海洋青鳉的摄食行为具有明显的抑制效应, Cd2+抑制海洋青鳉摄食的最低可见效应浓度为0.65 mg/L,摄食量、摄食成功率和摄食效率均随着Cd2+浓度的升高而降低。此外,在Cu2+和Cd2+胁迫下,对食物的响应时间有性别差异,雌性显著短于雄性,还存在群体显著短于个体等现象。  相似文献   

9.
Waterbuck activity was recorded at four-minute intervals for continuous periods of 12 hours on two or three consecutive days, and for single nocturnal periods. Feeding patterns of the male and female were similar and during the day there was no hour during which some feeding did not take place. Only male activity was recorded at night. This showed more intensive feeding but with periods of no feeding just after dark and just before dawn. The use of a four-minute recording interval was found to work well in practice.  相似文献   

10.
褐稻虱取食试验及防治探讨   总被引:5,自引:2,他引:3  
本文用茚三酮法, 以褐稻虱Nilaparvata lugens(stal)排泄的蜜露面积来测定其相对取食量.试验表明:取食量随虫期增大, 逐日取食分布各虫期呈现明显的峰期(图3);发育历期与累积取食量成幂函数关系: N(t)=0.0531t2.298式中N(t)=累积取食量, t=发育历期(天);褐稻虱各虫期取食率的变化;若以一龄若虫为1计算, 一一四龄若虫取食量比分别为1:1.66:2.10:3.16:10.26, 成虫为73.19;羽化后8天, 短翅型雌虫日均取食量比长翅型雄虫大6.33倍;按褐稻虱的取食行为, 化学防治适期以世代成虫初见期为宜.  相似文献   

11.
湖南土家族的体质特征   总被引:20,自引:8,他引:12  
以20至69岁的湖南土家族人为观察测量对象,根据1392人(男896,女496)的身高,1038人(男668,女370)的头部测量,364人(男235,女129)的五官测量和观察结果,分析该民族的体质特征,并与国内其他民族相比较。  相似文献   

12.
THE GUT FLORA OF THE CHICK. II. THE ESTABLISHMENT OF THE FLORA   总被引:1,自引:1,他引:0  
SUMMARY: Viable counts were made in three media of material from the crop, gizzard, duodenum, ileum and caeca of chicks. Groups of birds 2, 4, 7, 10, 13, 16 and 30 days old were studied. The results showed that a balanced gut flora is established one day after feeding. An indication of the actual development of the flora was obtained in chicks 4 hr after feeding. The relationship between the flora at different ages and that in newly-hatched chicks before feeding is discussed.  相似文献   

13.
Udo M. Savalli 《Ostrich》2013,84(4):129-134
Savalli, U. M. 1995. Morphology, territoriality and mating system of the Pintailed Whydah Vidua macroura. Ostrich 66: 129–134.

The biology of the Pintailed Whydah Vidua macroura was studied at the Kakamega Forest, western Kenya. This species is sexually dimorphic in plumage and size (males are brighter, long tailed and larger). Males defended large (1.4 ha) territories which contained areas of bare ground (9% of total area) suitable for feeding on grass seeds such as Paspalum scrobiculatum. There were two breeding peaks: during the long rains (April-August) and the short rains (November-December). Territorial interactions were frequent; a previously unreported tail-uphill-wiping display is described. Females frequently visited male territories and were pursued and courted by the males. Male tarsus length was weakly, but positively, related to the size of feeding area (a possible indicator of territory quality), but there were no other significant correlates with territory size, or frequency of intrusions. There were no significant correlates of female visitation rates (which do correlate with copulation frequency), so the basis of female choice (if any) remains unknown. Although this species has been classified as an exploded lekker, the possibility that females are attracted to resources (such as grass seeds) cannot be ruled out. Tail streamer length was not more variable than other morphological traits when fully grown, but was much more variable at the start of the breeding season while still growing.  相似文献   

14.
The pattern of sperm predominance in doubly mated female crickets, Gryllodes supplicans, was investigated using a radiation-sterility technique. Female G. supplicans made significant use of sperm from both males in fertilizing eggs; overall, first males to mate enjoyed a small advantage, fertilizing about 60% of the offspring produced subsequent to the second mating. The combined use of the sperm of both males in fertilizing eggs occurred soon after the second mating; evidently, mixing of ejaculates within a female's spermatheca does occur. Male G. supplicans provide females with a nuptial gift, the spermatophylax, which influences the time at which a female removes the externally attached sperm-ampulla; this in turn determines the quantity of sperm that is transferred. Moreover, the degree of sperm precedence achieved by a male may be positively related to the time at which the female removes his sperm ampulla. Thus males, by feeding females, ensure not only that a sufficient number of sperm are transferred to fertilize all of a female's eggs, but also may increase the certainty of their paternity. In mating systems in which females control sperm transfer and paternity is influenced by numbers of sperm (i.e., numerical sperm competition), an increase in prezygotic investment in females may be an adaptive male response.  相似文献   

15.
Barbara K.  Snow 《Ibis》1970,112(3):299-329
The Bearded Bellbird Procnias averano, a medium-sized sexually dimorphic cotingid, was studied for three years in the Northern Range of Trinidad. Its preferred habitat is primary forest at altitudes of 500–1,000 feet and with a rainfall near 100 inches. It is entirely frugivorous, taking mostly drupes. The seeds of the fruits eaten are regurgitated and nearly 2,000 were collected from below the male's calling perch and below nests. Most were from the families Lauraceae and Burseraceae, whose fruits have particularly nutritious pericarps. Adult males own a calling territory from which they call throughout most of the day, and throughout the year except for the period of moult. In each territory there are special saplings where display and mating take place. Only males call; the females are voiceless. The call is loud and far-reaching. In Trinidad P. averano has only two calls, the Venezuelan birds have a third more musical call which appears to have been lost by the Trinidad bellbird during the past 60 years. Both males and females visit the adult male in his calling territory. Here he performs a ritualized display to the visitor, which shows off his black and white plumage, the beard of wattles, and also a bare patch on the thigh. The visit of the female may culminate in mating. All aggressive behaviour observed was between males disputing over calling territories. The female builds the nest, incubates, and rears the chick on her own. The very inconspicious nest is built of twigs that readily interlock. Nearly all the twigs are from two species of tree, and it is suggested that the specialized nest-material may be essential, as the female bellbird builds only with the breast and feet. The clutch consists of a single egg. The incubation and fledging periods are both long, 23 and 33 days respectively. The female's visits to the chick are infrequent, brief, silent and inconspicuous. Many details of breeding behaviour indicate that the inconspicuousness of the nest is of paramount importance. The nestling is fed on fruit which the female regurgitates. The main breeding season is from April to July with a minor one in October and November. It takes two and a half years for the male to attain fully adult plumage, and at least two years to achieve a completely adult call. The relationship between type of nest, clutch-size, feeding habits and sexual bonds in tropical forest birds is discussed. The bellbird is an extreme example of a species in which the need for a very inconspicuous nest and a diet of fruit have combined to promote polygamy, with the emancipation of the male from the nest, and to reduce clutch-size to a minimum. The bellbird's structural adaptations to its method of feeding in flight are discussed and a comparison is made with the birds of paradise. The male's adaptations for its primary function of self-advertising are compared with the parallel adaptations evolved in the related Pipridae.  相似文献   

16.
R. A. Reed 《Ibis》1968,110(3):321-331
The migrant Diederik Cuckoo Chrysococcyx caprius was studied on a 72–acre area near the Klein Jukskei River near Johannesburg from 1955–1958. The birds first arrive in early October, after which the males take up territories and call continually until February; subsequent calls up to April are probably made by young birds.
Courtship displays, which involve courtship feeding, and egg-laying follow the birds' arrival by about a month. The Red Bishop Euplectes orix was the species most commonly parasitized, with smaller equal numbers of Cape Sparrows Passer melanurus and Masked Weavers Ploceus velatus . The cuckoos' eggs differ according to the host species and in two cases hatched between ten and 14 days after laying. The chicks normally evict their hosts' offspring on the second or third day after hatching. The fledging period appears to be roughly 19–20 days, and there is a period of post-fledging care lasting between 17 and 38 days, during which the chicks are fed different foods by different host species (grass seeds by bishops; insects of different sizes by weavers and sparrows).
The fact that the eggs and the calls of the chicks vary according to their host species suggest the existence of three separate host-specific strains in this area. The incidence of brood parasitism in Red Bishops' nests varied from 7–50% and averaged 25%.  相似文献   

17.
对家白蚁Coptotermes formosanus Shiraki雌雄繁殖蚁在初建群体形成过程中氨基酸含量变化的测定,初步认为与产卵、哺育幼蚁和交尾有密切关系。产卵高峰期、哺育幼蚁期和交尾期氨基酸含量骤然下降,而产卵间歇期又开始回升。同时发现,雌雄蚁体重的变化对氨基酸含量的变化没有明显影响。  相似文献   

18.
Reversed sexual dimorphism in size (RSD) occurs in most species of several taxonomic groups of birds. The hypotheses proposed to explain this phenomenon are examined theoretically, using inequalities to state selection in the most rigorous possible terms. The most pertinent empirical evidence is also examined critically. Proponents of hypotheses on the evolution of RSD have failed to consider the genetic constraints on the evolution of dimorphism. Selection for dimorphism can act on only that small portion of the genetic determination of body size that is sex limited. In general, selection for body size is much more likely to lead to a similar change (e.g. larger) in both sexes than to dimorphism. The most popular hypotheses involve selection for size-related differences in foraging ability. It is unlikely that there is variation in size-related foraging differences available for selection in a monomorphic, ancestral population. Foraging differences between the sexes cannot lead to the evolution of RSD; evolution of large and small morphs of both sexes is a more likely outcome. Selection for sex-role differentiation factors (e.g. large females lay larger eggs, small males are more agile in flight) can lead to the evolution of RSD, but only if the magnitudes of opposing selection for small males and for large females are equal. Combining selection for size-related foraging differences with selection for sex-role differentiation factors hinders the evolution of RSD until the sexes differ in size by 3 s.d . Empirical evidence supports this assertion: statistically significant differences between the sexes in the size of prey taken are found only in highly dimorphic species. The sex-role differentiation factors that have been proposed appear unlikely to provide the equal selection necessary for the evolution of RSD. Several authors have proposed that small size in males is selected for foraging ability and large size in females for some sex-role differentiation factor. Males cannot be more efficient foragers without females being less efficient and efficiency cannot be a factor only when the male is feeding his family. RSD cannot evolve in monogamous species if large females survive less well than small males. RSD might evolve as the result of sexual selection for small size in males and constraints on the reduction of size in females because of some factor associated with reproduction. Examination of seven studies indicating a relationship between female size and reproductive success shows very little unequivocal evidence for small size in females allowing breeding earlier in the season. Large size in females allows females to breed at a younger age in the sparrowhawk and pairs to form more rapidly in three species of sandpipers. Both of these may be the result of sexual selection. There are fewer theoretical problems with sexual selection as a cause for the evolution of RSD than with the other hypotheses. Empirical evidence for sexual selection is scarce but better than that for the other hypotheses. Evidence is contradictory for the selection of small size in males for agility in aerial displays for courtship or defence of territory. Large size in females does not appear to be the result of selection for competitive ability to obtain mates. Facilitation of female dominance and hence of the formation and maintenance of a pair bond is the most viable explanation of the evolution of RSD. It is most likely that all dimorphism (normal or reversed) is the result of sexual selection. RSD is correlated with birds in the diet in the Falconiformes and this is a central theme in the foraging hypotheses. This correlation may be because birds are abundant and available in a continuum of sizes, thus permitting but not causing the evolution of RSD or because species that prey upon birds are better equipped physically (and perhaps more likely behaviourally) to inflict damaging attacks on conspecifics and the greater RSD increases female dominance and the ease of pair formation.  相似文献   

19.
褐飞虱Nilaparvata lugens(Stal)属迁飞性水稻害虫,其成虫有短翅和长翅两种翅型。 褐飞虱迁入雌虫均未经过交配,其短翅型由一对显性等位基因控制。翅型分化同时受到遗传和内分泌系统的协调控制,外界条件如密度和寄主等因子通过内分泌系统来影响翅型的分化。褐飞虱翅型分化的敏感龄期雌虫为1~3龄,而雄虫为1-5龄;不同若虫蜜度处理对褐飞虱成虫的前翅形成有一定的影响。分蘖期水稻饲养的褐飞虱短翅型比例明显高于孕穗期水稻饲养的褐飞虱。不同密度下各生物型间的翅型分化差异不显著。迁入地的浙江各种群属温带型,其雌虫短翅率低且与密度呈显著负相关;菲律宾热带种群雌虫在不同密度下均为短翅型,而雄虫的短翅率随密度增加而上升。广西种群接近热带型,其雌虫短翅率高但不随密度而变化。试验各种群的雄虫在中等密度甚至高密度时其短翅率出现最高。  相似文献   

20.
布氏田鼠洞群内社群结构变动与序位的研究   总被引:10,自引:4,他引:6  
本文通过野外标志流放和实验室观察,研究了洞群内布氏田鼠社群结构的变动及其序位作用。该鼠社群结构变动有明显的季节性。繁殖期为变动期, 贮草期为稳定期。变动期在繁殖前期和繁殖盛期形成2个变动高峰。前者主要是成体(包括老体) 雄鼠的迁移, 后者迁移主体是亚成体鼠。贮草期间洞群成员相对稳定, 迁移减少。社群序位表现为2~3 个等级,即优势鼠、次优势鼠和从属鼠。优势鼠以老体雌鼠为多。繁殖期, 50%以上的从属鼠在陌生鼠群中提高了序位, 30%优势鼠可在陌生鼠中保持高序位。非繁殖期, 进入陌生群后鼠间争斗激烈, 获得优势的比例明显降低。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号