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1.
Maintenance of reedbeds and their associated avifauna requires intervention management to modify natural succession by means of, for example, reed cutting. Nest site density of Greylag Geese Anser anser in relation to time since reedbeds were last harvested was studied at Vejlerne nature reserve, Denmark (57°00–07'N, 8°50'–9°10'E). Low nest densities were found in areas in the first four years after cutting followed by high densities in areas unharvested for five or six years. Subsequently, nest density remained high for four to seven years (depending on site) before declining to low levels again. Areas cut in the year of study and areas cut more than 16 years before contained virtually no nests. The increase in nest density with time since last harvest seemed to be related to an increase in vegetation cover (reed stem density). Areas harvested more than 16 years before probably became too dense for the geese, and newly harvested areas had too low a shoot density, hence their low nest density. However, more detailed studies are needed to establish causal relationships.  相似文献   

2.
1. This study examined the nitrogen balance of free-living flightless moulting Greylag Geese, Anser anser , in relation to food quality, nitrogen absorption, food retention time and nitrogen excretion rates.
2. Food intake rates during moult were the same as those before and after the flightless period, but total daily time spent foraging fell by 58% from 9·45 h to 3·96 h. Dropping production during moult was 43%, and mean dropping mass 42% of that before and after moult, suggesting a considerable increase in food passage time through the gut during moult. Nitrogen absorption increased from 25% prior to moult to 47% during moult.
3. At the same time, excreted dry mass uric acid in faecal material fell by 68%, such that the proportion of nitrogen absorbed and retained in the body as a proportion of the nitrogen ingested in food rose from 16% prior to moult to 42% during moult.
4. Based on these significant increases in nitrogen absorption and decreases in nitrogen excretion, geese were able to compensate for reduced food intake and derive sufficient nitrogen from their diet to re-grow flight feathers.  相似文献   

3.
4.
In general, support by social allies may reduce stress, increase an individual's status and facilitate access to resources. In Greylag geese (Anser anser), offspring stay with their parents for an entire year or even longer and thereby enjoy social support in encounters with other flock members. We investigated the influence of spatial distance to one's allies on the outcome of agonistic encounters in a natural flock situation for a total of 12 sibling groups after fledging. In addition, we tested two groups of hand‐raised juvenile geese over a time span of 11/2 yr. Passive (i.e. not interfering) human supporters of different familiarity were placed at a standard distance during food provisionings, which produced a tight flock situation. Success in agonistic interactions increased with decreasing distance to members of their social unit. The hand‐raised juveniles were more successful in agonistic interactions and showed increased feeding rates when accompanied by a familiar human than when alone or with a non‐familiar human. The effect of the presence of familiar humans on success in agonistic encounters significantly decreased with increasing age, while feeding rates remained elevated. The positive effects of social support were particularly evident in females. We conclude that social support has similar effects and functions in the highly social greylag geese as reported for social mammals.  相似文献   

5.
Semen of Greylag (Anser anser L.) ganders was frozen according to a method previously elaborated by the authors for freezing the White Koluda gander semen. Semen was collected from five to eight Greylag ganders, twice a week during three succeeding reproductive cycles, by dorso-abdominal massage. Semen samples were diluted in the ratio of 1:1 or 2:1 (two parts semen: one part diluent) with EK diluent, supplemented by 6% DMF, equilibrated and pre-frozen to -140 degrees C at a rate 60 degrees C/min, before being transferred into liquid nitrogen container. Semen samples thawed in a water bath of 60 degrees C were used for twice a week insemination in a volume of 200 microl. Three Greylag and three White Koluda geese were involved in frozen-thawed semen fertilizing ability test. The reproductive cycle of wild geese lasts usually about 6-7 weeks. The ejaculate volume (30-140 microl) and sperm concentration (10x10(6) to 150x10(6) ml(-1)) are much lower than these of domestic ganders, but spermatozoa morphology is similar, particularly while compared to 1-year-old White Koluda ganders semen. There are about 90% of live spermatozoa and about 30% of live morphologically normal cells in Greylag gander fresh semen. The Greylag gander spermatozoa susceptibility to cryopreservation procedure is as high as in domestic ganders. Dilution ratio 2:1 resulted in higher number of live spermatozoa, which withstood cryoinjury stress. In relation to fresh semen about 60% of spermatozoa remained intact (on the basis of light microscope examination) in the frozen-thawed semen. Insemination of frozen-thawed semen resulted in 37.5% of fertile eggs in Greylag and 25.0% in White Koluda geese. Low fertility rate was caused by an insufficient number of live normal spermatozoa used for insemination (about three million in every dose).  相似文献   

6.
Juvenile geese start reacting to odours at the age of 11 to 20 h. In inexperienced goslings head-shaking is released by the odours of plants on which adult geese would not feed (e.g. lavender, violet etc.). Goslings aged 4 to 9 days show a quantitatively different reaction to different odours, such as sage, dwarf-pine, dill etc. Goslings quickly become habituated to odours, they will not react any more if an odorant is presented too often.  相似文献   

7.
The karyotype of the Italian goose originating from Anser anser was characterised on the basis of R and C bands. Chromosomal preparations obtained from an in vitro culture of blood lymphocytes were stained with the RBG and CBG techniques. The RBG technique enabled the analysis of the structure of nine pairs of chromosomes whereas the CBG technique - fourteen pairs ofchromosomes from the total ofeighty goose chromosomes. The morphology and the R and C banding patterns were described. The size and arrangement of the blocks of constitutive chromatin were determined. Ideograms of R and C banded patterns were drawn. The morphological structure of the analysed chromosomes was evaluated.  相似文献   

8.
The primary structures of the alpha D-chains of the minor component Hb D of Anser indicus, Anser anser and Branta canadensis are presented. Following chain separation by RP-HPLC, the amino-acid sequences were established by automatic Edman degradation of the globin chains and the tryptic peptides. The three chains show a high degree of homology. For the high altitude respiration the alpha 1 beta 1 interface at position alpha 119 is important. For the Bar-headed Goose a mechanism for high altitude respiration involving both Hb A having alanine at position 119 and Hb D having proline at that position is suggested. Furthermore, a possible genetical development of the avian alpha D-gene expression based on a new B alpha-box mutation in the three geese and an unusual 5' splice junction (GT/GC-transition) in the duck gene is discussed. We consider the possibility that the alpha D-gene is an intermediate between a functional gene, reduced in its expression, and a pseudogene.  相似文献   

9.
The Neusiedler See – Seewinkel National Park area is confronted with a remarkable increase in tourism and recreational activities during the last years. The “Koppel” area, situated on the eastern shore of the lake, is one of the most important breeding sites for Greylag Geese. Behaviour and distribution of the geese on the breeding site as well as touristic activities on the adjacent road leading along the Koppel were examined to investigate relations and interactions between the Greylag Goose population and tourism. Taking into account the excellent weather and breeding conditions in the year 2000 the results of the survey indicate a stable or even rising Greylag population, increasing numbers of visitors and high disturbance frequencies in the vicinity of the study area. The number of disturbances on the adjacent road seems to affect the suitability of the site in general, leading to a specific temporal and spatial distribution of the birds, whereas different disturbance qualities result in changes of the birds behaviour.  相似文献   

10.
Juan A. Amat 《Ecography》1995,18(2):155-163
Herbivory of Scirpus litoralis and 5 mantimus tubers by wintering greylag geese, Anser anser, was studied at the marshes of the Guadalquivir in southwestern Spain Exclosures were constructed to compare plant growth m grazed and in grazed sites Scirpus luoralis tubers are clustered, with clusters being interconnected by rhizomes Scirpus mantimus tubers develop individually, and are connected by rhizomes The geese forage on individual S mantimus tubers but take entire clusters of S litoralis tubers, from which only one tuber is normally consumed The reproductive mode of S mantimus, the main food plant of the wintering geese, was dependent on tuber size The proportion of tubers whose shoots bear inflorescences decreases with increasing tuber size, and the larger tubers reproduce vegetatively The geese feed on the smaller S mantimus tubers and the smaller S litoralis clusters Reasons for this preference may be that these tubers and clusters are easier to extract and also that small tubers require less time to break down in the gizzard The number of shoots of S litoralis and S mantimus in grazed sites was 88% and 32%, respectively, compared with that in ungrazed sites Nevertheless this difference reflects m part a decrease of 5 litoralis inside some exclosures during a five years period The length of shoots of both species was shorter in grazed than in ungrazed sites The size-related selection of tubers by geese may have a profound effect on the structure and dynamics of these plants populations, and the trade-off between sexual and asexual reproduction However, due to the clonal nature of the plants, interpretation of plant-goose interactions from an evolunonary perspective is difficult because of the elusive unit of selection involved  相似文献   

11.
应用多种色谱技术进行分离纯化,从朗德鹅胆汁85%乙醇提取物中分离得到6个化合物。经理化性质和光谱数据分析鉴定为苯乙酸(1)、鹅去氧胆酸(2)、鹅去氧胆酸乙酯(3)、棕榈酸-α-单甘油酯(4)、顺-6-十八碳烯酸(5)、(4E)-2-[2'-hydroxyhexadecanoylamino]-4-octadecane-1,3-diol(6)。化合物1、3、4和6为首次从该属动物胆汁中分得,其中化合物6为首次从陆生动物胆汁中分得的一种神经酰胺类成分。首次对化合物2、4和5进行抑制金属蛋白酶活性的实验,评价了三个化合物的生物活性。  相似文献   

12.
13.
Ten novel polymorphic microsatellite loci were isolated and characterized from the greylag goose, Anser anser, a long-term monogamous and biparental bird. Additionally, five new primers pairs were designed based on previously published microsatellite locus sequences from closely related species. Multiplex polymerase chain reactions conditions were optimized for all 15 primer pairs. The number of alleles ranged from two to 12 per locus with an observed heterozygosity ranging from 0.07 to 0.85. This marker set will be used to determine rates and origins of extra-pair and parasitic young in a population of individually banded greylag geese with known life histories.  相似文献   

14.
The feeding ecology of Dotterel Charadrius morinellus adults and chicks was studied on three Scottish breeding areas. On the basis of 2324 prey items identified from 234 faeces, we show that (i) birds feed selectively and (ii) age-related and seasonal differences in food selection occur.
The diet comprised mainly beetles (Coleoptera), sawflies (Symphyta) and the adults and larvae of Tipula montana. The faeces of adult Dotterel contained a high proportion of beetles, whereas chick faeces had more soft-bodied prey. However, when T. montana adults emerged en masse (every second year) both adults and chicks took more tipulids. On one area, larval T. montana comprised much of the diet soon after the birds arrived on their breeding grounds and just before leaving in autumn. The preferred feeding habitats were flat or gently sloping Racomitrium lanuginosum or Juncus trifidus heaths or the transition zone between moss heath and montane bog. Dwarf-shrub, grass-dominated and single bog communities were avoided. The preferred feeding habitats were those in which pitfall trap catches of the main prey were highest. A close juxtaposition of montane bog and R. lanuginosum heaths met the feeding requirements of both chicks and adults, respectively. Recent changes in the breeding distribution of Dotterel in Britain may be related to de- terioration in feeding and breeding habitat due to overgrazing by sheep and greater habitat acidification.  相似文献   

15.
The numbers of Pink-footed Geese Anser brachyrhynchus wintering in Britain have been increasing exponentially since the 1950s. The numbers of geese at virtually all roost sites have increased, but the most dramatic increase has been in Norfolk, the southernmost region occupied in Britain. This redistribution was most likely caused either by the increase in the population forcing greater numbers of geese towards more southerly sites as the result of a buffer effect, by a decrease in the quality of sites elsewhere in the range or by an increase in the attractiveness of Norfolk. Co-ordinated counts of geese around Britain and historical data of changes in agricultural practice in Norfolk were used to examine these possibilities. No evidence was found for buffer effects, degradation of sites elsewhere or an increase in food availability in Norfolk. The major difference between Norfolk and other Pink-footed Goose sites is in the food type available in Norfolk, namely harvested Sugar Beet Beta vulgaris remains. This food is of high quality and the geese are not disturbed whilst feeding on it because of its limited commercial value. The pattern of redistribution of Pink-footed Geese may therefore be the result of cultural learning of the benefits of feeding on Sugar Beet.  相似文献   

16.
Two-dimensional agarose gel (pH 8.6)-horizontal polyacrylamide gel (pH 9.0) electrophoresis of plasma proteins in the goose was done. This method resulted in improved separation of proteins in the pre-transferrin and transferrin regions. Preliminary evidence was presented for the existence of two new plasma protein polymorphisms.  相似文献   

17.
Adult Pink-footed Geese Anser brachyrhynchus from the Svalbard breeding population were neck-banded and resighted in staging and wintering areas outside the breeding season 1990–1999. We estimated annual and seasonal survival using capture–recapture statistical models. Mean annual survival was 0.829, declining over the study period from 0.90 to 0.79. The annual cycle was partitioned into three periods: summer (1 April–30 September), including both spring and autumn migration, autumn (1 October–31 December), including most shooting, and winter (1 January–31 March). The parsimonious model selected to describe seasonal survival included a declining trend in summer survival, constant autumn and winter survival with lower survival in the severe winter of 1996, and an additive effect of sex on summer and winter survival. Monthly survival was highest during winter. Decreasing summer survival was the main contributor to the overall decline in annual survival, and was attributed mainly to increasing natural mortality on the breeding grounds. Mean annual survival based on the seasonal survival probabilities was 0.835 for females and 0.805 for males. The effect of sex was most pronounced during summer and remains to be explained.  相似文献   

18.
Personality means suites of correlated behavioural traits, also referred to as “behavioural syndromes” or “personality dimensions”. Across animal taxa similar combinations of traits seem to prevail, which may have proximate foundation in common neuroendocrine mechanisms. Hitherto, these have been rarely studied in intact social settings. We investigated personalities of greylag goose males from a free-roaming flock that shows complex social relationships. In connection with our longitudinal study on the consistency of behavioural and physiological responses to multiple challenges, we asked whether and how single, personality-related behavioural traits correlate with each other to form personality dimension(s). We tested whether these dimensions were related to physiological characteristics that previously showed limited plasticity (heart rate (HR), baseline and stress-induced excreted immuno-reactive corticosterone (BM), and testosterone metabolites levels) and, furthermore, to age, body measures, and dominance rank. Principal-components analysis based on behavioural variables revealed two factors: 51.1% of variability was explained by “aggressiveness” and a further 19.1% by “sociability”. “Aggressiveness” comprised correlated measures of aggression, subordinance, boldness, vigilance, and proximity to the mate. This “aggressiveness” positively correlated with stress-induced BM levels, the HR increase during aggressive interactions, and with dominance rank, which may suggest proximate and functional contingencies of this personality dimension.  相似文献   

19.
Two-dimensional agarose gel (pH 8.6)-horizontal poly acrylamide gel (pH 9.0) electrophoresis of plasma proteins in the goose was done. This method resulted in improved separation of proteins in the pre-transferrin and transferrin regions. Preliminary evidence was presented for the existence of two new plasma protein poly morphisrns.  相似文献   

20.
A. D. FOX  H. BOYD  R. G. BROMLEY 《Ibis》1995,137(2):151-156
The relationships between yearlings and adult pairs of White-fronted Geese Anser albifrons were studied during pre-nesting, laying and early incubation in the central Canadian Arctic. Prior to nesting, females of lone pairs spent 75–81% of their time feeding, while males spent only 42–47% of time feeding and 46–50% alert. In pairs with one or more associated yearlings, both females and males fed significantly more and spent less time vigilant. Yearlings spent significantly less time (59%) feeding when alone compared with 71–76% when with pairs. Associations between yearlings and paired adults were most frequent before adult females began prospecting for nest sites. No prospecting pairs were associated with yearlings. After the egg-laying period, groups of geese, predominantly yearlings, made distraction flights over humans and terrestrial predators approaching nests, in contrast to the more cryptic behaviour of nesting pairs. The presence of groups of geese associated with some nest sites suggests that continuing parent-offspring relationships may involve assistance with nest defence.  相似文献   

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