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1.
We aimed to examine whether habitat preferences of raccoon dogs Nyctereutes procyonoides and badgers Meles meles can be revealed by using a non-invasive method, latrine surveys. We searched for latrines of these carnivores with scat detection dogs in SW Finland. We compared the results of latrine surveys with the results of a radio-tracking study conducted simultaneously in the same area. Our results showed that latrine surveys and radio-tracking gave fairly similar results: both methods revealed that raccoon dogs favoured deciduous forests, open woodland and reed beds but avoided fields, and badgers favoured deciduous and pine forests but avoided fields, gardens and reed beds. Latrines of both species were often located in the core areas but also along home range borders. Latrine survey revealed possible competition for space between the native badgers and alien raccoon dogs. Latrine survey is a non-invasive method, which gives accurate location points of animals. It could be developed further by combining it with bait-marking and by training the dogs to show us other signs of animals besides latrines.  相似文献   

2.
Diets of raccoon dog, red fox and badger were studied in southern Finland from 1990 to 1996 by collecting faeces from dens and latrines during May-July of each year. The frequency of occurrence and relative volume of each food item in the faeces were calculated. The raccoon dog was the most and the red fox the least omnivorous of these carnivores, according to the diversity index. Diet composition of all these species varied among areas, indicating that they are opportunistic feeders. Mammals and birds constituted the bulk of the fox diet, while invertebrates, frogs and plants were most frequently eaten by the badger. The frequency of earthworms in badger faeces varied between 16 and 77%, according to area. Voles and shrews were important to the raccoon dog, but it also frequently consumed other food items. The food niches of the badger and the raccoon dog overlapped more than that of the red fox and other species. The red fox was more carnivorous and fed on larger prey items than the others, but the food composition of the red fox in the present study reflects the prey carried to the den for the pups; thus, the diet of adult foxes may be more similar to that of the raccoon dog. In conclusion, these 3 carnivores share many resources, suggesting that competition may occur among them: however, their diets also differ to some extent, which helps them to avoid competition. Furthermore, the badger and the raccoon dog are dormant during winter, when food is scarcest, which may be the reason why all these species can coexist in rather unproductive boreal forests.  相似文献   

3.
The impact of landscape and habitat diversity on diets of invasive and native species is an important issue when planning management or conservation of wildlife. The aim of the present study was to examine the impact of the environment on the diets of invasive raccoon dogs Nyctereutes procyonoides and native badgers Meles meles in two spatial scales in southern Finland. We studied the relationship between habitat diversity and diet in several study areas in southern Finland (landscape scale) and the relationship between diet and different habitat patches around latrine sites in one study area (local scale). Diets of both species differed between the study areas. The higher was the diversity of habitats in the landscape, the higher was the diversity of diet. Diversity of diet of omnivorous carnivores may thus be used as an indicator of habitat diversity. Also, the higher was the proportion of gardens, the higher was the diversity of raccoon dog diet. Raccoon dog diet was in all areas more diverse than badger diet. Overlap of diets was the smallest in the most diverse area and highest in a managed area with fields and industrial forests. In local scale, positive relationships between habitat types and raccoon dog diet included those between birds and gardens, small mammals and spruce forest and meadows, and frogs and gardens and deciduous forests. The models for badgers included those between birds and reed beds, frogs and deciduous forests, and cereal and earthworms and fields.  相似文献   

4.
Monogamous canid home range size is often negatively correlated with population density. Home range size, in turn, may be affected by the habitat. Here we examined landscape features that may affect home range size of the invasive raccoon dogNyctereutes procyonoides (Gray, 1834), an important vector of diseases and parasites in Europe. The aim was thus to reveal the habitats where population density and the risk for epizootics is highest. We radio tracked 42 raccoon dogs in three areas in southern Finland between 2001 and 2007. There was an inverse relationship between home range size and the proportions of meadows and gardens, as well as habitat richness. Also mixed forests were more common in areas where home ranges were small. The risk for epizootics, such as rabies, is thus highest in areas which constitute of a mosaic of small patches of meadows, gardens and mixed forests. The preventive measures, such as bait vaccinations, against epizootics should therefore be concentrated in these areas which are mainly in and around villages.  相似文献   

5.
Abstract: Although domestic animal transmission of rabies has largely been mitigated, the disease remains a concern in both Europe and North America where wildlife transmission has caused epizootics. Raccoon (Procyon lotor) rabies was established in Alabama, USA, in 1975, primarily in the southeastern corner of the state. However, with the exception of isolated events, rabies has not continued to spread westward across the Alabama River. We monitored movements of 100 radiocollared raccoons on 2 sites within hardwood and agriculture habitats in a rabies enzootic area east of the Alabama River, in managed pine habitat area west of the river where rabies sporadically occurs, and in a mixed pine hardwood area outside of the known rabies enzootic area to determine if raccoon movements and habitat use in certain habitat types and the presence of a river may serve as natural barriers preventing the western spread of rabies in Alabama. We also examined raccoon contact rates to determine if they influence disease transmission through static and dynamic interactions. Raccoons in mixed pine-hardwood forest habitats had smaller home ranges and less overlap of ranges compared to the other 3 habitats. However, static interactions between habitats in the use of overlap areas did not differ (F11,129 = 1.63, P = 0.09). Rabies antibody titers were highest in the managed pine habitat (28%) even prior to oral vaccine bait distributions in spring of 2004 and 2005. Biomarker data from radiocollared and additional raccoons captured after the bait distribution west of the Alabama River demonstrated a low efficacy of the vaccine reaching the small southern raccoons. The combination of the river as a partial barrier, the high percentage of pine forested habitat west of the river, and limited spatial movements of raccoons within these forested habitats appears to have reduced the likelihood of rabies establishing west of the river. Understanding different host-habitat- disease systems is important for successful management of diseases. Based on our results, we recommend that the oral vaccine program continue to use the Alabama River as a partial barrier and baiting be concentrated in the fragmented bottomland hardwood forests and around larger bodies of water where raccoon densities are highest. Success of baiting strategies designed to take advantage of northern raccoon dynamics and habitat use may not be applicable to southern populations.  相似文献   

6.
Pulsatilla patens (L.) Mill. (Ranunculaceae) is a threatened plant which in Fennoscandia favours south-facing, warm slopes of pine-dominated esker forests. The cessation of cattle grazing, modern forestry practices, and especially efficient fire prevention have resulted in closure of undergrowth vegetation in these forests. Using generalized linear models (GLM), we studied the relationships between habitat factors (covers of field and ground layer and amount of litter) and the population structure of P. patens in 48 populations in Finland in order to identify favourable conditions for regeneration. The largest populations occurred at sites with intermediate values of both ground and field layer. The number of juvenile plants was also highest at intermediate values of ground layer. Dense moss layer and abundant litter had a negative effect on the flowering of P. patens. In conclusion, creation and maintenance of habitat heterogeneity to prevent the closure of undergrowth vegetation is of paramount importance for the successful reproduction of P. patens.  相似文献   

7.
ABSTRACT Population-level responses of amphibians to forest management regimes are partly dictated by individual behavioral responses to habitat alteration. We examined the short-term (i.e., 24-hr) habitat choices and movement patterns of 3 amphibian species—southern leopard frogs (Rana sphenocephala), marbled salamanders (Ambystoma opacum), and southern toads (Bufo terrestris)—released on edges between forest habitats and recent clear-cuts in the Upper Coastal Plain of South Carolina, USA. We predicted that adult frogs and salamanders would preferentially select forest using environmental cues as indicators of habitat suitability. We also predicted that movement patterns would differ in clear-cuts relative to forests, resulting in lower habitat permeability of clear-cuts for some or all of the species. Using fluorescent powder tracking, we determined that marbled salamanders selected habitat at random, southern toads preferred clear-cuts, and southern leopard frogs initially selected clear-cuts but ultimately preferred forests. Frogs exhibited long-distance, directional movement with few turns. In contrast, toads exhibited wandering behavior and salamanders moved relatively short distances before locating cover. Southern toads and southern leopard frogs moved farther in forests, and all 3 species made more turns in clear-cuts than in forests. Habitat selection by southern toads did not vary according to body size, sex, or the environmental cues we measured. However, marbled salamanders were more likely to enter clear-cuts when soil moisture was high, and southern leopard frogs were more likely to enter clear-cuts when relative humidity and air temperature were higher in the clear-cut than in adjacent forest. Although we found evidence of reduced habitat permeability of clear-cuts for southern leopard frogs and southern toads, none of the species exhibited strong behavioral avoidance of the small (4-ha) clear-cuts in our study. Further studies of long-term habitat use and the potential physiological and other costs to individuals in altered forests are needed to understand the effects of forest management on population persistence. To reduce potentially detrimental effects of clear-cutting on amphibians in the Southeast, wildlife managers should consider the vagility and behavior of species of concern, especially in relation to the size of planned harvests adjacent to breeding sites.  相似文献   

8.
Intensive forest management has caused loss and fragmentation of old‐growth forests and reduced the amount of dead wood throughout northwest Europe. Changes in habitat availability are reflected in occurrence patterns of habitat‐specialist species only after a certain time lag. Here we analyse the responses of wood‐decomposing fungi and saproxylic beetles inhabiting patches of spruce‐swamp forest to habitat quality, loss and isolation at three different spatial scales in eastern Finland and adjacent Russian Karelia, where forestry has been very marginal until recently. Both rare specialist species and common generalist species were included in the study to reveal whether their occurrence patterns differ. Variables describing habitat quality (density and continuity of host trees, patch area) turned out significant in explaining species' incidences (proportion of occupied host trees) in only a few cases, probably because of the relatively high quality of all study patches. Despite this fact, and consistent with our hypothesis, incidences of all the eight specialist species were higher in Russia than Finland, and the difference was significant in the two most strict habitat specialists, Pytho kolwensis and Phlebia centrifuga. In contrast, incidences of three out of four generalist species were higher in Finland than in Russia, and the difference was significant in Rhagium inquisitor. In a subset of 21 patches in Finland, we used a metapopulation model to predict the probability of each patch to be currently occupied by a species given the known spatiotemporal distribution of suitable forest stands during the last 50 years. The degree of isolation alone explained significantly the incidences of five species. However, including habitat variables into the models altered some of the effects. Moreover, inconsistent with our hypothesis, isolation appeared to also negatively affect some very common generalist species. Inclusion of these species in the study disclosed that apparently significant effects of spatiotemporal isolation should be interpreted cautiously.  相似文献   

9.
Data have been compiled on the distribution, habitat preferences and population sizes of 348 vertebrates reproducing in Sweden (excluding fish) and their species richness in different habitats and regions was investigated. Furthermore, we compared the habitat preferences and distribution of rare and common vertebrates. The relative species number (corrected for area) increases from the north (the hemiarctic/boreal zone) to the south (the temperate/hemiboreal zone). The relative number of species in major habitats is highest in farmland, lakes and running waters, and possibly also in the sea. However, the absolute number of species is highest in woodland, the dominant habitat in Sweden (56% of the land area excluding sea). Within woodlands, a large proportion of species occur in southern deciduous forests, in other deciduous forests and in mixed forests, while coniferous forests are less species-rich when the habitat area is taken into account. In farmland, the most species-rich habitats are meadows and forest edges, while marshes are the most species-rich habitats amongst lakes and running waters. Nationally rare species (<1000 individuals) have a smaller European range than common species, and they also have their European distribution centres further to the south than the common species. Of the species occurring in large parts of Sweden (that is, both in the north and the south) a low proportion (4.7%) are classified as rare compared with species occurring mainly in the north (20.6% rare) or mainly in the south (31.6% rare) of Sweden. There is a positive correlation between the number of rare species and the total species number in 41 subcategory habitats, and the proportion of rare species is similar in most habitats. A more detailed analysis (including effects of both regions and habitats) suggests that the proportion of rare species in a region is a result of differences between latitudes, but also of different habitats (when corrected for latitude effects). There are differences in the proportion of rare species between the nine most species-rich orders (for example, there is a high proportion of rare species in the order Carnivora and a low proportion in the order Rodentia), but the proportion of rare species in these orders is not independent of the habitats in which they occur, making it difficult to separate the effects of habitat preferences and taxonomy on rarity. The focusing of conservation work on relatively species-rich habitats in southern and middle Sweden — such as some farmland habitats (that is, meadows and forest edges), marshes (in connection with lakes and running waters) and forests with a relatively high proportion of deciduous trees — is of high priority if the conservation of biodiversity is a main goal. These are also the habitats with a high number of rare and red-listed species.  相似文献   

10.
Many owl species use the same nesting and food resources, which causes strong interspecific competition and spatio-temporal niche separation. We made use of a recent colonisation of Ural Owls (Strix uralensis) in southern Poland to compare habitat preferences of Tawny Owls (Strix aluco) allopatry and sympatry with Ural Owls. We investigated spatial niche segregation of Ural Owl and the Tawny Owl in sympatry and compared habitat preferences of Tawny Owls breeding in allopatry and sympatry. Tawny Owls breeding in sympatry with Ural Owls occupied forests with higher canopy compactness, sites located closer to forest border and to built-up areas, as well as stands with a higher share of fir and spruce and a lower share of beech as compared to sites occupied by Ural Owls. Allopatric Tawny Owls occupied sites with lower canopy compactness and bred at sites located further from forest borders and in stands with lower share of fir and spruce and a higher share of deciduous as compared to sympatric Tawny Owls. As Ural owls are dominant in relation to Tawny Owls, this indicates that the presence of Ural Owls prevents Tawny Owls from occupying deciduous-dominated and old stands located in forest interior areas, far from buildings and forest edges. The results support habitat displacement between the two species when breeding in sympatry. We also show that protection of large forest patches is crucial for the Ural Owl, a species still rare in central Europe, while small patches are occupied by the abundant Tawny Owl.  相似文献   

11.
Invasive mammals include good tree climbers that use tree cavities for resting and nesting. Tree cavities are important but limited resources in most forests; thus, some invasive mammals can be serious competitors for native cavity-using species, especially cavity-nesting birds. Despite the potential impact, such inter-class competition has rarely been considered. We examined the possibility of resource competition for tree cavities between the invasive raccoon Procyon lotor and the native Ural owl Strix uralensis. Both species are nocturnal and use tree cavities during daytime. We assessed an overlap in cavity use for both species as an indication of potential competition by monitoring 341 cavities during their breeding season in a natural park in Hokkaido, Japan. Of 341 potentially available cavities, raccoons and Ural owls used 37 and 32, respectively. The characteristics of 58 cavities used by raccoons or owls were compared to 49 random cavities to determine if they selected cavities with certain characteristics. As predicted from a large amount of tree cavities and a low raccoon density in this managed forest, we did not find direct evidence of competition, such as physical interaction, intrusion to cavities, or habitat segregation. Cavity types used by both species overlapped considerably in terms of height, entrance size, depth, and other characteristics: their habitats were widely overlapped. Further, in four cavities, one species was replaced by the other. Given the similar habitat requirements, the invasive raccoon could be a potential competitor for Ural owl when raccoon density increases and/or cavity availability decreases, which is the case for many forests in Japan. This study suggests that potential threats of resource competition among not only closely but also distantly related taxa should be taken into consideration when studying the impacts of invasive species.  相似文献   

12.
Aim A major floristic and climatic transition from aseasonal to seasonal evergreen tropical forest (the Kangar–Pattani Line; KPL) exists in the Indo‐Sundaic region of Southeast Asia. Mechanisms constraining species distribution here are at present poorly understood, but it is hypothesized that species differ in their tolerances of abiotic factors, in particular water availability. Under this hypothesis, we anticipate differences in performance or habitat preferences, or both, of species differing in distribution with respect to the KPL. The aim of this study is to test whether geographical distributions can be used to explain variation in growth, mortality and habitat preferences in co‐occurring tree species differing in their distribution in relation to the KPL. Location Pasoh Forest Reserve, Negeri Sembilan, Malaysia; south of the KPL. Methods All tree species within a 50‐ha forest dynamics plot were classified as widespread or southern based upon their distributions in relation to the KPL and as habitat specialists or generalists based on spatial association with soil‐based habitat categories. Growth and mortality rates, variation in growth and mortality with respect to soil type, and levels of habitat association were quantified for species with different geographical distributions. Results Differences existed in species performance based upon geographical distributions. Specifically, widespread species had lower growth rates than did species restricted to the aseasonal forests. Mortality rates did not differ as a function of geographical distribution. The growth responses of species to soil habitats also diverged, such that differences in performance of widespread species among soil types were more conservative than those of species restricted in their distribution to the aseasonal forests. However, the proportion of species showing positive habitat associations did not differ significantly between widespread and southern species. Main conclusions Distribution‐based differences in species performance and response to soil type support the hypothesis that species tolerant of wider climatic variation perform less well in any given environment due to limitations on plasticity. These performance differences provide quantitative evidence of the role of climatic transitions in determining tree species distributions in relation to the Kangar–Pattani Line in the Indo‐Malay region. Such differences in performance have important implications for our understanding of biodiversity gradients and responses of Indo‐Sundaic forests to climate change.  相似文献   

13.
Abstract We studied movements of the noctuid moths Xestia speciosa and X. fennica in a fragmented forest landscape including old-growth spruce forest corridors in eastern Finland. We individually marked and released 1,796 adults of the habitat generalist X. speciosa and 683 individuals of X. fennica, which prefers old-growth spruce forests. Moths were recaptured with 60 sugar-bait traps that were placed within habitat corridors, in the non-habitat matrix and in surrounding old-growth forest patches. Both species favoured the corridors during their movements and tended to avoid entering the matrix. We analysed recapture rates and movements of the recaptured moths. Results suggest that X. speciosa moves longer distances than X. fennica. Though corridors clearly canalized movements by both species, the impact of old-growth forest corridors at the larger landscape scale was less clear in X. fennica. Movement behaviour of the two sexes differed more than that of the two species.  相似文献   

14.
Despite the popularity of the saproxylic cerambycid Rosalia alpina as a flagship species, its ecology is still poorly know, especially in the southern part of its range. Detailed information on its habitat preferences is needed to plan appropriate management. We set our multiple spatial scale assessment of habitat preferences in a beech forest of central Italy whose landscape, featuring both unmanaged forest and two types of grazed open forest, allowed us to look at the influence of different land uses. Preferred trees occurred in open sites, and those close to tall undergrowth were avoided. A range of moribund or dead trees were used: those preferred had a lower percentage canopy closure, significantly thicker bark, and were more sun-exposed, than the average. Logistic regression showed that the most important variables for selection were distance from nearest occupied tree, bark thickness, undergrowth height and irradiation. Occurrence likelihood augmented as the distance from nearest other occupied tree increased. Despite being mostly unmanaged, forest was avoided, whereas open forest (with trees pruned by ‘shredding’) was used more than expected. Although intensive forestry limits the availability of dead wood, closed forest may be unsuitable when shadowing useful substrate. The disappearance of traditional forms of forest management as shredding and moderate cattle grazing may lead to woody vegetation expansion and habitat closure eventually threatening the persistence of R. alpina. The return to traditional habitat management would be beneficial to R. alpina, an issue that conservation plans should carefully take it into account.  相似文献   

15.
Pine forest structure in a human-dominated landscape system in Korea   总被引:1,自引:0,他引:1  
To elucidate the characteristics of spatial heterogeneity in a human-dominated landscape, vegetation and community structure of pine (Pinus densiflora andP. rigida) forests were studied at rural Teokseong-ri in Chollanam-do, in the southwestern part of Korea. Daily removal of undergrowth for firewood affects the stratification and species composition in the community. In general, stratification of the pine forest develops in proportion to its distance from the main habitat of farmers, involving the residential and cultivated land. In pine forests near the main habitat of farmers, sun-demanding herbaceous plants grow well, while in remote forests, Fagaceous plants such asQuercus serrata, Q. actissima andCastanea crenata grow well. This zonation results from the fact that removal of undergrowth is greater in the forest near the main habitat of farmers, than in the remote forest. Construction and maintenance of graveyards, however, prevents development of stratification of the forest even in remote stands.  相似文献   

16.
Distribution history and present status of the raccoon dog in Finland   总被引:1,自引:0,他引:1  
The raccoon dog Nyctereutes procyonoides Gray was introduced from the Far East in several areas of the USSR, mainly the European part, in 1929–55. The first raccoon dogs were seen in Finland in the latter half of the 1930s, and by the mid-1950s, the frontier of the first regular observations had reached the most southeasterly parts of the country. Since then, the raccoon dog dispersed through southern and central Finland at an average annual rate of 20 km. The rate of population increase, as well as present density, has been highest in southern and southeastern Finland, and lowest in the northern parts of the distribution area. The northern limit of the distribution lies nowadays in southern Lapland, only a little further north than two decades earlier, when most of southern and central Finland was already inhabited.
The length of the growing season seems to explain most of the variation in the population density between the provinces. The longer the growing season, the better the raccoon dog manages; in southern Finland where the summers are longer, the juveniles have enough time to grow and gather fat reserves before hibernation. Therefore, many of them survive the winter and even breed in the following spring. In the north, in contrast, juvenile mortality is high during the first winter because of the short summer. The food availability, the yield of wild berries and the abundance of small rodents, is mostly responsible for the annual variation in the population density. Near the northern limit of the distribution, climate may also cause some of the annual variation in population density.  相似文献   

17.
Sensitivity of bats to land use change depends on their foraging ecology, which varies among species based on ecomorphological traits. Additionally, because prey availability, vegetative clutter, and temperature change throughout the year, some species may display seasonal shifts in their nocturnal habitat use. In the Coastal Plain of South Carolina, USA, the northern long-eared bat (Myotis septentrionalis), southeastern myotis (Myotis austroriparius), tri-colored bat (Perimyotis subflavus), and northern yellow bat (Lasiurus intermedius) are species of conservation concern that are threatened by habitat loss. Our objective was to identify characteristics of habitat used by these species during their nightly active period and compare use between summer and winter. We conducted acoustic surveys at 125 sites during May–August and at 121 of the same 125 sites December–March 2018 and 2019 in upland forests, bottomland forests, fields, ponds, and salt marsh and used occupancy models to assess habitat use. The northern long-eared bat and southeastern myotis (i.e., myotis bats) used sites that were closer to hardwood stands, pine stands, and fresh water year-round. We did not identify any strong predictors of tri-colored bat habitat use in summer, but during winter they used bottomland forests, fields, and ponds more than salt marsh and upland forests. During summer and winter, northern yellow bats used sites close to fresh water and salt marsh. Additionally, during summer they used fields, ponds, and salt marsh more than upland and bottomland forests, but in winter they used bottomland forests, fields, and ponds more than upland forest and salt marsh. Our results highlight important land cover types for bats in this area (e.g., bottomland forests, ponds, and salt marsh), and that habitat use changes between seasons. Accounting for and understanding how habitat use changes throughout the year will inform managers about how critical habitat features may vary in their importance to bats throughout the year. © 2021 The Wildlife Society.  相似文献   

18.
Tropical forest conservation and restoration require an understanding of the movements and habitat preferences of important seed dispersers. With forests now being altered at an unprecedented rate, avian frugivores are becoming increasingly vital for forest regeneration. Seed movement, however, is highly dependent on the behavioral characteristics of their dispersers. Here, we examined the movements, habitat preferences, and range sizes of two African frugivores: the Black‐casqued (Ceratogymna atrata) and the White‐thighed (Bycanistes albotibialis) Hornbill, in the lowland rain forests of southern Cameroon. Using satellite transmitters, we tracked eight hornbills for 3 yr to characterize their movements and relate them to environmental landscape features. Hornbill movements differed significantly, with B. albotibialis ranging over larger areas (mean = 20,274 ha) than C. atrata (mean = 5604 ha), and females of both species covering over 15 times the area of males. Evidence suggests that movements are irruptive during particular periods, perhaps driven by low resource availability. In addition, hornbills often returned to the same localities within a year, although movements were not characterized as migratory. Both species displayed significant differences in habitat preference, with B. albotibialis utilizing disturbed habitat more frequently than Catrata (= ?22.04, = 2.2 × 10?16). Major roads were found to act as barriers for C. atrata, but not for B. albotibialis. The ability of both hornbill species to move large distances suggests hornbills will play a vital role in the maintenance and regeneration of rain forests in Central Africa as forest fragmentation increases and terrestrial vertebrates decline in numbers.  相似文献   

19.
The European Common Agricultural Policy has promoted the intensification of productive olive orchards and the abandonment of the unproductive ones. This strategy has resulted in a significant loss of biodiversity and ecosystem functionality of this type of agroecosystem. Here, we studied the blackcap Sylvia atricapilla, a common frugivorous bird species, in an olive-dominated agroecosystem of southern Spain to assess the effects of the abandonment of olive groves and undergrowth structure on habitat selection in this species. By means of radiotelemetry, we determined habitat selection of blackcaps during both the breeding (N = 30) and the non-breeding (N = 27) seasons of 2011 and 2012. We found that outside the breeding season, olive groves were widely used by blackcaps, which invariably preferred abandoned olive groves over intensively managed ones. Additionally, deciduous woods and poplar plantation were positively selected, whereas open habitats and Pinus forests were avoided. Generally, woody habitats without undergrowth or with herbaceous undergrowth were avoided. During the breeding season, the species selected mainly riverine habitats and poplar plantations, favoring habitats with well-developed undergrowth. Our results suggest that the blackcap could benefit from maintaining patches of abandoned olive groves freely left to natural succession within intensive olive groves. In such a landscape, ecological services (i.e., seed dispersal provided by frugivorous birds) and functioning could also improve as a consequence of these measures.  相似文献   

20.
Tibor  Farkas 《Ibis》1969,111(3):281-292
A preference for bushy evergreen undergrowth determines both the local and the general distribution of Cossypha natalensis. The lack of such undergrowth makes equatorial rain-forests unsuitable. Tropical and subtropical evergreen forests provide excellent conditions from this point of view, and they are thus the main habitat type from which C. natalensis has secondarily extended into tropical and subtropical deciduous forests with evergreen undergrowth.
Adult birds remain in or close to their territories throughout the year. First-year birds undertake longer movements during the winter. Breeding territories are relatively small, from 2,500 up to (exceptionally) 10,000 square yards (2,100-8,400 sq. m).
Breeding begins in October. Both sexes build the nest, but only the female incubates. In southern Africa there is one brood a year, and the care of the offspring is protracted. The juvenile moult begins in the third and ends in the sixth month; adults have only one (post-breeding) moult a year.
The begging behaviour of the young is somewhat different from that of most other turdine birds, and is considered to be more primitive. The ontogeny of the adult displays is described as observed in young birds kept in captivity.
The development of vocal behaviour is described. Special attention is given to the different functional forms of the song, and to two of its special features, imitation and a tonal quality termed vox humana.  相似文献   

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