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 15 毫秒
1.
《Ostrich》2013,84(3-4):148-153
Morphological measurements and blood samples were taken from 154 Lesser Flamingos Phoenicopterus minor, including adults (>3 years old), immature sub-adults (2–3 years old) and first-year juvenile birds of both sexes, captured at Lake Bogoria, Kenya (0°11'–20' N, 036°06' E) during 2001 and 2002. PCR amplification of the CHD-Z and CHD-W genes using DNA extracted from the blood samples was used to determine the sex of each bird. There were significant differences in mass and tarsus length among the three age groups, indicating that Lesser Flamingos continue to grow in skeletal size and mass between fledging and the attainment of adult plumage at 3–4 years of age. On average, males were significantly larger than females in all age groups, although there was substantial overlap between the sexes in all morphological measurements. The element with the least amount of overlap was head-and-bill length. Discriminant functions utilising head-and-bill length that correctly predict the sex of juvenile and immature birds with approximately 93% accuracy are presented. By adding total tarsus length, the sex of wild adult Lesser Flamingos is correctly predicted with approximately 98% accuracy. The same discriminant function developed for wild adult birds predicted the sex of 19 captive adult Lesser Flamingos of known sex with 100% accuracy.  相似文献   

2.
Among long-lived bird species, the partners of breeding pairs are often of similar age. This pattern is largely influenced by little variation in the age at first breeding, linked with high survival rate and prolonged pair bonds. Contrary to other long-lived colonial species, Greater Flamingos Phoenicopterus ruber roseus do not show mate fidelity over consecutive breeding seasons. We studied pairing patterns of Greater Flamingos breeding in the Camargue, southern France, between December 1989 and March 1992. In each year, significant correlations were observed between the ages of the male and the female in a pair. The pattern of age-assortative mating was confirmed independently in each year by comparing the frequency distribution of age differences within pairs with the theoretical distribution derived from the age distribution of paired birds of known age in the population, assuming random pairing with respect to age. There was no evidence of a differential time of return each year to the colony with age. Analysis of display behaviour suggested that age-as-sortative mating in the Greater Flamingo results from a directional pairing preference for older and more experienced individuals. The present study provides direct evidence that age-assortative mating can occur independently of mate fidelity.  相似文献   

3.
Maina, J.G. 2000. Inter-lake movements of the Lesser Flamingo Phoeniconaias minor and their conservation in the saline lakes of Kenya. Ostrich 71 (1 & 2): 126.

The Lesser Flamingo Phoeniconaias minor is the only algivore in the saline lakes of Kenya occurring in spectacular assemblages that form the tourism base. The flamingos show unpredictable, spontaneous, “nomadic” movements between the saline lakes whose precipitating ecological factors were not well established. Food, conductivity, breeding, predation and fresh water availability were regarded as the primary factors in spite of their global coverage in explaining animal movements. Evidence is emerging that food, especially algal species composition, density, and lake levels are the primary driving factors for these inter-lake movements, with other factors being consequences of these. Algal species composition and lake levels are subject to limnological processes in the lakes, climatic conditions and human activities in the catchment of the saline lakes. Environmental degradation is now a critical factor influencing the limnology of these fragile ecosystems with far ranging consequences on lake levels, algal species composition and succession. These changes determine flamingo utilization patterns within and between the lakes. This calls for a review of the conservation status and management of the saline lakes, home to a few but highly specialised species.  相似文献   

4.
Avian pox has a worldwide distribution, but prior to this investigation has not been reported in free-ranging flamingo populations. During observations of the first successful breeding of Lesser Flamingos on a purpose-built island, at Kamfers Dam near Kimberley, South Africa, multiple small, raised, crusted plaques on the legs and facial area were noticed on 30% of the fledgling flamingos. A diagnosis of avipoxvirus infection was made on the basis of the macroscopic, histologic, and electron microscopic features, and was further confirmed by DNA sequence analysis. The avipoxvirus detected was very similar to that previously detected in albatross and falcons.  相似文献   

5.
FRANK CEZILLY  ALAN R. JOHNSON 《Ibis》1995,137(4):543-546
Data on re-mating between and within breeding seasons were collected between 1983 and 1994 as part of a long-term study of the Greater Flamingo Phoenicopterus ruber roseus in the Camargue, southern France. Flamingos have bred in the Rhône delta for centuries and since 1972 have done so annually on an artificial island in the Etang du Fangassier. A sample of chicks has been ringed each year since 1977; many of these birds were later observed back at the breeding site and were used in this study. The mate-switching rate between consecutive breeding seasons was 98.3%. This result is contrary to what has been reported from captive flocks where extensive mate fidelity occurred between consecutive breeding seasons. Mate-switching also was observed in the Camargue within breeding seasons, following breeding failure, and seems to be linked to male breeding strategy in response to the need to synchronize hatching and the limited energy supply of breeding females. The absence of a long-term pair bond in Greater Flamingos contrasts with current views on the evolution of mate fidelity in relation to longevity in birds.  相似文献   

6.
To nest in the same breeding area, territory or even nest-site in successive years may provide a possibility to look at mechanisms involved in breeding habitat selection and could also be an important tool for conservation, management and restoration attempts. In this study we examine site fidelity towards the breeding area as well as the nesting site in a dense and stable population of the Lesser Grey Shrike Lanius minor, a long-distance migrant and highly endangered passerine species, at its present northern border of its breeding range. Overall we recovered 48 out of 146 (32.8%) adults between 1996 and 2000. Recovery rate is significantly higher for males (31 of 77, 40.25%) than for females (17 of 69, 24.6%). Recovery rate of nestlings is much lower since only 51 of 790 (6.5%) were recovered and there is no significant sex difference. Furthermore, our results from 1989 to 2000 revealed that more than 30% (97/319) of the nests were built in the same nest tree in successive years and more than half (183/319 = 57.4%) of the nests in the same or neighboring trees (up to 20 m), but very seldom by the same individuals. The fact that nest reuse in successive years is almost exclusively done by different individuals suggests habitat copying and public information of individual birds. Due to optimal ecological breeding conditions other parameters like inbreeding avoidance or increased genetic variability could be important factors in nest-site selection strategies and consequently result in a “disperse over stay strategy”.  相似文献   

7.
《Ostrich》2013,84(1-2):57-65
The Lesser Flamingo (Phoeniconaias minor) is thought to be highly nomadic. In East Africa, the number of individuals on a given lake has been shown to double or halve in a period of just two weeks. In general, interlake movements are believed to take place mostly at night. However, movement timing and patterns for individual birds are unknown. Between 12 and 23 October 2002, we affixed two solar-powered and two battery-powered satellite transmitters (PTTs) to four large (>2kg) adult male Lesser Flamingos at Lake Bogoria, Kenya. During the first three months, the four birds exhibited markedly different movement patterns. One moved 687km, making seven visits to four different lakes (mean stay: 11.4d). Another made five visits to only three different lakes (mean stay: 18.5 days), travelling only 263km. On two occasions, it remained on one lake for long periods (34 days and 70 days). A third moved among lakes in Kenya and Tanzania 44 times, visiting nine different lakes, spending an average of only 2.3 days at each and travelling a total of 4 792km in the process. The fourth is believed to have been predated on Lake Bogoria at the end of the first month. During the last six months of the study, the most active bird settled down and the behaviour of the three remaining birds was much more similar. They each spent long periods of time (e.g. 45-137d) at just one or two sites. During the study period, one bird made several short (21-81km) interlake flights during daylight hours. Flight speed was estimated to be approximately 68km h-1 during the only flight when speed could be calculated. Both solar-powered PTTs functioned well; light reaching the solar panels was not impaired by feathers or dried mineral crystals, both initial concerns. The solar-powered PTT with a pre-set 'on/off' duty cycle performed much better than the other with no pre-set duty cycle, indicating that small solar-powered units need substantial 'off' time to recharge their batteries, even in areas with 12h of sunlight daily. The key site network for Lesser Flamingos in East Africa consists of seven alkaline lakes in Kenya and Tanzania (Logipi, Bogoria, Nakuru, Elmenteita, Natron, Manyara and Eyasi) and an ephemeral fresh water wetland in central Tanzania (Bahi Swamp). The conservation status of these eight sites varies from well-protected (lakes Bogoria, Nakuru and Manyara) to completely unprotected (Logipi, Natron, Eyasi and Bahi Swamp), with Elmenteita being partially protected.  相似文献   

8.
From 1987 until 1995, life-history traits of the Lesser Sheathbill Chionis minor in the Kerguelen Archipelago were compared with those at other localities, where this species breeds in seabird colonies. At Kerguelen Island only, some pairs breed on shores free of penguin and cormorant colonies. Moreover, pairs, including nonbreeders, and solitary individuals maintain territories all the year round. Site and mate changes were not linked, and all divorces were permanent. Fidelity rates were similar in all localities and so were the annual survival rates of adults. The survival rate of immature individuals was highest at Kerguelen Island, where sheathbills laid smaller clutches, produced fewer fledglings and had lower breeding success than in the other islands. At Kerguelen Island, pairs breeding on shores had similar clutch sizes but fledged fewer offspring than those breeding in seabird colonies. Further, the proportion of vacant territories and nonbreeders was higher on shores. Kerguelen sheathbills devoted less time to food acquisition than those on Marion Island, being exceptionally kleptoparasitic, and spent a smaller part of their foraging time exploiting seabird colonies. Their diet was mainly algae. The differences on Kerguelen Island as compared with other localities were caused by the presence of an extensive intertidal zone on the former, which reduced competition, making many more sites suitable and the environment more predictable. These life-history and behavioural traits are discussed in relation to life-history theory. As differences were also found, although less extensive, within the Kerguelen Archipelago, we suggest that some traits represent an adaptive response to external constraints and that the life-history strategy of the Lesser Sheathbill is particularly opportunistic.  相似文献   

9.
When individuals have the opportunity to invest in offspring or siblings who are equally closely related and helpless, they should invest in offspring. Two reasons are proposed. Both depend ultimately on the fact that if Ego invests in kin other individuals may not behave in Ego's best interest.  相似文献   

10.
11.
In this study the removal of arsenic by the Water Hyacinth (Eichhornia crassipes) and Lesser Duckweed (Lemna minor) was monitored under a concentration of 0.15mgL(-1) of the element. Plant densities were 1kg/m2 for Lesser Duckweed and 4kg/m2 for Water Hyacinth on a wet basis. The arsenic was determined in foliar tissue and water samples by hydride generation atomic absorption spectroscopy. The element was monitored as a function of time during 21 days. No significant differences were found in the bioaccumulation capability of both species. The removal rate for L. minor was 140mg As/had with a removal recovery of 5%. The Water Hyacinth had a removal rate of 600mg As/had and a removal recovery of 18%, under the conditions of the assay. The removal efficiency of Water Hyacinth was higher due to the biomass production and the more favorable climatic conditions. This specie represents a reliable alternative for arsenic bioremediation in waters.  相似文献   

12.
Due to the great number of greater flamingos in captivity and their long life span, studying their behavior and welfare might be useful to improve the husbandry and breeding of this species in zoos. This study aimed to investigate factors affecting the breeding activity of captive greater flamingos (Phoenicopterus roseus) from 2012 to 2016. To estimate reproductive success, the number of pairs, eggs laid, and hatchlings were recorded. In addition, information on age, egg-laying history of the partners, and pair composition was collected. An increase in the number of pairs, eggs, and hatchlings was reported over the years. For each breeding season, there were pairs who laid more than once, especially in 2014 and 2015. Approximately 50% of pairs were monogamous between consecutive years; however, the percentage dropped gradually when comparing nonconsecutive years. Senescence and previous experience seemed to affect the reproductive success of the study flamingos. In conclusion, different factors can influence the reproduction of greater flamingos in zoos. All these factors are related to nonhuman animal welfare and need to be considered in developing and improving management practices.  相似文献   

13.
The sexes’ share in parental care and the social mating system in a marked population of the single‐brooded Lesser Spotted Woodpecker Dendrocopos minor were studied in 17 woodpecker territories in southern Sweden during 10 years. The birds showed a very strong mate fidelity between years; the divorce rate was 3.4%. In monogamous pairs, the male provided more parental care than the female. The male did most of the nest building and all incubation and brooding at night. Daytime incubation and brooding were shared equally by the sexes, and biparental care at these early breeding stages is probably necessary for successful breeding. In 42% of the nests, however, though still alive the female deserted the brood the last week of the nestling period, whereas the male invariably fed until fledging and fully compensated for the absent female. Post‐fledging care could not be quantified, but was likely shared by both parents. Females who ceased feeding at the late nestling stage resumed care after fledging. We argue that the high premium on breeding with the same mate for consecutive years and the overall lower survival of females have shaped this male‐biased organisation of parental care. In the six years with best data, most social matings were monogamous, but 8.5% of the females (N=59) exhibited simultaneous multi‐nest (classical) polyandry and 2.9% of the males (N=68) exhibited multi‐nest polygyny. Polyandrous females raised 39% more young than monogamous pairs. These females invested equal amounts of parental care at all their nests, but their investment at each nest was lower than that of monogamous females. The polyandrously mated males fully compensated for this lower female investment. Polygynous males invested mainly in their primary nest and appeared to be less successful than polyandrous females. Polyandry and polygyny occurred only when the population sex ratio was biased, and due to strong intra‐sexual competition this is likely a prerequisite for polygamous mating in Lesser Spotted Woodpeckers.  相似文献   

14.
Summary The Lesser Sheathbill Chionis minor is an opportunistic predator and scavenger that breeds on sub-Antarctic islands during the summer season, when many other seabirds are present, especially penguins on which it is kleptoparasitic. It is a poor flyer and over-winters on its breeding grounds, where it faces a diminished food supply and low temperatures. Its foraging behaviour was suspected to be plastic enough to respond to such a variable environment, and we show how this species enlarged its niche to survive in winter. Population movements, dietary changes and monthly weight gains were quantified during a 13-month period of observation. Mortality rates, calculated over a 19-year period of banding, appeared to be age dependent: they decrease, due to competition, from juveniles to subadults, adult non-breeders, and breeders. One of the survival strategies described here is, to our knowledge, unique among birds. After the Crested Penguin colonies have been deserted, some adult sheathbills (mainly females) remained territorial, extending their territory size and diet while their partners moved to previously undefended zones in King Penguin colonies (permanent and large in the Crozet archipelago), where they competed for a winter territory and subsequently associated with another mate. After this winter mating, mobile sheathbills returned the following summer to their breeding territory and previous mate.  相似文献   

15.
We studied movements of individually marked greater flamingos (Phoenicopterus ruber roseus) born in the Camargue, southern France, between their two most important breeding colonies in the western Mediterranean (Camargue and Fuente de Piedra, Spain) from 1986 to 1992. The two sites differ in the frequency with which they offer suitable conditions for breeding. Flamingos have bred each year in the Camargue since 1974, but in only 12 of the past 22 years at Fuente de Piedra. Higher colony fidelity is thus expected in the less variable environment (Camargue), but if dispersal occurs competition might be an important factor causing this dispersal. Following years during which breeding birds in the Camrgue were disturbed (1988 and 1990) a higher proportion of adults changed colonies between breeding attempts (= breeding dispersal, 12.4%), while only 0.4% of flamingos breeding in the Camargue dispersed in the other years. As expected, flamingos breeding at Fuente de Piedra showed a higher rate of breeding dispersal (8.14%). No differences were observed between males and females. The importance of breeding failure as a factor causing breeding dispersal in flamingos was also confirmed by the movements of individual birds. The proportion of young flamingos that moved from their natal colony to start breeding at Fuente de Piedra (= natal dispersal) was independent of sex and age, but increased when breeding access to the Camargue colony was more difficult. However, natal dispersal was also higher in 1988 and 1990 (40.5%) than in the remaining years (1.2%), as was breeding dispersal. We discuss possible ways in which the increased natal dispersal among inexperienced birds could be linked with the increased breeding dispersal of adults in the same year.  相似文献   

16.
17.
18.
In three flamingos (Phoenicopterus ruber), which died showing extensive necrotic inflammation of the skin of the webs and the legs, the presence of abundant mycelium and arthrospores was shown in the altered dermis and epidermis. From all the lesions Geotrichum Candidum was isolated in pure culture. Inoculation of suspensions of the fungus into domestic chickens and mice produced granulomas or more purulent nodules with central growth of abundant mycelium. From 20 of 28 experimental animals, G. candidum was reisolated from the lesions in pure culture 2 weeks after the inoculation. It is suggested that alteration of the skin by e.g., prolonged contact with pondwater, the presence of small wounds and the advanced age of the birds, acting as predisposing factors may be necessary in establishing this disease.  相似文献   

19.
The maintenance of fallows has been shown to prevent the loss of farmland biodiversity caused by agricultural intensification. These are mainly introduced as part of both obligatory and voluntary set-aside schemes. However, the obligatory set-aside has recently been abolished by the Common Agricultural Policy Health Check. In this study, we examine the role of fallow in fine-grained habitat use by a threatened farmland bird (Lesser Kestrel) during summer in northwestern Spain. To analyze Lesser Kestrel occurrence, we used generalized linear models, a theoretic-information approach and a hierarchical partitioning analysis. The best AIC-based models explaining occurrence of Lesser Kestrels showed that fallow was the more important habitat type followed, to a lesser extent, by dry cereal stubble and field margin. In contrast, irrigated crops negatively influenced occurrence. Heterogeneity of crop mosaic was not important in explaining occurrence of Lesser Kestrel. Fallows, like dry cereal stubbles and field margins, seem to be suitable for foraging given the abundance of high food resources and their availability due to shorter vegetation cover. The abolition of the obligatory set-aside could reduce the total surface of fallow land (approximately 40.9%), likely affecting habitat use by Lesser Kestrel through an increase of other non-preferred crops (e.g., irrigated crops) or by decreasing food resources. Agri-environment schemes focusing on the maintenance of low-intensive farming systems with a mosaic of crops and semi-natural habitats interspersed should be promoted in premigratory areas to maintain Lesser Kestrel.  相似文献   

20.
The time associated with speciation varies dramatically among lower vertebrates. The nature and timing of divergence is investigated in the fantastic dwarf gecko Sphaerodactylus fantasticus complex, a nominal species that occurs on the central Lesser Antillean island of Guadeloupe and adjacent islands and islets. This is compared to the divergence in the sympatric anole clade from the Anolis bimaculatus group. A molecular phylogenetic analysis of numerous gecko populations from across these islands, based on three mitochondrial DNA genes, reveals several monophyletic groups occupying distinct geographical areas, these being Les Saintes, western Basse Terre plus Dominica, eastern Basse Terre, Grand Terre, and the northern and eastern islands (Montserrat, Marie Galante, Petite Terre, Desirade). Although part of the same nominal species, the molecular divergence within this species complex is extraordinarily high (27% patristic distance between the most divergent lineages) and is compatible with this group occupying the region long before the origin of the younger island arc. Tests show that several quantitative morphological traits are correlated with the phylogeny, but in general the lineages are not uniquely defined by these traits. The dwarf geckos show notably less nominal species-level adaptive radiation than that found in the sympatric southern clade of Anolis bimculatus , although both appear to have occupied the region for a broadly similar period of time. Nevertheless, the dwarf gecko populations on Les Saintes islets are the most morphologically distinct and are recognized as a full species ( Sphaerodactylus phyzacinus ), as are anoles on Les Saintes ( Anolis terraealtae ).  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