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1.
Techniques for estimating the age of wild animals are crucial to many aspects of the study of population biology. Accurate estimates of the proportion of different age classes in wild rabbit populations would be very useful, and the possibility that it could be obtained from the pellet size holds great appeal. However, this suggestion has created controversy in the literature as this technique has not been validated. This study involved assessment of whether threshold fecal pellet diameters could be used to differentiate adult and juvenile rabbits. The proportion of adults in four wild rabbit populations living in semi-natural conditions was compared with the proportion of animal pellets greater than threshold diameters of 6 mm and 4 mm. Our results suggest that inferring a relationship between the proportion of pellets >6 mm diameter and the proportion of adults in a population is not applicable to European wild rabbits, and that the use of this method could produce erroneous interpretations. The use of a 4 mm pellet diameter threshold appeared to produce even more inaccurate results. Studies that use this technique should include validation, as the results can vary greatly among individuals and populations. 相似文献
2.
Recently, a new method for differentiating juvenile and adult rabbits based on faecal pellet size was published. According to this method, pellets >6 mm diameter are inferred to be deposited by adults, while those <6 mm are inferred to be from juveniles or kittens. In this study, we designed a simple experiment to test the accuracy of this methodology. Twelve adult rabbits were housed in individual outdoor cages and their pellets were removed every day for 10 consecutive days. Pellets were separated using a sieve according to their size and counted. Results showed that adult rabbits produce pellets >6 mm diameter in the same proportion as those <6 mm. We also observed a strong influence of the individual rabbit on pellet size; some rabbits produce a high proportion of pellets >6 mm, whereas others deposit mostly pellets <6 mm in size. Our findings demonstrate that pellet size is unsuitable for aging wild rabbits. Field biologists should therefore be cautious when employing the pellet size method of age determination in other wild animals in the absence of validating studies. 相似文献
3.
Roads have many effects on the mammal populations of their surroundings. Prey species are thought to establish dense populations in road verges due to a predation release effect, which arise as a side-effect of roadside avoidance by predators and/or predator roadkill. A species that has been suggested to benefit from predation release and attain high densities near roads is the European rabbit, a keystone species in Mediterranean ecosystems. We monitored rabbit relative abundance at three distances from a motorway (50, 450 and 850 m) during a 6 month period, as well as hunting and predator pressures, in a suitable area for rabbits. The lowest rabbit abundance was found next to the motorway (6.76 ± 8.87 pellets/m2 per month) and the highest abundance at an intermediate distance (17.65 ± 23.11 pellets/m2 per month). Hunting and carnivore pressures were highest at the sampling transect located farthest from the infrastructure. Thus, variability in rabbit abundance did not match the predation release effect found close to the motorway, and some sort of road avoidance or other process must underlie the observed abundance pattern. We advocate for a formal measurement of prey populations response to roads prior to any generalization as, in the case of rabbit, the response to roads and the potential cascading effects on other species may depend on landscape characteristics. 相似文献
4.
Conidiobolus thromboides is an entomophthoralean fungus with potential as a biological control agent of aphids. However, its application in biological control is limited due to its formulation requirements. The objective of this study was to develop and optimise a novel air-extrusion method to embed C. thromboides hyphae at high density in alginate pellets. An orthogonal experimental design was used to investigate selected combinations of parameters known to affect hyphal density within pellets. The diameter of pellets produced, and the calculated density of hyphae within them, ranged from 0.18 ± 0.09 to 3.17 ± 0.06 mm and from 0.02 to 350.56 mg/mm3 respectively. These data were used to predict the optimal parameter combination to deliver the greatest density of hyphae of C. thromboides per pellet: 1% sodium alginate, a 1:2 ratio of hyphae to sodium alginate, an orifice diameter of 0.232 mm and an air pressure of 0.05 MPa. Pellets made under the optimal conditions predicted produced a mean total of 4.3 ± 0.6 × 105 conidia per pellet at 100% relative humidity which was significantly greater than the mean total number of conidia produced from infected aphid cadavers of comparable size (9.35 ± 0.85 × 104) (p < 0.001). In conclusion, air-extrusion embedding appears to be a promising method for formulating in vitro-produced hyphae of C. thromboides for use in biological control. 相似文献
5.
Paul Chun Yih Lim Boon Yew Tan Kah Leng Ho Chee Keong Ching Wee Siong Teo 《Indian pacing and electrophysiology journal》2013,13(6):217-220
IntroductionBefore IS-1 (3.2 mm) standardization of pacemaker leads and connectors, 5/6 mm connector ports accomodated 5 mm or 6 mm diameter lead connector pins.Case reportA patient with sick sinus syndrome underwent implantation of a 5 mm unipolar atrial lead, mated to a 5/6 mm connector port Medtronic Spectrax Sx 5985 pacemaker. Pulse generator reached ERI in 2006, with change out to a Medtronic Sigma SSR306 (5/6 mm connector port) and preservation of the 5 mm lead. She was admitted in 2010 for atrial lead non capture from blood leak and corrosion of the header-connector pin apparatus.Discussion5/6 mm pacemaker header ports have a 5 mm flexible sealing ring at the port entrance to seal 5 mm or 6 mm lead connector pins. The inner barrel diameter of the connector port is 6 mm and insertion of a 5 mm lead results in a 0.5 mm tolerance circumferentially. Should the seal be compromised, blood can corrode the apparatus. To minimize this, we can employ (a) a cinching tie to further seal the silicone ring (b) universal adaptor sleeves (c) splice kits (d) lead adaptor kits. Aging leads, adaptor kits or sleeves themselves can result in lead failure. It may be safer to re-implant the entire system.ConclusionA 5/6 mm configuration pacemaker header connector port allows for significant tolerances when a 5 mm lead is used. Consideration must be made to prevent leaks. 相似文献
6.
Motivation tests were conducted to assess preference strength for diet form and a cage enrichment device by Orange-winged Amazon parrots (Amazona amazonica) held in individual cages, N = 10. Each cage was equipped with two trough-type feeders, one of which had a hinged lid that required lifting to access feeder content; cost of lifting the lid could be increased by the addition of up to 480 g upon it, ~1.5 times the mass of an Amazon parrot. Motivation tests were conducted using three different diet forms of pellets (regular-sized, 0.16 g/pellet (cylindrical-shaped); large-sized, 3.4 g/pellet (cylindrical); and over-sized, 3–5 g/pellet (cuboid-to-spheroid)) manufactured from the same diet formulation. When regular pellets were concomitantly freely available, birds were still highly motivated to gain access to either large-sized or over-sized pellets, with 7 of 10 birds lifting the maximum weight of 480 g. In motivation tests comparing over-sized vs. large-sized pellets, birds worked more for over-sized pellets (when large-sized pellets were freely available) than vice versa: motivation for over-sized pellets exceeded that for large-sized pellets by approximately 242.67 ± 64.4 g (F = 14.2, P = 0.0055; Sign Test, P = 0.0078). Additional tests assessed motivation to access 2.5 cm/side wooden cube enrichment devices when regular or over-sized pellets were freely available. Birds removed more cubes when fed regular pellets (Sign Test, P = 0.0078) and lifted an average of 221.33 ± 64.62 g more to access them (F = 11.73, P = 0.009; Sign Test, P = 0.0063), than when over-sized pellets were freely available, suggesting that enrichment devices may act as foraging substitutes. Likewise, both wooden cubes and over-sized pellets elicited comparable podomandibulation (handling with beak and foot) behavior, and podomandibulation was reduced when parrots were fed regular as opposed to over-sized pellets (58 ± 10 s [mean ± SE] vs. 4.27 min ± 31 s; P < 0.0001). Finally, there was no evidence of contrafreeloading: in control experiments, birds only removed pellets which were freely available, when the same pellets were concomitantly available in weighted-lid feeders (F = 120.20, P < 0.0001). In summary, these results show that captive Orange-winged Amazon parrots strongly prefer pellet forms that are substantially larger than what is commercially recommended for them; preferred forms more closely resemble that of native wild foods, such as palm fruits. 相似文献
7.
M.L. Pappas E. Karagiorgou G. Papaioannou D.S. Koveos G.D. Broufas 《Biological Control》2013,64(3):291-298
Chrysoperla agilis Henry et al. is one of the five cryptic species of the carnea group found in Europe. Identification of these species is mainly based on the distinct mating signals produced by both females and males prior to copulation, although there are also morphological traits that can be used to distinguish among different cryptic species. Ecological and physiological cryptic species-specific differences may affect their potential as important biological agents in certain agroecosystems. To understand the effects of temperature on the life-history traits of C. agilis preimaginal development, adult longevity and reproduction were studied at seven temperatures. Temperature affected the development, survival and reproduction of C. agilis. Developmental time ranged from approximately 62 days at 15 °C to 15 days at 30 °C. Survival percentages ranged from 42% at 15 °C to 76% at 27 °C. One linear and five nonlinear models (Briere I, II, Logan 6, Lactin and Taylor) used to model preimaginal development were tested to describe the relationship between temperature and developmental rate. Logan 6 model fitted the data of egg to adult development best according to the criteria adopted for the model evaluation. The predicted lower developmental threshold temperatures were 11.4 °C and 11.8 °C (linear model), whereas the predicted upper threshold temperatures (Logan 6 model) were 36.6 and 36.9 °C for females and males, respectively. Adult life span, preoviposition period and lifetime cumulative oviposition were significantly affected by temperature. The effect of rearing temperature on the demographic parameters is well summarized with the estimated values of the intrinsic rate of increase (rm) which ranged from 0.0269 at 15 °C to 0.0890 at 32 °C and the highest value recorded at 27 °C (0.1530). These results could be useful in mass rearing C. agilis and predicting its population dynamics in the field. 相似文献
8.
Olga N. Pozharitskaya Marina V. Karlina Alexander N. Shikov Vera M. Kosman Marina N. Makarova Valery G. Makarov 《Phytomedicine》2009,16(2-3):244-251
Taxifolin has been widely used in the treatment of cerebral infarction and sequelae, cerebral thrombus, coronary heart disease and angina pectoris. A reliable sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method with UV detection for the pharmacokinetic study of taxifolin in rabbit plasma after enzymatic hydrolysis was developed and validated for the first time. Taxifolin, with biochanin A as the internal standard, was extracted from plasma samples by liquid/liquid extraction after hydrolysis with β-glucuronidase and sulfatase. Chromatographic separation was conducted on a Luna C18 column (4.6 mm×150 mm, 5 μm particle size) and pre-column (2.0 mm, the same sorbent). Two-step linear gradient elution with acetonitrile and 0.03% water solution of trifluoroacetic acid as mobile phase at a flow rate of 1.0 ml/min was used. The UV detector is set at 290 nm. The elution time for taxifolin and biochanin A was approximately 7.9 and 18.3 min, respectively. The calibration curve of taxifolin was linear (r>0.9997) over the range of 0.03–5.0 μg/ml in rabbit plasma. The limit of detection (LOD) and limit of quantification (LOQ) for taxifolin were 0.03 and 0.11 μg/ml, respectively. The present method was successfully applied for the estimation of the pharmacokinetic parameters of taxifolin following intravenous and oral administration of lipid solution to rabbits. The absolute bioavailability of taxifolin after oral administration of lipid solution was 36%. 相似文献
9.
《Saudi Journal of Biological Sciences》2017,24(3):495-503
This study sought to reveal the effect of angiotensin II (Ang II)-induced atherosclerotic vulnerability in rabbits and to determine whether in vivo magnetic resonance imaging (MRI) can determine the effect of Ang II on atherosclerotic development over time. In total, 24 elderly male New Zealand white rabbits underwent an intravascular balloon injury in the left common carotid artery (LCCA) and were subsequently fed a high cholesterol diet for 12 weeks. At 8 weeks, rabbits were randomly assigned to receive either Ang II (1.4 mg/kg/d, Ang II group) or vehicle (phosphate-buffered saline, control) via a subcutaneous osmotic minipump for 4 weeks. The rabbits were imaged three times: at baseline and at 8 and 12 weeks. After the 12-week MRI scanning, rabbits were euthanized to obtain pathological and histological data. Atherosclerotic plaques were identified in the 21 rabbits that survived the 12-week trial. Typical feature of vulnerable plaques (VP), intraplaque hemorrhage, were observed in 6 of 10 animals (60.0%) in the Ang II group. The Cohen K value of MR imaging between the AHA classifications was 0.82 (0.73–0.91; P < 0.001). MRI revealed that the change in carotid morphology were significantly different between the Ang II and control group plaques. Our results support an important role for Ang II in plaque vulnerability by promoting intraplaque neovascularization and hemorrhage as well as inflammation. The vulnerable features induced by Ang II in rabbit carotid plaques could be accurately monitored with MRI in vivo and confirmed with histomorphology. 相似文献
10.
Rory Julien Michelland Valérie Monteils Sylvie Combes Laurent Cauquil Thierry Gidenne Laurence Fortun-Lamothe 《Anaerobe》2010,16(4):396-401
The archaeal community in the fermentative compartment and faeces of the cow and the rabbit were compared by analysis capillary electrophoresis single-stranded conformation polymorphism (CE-SSCP) profiles of 16S rRNA genes. Ruminal and faecal contents were sampled in five cows for three weeks. Hard and soft faeces were collected in 14 rabbits for three consecutive weeks and cæcal contents were sampled in the third week. The archaeal community differed according to the host species (ANOSIM-R = 0.53 and 0.72 respectively for the comparison of the fermentative compartments and faeces; P < 0.001) and to the location within the digestive tract of both species (ANOSIM-R = 0.37, 0.52 respectively for the cow and the rabbit; P < 0.001). In both species, the archaeal community of the digestive tract was stable over weeks and varied very little between individual animals. The structure (NS) and the richness index (9.9 ± 2.7, 10.1 ± 3.1 respectively, NS) of the archaeal community were similar for the cæcal content and the soft faeces which permitted to use the latter as a representative indicator. 相似文献
11.
ICP is an important cause of mortality in fulminant hepatic failure. The aim of this study was to prolonged survival in surgery-induced FHF rabbit with BAL. Four hours after induction of FHF, rabbits were connected to a 4-h whole blood perfusion through the BAL containing 1.2 × 109 fresh isolated porcine hepatocytes (estimated 30% of liver volume of rabbit) via an arterial-venous shunt. Survival times in control group, sham-BAL group and BAL group were14.4 ± 4.4 h, 12.6 ± 2.6 h and 22.6 ± 5.2 h, respectively (BAL vs. control, p = 0.026; BAL vs. sham-BAL, p = 0.006). BAL group remain ICP level less than 10 mmHg for near 13 h after FHF induction while 19 and 15 mmHg were observed in control and sham-BAL groups, respectively. BAL containing porcine hepatocytes significantly prolonged survival time by delayed increase of intracranial pressure compared with the control and sham-BAL groups. 相似文献
12.
Youngsoo Son Hannah Nadel Sunghoon Baek Marshall W. Johnson David J.W. Morgan 《Biological Control》2012,60(3):233-240
The effects of temperature on the development (egg–adult emergence) of Gonatocerus morgani Triapitsyn, a newly-described parasitoid of Homalodisca vitripennis (Germar), were determined at 14.8, 18.7, 23.5, 26.9, 28.7, 30.4, 32.8, and 33.8 °C in the laboratory. Survival rate (percent adult emergence from parasitized host eggs) varied significantly among the experimental temperatures, with the highest (59%) and lowest (0%) occurring at 30.4 and 33.8 °C, respectively. The survival rates (%) were fitted with a polynomial model to describe a temperature-dependent pattern. Developmental rates (1/d) across seven temperatures were fitted with the nonlinear Briere model, which estimated the lower threshold to be 8.06 °C, the optimal temperature to be 29.22 °C, and the upper threshold to be 33.49 °C. A linear model fitted to developmental rates at 14.8–28.7 °C indicated that 189.75 degree-days above the lower threshold of 9.71 °C were required to complete development. A simulation model of G. morgani adult emergence was constructed to predict daily counts over the entire range of constant temperatures by incorporating the survival rate model, the Briere model, and the Weibull model. In outdoor validation, a degree-day model for predicting adult emergence showed ?2 d differences between prediction and observation. Based on the observed temperature requirement, the insect could complete thirteen to sixteen generations per year in southern California, depending on weather and location. 相似文献
13.
The specific adsorption capacities (SAC) of the growing, resting and dead pellets for target dye were compared; the mechanisms responsible for difference of SAC between different kinds of pellets were elucidated. The results showed that the SAC of three kinds of biomass decreased in the order of the growing > the resting > the dead, and the ratio of SAC of the growing biomass to that of the dead one increased from 1.32 at 100 mg/L of initial dye concentration to 2.68 at 400 mg/L. The growing pellets accumulated the loaded dye inside the cells through energy consumption, both the thickened cell wall and the squeezed cytoplasm offered the greatest space for dye bioaccumulation, accounting for the highest SAC. In contrast, monolayer adsorption of dye onto the surface of pellets was the mechanism for the dead biomass, so the lowest SAC occurred due to the least adsorption space and sites. 相似文献
14.
《Animal Feed Science and Technology》1999,80(1):67-74
The feasibility of using Verano stylo (Stylosanthes hamata cv. Verano) and Guinea grass (Panicum maximum cv. Ntchisi) hays and their replacement values in concentrate diets for rabbits were determined. The intake and growth of the rabbits were monitored over a 7-week growth study following a 2-week adaptation period, while nutrient digestibility was determined over a 5-day period during the eighth week of the study. The DM intakes of the rabbits during the growth study were 53.1 g/day of the grass + concentrate (50 : 50) diet, 56.0 g/day of the all-concentrate diet and 64.8 g/day for the Verano stylo + concentrate (50 : 50) diet. The respective weight gains were 5.13, 8.44 and 8.35 g/day. Lower DM intake and consistent losses in weight of the animals were recorded on Verano stylo or Guinea grass alone. Verano stylo hay was better than Guinea grass hay. Thus, concentrate supplementation of forage diets is necessary for rabbits. Replacement of 0.50 of the concentrate with Verano stylo hay gave a similar performance to that for the all-concentrate diet. It is, therefore, possible to reduce the use of concentrates in the diets for growing rabbits in the dry season by replacing part of the diet with Verano stylo hay. 相似文献
15.
The first reports from Pfannmöller et al. (1994) and Lewis (2000) regarding the level of Neotyphodium colonization of grasses in Poland identified ratios ranging from 20 % to 60 %. To date, the studies of endophytes in Poland have focused mainly on the rate of endophyte infection in subsequent years of plantation use, the effect of endophytes on turf performance and the occurrence of endophytes in cultivars of meadow fescue, tall fescue and perennial ryegrass. The aforementioned studies were mainly conducted on breeding varieties of grasses. From 2007 to 2009, intensive studies on Neotyphodium occurrence in ecotypes of wild grasses in Poland were conducted. The results suggest that Neotyphodium species are quite common in Poland and colonize roughly 70 % of semi-natural, used or abandoned grasslands. In this paper we review studies that have been conducted thus far in Poland regarding the occurrence of Neotyphodium spp. in grasses. 相似文献
16.
Antonella Dalle Zotte Zoltán Princz Zsolt Matics Zsolt Gerencsér Szilvia Metzger Zsolt Szendrő 《Applied animal behaviour science》2009,116(2-4):273-278
Five-week-old Pannon White rabbits were housed in a closed climatized rabbitry and randomly assigned to either pens (56 rabbits) having a basic area of 1 m2 with a stocking density of 16 and 12 rabbits/m2 or to 18 individual cages (0.24 m2/cage). The pens and the cages were divided into two halves and animals could move freely between the two halves through swing doors. The walls of one half of the pens and cages were completely covered with mirrors while the other half was covered with white plastic panels. A 24 h video recording was made twice a week using infrared cameras and the number of rabbits in each pen and cage was counted every 15 min. The duration of the trial was 6 weeks. The lighting period was 16L/8D. In each half of the cage or pen, a feeder and nipple drinkers were available and feed intake was measured separately. Throughout the entire rearing period, 72% of the individually caged rabbits showed a preference for the cage half enriched with mirrors (P < 0.001). This preference decreased slightly with increasing age. Preference toward the cage half provided with mirror walls was independent of the time of day; in other words, during the active period (23:00–05:00) corresponding to the dark part of the day, rabbits continued to prefer the mirrored half even if the vision of the reflected image was reduced. The presence of conspecifics at different stocking densities (12 vs. 16 rabbits/m2) did not reduce this interest in mirrors: averaging the ages, 66% of animals living at 16 rabbits/m2 stocking density and 63% of those living at 12 rabbits/m2 density were found in the half pen with mirrors (P < 0.001). Group-penned rabbits showed a marked preference toward mirrors during the active period (73–76% for 12 and 16 rabbits/m2 stocking densities, respectively; P < 0.001). The results suggest that the presence of mirrors offers advantages perhaps related to comfort and welfare, and therefore might be used as environmental enrichment for fattening rabbits and advised for rabbits caged individually for long periods. 相似文献
17.
Warneckea populations from “sand-forest” or “sand-thicket” habitats in Tembe Elephant Park, South Africa, and Licuati Forest Reserve in adjacent southern Mozambique were previously thought to be a small-leaved form of W. sousae, which typically includes larger-leaved plants ranging from central Mozambique northward to Tanzania. We examine this hypothesis using molecular and morphological evidence. Maximum-likelihood phylogenetic analysis of combined nrDNA ETS and ITS sequence data failed to resolve W. sousae and the Maputaland populations as an exclusively monophyletic group. Instead, the Kenyan endemic W. mouririifolia was strongly supported as the sister species of W. sousae, and the Maputaland plants were resolved in a separate, strongly supported clade together with populations of an as-yet undetermined Warneckea species from northern Mozambique. A hypothesis of exclusive monophyly for the plants from Tembe and Licuati had moderate support in separate ETS and ITS1 analyses (bootstrap proportions of 88% and 81%, respectively). Statistically significant differences in leaf dimensions and internode length were found between the Maputaland plants and typical W. sousae. We conclude that the populations from Tembe and Licuati represent a distinct species, which we describe as W. parvifolia. The species differs from W. sousae in having shorter internodes (mostly 5–25 mm not 10–60 mm long), smaller leaves (mostly 14–32 × 8–19 mm not 40–76 × 22–52 mm), shorter petioles (mostly 1–1.5 mm not 1.5–6 mm long), smaller flowers (hypanthium 1 × 1.5–1.75 mm not 1.5–2 × 2 mm; calyx lobes 0.5 mm not 0.75 mm long; staminal filaments 3–4 mm not 5 mm long; style 4–5 mm not 9 mm long), and globose fruit (not obovoid). An IUCN conservation status of Endangered (EN) B1a, b(ii, iii) is indicated for W. parvifolia, due to its limited distribution and projected declines in its habitat quality and area of occupancy. 相似文献
18.
Most reptiles thermoregulate to achieve body temperatures needed for biological processes, such as digestion and growth. Temperatures experienced during embryogenesis may also influence post-hatching growth rate, potentially through influencing post-hatching choice of temperatures. We investigated in laboratory settings whether embryonic temperatures (constant 18 °C, 21 °C and 22 °C) influence selected body temperatures (Tsel) of juvenile tuatara (Sphenodon punctatus), providing a possible mechanism for differences in growth rates. We found that incubation temperature does not influence Tsel. Although the average daily mean Tsel was 21.6 ± 0.3 °C, we recorded individual Tsel values up to 33.5 °C in juvenile tuatara, which is higher than expected and above the panting threshold of 31–33 °C reported for adults. We found diel patterns of Tsel of juvenile tuatara, observing a general pattern of two apparent peaks and troughs per day, with Tsel being significantly lower around dawn and at 1500 h than any other time. When comparing our results with other studies on tuatara there is a remarkable consistency in mean Tsel of ~ 21 °C across tuatara of different ages, sizes and acclimatization histories. The ability of juvenile tuatara to withstand a wide range of temperatures supports their former widespread distribution throughout New Zealand and warrants further investigation into their plasticity to withstand climate warming, particularly where they have choices of habitat and the ability to thermoregulate. 相似文献
19.
José Guerrero-Casado Antonio J. Carpio Leire Ruiz-Aizpurua Francisco S. Tortosa 《Journal for Nature Conservation》2013,21(6):444-448
Rabbit populations in Iberia remain at low densities in several areas in which their endangered predators still coexist, and the recovery of these populations is therefore urgent if the integrity of Iberian Mediterranean ecosystems is to be maintained. The enhancement of wild rabbit populations has been attempted through the use of in situ extensive rabbit captive breeding enclosures (restocking plots), which reduce mortality caused by terrestrial predators and dispersal movements and permit the breeding of young individuals which can then naturally disperse to settle in the surrounding areas. However, their effectiveness, the role of its size, the optimal habitat management that should be promoted around them and the habitat features remains uncertain. Here, we show results from a four year study of an ambitious rabbit restocking plan on a landscape scale. We measured rabbit abundance in a vast area in which thirty-two restocking plots were built to create an initial rabbit population for further dispersion, in addition to an intensive habitat management program. We also compared rabbit abundance between managed and unmanaged UTM cells of 2.5 km × 2.5 km. Our results showed that rabbit abundance was three times higher in managed cells, but four years after restocking, rabbit abundances had only reached the threshold needed to support stable Iberian lynx presence (at least 10 latrines per km?1) in 9 of the 23 managed cells. Rabbit abundance was strongly affected by habitat treatment and scrub coverage. The increase of shelter was useful in low cover areas but ineligible in places with high scrub cover, where the increase of refuge plus scrub clearing to create pastures improve rabbit abundance more effectively. In the light of our results, restocking plots should be built only in places with suitable habitat, whereas pastures should be created in dense scrublands and refuge in low cover areas. 相似文献
20.
Juvenile Spinibarbus sinensis (n = 48, body length, 5.86 ± 0.10 cm, 25 °C) were fasted for 0, 0.5, 1, 2, 4 and 6 weeks. The fast-start performances of the experimental fish were assessed using high-speed video photography and the locomotive kinematics analysis. The morphological parameters including tail height (H2), tail length (L2), lateral body area (S1), median fin area (S2), dorsal cross section area (S3) and tail cross section area (S4) were also measured using TpsDig and the Photoshop. The results showed that 6 week starvation resulted in significant decreases in the escape distance (d), maximum linear velocity (Vmax) and maximum linear acceleration (amax) of center of mass in Stage 1 and Stage 2 of fast-start process (P < 0.05), however there were two relatively sTable phases in the Vmax and d, during the week 1–2 (Vmax = 0.67 ± 0.06 mm/ms; d = 8.86 ± 0.73 mm) and week 4–6 (Vmax = 0.31 ± 0.04 mm/ms; d = 3.70 ± 0.56 mm). When compared with the control group (0 week starvation group), only the 6 week starvation group showed the significantly different response time (t) with average t = 9.20 ± 0.37 ms in week 1–4. There were no significant difference in mass center turning angles at first stage (Ta1) , second stage (Ta2) and the sum of two stages (Ta(1+2)) was also not different (P > 0.05). The fish did not show any directional preference for left or right during escape turning, and all of the related parameters also remained unchanged among treatment group (P > 0.05). The areas of dorsal body cross-section decreased more acutely (P < 0.05) than caudal body cross-section (45.4% vs 38.0%) during the entire starvation period while no significant differences were observed in both the tail height and tail length among all treatment groups (P > 0.05). The results indicated that fast-start performance of juvenile S. sinensis is affected by the starvation; metabolic energy related traits such as the maximum linear velocity and the maximum linear acceleration decreased significantly after starvation; whereas traits with no direct link to metabolic energy such as the response time and turning angle remained unchanged during starvation. The lack of starvation induced change in the maneuverability of the fish suggests that fast-start ability related to escape strategy is relatively well conservative in juvenile S. sinensis. 相似文献