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1.
Riddhika Kalle Tharmalingam Ramesh Qamar Qureshi Kalyanasundaram Sankar 《Acta theriologica》2011,56(4):335-342
Density of tiger Panthera tigris and leopard Panthera pardus was estimated using photographic capture–recapture sampling in a tropical deciduous forest of Mudumalai Tiger Reserve, southern
India, from November 2008 to February 2009. A total of 2,000 camera trap nights for 100 days yielded 19 tigers and 29 leopards
within an intensive sampling area of 107 km2. Population size of tiger from closed population estimator model Mb Zippin was 19 tigers (SE = ±0.9) and for leopards Mh Jackknife estimated 53 (SE = ±11) individuals. Spatially explicit maximum likelihood and Bayesian model estimates were 8.31
(SE = ±2.73) and 8.9 (SE = ±2.56) per 100 km2 for tigers and 13.17 (SE = ±3.15) and 13.01 (SE = ±2.31) per 100 km2 for leopards, respectively. Tiger density for MMDM models ranged from 6.07 (SE = ±1.74) to 9.72 (SE = ±2.94) per 100 km2 and leopard density ranged from 13.41 (SE = ±2.67) to 28.91 (SE = ±7.22) per 100 km2. Spatially explicit models were more appropriate as they handle information at capture locations in a more specific manner
than some generalizations assumed in the classical approach. Results revealed high density of tiger and leopard in Mudumalai
which is unusual for other high density tiger areas. The tiger population in Mudumalai is a part of the largest population
at present in India and a source for the surrounding Reserved Forest. 相似文献
2.
Erica Di Pierro Ambrogio Molinari Guido Tosi Lucas A. Wauters 《Ecological Research》2008,23(3):529-542
When animal home ranges overlap extensively in species lacking overt territorial behaviours, identifying exclusive core areas
within individual ranges can be difficult. By analysing the size and overlap of successively smaller core areas among individual
Eurasian red squirrels (Sciurus vulgaris), we determined exclusive areas within the home ranges of resident males and females. Possible effects of habitat composition
and food supplies were explored by monitoring squirrels in different conifer forests and during years with low and high tree
seed production. Using outlier-exclusive cores (OEC) revealed that the total ranges consisted of large sally zones (on average,
35% of the total minimum convex polygon [MCP] range) around home ranges with multi-nucleate cores. The mean OEC home range
size did not differ between the sexes but was larger with poor food availability. Home ranges (99% incremental cluster polygons
[ICP]) overlapped extensively between sexes (average overlap high food–low food: males by females 21–40%, females by males
43–45%) and among males (males by males 26–44%), while intrasexual overlap among females was low (9–10%). The overlap of inner
cores among females rapidly approached zero, suggesting the intrasexual territoriality of 75% core areas. This was not the
case among male squirrels, for which intrasexual overlap averaged only 4% at 50% but 18% at 75% core areas. Even the smallest
inner cores had some degree of intersexual overlap, indicating that complete territoriality did not occur in this species.
Female home ranges were more strongly affected by annual fluctuations in food supplies than male ranges. Females reduced the
size of their food-based intrasexual territories when food availability increases. Males probably benefit from using larger
home ranges and core areas, which overlap with the ranges of several females, by increasing their probability of successful
mating. 相似文献
3.
Brendan P. Kelly Oriana H. Badajos Mervi Kunnasranta John R. Moran Micaela Martinez-Bakker Douglas Wartzok Peter Boveng 《Polar Biology》2010,33(8):1095-1109
Population structure and patterns of habitat use among ringed seals (Phoca hispida) are poorly known, in part because seasonal movements have not been adequately documented. We monitored the movements of
98 ringed seals in the Beaufort and Chukchi seas between 1990 and 2006 using three forms of telemetry. In the winter—spring
period (when the seals were occupying shorefast ice), we used radio and ultra-sonic tags to track movements above and below
the ice, respectively. We used satellite-linked transmitters in summer and fall (when the seals ranged away from their winter
sites) to track at-sea movements. In the shorefast ice habitat, the home ranges of 27 adult males ranged from <1 to 13.9 km2 (median = 0.628) while the home ranges of 28 adult females ranged from <1 to 27.9 km2 (median = 0.652). The 3-dimensional volumes used by 9 seals tracked acoustically under the ice averaged 0.07 (SD = 0.04) km3 for subadults and adult males and 0.13 (SD = 0.04) km3 for adult females. Three of the radio-tracked seals and 9 tracked by satellite ranged up to 1,800 km from their winter/spring
home ranges in summer but returned to the same small (1–2 km2) sites during the ice-bound months in the following year. The restricted movements of ringed seals during the ice-bound season—including
the breeding season—limits their foraging activities for most of the year and may minimize gene flow within the species. 相似文献
4.
Kerry L. Nicholson Paul R. Krausman Adrian Munguia-Vega Melanie Culver 《European Journal of Wildlife Research》2011,57(6):1151-1163
Spatial and temporal interactions among individual members of populations can have direct applications to habitat management
of mountain lions (Puma concolor). Our objectives were to evaluate home range overlap and spatial/temporal use of overlap zones (OZ) of mountain lions in
Arizona. We incorporated spatial data with genetic analyses to assess relatedness between mountain lions with overlapping
home ranges. We recorded the space use patterns of 29 radio-collared mountain lions in Arizona from August 2005 to August
2008. We genotyped 28 mountain lions and estimated the degree of relatedness among individuals. For 26 pairs of temporally
overlapping mountain lions, 18 overlapped spatially and temporally and eight had corresponding genetic information. Home range
overlap ranged from 1.18% to 46.38% (
[`(x)] = \text24.\text43 \overline x = {\text{24}}.{\text{43}} , SE = 2.96). Male–male pairs were located within 1 km of each other on average, 0.04% of the time, whereas male–female pairs
on average were 3.0%. Two male–male pairs exhibited symmetrical spatial avoidance and two symmetrical spatial attractions
to the OZ. We observed simultaneous temporal attraction in three male–male pairs and four male–female pairs. Individuals from
Tucson were slightly related to one another within the population (n = 13, mean R = 0.0373 ± 0.0151) whereas lions from Payson (n = 6, mean R = −0.0079 ± 0.0356) and Prescott (n = 9, mean R = −0.0242 ± 0.0452) were not as related. Overall, males were less related to other males (n = 20, mean R = −0.0495 ± 0.0161) than females were related to other females (n = 8, mean R = 0.0015 ± 0.0839). Genetic distance was positively correlated with geographic distance (r
2 = 0.22, P = 0.001). Spatial requirements and interactions influence social behavior and can play a role in determining population density. 相似文献
5.
Dave Parrott Anthony Prickett Stéphane Pietravalle Thomas R. Etherington Mark Fletcher 《European Journal of Wildlife Research》2012,58(1):23-33
Walked spotlight transect surveys with distance sampling were used to estimate regional population densities of badger (Meles meles), fox (Vulpes vulpes) and brown hare (Lepus europaeus) in south-west England (Cornwall, Devon, Gloucestershire, Herefordshire) and Wales (Pembrokeshire, Borders, North Wales).
All regions were surveyed during spring 2006 with English regions re-surveyed in autumn 2006. In each region, surveys were
conducted in a random sample of 19.6 km2 areas (mean areas per region: spring = 19, autumn = 25). Within each survey area, a semi-random transect was established
in each of a random sample of fields (open habitat almost exclusively pasture). Transects were subsequently walked at night
with spotlights (mean transects per survey area: spring = 21, autumn = 21). Each area was surveyed twice during a season.
Total transect length per region ranged from 137 to 193 km in spring and 230 to 250 km in autumn. The mean density of species
per region was: badger 1.5–4.8 km−2, fox 1.0–4.0 km−2, hare 0.4–4.6 km−2. The study has provided baseline estimates of regional densities against which any future equivalent surveys can be compared.
It has also illustrated the practical application of large-scale walked distance sampling to surveys of British mammals. 相似文献
6.
The raccoon dog Nyctereutes procyonoides, a medium-sized canid, is a representative of the East Asian fauna and has been introduced to Europe during the years 1928–1953.
Today, this alien carnivore is a widespread species in Eastern Europe, Finland and Germany. In our study, we determined home
range sizes of raccoon dogs in an agricultural landscape in Northeast Germany between 2001 and 2004 by very high frequency
radio tracking. Those data are useful for estimation of predator densities in respect to conservation of biodiversity and
also to develop models for disease and parasite transmission. Yearly average home range sizes were calculated as 95% fixed
kernel: 1.83 km2 ± 1.54 and as 50% fixed kernel (=core areas): 0.50 km2 ± 0.49. We documented seasonal differences in home range sizes as well as overlapping of home ranges from 0.65% up to 67%.
Some individuals’ home ranges recorded during the same season showed a clear shifting between different years. Abandoned badger
dens, located in the core areas of raccoon dogs home ranges, were important during the whole year and particularly used in
the winter period. Therefore, distribution of those dens had some influence on the spatial distribution of raccoon dogs in
the study area. Based on mean annual home range size, we estimated the mean local population density during winter as 1.1
individuals per square kilometre and during summer as 4.90 individuals per square kilometre. 相似文献
7.
Ines Fürtbauer Oliver Schülke Michael Heistermann Julia Ostner 《International journal of primatology》2010,31(4):501-517
Information on basic reproductive parameters and life-history traits is crucial for the understanding of primate evolution,
ecology, social behavior, and reproductive strategies. Here, we report 4 yr of data on reproductive and life-history traits
for wild female Assamese macaques (Macaca assamensis) at Phu Khieo Wildlife Sanctuary, northeastern Thailand. During 2 consecutive reproductive seasons, we investigated reproductive
behavior and sexual swelling size in 16 females and collected 1832 fecal samples. Using enzyme immunoassays, we measured fecal
estrogen and progesterone metabolites to assess ovarian activity and timing of ovulation and to ascertain conceptions and
pregnancies. Timing of reproduction was strictly seasonal (births: April–July, 86% in April–June, 4 yr, n = 29; conceptions: October–February, 65% in December–January, 2 yr, n = 17). Females showed no cyclic ovarian activity outside the mating season and conceived in their first or second cycle (mean:
1.2 cycles to conception, n = 13). Gestation length was on average 164.2 d (range: 158–170, n = 10), and females had their first infant at an age of 5 yr (n = 4). Interbirth intervals were bimodally distributed, with females giving birth on average every 13.9 or 23.2 mo. Shorter
interbirth intervals were linked to early parturition within the birth season. Most females displayed subcaudal sexual swellings
which, however, did not reliably indicate female reproductive status or fertility. Overall, our results fall within the range
of findings reported for other macaque species. These results thus add to the growing body of information available for wild
macaques, facilitating comparative studies for a better understanding of interspecific differences in social and reproductive
patterns. 相似文献
8.
Yankuo Li Zhigang Jiang Chunwang Li Cyril C. Grueter 《International journal of primatology》2010,31(4):609-626
The distribution of food resources in time and space may affect the diet, ranging pattern, and social organization of primates.
We studied variation in ranging patterns in a group of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) over winter and summer in response to variation in their diet in the Qingmuchuan Nature Reserve, China. There was a clear
diet shift from highly folivorous in winter to highly frugivorous in summer. The home range was 8.09 km2 in summer and 7.43 km2 in winter, calculated via the 95% kernel method. Corresponding to the diet shift, the focal group traveled significantly
longer distances in summer (mean 1020 ± 69 m/d) than in winter (mean 676 ± 53 m/d); the daily range was also significantly
greater in summer (mean 0.27 ± 0.02 km2/d) than in winter (mean 0.21 ± 0.01 km2/d). There was no significant variation in home range size between winter and summer, and the monkeys did not use geographically
distinct ranges in summer and winter. However, overlap in the actual activity area and core range between winter and summer
was only 0.13 km2, representing 4.4% of the summer core area and 5.3% of the winter core area. Differences were apparent between summer and
winter ranging patterns: In summer, the group traveled repeatedly and uninterruptedly across its home range and made 3 circles
of movement along a fixed route in 31 d; in winter, the activity area was composed of 3 disconnected patches, and the focal
group stayed in each patch for an average of 8 successive days without traveling among patches. Winter range use was concentrated
on mixed evergreen and deciduous forest patches where leaves and fruits were available, whereas the summer range pattern correlates
significantly positively with the distribution of giant dogwood (Cornus controversa) fruits. Thus it appears that the diet shift of Sichuan snub-nosed monkeys between winter and summer caused the monkeys to
use their home range in different ways, supporting the hypothesis that food resources determine primate ranging patterns. 相似文献
9.
Steven C. Minta 《Oecologia》1993,96(3):402-409
I tested the following hypotheses of territorial polygyny on badgers (Taxidea taxus: Carnivora; Mustelidae): Competition among adult females for food should result in intrasexual territoriality, while male
competition for females should result in larger territories that encompass multiple female territories. The sagebrush-grassland
study area (Wyoming, USA) contained a depauperate terrestrial fauna with a dense badger population preying on high densities
of ground squirrels (Spermophilus armatus). Implant telemetry generated locations for analysis of home range and spatio-temporal interaction. During the summer breeding
season males doubled movement rates and nearly tripled home range areas to overlap those of females. Before and after the
breeding season, males reduced their home ranges to sizes nearer those of stable female ranges (
=2.82 km2). Unexpectedly, home range overlap between males and females was no different than intrasexual overlap. However, analysis
of spatio-temporal interaction revealed that females spatially avoided one another, while males were spatially and temporally
attacted to one another, similar to that of male-female interactions. Presumably, olfactory mechanisms allow resource tracking
and lagged communication. Male-male territoriality was not viable, most likely because the high density of badgers, combined
with the severely male-biased sex ratio (1.75:1), effectively increased intruder pressure — as a resource, receptive females
were too mobile and spatially unpredictable within their home ranges. Consequently, males monitored and searched widely for
relatively scarce females during the breeding season with the effect of attracting each other. Male mobility, home range size,
and possibly aggression increased with age, suggesting age-related breeding tactics, although dominance could only be surmised.
This and other studies suggest how the spatial, temporal, and dominance components of carnivore resource partitioning and
sociality will be understood better by unraveling the interplay of olfactory processes, attributes of disparate resources
(e.g., food vs. females), seasonality, and population density and age-sex structure. 相似文献
10.
We examined vervet monkey (Chlorocebus pygerythrus) space use using GPS/UHF telemetry data from 10 vervet monkeys across six troops over 9 months within a 420 ha suburban eco‐estate. We documented a mean home range of 0.99 km2 (95% MCP) and 1.07 km2 (95% KDE) for females (n = 6), 1 km2 (95% MCP) and 1.50 km2 (95% KDE) for males (n = 4) and 0.87 km2 (95% MCP) and 1.12 km2 (95% KDE) for troops (n = 6), respectively, indicating that males and larger troops had larger home ranges. These relatively small home ranges included shared territorial boundaries and high home range overlap. Vervet monkey movements indicated higher morning activity levels, and habitat selection indicated significantly more use of golf course, urban residential and forest, thicket and woodland areas, and avoidance of wetland, grassland and shrub, and urban built‐up areas. Our results suggest that modified habitat use by vervet monkeys is a consequence of behavioural facilitation to access highly available food resources, thereby facilitating their persistence in green spaces in urban areas of South Africa. Conflict management is dependent on the conservation of sufficient natural habitats and food resources, to minimise their dependence on anthropogenic supplementary food resources and consequently reduce human–monkey conflict. 相似文献
11.
Patrick S. Nadeau Scott G. Hinch Kimberly A. Hruska Lucas B. Pon David A. Patterson 《Environmental Biology of Fishes》2010,88(3):241-251
In 2005 and 2006, adult sockeye salmon (Oncorhynchus nerka) were captured en route to spawning grounds and placed in either a slow (∼ 0.1 m·s−1) or fast (∼0.4 m·s−1) water velocity treatment for 18 days in order to assess how migrational energy depletion during the final stages of maturation
affected physiological condition and survival. Fish in the fast treatment utilized more energy than the slow treatment in
2005 (0.91 MJ kg−1 vs. 0.43 MJ kg−1; P = 0.010), and 2006 (0.72 MJ kg−1 vs. 0.37 MJ kg−1; P = 0.021). Non-treatment fish captured upon arrival at spawning grounds showed energy levels intermediate to the two treatments
in 2005 and lower than both in 2006, suggesting that energy use during the treatments were within levels normally experienced
by this population. No differences in survival were found between treatments (P > 0.05), although females had lower survival than males in both years (both P < 0.01). After 18 days, surviving fish from the fast treatment showed signs of elevated physiological stress relative to
fish from the slow treatment. Specifically, plasma osmolality was lower in fast fish in 2005 (P < 0.001), as was plasma chloride in both years (both P < 0.02). In 2006, plasma lactate was higher (P = 0.014) in fast fish. Within the ranges of energetic depletion that were examined here, a more energy-intensive migration
can have a substantial influence on the physiological condition and stress of adult sockeye salmon, but not on survival. 相似文献
12.
The aim of the study was to estimate home range areas and distance of movement away from a squaretail coralgrouper (Plectropomus areolatus) spawning aggregation site located within a small-scale 1.5 km2 Marine Protected Area (MPA) in Pohnpei, Micronesia. Fifteen P. areolatus were acoustically tagged and re-located within a ca. 50 km2 search area over a 4-month period that included reproductive and non-reproductive months. All relocated fish were found in
areas of moderate to high coral cover either on the fore reef or inside the lagoon in home ranges of 0.048 ± 0.018 km2 (μ ± S.E.). Variability in home range area (0.004–0.12 km2) and distance of movement from aggregation sites following spawning (0.02–23.0 km; 5.3 ± 3.6 km, μ ± S.E.) was observed,
but did not appear to be sex specific. Five of the six relocated individuals were found within 0.02–6.1 km of the aggregation.
This evidence and that from recent tag-recapture studies of epinephelids suggest that a substantial proportion of individual
P. areolatus spawning populations reside within close proximity to their respective aggregation sites. Reproductive populations could
be protected by MPAs of moderate scale (10 s of km2) that include aggregation sites, migratory corridors and adjacent home range habitats. 相似文献
13.
Ranging of <Emphasis Type="Italic">Rhinopithecus bieti</Emphasis> in the Samage Forest,China. I. Characteristics of Range Use 总被引:1,自引:1,他引:0
Cyril C. Grueter Dayong Li Carel P. van Schaik Baoping Ren Yongcheng Long Fuwen Wei 《International journal of primatology》2008,29(5):1121-1145
We quantified the home range and explored the style of ranging of black-and-white snub-nosed monkeys (Rhinopithecus bieti) in the subtropical-temperate montane Samage Forest (part of Baimaxueshan Nature Reserve) in the vicinity of Gehuaqing. Over
14.5 mo, we took positional records of the study band via a GPS receiver at 30-min intervals, and found that they covered
an area of 32 km2. Over a 10-yr period, the group even ranged in an area of 56 km2, which is among the largest home range estimates for any primate. The large home range was probably due to the combined effects
of large group size (N > 400) and forest heterogeneity, with seasonally food-rich areas interspersed with less valuable areas. The subjects did
not use their home range uniformly: 29% of the grid cells had more location records than expected based on a uniform distribution,
thus representing a core area, albeit a disjunct one. A continuous 1-mo group follow in the fall revealed that the band traveled
on average 1.62 km/d and that days of concentrated use of a particular forest block were followed by more extensive marches.
Neither climate nor human disturbance parameters correlate significantly with monthly estimates of the group’s home range
size. Even though there is no significant correlation between temporal availability of plant phenophases and range size, our
observations implicate temporal and spatial availability of food as a determinant of home range use of the focal group. Winter,
spring, and summer home ranges are equally large: 18.2, 17.8, and 18.6 km2, respectively. Home range decreased markedly in fall (9.3 km2), probably because the band obtained sufficient food resources (fruit) in a smaller area. The large winter range is best
attributed to the exploitation of dispersed clumped patches of mature fruits.
Cyril C. Grueter and∙Dayong Li contributed equally to the paper. 相似文献
14.
The seasonal home range size and spatial relationships of 16 adult genetsGenetta genetta Linnaeus, 1758 (6 males and 10 females) were estimated in a Mediterranean habitat of northeastern Spain. Genets minimum density
was estimated as 0.98/km2. Mean annual home range was 113.1 ha in males and of 72.0 ha in females. Males had larger home ranges than females in all
seasons, but differences were only significant in winter. Home range size changed seasonally and showed a similar pattern
in both sexes, with lower values in summer (males — 41.2 ha, females — 29.0 ha) and maximum ones in spring (males — 78.8 ha,
females — 56.1 ha). Animals displayed spatial fidelity throughout the year. Core areas (MCP50) represented 27% and 19% of
total home range size for males and females, respectively. Resting home ranges (based on locations of inactive animals) were
9 times lower than overall home range size. Individuals of the same sex overlapped less than individuals of different sexes,
especially with regard to core areas, which showed almost no overlap. The results obtained suggest that (1) different factors
are likely to affect the space use of genets, such as body mass, food abundance and reproductive cycle; (2) genets use space
in a heterogeneous way, with areas of greater activity than others within their home range; (3) there was intrasexual segregation
with regard to space use. 相似文献
15.
Julie Marmet Benoît Pisanu Jean-Louis Chapuis 《European Journal of Wildlife Research》2009,55(5):497-504
Home range size, range overlap, and multiyear site fidelity were investigated for introduced Siberian chipmunks (Tamias sibiricus) in a French suburban forest from bimonthly trapping sessions for 4 years (2004–2007). Annual home range sizes (100% minimum
convex polygon, ±SE) were estimated from 39 trapping histories of 28 different adult residents. Males (N = 13, 1.86 ± 0.32 ha) had a home range 2.5 times larger than females (N = 26, 0.71 ± 0.08 ha); a male home range included significantly more trapping centers (arithmetic mean of capture locations)
of females (5.5 ± 0.7) than of males (2.3 ± 0.5). Chipmunks exhibited strong multiyear site fidelity: mean distance between
annual trapping centers of individuals trapped over two successive years was small (N = 82, 26 ± 2 m) compared to the largest home range length (ranging from 36 to 281 m); overlap between annual home range sizes
of residents was 84 ± 5% (N = 11). These results improve our understanding of the space occupation of this unknown species in a novel environment. 相似文献
16.
Solovchenko A Khozin-Goldberg I Recht L Boussiba S 《Marine biotechnology (New York, N.Y.)》2011,13(3):527-535
In order to develop a practical approach for fast and non-destructive assay of total fatty acid (TFA) and pigments in the
biomass of the marine microalga Nannochloropsis sp. changes in TFA, chlorophyll, and carotenoid contents were monitored in parallel with the cell suspension absorbance.
The experiments were conducted with the cultures grown under normal (complete nutrient f/2 medium at 75 μmol PAR photons/(m2 s)) or stressful (nitrogen-lacking media at 350 μmol PAR photons/(m2 s)) conditions. The reliable measurement of the cell suspension absorbance using a spectrophotometer without integrating
sphere was achieved by deposition of cells on glass–fiber filters in the chlorophyll content range of 3–13 mg/L. Under stressful
conditions, a 30–50% decline in biomass and chlorophyll, retention of carotenoids and a build-up of TFA (15–45 % of dry weight)
were recorded. Spectral regions sensitive to widely ranging changes in carotenoid-to-chlorophyll ratio and correlated changes
of TFA content were revealed. Employing the tight inter-correlation of stress-induced changes in lipid metabolism and rearrangement
of the pigment apparatus, the spectral indices were constructed for non-destructive assessment of carotenoid-to-chlorophyll
ratio (range 0.3–0.6; root mean square error (RMSE) = 0.03; r
2 = 0.93) as well as TFA content of Nannochloropsis sp. biomass (range 5.0–45%; RMSE = 3.23 %; r
2 = 0.89) in the broad band 400–550 nm normalized to that in chlorophyll absorption band (centered at 678 nm). The findings
are discussed in the context of real-time monitoring of the TFA accumulation by Nannochloropsis cultures under stressful conditions. 相似文献
17.
Pedro Bernardo Sarmento Joana P. Cruz Catarina I. Eira Carlos Fonseca 《European Journal of Wildlife Research》2010,56(1):59-66
Using camera-trapping techniques, the present study, conducted from 2005 to 2007, provides common genet abundance estimates
in Serra da Malcata Nature Reserve (central-eastern Portugal). We estimated genet abundance using the software CAPTURE. It
was possible to obtain a capture success of 1.49 captures/100 trap-nights. Considering the heterogeneity model (Mh), which presents higher biological significance, the estimated density varied between 0.50 (95% CI = 0.43–0.56 genets/km2) to 0.92 (95% CI = 0.87–0.97 genets/km2) genets/km2 with an average density value of 0.70 genets/km2 (95% CI = 0.58–0.82 genets/km2). These estimates emphasized this technique as a reliable method for assessing average genet density over large spatial scales
and for monitoring future changes in genet numbers. In terms of habitat selection, genets selected Quercus rotundifolia and Arbutus unedo woodlands and avoided Erica spp. and Cistus ladanifer scrubland and Eucalyptus stands. Considering the landscape heterogeneity outside the reserve, our study emphasizes the importance of the protected
area for small carnivore conservation. 相似文献
18.
Malaysia is the world’s leading producer of palm oil products that contribute US$ 7.5 billion in export revenues. Like any
other agro-based industries, it generates waste that could be utilized as a source of organic nutrients for microalgae culture.
Present investigation delves upon Isochrysis sp. culture in POME modified medium and its utilization as a supplement to Nanochloropsis sp. in rotifer cultures. The culture conditions were optimized using a 1 L photobioreactor (Temp: 23°C, illumination: 180 ∼ 200 μmol
photons m−2s−1, n = 6) and scaled up to 10 L outdoor system (Temp: 26–29°C, illumination: 50 ∼ 180 μmol photons m−2s−1, n = 3). Algal growth rate in photobioreactor (μ = 0.0363 h−1) was 55% higher compared to outdoor culture (μ = 0.0163 h−1), but biomass production was 1.3 times higher in outdoor culture (Outdoor = 91.7 mg m−2d−1; Photobioreactor = 69 mg m−2d−1). Outdoor culture produced 18% higher lipid; while total fatty acids (FA) was not significantly affected by the change in
culture systems as both cultures yield almost similar concentrations of fatty acids per gram of sample (photobioreactor = 119.17 mg
g−1; outdoor culture = 104.50 mg g−1); however, outdoor cultured Isochrysis sp. had 26% more polyunsaturated fatty acids (PUFAs). Rotifers cultured in Isochrysis sp./ Nanochloropsis sp. (1:1, v/v) mixture gave similar growth rate as 100% Nanochoropsis sp. culture (μ = 0.40 d−1), but had 45% higher counts of rotifers with eggs (t = 7, maximum). The Isochrysis sp. culture successfully lowered the nitrate (46%) and orthophosphate (83%) during outdoor culture. 相似文献
19.
Schizopygopsis younghusbandi younghusbandi is an endemic species whose distribution is restricted to the middle reaches of the Yarlung Zangbo River, being one of the
most important commercial fishes in this area. Age and growth of 606 specimens captured between October 2002 and April 2005
were studied. The range in standard length (L) was 65.7–387.3 mm and total weight (W) was 3.3–772.0 g. The relationship between
L and W was W = 0.000909L2.2493 for males and W = 0.000259L2.4781 for females. Age, determined from anal scales and lapillus otoliths, ranged from 3 to 18 years. The parameters of von Bertalanffy
growth functions, estimated by back-calculated length, were L¥ = 442.7mm LL_\infty = 442.7mm\;L, k = 0.0738 year−1 and t
0
= −1.4 year for males, and L¥ = 471.4mm LL_\infty = 471.4mm\;L, k = 0.0789 year−1 and t
0 = 0.2 year for females. Males and females exhibited statistically significant differences in growth. χ
2-test indicated that von Bertalanffy growth functions could well describe the growth of S. y. younghusbandi. The longevities were 39.2 and 38.2 years for males and females, respectively. Growth inflexion points were 10.2 and 12.0 years
for males and females, respectively, but 84.8% of the captures were at the smaller ages. So conservation and management schemes
for this population should be considered urgently. In addition, we found that populations from the upstream of the Lhasa River,
the downstream of the Lhasa River and the middle reaches of the Yarlung Zangbo River showed statistically significant differences
in growth patterns. 相似文献
20.
The growth rate, reproductive aspects, and natural mortality of chimaeras and ratfish are poorly known. In this study, life-history
parameters for cockfish Callorhinchus callorhynchus (Holocephali—Callorhinchidae) are estimated, which is an important fish resource exploited in Chile. Specimens were sampled
from the artisanal fishery captures, from November 2006 to November 2007. The standard length (SL) of males fluctuated between
20 and 62 cm, and between 21 and 70 cm for females. Von Bertalanffy growth parameters were estimated through length-frequency
data analysis using MULTIFAN. The length-weight relationship and von Bertalanffy growth parameters were significantly different
for males and females, as well as the length at 50% maturity. For males a model with 5 age-classes was the best, with asymptotic
length L
∞ = 52 cm SL, growth coefficient K = 0.473 yr−1, and age at length zero t
0 = −0.690 yrs. For females the best model was represented by 10 age-classes (L
∞ = 70.3 cm SL, K = 0.193 yr−1, t
0 = −1.158 yrs) in the length-frequency data sets. Length at 50% maturity of males was estimated in 43.7 cm SL, and in 50.2 cm
SL for females. The natural mortality rate fluctuated between 0.42 and 0.82 yr−1 for males and between 0.12 and 0.37 yr−1 for females, depending upon the method used. It is concluded that C. callorhynchus is a species with life-history parameters significantly different between males and females, and such differences should
be taken into account in future population dynamics analysis. 相似文献