Use of sand wave habitats by silver hake

Silver hake Merluccius bilinearis are common members of fish communities in sand wave habitats on Georges Bank and on Stellwagen Bank in the Gulf of Maine. Observations of fish size v . sand wave period showed that silver hake are not randomly distributed within sand wave landscapes. Regression analyses showed a significant positive relationship between sand wave period and fish length. Correlation coefficients, however, were low, suggesting other interactions with sand wave morphology, the range of current velocities, and available prey may also influence their distribution. Direct contact with sand wave habitats varied over diel periods, with more fish resting on the seafloor during daytime than at night. Social foraging, in the form of polarized groups of fish swimming in linear formations during crepuscular and daytime periods, was also observed. Sand wave habitats may provide shelter from current flows and mediate fish–prey interactions.     

Use of saltwater and freshwater habitats by wintering redheads in southern Texas

Behavioral data were gathered for redheads (Aythya americana Eyton) using saltwater and freshwater habitats in southern Texas, the northern portion of their major wintering range, in 1989–90. Saltwater and freshwater habitats were used for different purposes by wintering redheads. Approximately 41% of all redheads in saltwater habitats were feeding, while only 0.1% of redheads in freshwater habitats were feeding. Redheads in saltwater habitats drank infrequently (0.3%), but 7.5% of redheads in freshwater wetlands were drinking. Only 23 courting activities were observed, but all occurred in freshwater wetlands. This study showed that redheads depend on saltwater habitats for feeding, which confirmed similar results from recent studies of redheads in the central and southern portions of the Laguna Madre in southern Texas. This study also showed that redheads depend on freshwater wetlands as sources of drinking water. This concurred with data on redhead behavior in the central portion of the Laguna Madre in Texas, but not for redheads wintering in the southern part of the Laguna Madre. Both habitats, saltwater and freshwater, must be considered as integral components of the redhead winter range throughout southern Texas.     

Use of foraging habitats by bats in a Mediterranean area determined by acoustic surveys: conservation implications

We determined habitat use by foraging bats by broad-band acoustic surveys in 10 habitat types from a Mediterranean area (southern Italy). We applied discriminant functions to identify time-expanded echolocation calls from free-flying bats.
Moon phase and cloud cover had no effect on bat activity. Only Hypsugo savii was influenced by temperature, and activity of Myotis daubentonii and Myotis capaccinii was reduced at higher wind speeds. Both total numbers of bat passes and feeding buzzes were highest over rivers and lakes. Pipistrellus kuhlii and H. savii were most frequently recorded. Pipistrellus kuhlii , Pipistrellus pipistrellus and Tadarida teniotis proved generalists in using foraging habitats.
Water sites and conifer plantations were respectively the most and the least used habitats by H. savii . Rivers were especially important to Myotis bats, Miniopterus schreibersii and Pipistrellus pygmaeus . Unlike P. kuhlii , P. pipistrellus was frequent in beech woodlands; P. pygmaeus made a considerable use of chestnut woodlands and Myotis spp. were moderately active in both these woodland types.
A large number of endangered or vulnerable species featured in riparian habitats, broadleaved woodlands and olive groves. Riparian and woodland habitats constitute an important target for conservation. Typical land use forms such as woodlands used for chestnut production and traditionally managed olive groves should be encouraged in conservation plans. The negative impact of urbanisation on bats might be counteracted by fostering trees, gardens and small cultivated patches. Farmland practices should encourage landscape complexity and limit the use of pesticides.     

气候变化对中国马可波罗盘羊适宜生境的潜在影响

气候变化可能造成生物多样性下降和物种灭绝.开展气候变化对濒危野生动物分布格局影响的研究,对识别野生动物优先保护区、制定相关保护策略具有重要价值.本研究基于2017-2018年在新疆塔什库尔干野生动物自然保护区野外调查获得的马可波罗盘羊(Ovis ammon polii)分布位点,采用最大熵模型预测了气候变化下其适宜生境...     

Colonization of new habitats by earthworms

Summary In this paper a simple model is used to study the dispersal of earthworm populations into new habitats. Simple models do not describe processes accurately, but can help gain insight into the functioning of ecosystems or processes in ecosystems. Using information on reproduction, survival and dispersal at the level of the individual, the velocity of earthworm population expansion was calculated. Dispersal of earthworms can be active or passive. The parameters of active and passive dispersal were calculated from field experiments in one of the Dutch polders. Parameters of reproduction and survival were estimated from published data. The effects of processes at the individual level on the velocity of population expansion were studied for two species (Aporrectodea caliginosa and Lumbricus rubellus). The model shows that passive transport has a major influence on the velocity of population expansion, which is strongly increased even if this transport involves only a very small part of the population. At a high level of passive transport, however, death induced by this mode of dispersal can have a negative influence on population expansion. In the discussion it is indicated that optimising growth conditions of the earthworms might be the easiest way to promote population expansion. However, promoting dispersal by passive mechanisms can also be very important.Communication no. 36 of the Dutch Programme on Soil Ecology of Arable Farming Systems     

Use of space and habitats by meadow voles at the home range,patch and landscape scales

Using capture/recapture methods, we examined the spatial usage patterns of Microtus pennsylvanicus within and between experimentally created habitat patches of three sizes (1.0, 0.25 and 0.0625 ha) and between a 20-ha fragmented and a 20-ha continuous habitat landscape. We tested the prediction that home ranges near patch edges would be qualitatively different from those in patch interiors, and that the edge:interior habitat ratio could be used to make predictions concerning the dispersion and spatial use of individuals occupying different sized patches and between landscapes with different habitat structure. We found adult females on patch edges to have larger and more exclusive home ranges, larger body sizes, longer residence times, and to reproduce at a higher frequency than those in patch interiors. These edge effects also appeared to be largely responsible for the greater proportion of larger, reproductive females we found in small than larger patches and in the fragmented than in the continuous habitat (control) landscape. The selection of higher quality edge habitats by dominant females and the relegation of sub-dominants to patch interiors provides an explanation for the observed differences in the distribution and performance of females over patches and between landscapes.     

A comparison of the occurrence of common dental abnormalities in stabled and free-grazing horses

The purpose of this study was to gain evidence on the prevalence of dental abnormalities in stable-kept horses in comparison with free-living horses. It is expected that free-living horses that graze for as much as 16 h/day will have fewer dental abnormalities than stable-kept horses. In this study, the latter group was fed a diet that was based on a relatively high-energy, cereal-based feed. This was thought to be a representative of common practice in domesticated, stable-kept horses. Compound diets such as this have previously been shown to increase the frequency of chewing cycles and decrease mediolateral excursion. The occurrence of 10 named dental abnormalities present in the dentition of 60 Thoroughbred-type horses was recorded. Half of the population was at grass all year round in New South Wales, Australia. The remainder were stabled for 24 h/day in Gloucestershire, UK. All horses were between 5 and 15 years of age. The same, experienced, equine dental technician examined all horses using a full-mouth speculum and produced a routine dental chart. Stable-kept horses had a significantly higher total occurrence of abnormalities (P < 0.001) than free-living horses. The stable-kept group had a significantly higher prevalence of exaggerated transverse ridging across the occlusal surface of the cheek teeth, focal or ramped overgrowths of the cheek teeth and periodontal disease (P < 0.01 in all cases). All horses in both groups had some occurrence of sharp edges of the buccal and lingual edges of the cheek teeth. The results are in agreement with anecdotal evidence that a fibre-based, grazed diet results in fewer dental abnormalities. However, sharp edges may occur even with what is perceived as a 'natural' diet.     

Use of progestagen-gonadotrophin treatments in estrus synchronization of sheep

The main objective of this study was to investigate the effectiveness of certain progestagen-gonadotrophin treatments on synchronization of estrus in sheep. In Experiment I, 30 Chios ewes were treated at the beginning of the breeding season with medroxyprogesterone acetate (MAP) intravaginal sponges for 12 days and a single i.m. treatment of either FSH (Group 1,10 IU, n = 8; Group 2, 5 IU, n = 8; Group 3, 2.5 IU, n = 8) or eCG (Group 4, 400 IU, n = 6) at the time of sponge removal. Ten days after sponge removal laparotomy was performed to record ovarian response. Clinical estrus was observed in more (though not at a significant level) FSH treated than eCG treated sheep (62.5% versus 33.3%). Administration of 400 IU eCG resulted in the highest mean number of CL perewe ovulating (2.8 +/- 0.2), with administration of 10 IU FSH producing the next best results (2.1 +/- 0.3). Statistically significant differences in the mean number of CL per ewe ovulating were found only between ewes in Group 3 (1.7 +/- 0.4) and Group 4 (2.8 +/- 0.2) (P < 0.05). In Experiment II, 53 Chios and 30 Berrichon ewes were treated during the mid-breeding season with MAP intravaginal sponges for 12 days and a single i.m. treatment of either 10 IU FSH (27 Chios and 16 Berrichon ewes) or 400 IU eCG (26 Chios and 14 Berrichon ewes), at the time of sponge removal. Ewes that were in estrus on Days 2-4 and 19-23 after sponge removal were mated to fertile rams. No significant differences were recorded between treatment or breed groups in the proportions of ewes observed in estrus after treatment. In the Berrichon breed, FSH administration resulted in higher lambing rates (93.8% versus 57.1%, P < 0.05) and higher mean number of lambs born per ewe exposed to rams (1.4 +/- 0.2 versus 0.8 +/- 0.2, P < 0.05) than that of eCG. After treatment with eCG, the mean number of lambs born per ewe exposed to rams was higher in the Chios than the Berrichon breed (1.4 +/- 0.2 versus 0.8 +/- 0.2, P < 0.05). After treatment with FSH, the lambing rate was higher in the Berrichon than the Chios breed (93.8% versus 63.0%, P < 0.05). In conclusion, a single FSH treatment (5 or 10 IU) at the end of progestagen treatment appears to be more effective than eCG for the induction of synchronized estrus in sheep at the beginning of the breeding season, with no cases of abnormal ovarian response observed. During the mid-breeding season FSH (10 IU) appears to be equally as effective as eCG (400 IU) in respect of lambing rate and mean number of lambs born per ewe.     

Use of agroecosystem matrix habitats by mammalian carnivores (Carnivora): a global‐scale analysis

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Fostering in sheep. IV. Use of restraint

Fostering an additional lamb on to a ewe with a single lamb of her own was attempted in Dorset, Corriedale and Merino ewes restrained by the neck in pens for up to 12 days. Fostering occurred more rapidly in Dorsets than in Merinos, and success rates tended to be higher in Dorsets (81%) than the other breeds (73% in Corriedales and 69% in Merinos). The use of screens at the level of the ewe's neck to limit her olfactory examination of the lambs was more successful than when full olfactory contact was allowed. The prevention of any close olfactory contact resulted in an intermediate rate of acceptance, even though acceptance was apparently based on olfaction, as shown by universal rejection of strange alien lambs. Acceptance tests done within a few minutes of release from restraint were found not to reflect accurately the final level of acceptance, since some lambs came to be accepted within a day of being released. Further acceptances, that developed several days after release into a flock of ewes and lambs, emphasize an important role of the lamb in maintaining contact with the ewe. With few exceptions, lambs accepted when released from the pens were still accepted after a week or so in the flock.Dorset ewes given one or two foster lambs in the absence of their own lamb accepted the fosters within 9 days.Restraint fostering had no apparent harmful effects on the ewes or lambs, but had the disadvantages of being laborious and of soiling the ewes' wool. It has the advantage of providing lambs with an assured milk supply, and could prove useful for ewes that have failed to accept lambs under other methods.     

Use of Clonostachys rosea against sheep nematodes developing in pastures

The fungus Clonostachys rosea f. rosea has the potential to control gastrointestinal nematodes (GIN) of sheep. A study was conducted using adult Merino sheep. Gender, egg count and initial body weights (BWs) were used to categorise animals into four groups which were randomly assigned to one of four C. rosea dietary treatments. Treatments were mixed with a complete diet and fed to sheep once daily for 10 weeks. There was no effect of treatment on eggs per gram of faeces. However, treatments reduced the number of larvae per gram in faecal cultures (P < 0.001) and larval development (LD) time (P < 0.001). Efficacy of treatments increased (P < 0.001) with time. On Day 70, treatments of 0.25, 0.5 and 1.0 g of C. rosea chlamydospores per kilogram BW reduced LD time by 33, 72 and 89%, respectively, whereas in the control, LD was reduced by only 2.6%. C. rosea significantly (P < 0.001) reduced numbers of third-stage larvae (L₃) found in pastures. Our findings suggest that daily feeding with C. rosea has a potential to reduce larval stages of GIN in pastures.     

Invasibility of native habitats by Argentine ants,

The Argentine ant, Linepithema humile, was found established in New Zealand in 1990. During summer 2001/2002 the spread of Argentine ants from urban environments into native habitats was investigated. During an initial large-scale survey around the northern cities of Auckland and Whangarei, Argentine ants were observed at 35 of 211 sites. Eight sites in Auckland were subsequently surveyed in greater detail to determine the extent of movement by Argentine ants into native habitats. The presence of Argentine ants was determined every 10 m along a total of 28 transects into native forest, scrub and mangrove habitats. Argentine ants moved up to 20 m into forest habitats. In habitats with more open canopy (mangrove and scrub), ants moved at least 30 m and 60 m, respectively. We predict that open habitats and relatively open canopy scrub environments in northern New Zealand are likely to be vulnerable to invasion, and to experience the highest densities and the greatest impacts of Argentine ants. Our preliminary data, coupled with data from other parts of the world suggests that intact indigenous forest in New Zealand will probably not be invaded. Indigenous forests are likely to have Argentine ants only at the boundary with open habitat, but in highly fragmented landscapes the impact could be significant.     

内蒙古天然与放牧草原温室气体排放研究

采用静态箱-气相色谱法测定内蒙古典型草原温室气体排放。结果表明,四类天然草原吸收CH4、排放N2O和CO2各自有其相对固定的季节变化形式,四类草原和大气交换温室气体通量的变化形式基本一致,受年度气候变化所控制,而土壤、植被类型、降雨量等天然因素和放牧强度等人为因素仅影响排放强度。与天然羊草草原相比,自由放牧降低了羊草草原对CH4的吸收和N2O排放,增加了CO2的排放。     

Use FMEA method for environmental risk assessment in ore complex on wildlife habitats

Human activities are the most effective cause of wildlife habitat destruction and loss of quality. Some of these activities are the construction, operation, and utilization of mines. The present study investigates factory activity in the GolGoharSirjanOre Complex (Kerman province) and environmental risk assessment of the activities done by this complex on wildlife habitat. In order to identify the significant aspects of the complex, the Failure Mode and Effects Analysis (FMEA) method is used. To determine the risk priority number, the significant aspects resulted from the multiplication of the criteria including probability of occurrence, the probability of detection, and severity of the effect. Based on the results of the current study, most of the activities of GolGoharSirjan Complex can have a significant adverse impact on the habitat of birds such as bustard Chlamydotisundulata (Vulnerable [VU]) and Podocespleskei, and mammals such as Striped Hyaena (Hyaenahyaena) (Near Threatened [NT]) and Capra aegagrus (Wild Goat) (VU). Some of the most important activities related to the activity include: Crusher (Risk Priority Number [RPN] = 720), the concentration of iron ore (RPN = 640), mining (RPN = 486), Stalker and Reclaiming (RPN = 504), and the transport of heavy machinery (RPN = 432). Significant aspects such as the emission of dust into the air; Nitrogen Oxide (NOX), Sulphur Oxide (SOX), and Hydrogen Sulfide (H2S) gas emissions to air; vibration; noise; and industrial waste discharges significantly influence the environment. The results of measurements of environmental pollutants that are carried out by reliable environmental laboratories have shown that the amount of pollutants mentioned are above the standard limit determined by the Iranian Department of Environment.     

Use of immobilized proteinases for purification of sheep smallpox virus]

A possible use of papain and trypsin immobilized on Biogel P-100 for purification of DNA-containing sheep smallpox viruses was studied. It was shown that the enzymes depolymerize tissue proteins, resulting in a 90% purification of the viruses without causing any considerable morphological changes in the virion structure. It was concluded that fixed proteinases can be effectively used at the final stage of purification of tissue virus-containing suspensions.     

Feeding habitats of blue sheep (Pseudois nayaur) during winter and spring in Helan Mountains, China

The feeding habitat selection of blue sheep (Pseudois nayaur)was studied by direct observation method in the Helan Mountains,China during winter (from November to December)and spring (from April to June)from 2003 to 2004.We established 25 line transects to collect information on feeding habitats used by blue sheep.Blue sheep in the study area preferred mountain savanna forests,a habitat dominated by Ulmus glaucescens,with medium tree density (＜4 individuals/400 m2),moderate tree height (4-6 m),higher shrub density (＞5 individuals/100 m2),higher shrub (＞1.3 m),higher food abundance (＞50 g),moderate distance to human disturbance (＜500 m),and mild distance to bare rock (＜2 m).Such habitats characterized by 12 ecological factors were preferred as feeding areas by blue sheep during winter.Similar to habitat selection by the species during winter,blue sheep also showed a preference for mountain savanna with tree dominated by Ulmus glaucescens and medium tree density (＜4 individuals/400 m2)during spring.Nevertheless,blue sheep preferred medium tree height (＜6 m),moderate tree density (5-10 individuals/100 m2),medium shrub height (1.3-1.7 m),higher food abundance (＞100 g),moderate altitude (＜2 000 m),moderate distance to water resource (＜500 m),and medium hiding cover (50%-75%)during spring.Selection of the feeding habitats by sheep showed a significant difference in vegetation type,landform feature,dominant tree,tree height,shrub density,distance to the nearest shrub,food abundance,slope direction,slope degree,distance to water resource,and hiding cover between winter and spring.Results of principal components analysis indicated that the first principal component accounted for 24.493%of the total variance among feeding habitat variance during winter,with higher loadings for vegetation type,dominant tree,tree height,distance to the nearest tree,shrub density,shrub height,altitude,distance to water resource,and distance to human disturbance.In spring,the first principal components explained 28.777%of the variance,with higher loadings for vegetation type,distance to the nearest tree,shrub height,distance to the nearest shrub,food abundance,altitude,and distance to human disturbance.