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金钱豹饲养与繁殖的观察 总被引:1,自引:0,他引:1
金钱豹(Panthera pardus)在自然界的数量日益减少,已被列为国家重点保护动物。为了解金钱豹的繁殖规律,以便更好地保护繁衍,增加数量,我们进行了以下观察。1饲养管理繁殖实验的5只金钱豹(3♀、2♂),分别来自昆明、青海、合肥、齐齐哈尔。均关养在笼舍内,各占一套间,有内室和室外活动场,面积约24m2,四周及顶部均为钢筋笼,混凝土地面,内室设有木制产箱(1.25×0.80×0.85米)。每天冲洗兽舍一次,每周消毒一次,常保持内室卫生干燥,夜间大多将豹关入内室休息。每年春、秋两季分别对金钱豹检查、驱虫一次。由于金钱豹行动灵活敏捷,善于攀援纵跃,一… 相似文献
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褐马鸡(Crossoptilon mantchuricum)是我国一类保护动物,而庞泉沟为保护褐马鸡的国家级自然保护区。保护珍稀濒危动物,除划定自然保护区管理保护之外,开展就地人工饲养繁殖,为进一步研究褐马鸡的生态和生物学以及人工驯化提供科学依据,并可探讨放还大自然的途径,在理论和实践方面均具有一定意义。有关褐马鸡就地人工饲养,张兆海(1983)曾有报道,但尚未解决繁殖问题。我们于1984~1986年就地人工饲养繁殖连续三年成功。现报道如下:一、笼舍庞泉沟自然保护区位于山西省吕梁山中段,地处东经111°22′—111°33′,北纬37°45′—37°55′,海拔16… 相似文献
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林业生产中的生物固氮利用 总被引:4,自引:0,他引:4
据统计,全球每年生物固氮总量约为175×10~6t(吨)。其中耕地固氮量达44×10~6t;全球林地面积约41×10~6hm~2(公顷),其固氮总量也可达40×10~6t;而全世界每年工业生产的氮肥约60×10~6t。可见生物固氮在农业和林业生产上的规模和作用是很大的。有关生物固氮与农业的关系已有人作了专题论述,本文专就固氮与林业的关系谈些看法。 相似文献
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充分利用福建滨海沙滩植被资源发展种植业 总被引:1,自引:0,他引:1
福建滨海沙滩位于北纬23°37′—27°10′范围,面积约5.33×10~4ha,已植防护林近2.0×10~4ha,尚约有3.34×10~4ha 未开发利用,其中分布于闽江口以南岸段和岛屿约2.86×10~4ha, 相似文献
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笼养褐马鸡的繁殖行为与雏鸟生长发育 总被引:2,自引:0,他引:2
作者于1984年、1985年、1990年对褐马鸡在人工饲养下的发情、交配、产卵、繁殖等进行了观察,6只褐马鸡平均产卵为22.5(15—28)枚。14枚褐马鸡卵孵化天数为26.17(26.13—27.00)天,1—7天平均每天水分散失为0.29克,8—14天平均每天水分散失为0.27克,15—21天平均每天水分散失为0.23克,22—26天平均每天水分散失为0.28克,褐马鸡卵从孵化到出雏平均水分散失为6.9克,平均每天水分散失为0.27克,褐马鸡卵在人工孵化期间,卵重的变化以前尚未见报道。 相似文献
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黑龙江省三江平原丹顶鹤的数量分布 总被引:2,自引:0,他引:2
在地面调查的基础上,我们使用Y-11轻型飞机对黑龙江省三江平原地区的丹顶鹤的数量分布近行了调查,调查时飞行高度80米,航速140公里/小时,续航里程共3748公里。调查结果表明,丹顶鹤在三江平原主要分布在8个地区,其中嘟噜河下游、洪河自然保护区、七星河流域和兴凯湖低地是主要繁殖地,总数量共309只。 相似文献
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Corm tissue of Isoetes muricata Dur. was fixed in glutaraldehyde and postfixed in osmium tetroxide for electron microscopy. Very young secondary sieve elements can be distinguished from contiguous cambial cells by their distinctive plastids and by the presence of crystalline and/or fibrillar proteinaceous material in dilated cisternae of rough endoplasmic reticulum (ER). At maturity, the sieve elements are lined by the plasmalemma and a parietal, anastomosing network of smooth ER. Degenerate nuclei persist in all mature sieve elements. In addition, mature sieve elments contain plastids and mitochondria. Sieve-area pores are present in all walls. The lateral meristem of I. muricata consists of 2–3 layers of cells year-round. Judging from numerous collections made between October 1972 and July 1975, new sieve-element differentiation precedes cambial activity by about a month. Early in May, 1–2 cells immediately adjacent to already mature sieve elements differentiate directly into sieve elements without prior division. In early June, at about the time sieve-element differentiation is completed, cambial division begins. Division is sporadic, not uniform throughout the meristem. Dormancy callose accumulates in the secondary sieve elements in late October, and is removed in early May, at about the same time new sieve-element differentiation begins. Cells of the dormant cambium are characterized by the presence of numerous small vacuoles and large quantities of storage materials, including lipid droplets, starch grains, and tannin. By contrast, active cambial cells contain few large vacuoles with little or no tannin, and they have little storage material. 相似文献
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THE ROLE OF PREDATION IN THE ECOLOGY OF THE RINGED SEAL IN BARROW STRAIT, NORTHWEST TERRITORIES, CANADA 总被引:4,自引:0,他引:4
Predation on ringed seals ( Phoca hispida ) was examined in Barrow Strait between March and May 1984 to 1986. Polar bears were the most important predator. Evidence of bear predation was observed at 18–30% of the ringed seal subnivean structures we located. Ten to 24% of predation attempts were successful, with pups making up 75% to 100% of the seals killed. Bears killed an average of 0.08 to 0.51 seals/km2 , which comprised 8 to 44% of the estimated annual pup production. Bears were successful on average in 11.3% of their attempts to kill pups hidden inside birth lairs. On southeast Baffin Island where snow was soft and pups were exposed, bears were successful in 33.5% of their attempts to kill a seal. Negative correlations were found between mean snow depth and predation by polar bears ( r = -0.896, P = 0.04, n = 5) in 1985, and between snow depth and the number of predation attempts ( r = -0.613, P = 0.02, n = 14) in 1986. 相似文献
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Distraction displays are conspicuous behaviours functioning to distract a predator's attention away from the displayer's nest or young, thereby reducing the chance of offspring being discovered and predated. Distraction is one of the riskier parental care tactics, as its success derives from the displaying parent becoming the focus of a predator's attention. Such displays are prominent in birds, primarily shorebirds, but the last comprehensive review of distraction was in 1984. Our review aims to provide an updated synthesis of what is known about distraction displays in birds, and to open up new areas of study by highlighting some of the key avenues to explore and the broadened ecological perspectives that could be adopted in future research. We begin by drawing attention to the flexibility of form that distraction displays can take and providing an overview of the different avian taxa known to use anti-predator distraction displays, also examining species-specific sex differences in use. We then explore the adaptive value and evolution of distraction displays, before considering the variation seen in the timing of their use over a reproductive cycle. An evaluation of the efficacy of distraction compared with alternative anti-predator tactics is then conducted via a cost–benefit analysis. Distraction displays are also found in a handful of non-avian taxa, and we briefly consider these unusual cases. We conclude by postulating why distraction is primarily an avian behaviour and set out our suggestions for future research into the evolution and ecology of avian distraction displays. 相似文献
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ABSTRACT. Flight-song displays usually include distinctive vocalizations and behaviors that are probably energetically expensive and also likely to attract the attention of aerial predators. We observed flight songs performed by Dusky Flycatchers ( Empidonax oberholseri ) in two breeding populations. During 15 yr at Tioga Pass, California, we observed the display twice and, during 9 yr at Steamboat Mountain, British Columbia, we observed 21 flight-song displays. These displays were generally observed later in the breeding season, suggesting that they were not used for courtship, mate attraction, or territory defense. However, for 83% of these displays, a raptor was observed to be present, usually either an American Kestrel ( Falco sparverius ) or a Sharp-shinned Hawk ( Accipiter striatus ). We hypothesize that these displays, like stotting or other pursuit-deterrent signals, may be directed at small raptors that represent a greater threat to Dusky Flycatchers and might deter attack by signaling awareness. However, because only males were observed performing flight-song displays, it is also possible that these displays serve to alert mates and offspring about the presence of an aerial predator and reduce their vulnerability to attack. 相似文献
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D. J. Pearson 《Ibis》1981,123(2):158-182
Some 5700 Ruffs were ringed in the southern Kenyan rift valley during 1967–79, mainly at Lakes Nakuru and Magadi. These have produced 15 recoveries outside East Africa, 14 in Siberia between 73° and 154°E and one in India. Adult males returned to Kenya mainly during August, and females during late August and early September. Females greatly outnumbered males at all times. Most wintering males departed late in March and early in April, but females not until about a month later. First-year birds appeared from the end of August, but remained in low numbers until late October or November. Most departed during April and May, but a few females oversummered. First-year birds typically accounted for about 25% of the wintering Nakuru females, but about 50% of those at Magadi. At both sites they accounted for a higher proportion of male birds than females. Most of the birds at Nakuru throughout late August to May appeared to be local winterers, and many individuals remained in the area for many months each year. Retrapping indicated that approximately 60% of each season's birds returned the following season. Adult males and most adult females commenced pre-winter wing moult before arrival, but completed most of it in Kenya. Males moulted 3–4 weeks ahead of females, and most had finished before December. Females typically finished during December and early January. Most second year birds timed their pre-winter moult similarly to older adults. Suspension was recorded in over 15% of all moulting birds examined. Adult pre-summer moult involved most or all of the tertials, some or all of the tail feathers, most of the inner wing coverts and the body and head plumage. It occurred mainly during January to March (males) or February to April (females), although tertial renewal commonly began a month earlier. Males showed no sign in Kenya of the supplementary prenuptial moult. First-year birds moulted from juvenile into first winter body plumage during late September to November. They underwent a pre-summer moult similar in extent and timing to that of adults, and again about a month earlier in males than females. Spring feathers acquired were often as brightly coloured as those of adults. About 15% of first-year birds renewed their outer 2–4 pairs of large primaries during January to April. Adult and first-year birds fattened before spring departure, commonly reaching weights 30–60% above winter mean. Weights of adult males peaked early in April, those of adult females early in May, and those of first-winter females later in May. Weights were relatively high also during August and September. This was due to the arrival of wintering birds carrying ‘spare’ reserves, and also apparently to the presence of a late moulting fattening passage contingent. The wing length of newly moulted adults was about 3 mm longer than that of newly arrived first-year birds, but there was no evidence of an increase in the wing kngth of adults with successive moults. Adult wing length decreased by 4–5 mm between the completion of one moult and the middle stages of the next. The migrations and annual timetable of Kenyan wintering Ruffs are discussed, and their moult strategy is compared with that of other Holarctic waders. 相似文献
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R. Charles Long 《Ostrich》2013,84(3):85-104
Coppinger, M. P., Williams, G. D. &; Maclean, G. L. 1988. Distribution and breeding biology of the African Skimmer on the Upper and Middle Zambezi River. Ostrich 59: 85–96. Observations were made on the distribution and breeding biology of the African Skimmer Rynchops flavirostris from May to November 1986 and April to December 1987, along 1550 km of the Zambezi River from its source to the Luangwa-Zambezi confluence at the Mozambique border. The 280-km Angolan section was omitted. Bird habitats along the river were mapped and the distribution of the African Skimmer was compared with the availability of its breeding habitat. 35 breeding colonies were found of which 33 were on the Barotse floodplain. Eggs were noted during August, September and October; they were laid in scrapes on bare sand in clutches of mostly 2–3. 260 eggs were measured from 101 clutches (a 39,6 x 28,4 mm). Both parents incubated and cared for the young. In hot weather, adults drank often and belly-wetted at nest relief. Chicks stayed in the nest for two days and were almost constantly shaded by the parents. Distraction displays by the adults were observed. The Upper and Middle Zambezi African Skimmer population was estimated to be 1428 birds. The important breeding areas were noted and possible threats to their conservation are discussed. 相似文献
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P. A. Zino 《Ibis》1971,113(2):212-217
The breeding of Cory's Shearwater on Selvagem Grande was studied during the seasons of 1968 and 1969, on a number of specially timed visits. After a pre-laying exodus (duration not determined) the birds returned in a mass to the island on 26 May 1969 and laying began immediately reaching its peak on 31 May. Egg dimensions and weights are tabulated. In most cases the female handed over to the male immediately after laying, and the two sexes incubated in alternating spells averaging about six days. The incubation period averaged 53-8 days. The chicks reached their maximum weight at about 53 days, but the fledging period was not determined. In 1968 young birds were leaving the nest on 22–25 October, about 90 days after the 1969 mean hatching date. Herring Gulls were important egg predators, but losses of chicks were few, 29 out of a sample of 30 being alive at the age of about 60 days. 相似文献