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1.
A two year study was carried out on Gehyra variegata (Dumeril & Bibron) in the Pilliga Scrub by means of visits of six days duration in each month of the year. Animals were individually marked by toe-clipping and a mark-recapture programme was carried out throughout the study.
This arboreal gecko lives below the bark of dead trees or stumps most commonly at a height of two to three feet from the ground.
The mark-recapture programme provided extensive data on the population, its movements, growth, tail loss and regeneration. Monthly samples were collected for intestinal analysis and for gonadal studies. These together with behavioural observations provided a well corroborated picture of the biology of this small gekkonid lizard.  相似文献   

2.
A breeding population of Rana japonica was studied at a marsh on the campus of Hiroshima University in Higashi-Hiroshima during the five years 1995-1999. The mark-recapture study showed that the size of the breeding population varied from year to year, and increased more than twofold in 1999 in comparison with the preceding years. The sex ratio of the breeding population (male/female) was from nearly 1.0 to 1.6. Frogs of both sexes were estimated to breed for the first time at the age of one or two years, and their maximum age was four years according to skeletochronology using phalanges and mark-recapture. Modes of the estimated ages were one year for males during the study years except 1997, but one or two years for females. Two thirds of breeding frogs, irrespective of their sex, were estimated to breed only once throughout their lives.  相似文献   

3.
Axillary buds and bark samples of resistant, moderately resistant and susceptible (control) cassava genotypes either naturally infected under field conditions or experimentally inoculated by grafting were indexed for African cassava mosaic virus (ACMV). Virus detection was carried out using enzyme‐linked immunosorbent assay and polymerase chain reactions to determine the distribution of the virus within the plant and elucidate the genotypes response to virus movement. Significantly more bud and bark samples were positive for virus on the susceptible genotype TME 117 than resistant genotypes TMS 30001 and TMS 91/02319, or the moderately resistant genotype TMS 30572. Detectable virus concentration was significantly lower in the buds of moderately resistant and resistant genotypes than the susceptible control. Under field conditions, it was significant that more primary stem buds were infected than the buds of secondary and tertiary stems but such a gradient was not obvious with bark samples. Shoots that had asymptomic new leaves after the initial symptomatic leaves had no virus in their buds, but some of the bark samples from the same plants tested positive. A significant interaction was observed between year and stem type, and among year, genotype and stem type with respect to virus detection in bud and bark samples. Restriction of virus movement into axillary buds occurred in all the resistant and moderately resistant genotypes. This may explain ACMV‐infected stem cuttings of resistant genotypes producing healthy plants in subsequent generation.  相似文献   

4.
The otoliths of the scarid Scarus schlegeli (Bleeker) from the Lizard Island on the northern Great Barrier Reef showed a series of clear periodic bands. The rate at which bands are deposited on the otoliths was distinguished by mark-recapture experiments using tetracycline and marginal increment analysis. Mark-recapture experiments were carried out both in the field and in a large aquarium system. One otolith band was deposited during the liberty periods of July 1990 to April and September 1991 while two similar bands were formed from November 1989 to February 1991. The marginal increment analysis indicated that annual bands were formed around the austral summer. Scales also displayed regular period check marks. These provided relatively reliable aging estimates for the younger fishes up to 5 years.  相似文献   

5.
Lindgren funnel traps baited with aggregation pheromones are widely used to monitor and manage populations of economically important bark beetles (Coleoptera: Scolytidae). This study was designed to advance our understanding of how funnel trap catches assess bark beetle communities and relative abundance of individual species. In the second year (2005) of a 3-yr study of the bark beetle community structure in north-central Arizona pine (Pinus spp.) forests, we collected data on stand structure, site conditions, and local bark beetle-induced tree mortality at each trap site. We also collected samples of bark from infested (brood) trees near trap sites to identify and determine the population density of bark beetles that were attacking ponderosa pine, Pinus ponderosa Douglas ex Lawson, in the area surrounding the traps. Multiple regression models indicated that the number of Dendroctonus and Ips beetles captured in 2005 was inversely related to elevation of the trap site, and positively associated with the amount of ponderosa pine in the stand surrounding the site. Traps located closer to brood trees also captured more beetles. The relationship between trap catches and host tree mortality was weak and inconsistent in forest stands surrounding the funnel traps, suggesting that trap catches do not provide a good estimate of local beetle-induced tree mortality. However, pheromone-baited funnel trap data and data from gallery identification in bark samples produced statistically similar relative abundance profiles for the five species of bark beetles that we examined, indicating that funnel trap data provided a good assessment of species presence and relative abundance.  相似文献   

6.
Mopane veld is of great value to the general ungulate spectrum in times of drought, and it is capable of retaining its dominance in a community even in the presence of extremely heavy browsing pressure imposed by large browsing mammals. Scrub mopane (hedges) has been regarded as resulting from excessive browsing pressure by large mammals, especially elephants. Both the nutrient and chemical composition of mopane twig bark were investigated, the seasonal results being related back to the seasonal utilization of branches by large mammals. Mopane twigs were most palatable in winter. Eland feed on mopane throughout the year irrespective of palatability. Elephants were rarely present in the scrub mopane area before the onset of spring rains, when the major mopane leaf flush occurs independently of rainfall. The impact of both species was not excessive and recruitment of mopane seedlings does occur. Herbivore browsing is responsible for a mopane morph which buds early and continues to produce accessible, nutritious leaves even when heavily browsed. Many browsing ungulates are reliant on this resource during the stressful transition from spring to summer in south-eastern Botswana.  相似文献   

7.
We describe and evaluate a new telemetry system based on GSM (Global System for Mobile Communications) mobile phone technology that may provide mark-recapture data for single year survivorship studies. These phone-tags automatically attempt to send an SMS text message once every two days. The successful receipt of a text message ashore constitutes a resighting event within the coastal zone of GSM coverage. Haul-out data and coastal location data are incorporated into the messages. Data are presented for a three-month period (January-March) following tag deployment on 59 gray seal ( Halichoerus grypus ) pups at the Isle of May (Scotland). An average of 15.5, 4.1, and 8.2 seals succeeded in registering within each three-day period in January, February, and March, respectively. Tags registered with a wide geographical range of GSM radio cells on the Scottish and English east coasts, and also from Norway and Germany. Haulout records covering 54% of the animals' time were received. With future modifications to the tags, this figure should approach 100%. The median delay to network registration was 9.6 sec from a seal in the sea (not hauled out). These data show that GSM mobile phone telemetry is a useful technique to obtain haul-out and mark-recapture data.  相似文献   

8.
1.?Trade-offs among life-history traits are common because individuals have to partition limited resources between multiple traits. Reproductive costs are generally assumed to be high, resulting in reduced survival and fecundity in the following year. However, it is common to find positive rather than negative correlations between life-history traits. 2.?Here, we use a data set from the individual-based study of red deer on the Isle of Rum to examine how these costs vary between individuals and at different ages, using multi-state mark-recapture methodology. 3.?Females that had reproduced frequently in the past incurred lower costs of reproduction in terms of survival in the following year and were more likely to reproduce in two consecutive years. Older individuals and those that had not reproduced frequently exhibited higher costs. 4.?These results highlight the importance of considering heterogeneity and individual quality when examining trade-offs and demonstrate the effectiveness of using detailed long-term data sets to explore life-history strategies using multi-state mark-recapture models.  相似文献   

9.
为了掌握危害枫香树Liquidambar formosana的小蠹种类及其危害情况,采用踏查和木段诱集两种方法于2016-2020年对我国枫香树有分布的11个代表省份或地区进行了系统调查.共调查鉴定危害枫香树的小蠹种类共18属34种,增加了地区分布新记录16种,其中对枫香造成严重危害的1种,造成中度危害的有3种,对上述...  相似文献   

10.
We used both direct (mark-recapture) andindirect (microsatellite analysis)methodologies to investigate dispersal betweentwo putative populations of brook charr (Salvelinus fontinalis) in Freshwater River,Cape Race, Newfoundland, Canada. Over a 5-yearstudy period, mark-recapture data revealed somemovement by fish, but the proportion ofrecaptured fish migrating from one populationarea to another was low (0–4.1%).Additionally, during sampling periods in thespawning seasons, no fish was found in thealternate population area to that of its firstcapture. Despite this pattern of limitedmovement, microsatellite analysis based onsixteen polymorphic loci provided no evidenceof genetic differentiation. Indirect estimatesof dispersal parameters varied greatly betweendifferent methods of analysis. While use of acoalescent-based model yielded estimatedmigration rates congruent with the results ofthe mark-recapture study, other methodsresulted in much higher estimates of migrationbetween the populations. In particular, thelack of genetic differentiation coupled withlikely violations of the assumed island modelprevented generation of meaningful estimates ofdispersal using Fst. The disparitiesbetween migration rates estimated from themark-recapture work and from the differentindirect methods highlight the difficulties ofusing indirect methods to estimate dispersal onan ecological timescale. However,mark-recapture methods can fail to detecthistorical or episodic movement that isimportant in an evolutionary context, and wetherefore argue that a combination of directand indirect methods can provide a morecomplete picture of dispersal than eitherapproach alone.  相似文献   

11.
Changes in the vegetation of Australia since white settlement have been much discussed in recent times. In particular, the changes that have been reported to have occurred in the Pilliga forests in northern New South Wales have been used as a reference for other areas of the State. Two periods of pine regeneration are believed to have occurred in the Pilliga, but preliminary research concerning the history of these forests has uncovered various sources of information indicating that the story is a more complex. Climatic data, archival records and the biology and ecology of various flora and fauna are examined in this paper in a preliminary attempt to gain a more accurate picture of change or stability in the vegetation of this region.  相似文献   

12.
Accurate assessments of population parameters, such as survival and abundance, are critical for effective wildlife conservation. In order for wildlife managers to undertake long-term monitoring of populations, the data collection must be as cost-effective as possible. Two demographic modelling techniques commonly used are mark-recapture and mark-resight. Mark-resight can be used in conjunction with biotelemetry methods and offers a more cost effective alternative to the traditional mark-recapture models. However, there has been no empirical comparison of the demographic parameters obtained from the two modelling techniques. This study used photographs of natural markings to individually identify wobbegong sharks (Orectolobus maculatus) sighted during underwater surveys over a 2 year period, during eight distinct sampling periods, and analysed with Pollock’s robust design mark-recapture models. These estimates were then compared, using z tests, with Poisson-lognormal mark-resight models that used resightings of sharks previously tagged with telemetry transmitters, and the telemetry data to calculate the number of marked animals present in each sampling period. Sharks were categorised into four groups according to their sex and age-class (adult/juvenile). The results indicated that there was a high degree of transience in the population, with 62 % of sharks only being sighted in one sampling period. Based on normalized Akaike weights, there was no single ‘best’ model for either type of modelling technique and model averaging was used to determine the demographic estimates. Both models showed higher abundance of wobbegongs in the austral spring and summer seasons, however, the models produced statistically different results for five of the eight sampling periods. The mark-recapture model estimated apparent survival between 78 and 95 %, whereas the mark-resight models estimated it between 48 and 97 %. Crucially, there was no statistical difference between the survival estimates from corresponding sex/age-class. The temporary emigration parameters differed substantially between the model types. The mark-recapture model showed support for Markovian movement, whereas the mark-resight supported random emigration. The timing of the tagging events likely biased the abundance and temporary emigration parameters estimated by mark-resight models and must be taken into consideration when designing a mark-resight study. Despite this, this study shows that robust demographic estimates, that are comparable to labour intensive mark-recapture estimates, can still be obtained using mark-resight methods. Given the substantial increase in biotelemetry studies of medium and large sized vertebrates, mark-resight models may play an important future role in estimating demographic parameters.  相似文献   

13.
This research study purports to verify the effect produced on the motivation of physical education students of a multi-dimensional programme in dance teaching sessions. This programme incorporates the application of teaching skills directed towards supporting the needs of autonomy, competence and relatedness. A quasi-experimental design was carried out with two natural groups of 4th year Secondary Education students - control and experimental -, delivering 12 dance teaching sessions. A prior training programme was carried out with the teacher in the experimental group to support these needs. An initial and final measurement was taken in both groups and the results revealed that the students from the experimental group showed an increase of the perception of autonomy and, in general, of the level of self-determination towards the curricular content of corporal expression focused on dance in physical education. To this end, we highlight the programme''s usefulness in increasing the students'' motivation towards this content, which is so complicated for teachers of this area to develop.  相似文献   

14.
Lantana (Lantana camara) poses a serious threat to the biodiversity of the dry rainforest vegetation at Forty Mile Scrub National Park, Queensland, Australia, by outcompeting native species and increasing vulnerability to fire. This pilot study tests the effectiveness of three weed control methods (hand pulling, a glyphosphate‐based foliar spray herbicide and a picloram‐ and triclopyr‐based basal bark herbicide) in removing lantana and their success in reducing lantana fuel loads. The foliar spray herbicide was the most effective in killing lantana, while manual pulling resulted in the largest decrease in fuel height. We suggest that foliar spraying will be most efficient for combating large infestations of lantana, while hand pulling techniques are recommended for creating firebreaks or when minimizing damage to native species is paramount.  相似文献   

15.
Long-term field studies on placozoans (Trichoplax adhaerens), including both substrate sampling and slide sampling, were carried out at a subtidal site near Shirahama, Japan. Samples of natural substrate materials from the field, such as stones, shells, or fragments of coral, were particularly useful for obtaining placozoans. Results from the substrate sampling indicate that placozoans are present year-round at the study site. Large intermittent peaks in the number of animals collected at the study site occurred roughly once a year, between late summer and the beginning of winter. Placozoans were present every year from 1989 through 2000. A seawater aquarium was also studied and provided a considerable number of placozoans for more than 1 year.  相似文献   

16.
The Pilliga forest in northern inland New South Wales, Australia, is one of the largest surviving remnants of native forest on the western slopes of the Great Dividing Range. The Pilliga landscape is a challenging environment for molluscs, dominated by dry sclerophyll forest and with limited and largely ephemeral aquatic habitats. A field survey of the area in 2006–2012 identified a surprisingly rich and relatively intact aquatic native molluscan fauna with five species of bivalves in three families and nine species of freshwater gastropods (four families), including some rare species and range extensions. The native land snail fauna comprised 18 species (six families), including an unusually rich pupillid fauna with nine species. Some range extensions are recorded and some species are narrow-range endemics. The distributions of many aquatic and terrestrial species were correlated with geology or soil type. Introduced molluscs were predominantly found in anthropogenic habitats and include two freshwater gastropods (two families) and nine terrestrial snails and slugs (eight families). This study provides insight into the original molluscan fauna of the western slopes prior to landscape-scale agricultural development and provides a benchmark for future reference.  相似文献   

17.
The influences of wildfire through population dynamics and life history for two species of small mammals in a south-east Queensland heathland on Bribie Island are presented. Trapping results provided information on breeding, immigration and movement of Melomys burtoni (Grassland melomys) and Rattus lutreolus (Swamp rat). We first investigated and optimized the design of trapping methodology for producing mark-recapture population estimates to compare two adjacent populations, one of which was subjected to an extensive wildfire during the two year study. We consider how well rodents survive wildfire and whether the immediate impacts of fire or altered habitat have the greatest impact on each species. We found the R. lutreolus population was far more influenced by the fire than the M. burtoni population both immediately after the fire and over 18 months of vegetation recovery.  相似文献   

18.
李明  龙正权 《昆虫知识》1998,35(6):340-343
本文首次报道了杨白织潜蛾LeucopterasusinellaHerrich-Schaffer在贵州的发生危害情况,详细记述了杨白纹潜蛾各虫态的形态特征和生物学特性。在贵阳和铜仁地区,杨树受害株率达95%~100%,受害叶率达75%以上,受害叶每叶虫数3.6米以上,株虫口密度84.8头以上。该虫在铜仁地区1年发生5代,越冬代9月上旬化蛹,翌年4月上旬羽化。成虫寿命4~8天。卵块产于叶片正面贴近主脉或主侧脉处,卵历期2~5天,每卵块平均16卵粒。幼虫孵化时从卵壳底部咬孔潜入叶片组织取食叶肉,历期8~20天,幼虫老熟后咬破上表皮钻出,在被害叶片背面或吐丝下垂至下部叶片的叶背或下部主干与分技交界处的树皮裂缝中织“H”形茧化蛹。第一至第四代蛹历期为8~11天。本文还提出了该虫的防治方法。  相似文献   

19.
Monitoring trends in abundance of pinnipeds typically involves counting seals at terrestrial haul-out sites during the breeding season. Counts of seals made at other times of the year are typically lower; however, it is often unknown whether this is because fewer animals are present or whether lower counts simply reflect a reduction in haul-out probability. Here we illustrate how photo-identification data from an individual-based study of harbor seals (Phoca vitulina) can be used to estimate seasonal variation in abundance and site fidelity. Monthly data collected over a two-year period were analyzed using a mark-recapture mark-resight model accounting for individuals transitioning between observable and unobservable states. Levels of site fidelity were high throughout the year and abundance estimates showed no seasonal pattern. This suggests that individual seals used haul-out sites to the same extent throughout the year, and that peaks in counts during the breeding season are a result of seasonal changes in haul-out probability. The results of this study have implications for understanding population sub-structuring, gene flow and disease spread.  相似文献   

20.
Ecosystem research by the working group Water Quality Research Loosdrecht lakes (WQL) was carried out from 1979 to 1990. A coordinated research programme, involving several research institutes and laboratories in The Netherlands, was initiated in 1983, i.e. a year before the reduction of external phosphorus loading by stripping, became effective. The paper summarizes the main results, with emphasis on insight they provide into the lake ecosystems.  相似文献   

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