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1.
Abstract Prime mallee lands that once supported high densities of malleefowl, Leipoa ocellata in New South Wales have been extensively cleared for agriculture. Malleefowl are now restricted largely to more and habitat. Given the added competition from introduced herbivores, there is concern that these marginal habitats may not contain sufficient food resources to support viable populations of malleefowl, particularly in times of drought. An opportunistic feeding strategy and omnivorous diet enable malleefowl to exploit a diverse array of food items. Vegetative and invertebrate food resources available to malleefowl in marginal mallee lands were monitored over a period of 1 year during drought. Food resources were varied, transient and patchily distributed. Composition and abundance fluctuated considerably, but potential food was never entirely absent. Despite the prevailing drought, food was obtainable throughout the year provided malleefowl adapted to the fluctuating availability of each of the various potential food resources. Reduced food resources in marginal habitat is not implicated as a major factor in the demise of the malleefowl. Food was most abundant between August and November, inclusive, due largely to the abundance of herbs, the diverse supply of buds, flowers and fruit on perennial shrubs, and the sporadic proliferation of cockroaches. Food availability was least, and therefore most critical, during February, March and June. The most favourable time of the year, in terms of available food resources, for the release of captive-bred individuals was during spring, around September.  相似文献   

2.
Zusammenfassung Acht Wochen lang wurden Thermometerhühner(Leipoa ocellata) im Freiland und unter Gehegebedingungen beobachtet. Im Gegensatz zu den Angaben in der Literatur konnten — in verschiedenen sozialen Kombinationen unterschiedlich stark ausgeprägte — soziale Beziehungen festgestellt werden. Individuen einer Gruppe von Jungvögeln sind in ihren Aktivitäten leicht aufeinander abgestimmt und suchen gegenseitge Nähe während der Ruhephasen. Jungvögel zeigen gegenüber ihren Eltern Ansätze positiven sozialen Verhaltens. Zwischen den Partnern eines Paares liegt eine hochentwickelte Paarbindung vor. Sie äußert sich in ständiger räumlicher Nähe, in zeitlicher Synchronisation der Aktivitäten und in besonderen, offensichtlich speziell zur Aufrechterhaltung der Paarbindung dienenden Verhaltensweisen. Zu ihnen gehören ein Rufduett, ein Begrüßungszeremoniell auf dem Bruthügel sowie zeitlich vom Fortpflanzungsgeschehen weit abgesetzte Kopulationen. Die offensichtlichen Widersprüche zwischen den Literaturangaben und den eigenen Befunden werden diskutiert: Die Stärke der Paarbindung stellt sich auf weiteren Stadien des Brutzyklus möglicherweise anders dar, da der Grad physiologischer Belastung für und im Jahresverlauf sehr unterschiedlich sein kann. Sie ist wahrscheinlich auch von ökologischen Gegebenheiten abhängig und kann als Anpassung an extrem unwirtliche, aride Lebensräume im Beobachtungsgebiet gedeutet werden. Schließlich lassen auch theoretische Überlegungen eine ausgeprägte Paarbindung beiLeipoa erwarten: Der extrem hohe Brutpflegeaufwand, der sich über elf Monate im Jahr erstreckt, läßt Mechanismen zur Sicherstellung dieser Investition nur in die eigenen Nachkommen erwarten.
Observations on the Mallee Fowl(Leipoa ocellata) in Australia
Summary During a period of eight weeks, field and aviary observations have been conducted on the Mallee Fowl(Leipoa ocellata) in Australia. Social interactions — although of different degrees in different contexts — could be observed: Juvenile birds are slightly synchronized in their activities and approach each other for resting. Juvenile birds do show indications of positive social reactions with their parents. Adult birds are characterized by a very strong pair-bond. This is seen in an accurate temporal synchronization of behavioural activities, in close spatial proximity and in special behaviour patterns which seem mainly to serve the maintenance of the pair-bond (call-duet, greeting ceremonies, and copulations several months in advance of the onset of the reproductive period). The strong pair-bond observed in our studies is in marked contrast to the statements in the literature. Such contradictions may be due to differences in the time and the area of observation: During the period of our observations, after the end of the breeding season, the physiological and behavioural demands on both sexes are almost identical, and an equal sharing of duties at the mound does seem to be adaptive. The extremely hard environmental conditions in the arid habitat, where our observations have been conducted, may also have resulted in a tighter pair-bond than is observed in coastal populations of the Mallee Fowl. Furthermore, from theoretical considerations about the large amount of parental investment (up to eleven months per year devoted to activities at the mound inLeipoa) a tight pair-bond as described in this study was to be expected.


Dem Andenken an Harry J. Frith gewidmet, dem viel zu früh verstorbenen Pionier auf dem Gebiet der Megapodiiden-Forschung

Mit Unterstützung der Deutschen Forschungsgemeinschaft  相似文献   

3.
Information on the movement ecology of species can assist with identifying barriers to dispersal and appropriate management actions. We focus on the threatened Malleefowl (Leipoa ocellata) whose ability to move and disperse within fragmented landscapes is critical for their survival. We also investigate the possible effects of climate change on Malleefowl movement. We used solar-powered GPS telemetry to collect movement data and determine the influence of breeding status, remnant vegetation patches and environmental variables. Seven Malleefowl were tracked between 1 and 50 months, resulting in 20 932 fixes. While breeding, Malleefowl had significantly smaller home ranges (92 ± 43 ha breeding; 609 ± 708 ha non-breeding), moved shorter daily distances (1283 ± 605 breeding; 1567 ± 841 non-breeding) and stayed closer to the incubation mound (349 ± 324 m breeding; 3293 ± 2715 m non-breeding). Most Malleefowl effectively disassociated from the mound once breeding stopped, with two birds dispersing up to 10.2 km. Movement patterns were significantly correlated with the size of the remnant native vegetation patch, with smaller home ranges being utilized in small patches than in large patches. One male almost exclusively remained within a 107-ha patch for over 4 years, but a female crossed between closely spaced uncleared patches. Long-range movements of nearly 10 km daily displacement were recorded in large remnants almost exclusively when not breeding. Temperature and rain had a significant effect on movement: modelling suggests daily distances decline from 1.3 km at 25°C to 0.9 km at 45°C, with steeper declines over 30°C. The influence of patch size on movement patterns suggests that Malleefowl movement may be governed by the size of remnant patches and that habitat continuity may be important for facilitating recolonization after catastrophic events and maintaining genetic diversity. Climate change may reduce Malleefowl movement during hot, dry periods possibly affecting breeding success.  相似文献   

4.
The present study investigated aspects of betaine metabolism in an elasmobranch fish, the winter skate (Leucoraja ocellata). Based on the level of choline dehydrogenase (ChoDH) activity, the liver and kidney appear to be the major sites of betaine synthesis and the mitochondrial localization of ChoDH and betaine aldehyde dehydrogenase (BADH) indicates that the metabolic organization of betaine synthesis in winter skate is similar to other vertebrates. Food deprivation did not affect white muscle betaine content, and prolonged starvation (70 days) appeared to decrease the total hepatic betaine synthetic capacity. There was no decrease in ChoDH or BADH activity at the mitochondrial level with starvation, suggesting any decrease is due to catabolism of hepatic reserves rather than downregulation of betaine synthesis. Skates fed a high betaine diet (frozen squid approximately 55 micromol g(-1)) had elevated white muscle betaine content compared to those fed a low betaine diet (frozen herring <2 micromol g(-1)); however, high dietary betaine intake did not affect the activity of betaine synthesizing enzymes in liver. Acclimation to elevated salinity (120 and 130% seawater) did not result in an increase in white muscle betaine content. Taken as a whole, the present data suggest that diet is a major determinant of muscle betaine in the winter skate and that betaine is of marginal importance as an intracellular osmolyte in this species.  相似文献   

5.
The development of Cyclotella ocellata Pantocsek was studied systematically in the eutrophic, dimictic hardwater Lake Dagow from March to October, 1994. Cyclotella ocellata was the most important centric diatom in the lake with a maximum cell density of 6 × 106 cells 1−1. The seasonal development, characterized by a spring and a summer maximum, is considered in relation to environmental factors and the succession of the phytoplankton community. The amount of Cyclotella ocellata biomass as a proportion of the total phytoplankton biomass varied from 0.5 to 35%. In addition, seasonal changes in cell size and feature associated with sexual reproduction of Cyclotella ocellata were documented. Light and electron microscopic investigations demonstrate an extremely wide range of morphological variability of this natural population.  相似文献   

6.
7.
8.
For a long time, Cercosaura ocellata was considered polytypic, with three subspecies: C. ocellata ocellata, C. ocellata petersi and C. ocellata bassleri. Recently, C. ocellata bassleri was elevated to full species, based on analysis of a few molecular samples from Peru. This species complex is widely distributed in South America, occurring in Amazonia, Cerrado, Atlantic forest and Pampa biomes. The monophyly and species diversity of C. ocellata are still unstudied. Here, we infer phylogenetic relationships and species diversity of this group analysing 2326 base pairs of three mitochondrial (12S, 16S, and ND4) and one nuclear (c-mos) genes. Our taxon sampling of 115 specimens includes 72 samples of C. ocellata and sequences of other Cercosaura species and closely related Cercosaurinae. Maximum likelihood phylogenetic analysis recovered the monophyly of Cercosaura and that of C. ocellata with strong support. Our analyses suggest that C. ocellata is a complex of cryptic species, which possibly started diversifying in Amazonia.  相似文献   

9.
Seven aphid species (Eucalipterus tiliae, Tuberculatus annulatus, Euceraphis betulae, Cavariella konoi, Acyrthosiphon ignotum, A. pisum, Macrosiphoniella artemisiae) were tested as prey for larvae of Anatis ocellata and all were essential prey. Nine aphid species (Chaitophorus tremulae, Cavariella konoi, Aphis farinosa, Eucalipterus tiliae, Euceraphis betulae, Macrosiphoniella artemisiae, Acyrthosiphon ignotum, Aphis spiraephaga, Aphis fabae) were tested as prey for Calvia quatuordecimguttata. The former six species were 'essential' food, while the latter three aphid species were unsuitable food for C. quatuordecimguttata. The experiments were conducted under laboratory conditions with no choice of prey. Some of the checked 'essential' prey apparently do not represent food in the field as they occur in other habitats than the studied coccinellid species that are common on trees.  相似文献   

10.
Leiolepis ocellata is a lizard species distributing in topographically diverse habitats in northern Thailand. To explore its evolutionary history, 113 samples of L. ocellata were collected from 11 localities covering its distributional range in northern Thailand, and sequenced for mtDNA fragments (Cyt b and ND2). Pairwise comparisons across sampling localities yielded significant genetic differentiation (F ST and Jost''s D) but no clear pattern of isolation by distance could be demonstrated based on the Mantel test. Phylogenetic and network analyses highlighted six haplogroups. Their divergence times were estimated to occur during the Pleistocene, much more recent than major orogenic events affecting northern Thailand. Instead, the results suggested that lineage divergences, of particularly eastern and western haplogroups of the region, coincided with the major rivers in the region (Yom river and Ping river, respectively), indicating vicariance in response to riverine barriers. Furthermore, ecological niche modeling suggested an expansion of suitable habitats of L. ocellata, when LGM‐liked conditions. This expansion potentially facilitated their dispersal among adjacent localities leading to lineage diversification and genetic admixture, after the riverine divergence.  相似文献   

11.
Anaerobic bacteria tentatively identified as species of Catenabacterium were recovered from brain, liver, kidney and blood of fish involved in a massive epizootic of grey mullet (Mugil cephalus) and redfish (Sciaenops ocellata). Pathogenicity was demonstrated for grey mullet (M. cephalus) and sea catfish (Arius felis) but not for channel catfish (Ictalurus punctatus) or white mice. Diseased fish were disoriented, weak and swimming at the surface of the water. Thioglycolate and salt bovine blood agar containing 40 microg/ml gentamicin were useful as selective culture media.  相似文献   

12.
The authors subjected peripheral blood smears of Torpedoes to cytochemical analysis of lipids, protein, neutral and acid polysaccahrides and of some enzymatic activities, i.e. adenosine triphosphatase (ATP-ase), acid and alkaline phosphatase, aliesterase and peroxidase. It was found that neutrophilic granulocytes are intensely PAS and aliesterase positive and weakly ATP-ase positive. Eosinophilic granulocytes show the presence of neutral polysaccharides in the matrix (which is PAS positive) and strong ATP-ase and acid phosphatase activities in the granules. Lymphocytes sometimes contain weakly PAS and aliesterase positive granules. Monocytes show some small PAS positive granules and weak acid phosphatase and aliesterase activities. Thrombocytes contain some peripheral granules which are PAS positive and slightly ATP-ase positive. There are no transitional forms between the various cellular types. The results confirm the classification of leukocytes of Torpedoes into neutrophilic granulocytes, eosinophilic granulocytes, lymphocytes, monocytes and thrombocytes and contribute some informations about the histoenzymatic content of Elasmobranch leukocytes.  相似文献   

13.
Good AG  Muench DG 《Plant physiology》1993,101(4):1163-1168
The onset of anaerobiosis in barley root tissue (Hordeum vulgare L. cv Himalaya) results in the following metabolic responses. There are rapid increases in the levels of pyruvate, lactate, and ethanol. Malate and succinate concentrations increase over the first 12 h, after which they return to the levels found in oxygenated root tissue. Alanine concentration increases over the first 12 h, and this is matched by a corresponding decrease in aspartate. The initial stoichiometric decline in aspartate and increase in alanine suggests that the amino group of aspartate is conserved by transaminating pyruvate to alanine. Aspartate catabolism also probably provides the initial source of carbon for reduction to succinate under anoxic conditions. Under long-term anaerobiosis (>24 h), there is no further accumulation of any of the fermentative end products other than ethanol, which also represents the major metabolic end product during long-term anaerobiosis. Although a number of the enzymes involved in fermentative respiration have been found to be induced under anaerobic conditions, neither aspartate amino-transferase nor malate dehydrogenase is induced in barley root tissue. The observations suggest that the long-term adaptations to hypoxic conditions may be quite different than the more well-characterized short-term adaptations.  相似文献   

14.
Newly born and neonate Torpedo ocellata were obtained from gravid females caught during the autumn off the Mediterranean coast of Israel. The young torpedos, which weighed about 11 g, were fed with live Blennius pavo Risso, and doubled their weight in about 4 months. The behaviour of the torpedo during feeding was examined and photographed. When attacking a fish, the torpedo emerges from being buried in the sand and assaults the approaching prey. First, the prey is trapped under the torpedo and then directed towards the ray's mouth by its body movements. Newborn and neonate torpedos are able to discharge their electric organ. The amplitude of the discharge of one day-old fish is approximately 4 V. It increases dramatically during the first three weeks of life to 20 V, reaching an asymptotic level of about 26 V, by the end of the fourth month.  相似文献   

15.
16.
Final instar caterpillars of the poplar hawkmoth ( Laothoe populi ) are usually yellow-green when they have been feeding on Salix fragilis but white when on Populus alba. Similarly final instar caterpillars of the eyed hawkmoth (Smerinthus ocellata) vary in colour from yellow-green when fed on Salix cinerea or S. fragilis to grey-green when fed on Salix ripens or S. alba. Most caterpillars of these two moths are thus very cryptic to the human eye. It has already been shown that colour matching is brought about by young caterpillars changing colour depending on the colour of the substrate perceived by their eyes. Evidence is presented here for selective predation, probably by birds. Yellow-green poplar hawk caterpillars disappeared from P. alba more rapidly than did white caterpillars, but there was no significant difference in the survival of the two colour forms on S. fragilis. Yellow-green caterpillars survived better on S. fragilis than on P. alba , but there was no significant difference in the survival of white caterpillars on the two plants. Reasons why selective predation did not occur in all of the experiments are discussed.  相似文献   

17.
Cercariae and schistosomula of Trichobilharzia ocellata were cultured to the organogeny stage in vitro in a medium based on Earle's saline (gassed with 5% CO2 in air) and containing lactalbumen hydrolysate and duck or chicken serum together with homologous red cells. Similar results were obtained irrespective of whether cercariae, schistosomula recovered from the skin of ducklings or chickens, or schistosomula recovered after cercariae had penetrated gelatine membranes were used to initiate cultures. A lipid coat developed around the body of each worm during the first 2–3 days in vitro, but subsequently it became dislodged. The worms ingested red cells, and the caeca became dark with haematin after a few days but by day 10 they were generally translucent. Maximum development was achieved at day 12; by this time males had attained a length of 2·1 mm and females 1·4 mm. Worms cultured for 7 and 9 days were injected into the leg veins of ducks and patent infections were established.  相似文献   

18.
19.
The metabolism of glycolate by Eurasian watermilfoil (Myriophyllum spicatum L.), a submersed angiosperm, was studied by feeding radioactive glycolate and glyoxylate and by analysis of glycolate and glycolic acid oxidase. Evidence for operation of the glycolate pathway is given. Glycolic acid oxidase occurs at levels comparable to amounts in species showing photorespiration. This species has a high affinity for CO2 and a possible mechanism for it is described.  相似文献   

20.
To further elucidate the role of bis(monoacylglycero)phosphate in lysosomes, its metabolism was assessed by incubation of intact and disrupted macrophages in the presence of labeled lipid precursors. In rabbit pulmonary macrophages bis(monoacylglycero)P accounted for 17.9% and acylphosphatidylglycerol for 2.6% of phospholipid phosphorus. Major fatty acids in bis(monoacylglycero)P were oleic (47%), linoleic (29%), and arachidonic (6.4%); those in acylphosphatidylglycerol were of similar distribution except for a high content of palmitic acid (20%). When homogenates of rabbit pulmonary and peritoneal macrophages, rat pulmonary macrophages, and human blood leukocytes were incubated with sn[(14)C]glycerol-3-phosphate and CDP-diacylglycerol at pH 7.4, there was labeling of bis(monoacylglycero)P and acylphosphatidylglycerol that correlated with content of bis(monoacylglycero)P. When intact rabbit pulmonary macrophages were incubated for 60 min with [(3)H]glucose and [(32)P]orthophosphate, small amounts of label appeared in bis(monoacylglycero)P and only traces in acylphosphatidylglycerol. In contrast, incubation of intact cells with the (14)C-labeled fatty acid precursors palmitic, oleic, and arachidonic acids resulted in much greater labeling of the two lipids. Labeling of phospholipids was greatest with arachidonate as precursor and least with palmitate; after 60 min, labeling of bis(monoacylglycero)P with arachidonate was 10- and 50-fold greater than with oleate and palmitate, respectively, and was exceeded only by that of phosphatidylcholine. Calculated ratios of labeling of fatty acid to P, particularly those for arachidonate, were much greater for bis(monoacylglycero)P and for acylphosphatidylglycerol than for other phospholipids. This suggests a uniquely high turnover of fatty acids in bis(monoacylglycero)P and acylphosphatidylglycerol and thus a more specific role for these compounds in metabolism of complex lipids in the lysosome.-Huterer, S., and J. Wherrett. Metabolism of bis(monoacylglycero)phosphate in macrophages.  相似文献   

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