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1.
Ground-feeding birds are considered important in the epidemiology of Toxoplasma gondii because they serve as indicators of soil contamination by oocysts, and birds of prey are indicators of T. gondii prevalence in rodents and other small mammals. Cats excrete environmentally resistant oocysts after consuming tissues of T. gondii -infected birds. In the present study, sera and tissues from 382 wild birds from Colorado were tested for T. gondii infection. Antibodies to T. gondii were found in 38 birds with the use of the modified agglutination test (MAT, 1∶25 titer). Tissues (brains, hearts) of 84 birds were bioassayed in mice. Viable T. gondii was isolated from 1 of 1 barn owl (Tyto alba), 1 of 5 American kestrels (Falco sparverius), 1 of 7 ferruginous hawks (Buteo regalis), 1 of 4 rough-legged hawks (Buteo lagopus), 2 of 13 Swainson's hawks (Buteo swainsoni), and 1 of 25 red-tailed hawks (Buteo jamaicensis). This is the first time T. gondii has been isolated from the barn owl, ferruginous hawk, rough-legged hawk, and Swainson's hawk.  相似文献   

2.
Prevalence of Toxoplasma gondii in raptors from France   总被引:1,自引:0,他引:1  
Little is known about the prevalence or importance of Toxoplasma gondii infections in raptors. Sera from Eurasian Buzzards (Buteo buteo, n=14), Tawny Owls (Strix aluco, n=12), Barn Owls (Tyto alba, n=18), Eurasian Sparrowhawk (Accipiter nisus, n=1), and Common Kestrels (Falco tinnunculus, n=8) were examined for agglutinating antibodies using the modified agglutination test at 1:25 dilution. Antibodies were not detected in Common Kestrels and the Eurasian Sparrowhawk but were detected in 11 Eurasian Buzzards (79%), six Tawny Owls (50%), and two Barn Owls (11%). Toxoplasma gondii, genotype II, was isolated from the brain of an adult Tawny Owl.  相似文献   

3.
There is a lack of information concerning the prevalence of Toxoplasma gondii infection in wild birds in Mexico. In the present study, serum samples and tissues from 653 birds from Durango State, Mexico, were evaluated for T. gondii infection. Antibodies to T. gondii (modified agglutination test, titer 1∶25 or higher) were found in 17 (2.6%) of the 653 birds, including 1 of 2 curve-billed thrashers (Toxostoma curvirostre), 2 (1 Anas platyrhynchos, 1 Anas diazi) of 4 ducks, 1 of 2 eagles (Aquila sp.), 5 (27.8%) of 18 great-tailed grackles (Quiscalus mexicanus), 7 (1.3%) of 521 rock pigeons (Columba livia), and 1 (14.3%) of 7 quail (Coturnix coturnix). The seroprevalence of T. gondii infection in birds captured in a park outside the city zoo (11.6%, 8/69) was significantly higher than that found in birds from other regions (1.5%, 9/584, OR = 8.38; 95% CI: 2.82-24.77; P = 0.0001). Brains and hearts of 23 birds (17 seropositive, 6 seronegative) were bioassayed in mice for the isolation of T. gondii . Viable T. gondii was isolated from 1 of 7 seropositive pigeons. The DNA obtained from the T. gondii isolate from the pigeon was genotyped using the PCR-RFLP typing using 11 markers (B1, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) and revealed an atypical genotype. This is the first report of T. gondii infection in great-tailed grackles, the Mexican duck, and curved-billed thrashers and the first survey of wild birds in Mexico.  相似文献   

4.
Electrocution by power lines is one of the main causes of non-natural mortality in birds of prey. In an area in central Spain, we surveyed 6304 pylons from 333 power lines to determine electrocution rates, environmental and design factors that may influence electrocution and the efficacy of mitigation measures used to minimise electrocution cases. A total of 952 electrocuted raptors, representing 14 different species, were observed. Electrocuted raptors were concentrated in certain areas and the environmental factors associated with increased electrocution events were: greater numbers of prey animals; greater vegetation cover; and shorter distance to roads. The structural elements associated with electrocutions were shorter strings of insulators, one or more phases over the crossarm, cross-shaped design and pylon function. Of the 952 carcasses found, 148 were eagles, including golden eagle (Aquila chrysaetos), Spanish imperial eagle (Aquila adalberti) and Bonelli's eagle (Aquila fasciata). Electrocuted eagles were clustered in smaller areas than other electrocuted raptors. The factors associated with increased eagle electrocution events were: pylons function, shorter strings of insulators, higher slopes surrounding the pylon, and more numerous potential prey animals. Pylons with increased string of insulators had lower raptor electrocution rates than unimproved pylons, although this technique was unsuccessful for eagles. Pylons with cable insulation showed higher electrocution rates than unimproved pylons, both for raptors and eagles, despite this is the most widely used and recommended mitigation measure in several countries. To optimize the application of mitigation measures, our results recommend the substitution of pin-type insulators to suspended ones and elongating the strings of insulators.  相似文献   

5.
JEAN-MARC THIOLLAY 《Ibis》2006,148(2):240-254
Comparative large‐scale roadside counts (8353 km), through Burkina Faso, Mali and Niger, conducted in 1969–73, were repeated 30–35 years later with the same observer and methodology and at the same season. The transect was divided into three geographical zones and between protected and unprotected areas. All diurnal raptors were recorded (22 801 individuals), as well as large game birds. Large vultures suffered a dramatic decline (98%) outside protected areas. The Hooded Vulture Necrosyrtes monachus population also collapsed in some regions, but survived in central Burkina Faso. Conversely, their abundance index did not decrease significantly in national parks. Four eagle species decreased by 86–93% and seven were not even recorded in the later study outside protected areas; by contrast, in national parks, only three species had declined marginally. Smaller Accipitridae (kites, goshawks, buzzards) also exhibited significant declines outside but not within national parks where woodland species reached their highest densities. The Common Kestrel Falco tinnunculus, mostly European migrants, declined sharply everywhere. African falcons decreased only outside protected areas. Among Palearctic migrants, Montagu's Circus pygargus and Pallid Harriers C. macrourus decreased significantly, Short‐toed Eagle Circaetus gallicus less markedly, and Marsh Harrier Circus aeruginosus and Booted Eagle Hieraaetus pennatus not at all. Similar trends had previously been documented in Cameroon. They are associated with human population growth and development, global habitat degradation and ecosystem impoverishment (woodcutting, agricultural intensification, overgrazing, desertification). Heavy use of pesticides, control of locust outbreaks and overhunting have suppressed major food sources. Vultures may suffer from a shortage of carcasses, poisoning for predator control or persecution for trade of meat and body parts. Protected areas play a prominent role in the maintenance of vulture and eagle populations, even though they currently cover less than 2% of the Sudan zone and are virtually absent in the Sahel.  相似文献   

6.
Potential factors influencing spermatozoa survival to cryopreservation and thawing were analyzed across a range of the following avian species: domestic chicken (Gallus domesticus), domestic turkey (Meleagris gallopavo), golden eagle (Aquila chrysaetos), Bonelli's eagle (Hieraaetus fasciatus), imperial eagle (Aquila adalberti), and peregrine falcon (Falco peregrinus). Studies focused on spermatozoa tolerance to the following: 1) osmotic stress, 2) different extracellular concentrations of the cryoprotectant dimethylacetamide (DMA), 3) equilibration times of 1 versus 4 h, 4) equilibration temperature of 4 versus 21 degrees C, and 5) rapid versus slow cooling before cryopreservation and standard thawing. Sperm viability was assessed with the live/dead stain (SYBR-14/propidium iodine). Sperm viability at osmolalities >/=800 mOsm was higher (P: < 0.05) in raptor than poultry semen. Return to isotonicity after exposure to hypertonicity (3000 mOsm) decreased (P: < 0.05) number of viable spermatozoa in chicken, turkey, and golden and Bonelli's eagle spermatozoa but not in imperial eagle or peregrine falcon spermatozoa. Differences were found in spermatozoa resistance to hypotonic conditions, with eagle species demonstrating the most tolerance. Semen, equilibrated for 1 h (4 degrees C) in diluent containing DMA (> or =2.06 M), experienced decreased (P: < 0. 05) spermatozoa survival in all species, except the golden eagle and peregrine falcon. Number of surviving spermatozoa diminished progressively with increasing DMA concentrations in all species. Increased equilibration temperature (from 4 to 21 degrees C) markedly reduced (P: < 0.05) spermatozoa survival in all species except the Bonelli's eagle and turkey. Rapid cooling was detrimental (P: < 0.05) to spermatozoa from all species except the imperial eagle and the chicken. These results demonstrate that avian spermatozoa differ remarkably in response to osmotic changes, DMA concentrations, equilibration time, temperature, and survival after fast or slow freezing. These differences emphasize the need for species-specific studies in the development and enhancement of assisted breeding for poultry and endangered species.  相似文献   

7.
为了解红角鸮(Otus scops)的繁殖状态,2009年5~8月,在内蒙古赛罕乌拉国家级自然保护区,以直接观察法对红角鸮的繁殖生态进行了研究。结果表明,所观察的4个巢址全部是以柳树为主干的树洞巢,巢内铺垫物较少或无铺垫,巢距地面的平均高度为91.3cm,巢内径平均为13.5cm,巢外径平均为15.0cm,巢深平均32.0cm(n=4)。平均窝卵数为3.75,对其中一窝进行测量,4枚卵平均量度是28.9mm×24.6mm,重量9.5g。雏鸟孵出后,雌性亲鸟承担主要育雏任务,雄性亲鸟日间停歇于离巢不远的树上负责警戒工作,夜间与雌鸟共同哺育雏鸟。小型鼬科动物的捕食可能是干扰红角鸮繁殖成功率的主要因素。  相似文献   

8.
We compared helminth communities in 6 species of birds of prey from the Calabria region of southern Italy. In total, 31 helminth taxa, including 17 nematodes, 9 digeneans, 3 acanthocephalans, and 2 cestodes, were found. All helminth species were observed in the gastrointestinal tract, except for 3 spirurid nematodes. Most of the parasite species were detected in at least 2 hosts, but 13 helminth species were found in only 1 host. At the infracommunity level, the overall species richness and Brillouin's index of diversity varied by host, with the highest values in a generalist feeder, the Eurasian buzzard (Buteo buteo), and the lowest in a specialist, the western honey buzzard (Pernis apivorus). Species richness was gender dependent only in the sparrow hawk (Accipiter nisus). The helminth communities were characterized by different dominant species, namely, Centrorhynchus spp. (Acanthocephala) in the Eurasian buzzard and common kestrel (Falco tinnunculus), Parastrigea intermedia (Digenea) in the marsh harrier (Circus aeruginosus), Physaloptera alata (Nematoda) in the sparrow hawk, Serratospiculum tendo (Nematoda) in the peregrine falcon (Falco peregrinus), and Strigea falconis (Digenea) in the western honey buzzard. Statistical analyses confirmed a highly significant difference of helminth infracommunity structure among host species. We conclude that in the Calabria region of southern Italy, each of the raptor species studied is distinct in terms of its helminth communities, and more diverse feeding habits of the host correspond with richer helminth communities.  相似文献   

9.
We compared the helminth communities of 5 owl species from Calabria (Italy) and evaluated the effect of phylogenetic and ecological factors on community structure. Two host taxonomic scales were considered, i.e., owl species, and owls vs. birds of prey. The latter scale was dealt with by comparing the data here obtained with that of birds of prey from the same locality and with those published previously on owls and birds of prey from Galicia (Spain). A total of 19 helminth taxa were found in owls from Calabria. Statistical comparison showed only marginal differences between scops owls (Otus scops) and little owls (Athene noctua) and tawny owls (Strix aluco). It would indicate that all owl species are exposed to a common pool of ‘owl generalist’ helminth taxa, with quantitative differences being determined by differences in diet within a range of prey relatively narrow. In contrast, birds of prey from the same region exhibited strong differences because they feed on different and wider spectra of prey. In Calabria, owls can be separated as a whole from birds of prey with regard to the structure of their helminth communities while in Galicia helminths of owls represent a subset of those of birds of prey. This difference is related to the occurrence in Calabria, but not Galicia, of a pool of ‘owl specialist’ species. The wide geographical occurrence of these taxa suggest that local conditions may determine fundamental differences in the composition of local communities. Finally, in both Calabria and Galicia, helminth communities from owls were species-poor compared to those from sympatric birds of prey. However, birds of prey appear to share a greater pool of specific helmith taxa derived from cospeciation processes, and a greater potential exchange of parasites between them than with owls because of phylogenetic closeness.  相似文献   

10.
报道寄生于北京猛禽的2种旋尾类线虫,其中一种为新种,另一种为中国新纪录种。作者分别对其做了光镜和电镜观察。北京副旋翼线虫,新种Paraspiralatus beijingensis sp.nov.采自于雕鸮的口腔和胃内,它与P. sakeri Gibbons,Nicholls &Bailey,2004的不同之处在于具有单个的肛前乳突,右交合刺远末端弯向背侧并稍微膨大而P. sakeri的交合刺远末端是直的,不膨大,呈钝尖形。纵纹腹小鸮无肛线虫Aprocta noctuae Spaul,1928采自红角鸮的体腔。本次所观察标本在形态上,如交合刺的长短和形状,尾乳突的数目和排列,阴门的位置,卵的大小等,都与前人对A. noctuae的描述一致。但是电子扫描电镜结果显示,A. noctuae的头端具有8个头乳突而不是4个,线虫角质层具有精细的横纹。A. noctuae为我国新纪录种。标本保存于河北师范大学生命科学学院。  相似文献   

11.
Soaring birds migrate in massive numbers worldwide. These migrations are complex and dynamic phenomena, strongly influenced by meteorological conditions that produce thermal and orographic uplift as the birds traverse the landscape. Herein we report on how methods were developed to estimate the strength of thermal and orographic uplift using publicly available digital weather and topography datasets at continental scale. We apply these methods to contrast flight strategies of two morphologically similar but behaviourally different species: golden eagle, Aquila chrysaetos, and turkey vulture, Cathartes aura, during autumn migration across eastern North America tracked using GPS tags. We show that turkey vultures nearly exclusively used thermal lift, whereas golden eagles primarily use orographic lift during migration. It has not been shown previously that migration tracks are affected by species-specific specialisation to a particular uplift mode. The methods introduced herein to estimate uplift components and test for differences in weather use can be applied to study movement of any soaring species.  相似文献   

12.
Prevalence of anthrax spores in feces of raptors was determined from samples collected in November-December 2000 and April-May 2001 in an agricultural region of Santa Fé province, Argentina. Feces were tested from 48 birds of six raptor species. One of 14 chimango caracaras (Milvago chimango) and one of eight road-side hawks (Buteo magnirostris) tested positive. The prevalence of Bacillus anthracis spores in feces for the six species was 4% (n=48). The prevalence was 7% (n=14) for chimango caracaras, 13% for road-side hawks (n=8), and 0% for the remaining species (Burrowing owl [Speotyto cunicularia] [n=17], Swainson's hawk [Buteo swainsoni] [n=3], Aplomado falcon [Falco femoralis] [n=2], and American kestrel [Falco sparverius] [n=4]). Grouped by their feeding habits, prevalence for scavenger species was not significantly different than for predators (7% vs. 3%, P>0.999). This study provides evidence that in central Argentina scavenger and non-scavenger raptors may have a role in the epidemiology of anthrax. Long-term studies to determine the extent of this potential involvement in the epidemiology of anthrax in central Argentina are required.  相似文献   

13.
The short-eared owl (Asia flammeus), which lives in open wetland habitats, has been threatened and become endangered in South Korea due to the destruction and loss of its habitats. However, the diet of the short-eared owl remains to be studied. The prey of the short-eared owl was monitored using molecular methods as an alternative tool. A total of 121 pellets of the species were collected in the Dalsung wetland. Of these pellets, about 30% (n = 33) were selected for prey identification in 2002 (n = 12), 2003 (n = 6) and 2006 (n = 15). Two hundred and thirty-two bone fragments were successfully analyzed and 9 prey species were detected. In an expanded analysis, excluding 4 pellets used for the preliminary analysis, small mammals constituted the highest percentage (89.1%): 47.6% Eurasian field mouse (Apodemus agrarius); 27.2% European harvest mouse (Micromys minutus); 6.1% Japanese wild house mouse (Mus musculus); 5.4% Asian lesser white-toothed shrew (Crocidura shantungensis); and 2.7% Norway rat (Battus norvegicus). Not only small mammals, but birds and amphibians were also identified: 4.1% Japanese quail (Cotumix japonica); 3.4% vinous-throated parrotbill (Paradoxornis webbianus); 0.7% eastern turtle dove (Streptopelia orientalis); and 2.7% Kori salamander (Hynobius yangi). This result would be valuable in understanding the feeding ecology of the short-eared owl in its wetland habitats.  相似文献   

14.
Few studies have investigated the role of raptors as natural reservoirs of Chlamydiaceae spp. and the preferred anatomical sites where these bacteria can be detected in non-symptomatic wild birds. We investigated the occurrence of Chlamydiaceae in 54 non-symptomatic adult free-living birds belonging to 14 species sampled upon reception in a raptor rehabilitation centre in Spain, and ten juvenile birds from five species born and reared in the centre for subsequent release into the wild. Swabs from conjunctivae, choanae and cloacae were taken to detect Chlamydiaceae DNA by a family-specific polymerase chain reaction (PCR) and a nested genus- and species-specific PCR. Chlamydiaceae DNA was detected in adult raptors belonging to 12 species (85.7%), mainly in conjunctival (40.6%) and, to a lesser extent, choanal (17.2%) swabs, but never in cloacal samples. Neither the genus nor the species of Chlamydiaceae could be confirmed by the nested PCR assay. Our results suggest that most of the raptor species investigated, especially the Common Kestrel (Falco tinnunculus) and Eurasian Griffon Vulture (Gyps fulvus), can be natural reservoirs of Chlamydiaceae spp. in the wild. Failure to identify the organisms at genus and species level might have been due to the poor quality and low concentration of DNA in the samples or to the presence of hitherto unclassified Chlamydiaceae species.  相似文献   

15.
掌握野生动植物本底资源是各级自然保护区生物多样性监测研究和保护管理的重要环节。为了建立龙溪-虹口国家级自然保护区内兽类和鸟类多样性资源的长期监测机制,于2013年9月至2014年11月,我们采用红外相机技术在龙溪沟和虹口峡谷等区域按公里网格布设了57个监测点,调查地面活动的兽类和鸟类。红外相机累计工作达11,847个工作日,共记录到兽类和鸟类物种61种,其中兽类5目12科21种,鸟类3目10科40种,包括猎隼(Falco cherrug)、光背地鸫(Zoothera mollissima)、长尾地鸫(Zoothera dixoni)、灰翅鸫(Turdus boulboul)、锈脸钩嘴鹛(Pomatorhinus erythrogenys)、红嘴鸦雀(Conostoma aemodium)和褐鸦雀(Paradoxornis unicolor)7种鸟类为保护区新记录种。调查到的兽类被列为国家I级和II级重点保护野生动物的分别为4种和5种,被IUCN红色名录评估为“濒危EN”和“易危VU” 的物种各3种,被评为 “近危NT”级别的物种有4种;鸟类被列为国家II级重点保护野生动物的有5种,被IUCN红色名录评估为“濒危EN”的物种有1种。本次调查补充更新了龙溪-虹口自然保护区地栖息鸟类名录,初步了解了保护区内地面活动大中型兽类和鸟类的物种组成和分布,为保护区建立野生动物红外相机常规监测和保护管理提供了基础数据。  相似文献   

16.
Mycoplasmas are well-known avian pathogens of poultry and some passerines. Although reported in birds of prey, their role as pathogens is still unclear. Healthy, free-ranging raptor nestlings sampled during a routine ringing (banding) program, and birds of prey from rehabilitation centers, tested positive for Mycoplasma spp. by culture and a genus-specific polymerase chain reaction (PCR). Given the lack of clinical signs and disease, we suggest that mycoplasmas in raptors may be commensal rather than pathogenic. Using immunobinding assay and species-specific PCR tests, Mycoplasma buteonis, M. falconis, and M. gypis were identified; M. falconis was only detected in falcons. Additionally, some isolates could not be identified. This is the first report of Mycoplasma spp. isolations from Western Marsh Harriers (Circus aeroginosus), a Eurasian Hobby (Falco subbuteo), and a Barn Owl (Tyto alba).  相似文献   

17.
Humans accumulate porphyrins in the body mostly during the course of porphyrias, diseases caused by defects in the enzymes of the heme biosynthesis pathway and that produce acute attacks, skin lesions and liver cancer. In contrast, some wild mammals and birds are adapted to accumulate porphyrins without injurious consequences. Here we propose viewing such physiological adaptations as potential solutions to human porphyrias, and suggest certain wild animals as models. Given the enzymatic activity and/or the patterns of porphyrin excretion and accumulation, the fox squirrel, the great bustard and the Eurasian eagle owl may constitute overlooked models for different porphyrias. The Harderian gland of rodents, where large amounts of porphyrins are synthesized, presents an underexplored potential for understanding the carcinogenic/toxic effect of porphyrin accumulation. Investigating how these animals avoid porphyrin pathogenicity may complement the use of laboratory models for porphyrias and provide new insights into the treatment of these disorders.  相似文献   

18.
Seasonal changes in spatial distribution of search effort of birds that prey on small mammals were studied in two structurally different coniferous forest habitats in the northern boreal zone in SE Norway. During the season with snow cover both the proportion of Microtus relative to that of Clethrionomys in the predators' diet, and their use of a clear-cut relative to that of older forest were lower than during the snow-free season. This was related to a lower relative availability of prey ( Microtus agrestis and M. oeconomus ) in the clear-cut when the ground was snow-covered than when it was snow-free. Based on this local pattern I suggest the following explanation for differences in migratory strategy between raptors that prey on small mammals in Fennoscandian boreal zones: species that migrate to snow-free areas in winter are either adapted to hunt by the energetically expensive method of quartering in open grassland habitats, where prey ( Microtus ) availability is relatively low during periods with snow cover (hen harrier Circus cyaneus , short-eared owl Asio flammeus , and longeared owl A. otus ), or by sit-and-wait in open grassland and forest habitats, the latter with relatively high prey availability during periods with snow cover, but unable to locate concealed prey (kestrel Falco tinnuculus , common buzzard Buteo huteo , and roughlegged buzzard B. lagopus ). In contrast, species that remain in areas with permanent snow cover during winter use the energetically cheap sit-and-wait tactic, and are able to hunt in closed forest habitat and localize concealed prey (the remaining owl species). Interspecific differences in prey availability as determined by hunting habitat and hunting mode is probably more important in shaping the migration patterns of Fennoscandian owls than is nest site availability.  相似文献   

19.
Since the early 1990s, large and rapid population declines of three species of vulture ( Gyps spp.) endemic to south Asia have occurred on the Indian subcontinent and have led to these species being listed by IUCN as critically endangered. Evidence of rates of population decline, cause of death and toxicity is consistent with these declines being caused by poisoning of vultures through the ingestion of tissues from livestock treated with the anti-inflammatory drug diclofenac. In this paper, analysis of repeated surveys in and near protected areas widely spread across India shows that populations of two other vulture species, Egyptian vulture Neophron percnopterus and red-headed vulture Sarcogyps calvus , have also declined markedly and rapidly, but probably with a later onset than Gyps vultures in the same region. The declines continued at least up to 2003. It is recommended that these two species are considered for inclusion in the IUCN Red List and for urgent remedial conservation measures. Research is needed to determine whether or not the principal cause of these declines is diclofenac poisoning and to establish population trends in other scavenging birds in the Indian subcontinent.  相似文献   

20.
Organ samples from free-living raptors from the federal states of Berlin and Brandenburg in eastern Germany were tested for Newcastle disease virus (NDV; n = 331) and Chlamydia psittaci (n = 39) by polymerase chain reaction (PCR). In 18 individuals NDV nucleic acids were detected. These samples originated from barn owls (Tyto alba; n = 15, 28%), tawny owl (Strix aluco; n = 1, 5%), common buzzard (Buteo buteo, n = 1, 1%), and European kestrel (Falco tinnunculus; n = 1, 4%). In 29 (74%) of 39 samples C. psittaci was detected. Chlamydia psittaci is common in free-living birds of prey in the investigated area.  相似文献   

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