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1.
We present logistic regression models predicting the distribution and abundance of a threatened cryptic lizard, Delma impar (Pygopodidae), in the Australian Capital Territory (ACT). The models incorporate current habitat and historical land use and habitat change (woodland clearance, ploughing, grazing, fertilizer application). Information on historical land use was acquired from land survey maps, aerial photographs and from floristic indices of land management. Floristic indices were developed from a survey of local agronomists who scored individual plant species, responses to grazing, ploughing and fertilizer application. Floristic indicies proved to be more informative than floristic ordination analyses. It emerged that historical factors were of key importance for predicting the distribution and abundance of D. impar. Since European settlement, D. impar has apparently spread from primary (naturally treeless grasslands) into secondary grasslands (grassland formerly with an overstorey of trees) and has been locally excluded by some farming activities such as ploughing. We conclude that a combination of current habitat and past changes in habitat may be necessary to understand the current distributions of plant and animal species that have limited dispersal ability and that are susceptible to local temporary habitat destruction. Active conservation strategies involving, for example, assisted dispersal, may be important for these species.  相似文献   

2.
Reillo PR  Durand S  Burton M 《Zoo biology》2011,30(3):328-341
We describe the rearing and development of the first imperial parrot (Amazona imperialis) hatched and raised in captivity. A single egg was hen-incubated for 28 days, and the chick was parent-fed for ~14 days, after which it was removed for hand-rearing. Similar to wild, parent-reared imperial nestlings, the chick developed fully within 12 weeks, weaning at 540 g body weight. Endangered and endemic to Dominica, the imperial is a vital flagship for oceanic rainforest conservation. Chronicling the neonatal development of A. imperialis helps illuminate the natural history of this enigmatic species, whose secretive nesting habits and low population density have frustrated a detailed understanding of its ecology and reproduction.  相似文献   

3.
Two clutches of the red‐necked Amazon parrot, or Jaco (Amazona arausiaca), are described for the first time from intra‐cavity video recordings of natural nests in Dominican rainforest trees. Using a mini‐camera mounted on a telescoping pole, a clutch of two live chicks (∼8 weeks old) and one dead chick (∼5 weeks old at time of death), and another clutch of one live chick (∼4 weeks old) and two unhatched eggs were discovered in nesting cavities roughly 15 m from the ground in Carapite (Amanoa caribaea) and Gommier (Dacryodes excelsa) trees, respectively, near 600 m elevation. Information from these sightings is essential for quantifying the life history of the Jaco, a flagship species for Dominica's imperiled rainforest ecosystem. Zoo Biol 18:63–70, 1999. © 1999 Wiley‐Liss, Inc.  相似文献   

4.
Aim To investigate the distribution of Australian species of Sauropus. The information obtained is used to (1) identify areas of highest richness and centres of endemism, (2) investigate latitudinal gradients of richness and range size, (3) determine the types of rarity shown, and (4) provide hypotheses on historical biogeography of the genus within Australia. Location Australia. Methods Specimens from 17 herbaria and field searches were examined and label and field information collated on distribution, habit and habitat. Distribution information was used to map all species within 784 grid cells of 1° × 1° and within the 97 Australian ‘ecological regions’. Morphometric cluster analysis of species was conducted using Kulczynski association and flexible UPGMA on 23 character states. Simple regression was used to correlate species richness, density and range size to changes in latitude. CLIMEX is used to match the climate of the region of highest richness in Australia with other areas of the world. Results Species richness was highest within the tropical north of Australia, and most species were associated with tropical savanna woodlands. Two areas were identified as centres of endemism and these corresponded closely to areas of high species richness. Four morphological groups were identified. One species (Sauropus trachyspermus) was found to be widespread, however all other species had small geographical ranges. Species richness and range size were significantly correlated with changes in latitude. Ten species were found to be of the rarest type, warranting conservation initiatives. Main conclusions Two regions of high richness and endemism of Sauropus occur, Thailand and Australia. Within Australia, the Kakadu‐Alligator River and the Cairns‐Townsville areas were identified as centres of endemism and high species richness for Sauropus. Australian Sauropus in general occur in similar communities and climates as other members of the genus elsewhere. Ten of the 27 species of Australian endemic Sauropus are extremely rare and warrant conservation initiatives. Correlations of latitude to species richness are potentially due to Sauropus radiating from the climatically stable top end of Australia. Increasing range size in more southern latitudes may also be due to stability of climates in the top end or because there is more available land area at these latitudes. Sauropus micranthus, the only non‐endemic species, is probably a more recent invader from the Tertiary period when tropical rain forests where more extensive and congruent with those of New Guinea.  相似文献   

5.
A new species, Linum vuralianum Yılmaz & Kaynak, is described and illustrated from west Anatolia, Turkey. It is closest to L. flavum L., but differs by its annual or biennial life form, the presence of rosette leaves at anthesis, and the absence of staminodes. The World Conservation Union (IUCN) threat category and observations on the population are noted. The geographical distribution of the new species and its related taxon is given.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 459–462.  相似文献   

6.
The phylogenetic relationships of extant and extinct Megalyridae are analysed at the genus level. The dataset comprises seven outgroup taxa, all eight extant genera and a number of extinct taxa that have been associated with Megalyridae, including two genera from Maimetshidae, whose affinity with Megalyridae is uncertain. Analytical results are unstable because some of the fossil taxa have many missing entries. The most stable results are produced when the maimetshid taxa and Cretodinapsis are excluded. When included, these taxa fall outside crown‐group Megalyridae, the maimetshid taxa being the sister of Orthogonalys (Trigonalidae). Based on the results of our analyses, we synonymize the fossil genera Rubes Perrichot n.syn . and Ukrainosa Perrichot & Perkovsky n.syn . with Prodinapsis, creating the new combinations Prodinapsis bruesi n.comb . and Prodinapsis prolata n.comb . When comparing past and present distributions of Megalyridae with the results of the phylogenetic analyses, it is evident that the genera radiated in the Mesozoic, and that the family as a whole was much more widespread then. The present‐day distribution is essentially relictual, with range contraction since the early Tertiary probably being the result of climate deterioration, which caused the disappearance of tropical forests throughout the Palaearctic.  相似文献   

7.
In this paper, one new species, four new varieties and thirteen new records of Characeae from Hunan, China, are reported. They are Chara quadriscutulum, sp. nov., Nitella axilliformis var. biformis, var. nov., N. microcarpa var. unicarpa, var. nov., Chara braunii var. cylindrospora, var. nov., C. hydropitys var. hunanensis, var. nov., Nitella microcarpa Braun, N. leptoclada Braun, N. annandalei Pal, N. confervacea A. Braun, N. gracilliformis J. Groves, N. inversa Imahori, N. musashiensis Morioka, N. paucicostata T. F. Allen, N. acuminata var. gollmeriana (A. Br.) Zanev. et Wood, Tolypella boldii Sawa. Chara longifolia Robinson, C. pistianensis J. Vilhelm, C. grovesii Pal.  相似文献   

8.
Sustainable ecotourism development and conservation depend on understanding factors that affect flagship species. This study analysed environmental factors and their effects on flagship species: African buffalo (Syncerus caffer), red-river hog (Potamochoerus porcus), olive baboon (Papio anubis), duiker (Cephalophus spp.), and crocodile (Crocodylus niloticus) distribution in Bomfobiri Wildlife Sanctuary (BWS). Secondary data (camp reports 2017–2019) showed flagship species distribution across four vegetation types in 14 sites. Field observations were used to reconstruct camp report information using GPS coordinates to show animal distribution. Environmental factors were assessed based on the scope and severity of their threats to the species. PAST ver.3.06 was used to analyse animal and vegetation data. A total of 995 individual animals were recorded. Riverine forest (n = 325) had the highest, followed by semi-deciduous (n = 316), and woodland Savanna (n = 192). Bushfire was the major predictive factor on animal distribution, followed by grazing pressure, farming activities, elevation, and erosion. These findings imply that an increased scale of disturbances reduces the chance of sighting flagship animals. A higher concentration of these species in riverine and semi-deciduous forests calls for increased patrols as a conservation measure. Constructing viewing platforms and hiking trails in areas of higher animal activity would improve ecotourism development.  相似文献   

9.
This paper reviews the historical emphases in zoo behavioral research and the contribution of these studies to animal management and to advancement in the behavioral sciences. Some examples are provided from research conducted at the National Zoological Park and elsewhere. The potential for doing behavior studies of excellence in zoos and aquariums has become more complicated in recent years by 1) changes in the aims and objectives of modern zoological parks, especially the increasing emphasis on conservation, 2) changes in focus in the science of animal behavior itself, and 3) the tendency of trained behaviorists to assume positions as curators and directors without time for research. These issues represent challenges to be overcome so that zoos can continue to be important sites for the study of animal behavior and contribute to the science of animal management and conservation, as well as the advancement of theory in biology. © 1992 Wiley-Liss, Inc.  相似文献   

10.
The Alpine ibex Capra ibex and the wild goat Capra aegagrus are the only caprids known to have existed in the Balkan Peninsula. The agrimi is a feral primitive form of the domestic goat Capra hircus but may constitute an island subspecies of C. aegagrus endemic to Crete, Greece. Here, the distribution of C. ibex and C. aegagrus in this southernmost Balkan country was reviewed for the period from Middle Pleistocene until today through a scientific and historical document search. Such knowledge should provide directions to future conservation plans for these species and aid in tracing the origins of agrimi. Fossil locations indicate that both species lived in this country at elevations of similar altitude (≥10–?≤?2,497 m a.s.l.). C. ibex colonised Greece naturally, perhaps, not earlier than 126,000 years ago. It was spread over most of the mainland (36–41° N and 20–24° E) where from it disappeared after 5600 BC due to hunting. C. aegagrus constituted an exotic in Europe. Man introduced it to insular and mainland Greece (between 35–40° N and 19–26° E) from around 8600 and 7000 BC, respectively. It went extinct on the mainland probably before 6000 BC. Only C. ibex should, therefore, be restored to its former Balkan ranges. This review provides further support for the wild origin hypothesis for agrimi.  相似文献   

11.
12.
Long-term vegetation studies are needed to better predict the impact of future climate change on vegetation structure and distribution. According to the IPCC scenario, the Mediterranean region is expected to undergo significant climatic variability over the course of this century. Cedrus libani (A. Rich), in particular, is currently distributed in limited areas in the Eastern Mediterranean region, which are expected to be affected by such climate change. In order to predict the impact of future global warming, we have used fossil pollen data and model simulations. Palaeobotanical data show that C. libani has been affected by both climate change and human activities. Populations of C. libani survived in refugial zones when climatic conditions were less favourable and its range extended during periods of more suitable climate conditions. Simulations of its future geographical distribution for the year 2100 using a dynamic vegetation model show that only three areas from Mount Lebanon may allow its survival. These results extrapolated for cedar forests for the entire Eastern Mediterranean region show that forests in Syria are also threatened by future global warming. In southern Turkey, cedar forests seem to be less threatened. These results are expected to help in the long-term conservation of cedar forests in the Near East.  相似文献   

13.
Puccinellia pungens (Pau) Paunero is a narrowly endemic grass found in two continental saline lagoons of north-eastern Spain. This rare plant has been classified as 'at risk of extinction' in several national and European catalogues of endangered species. Recent demographic studies indicate that population sizes greatly exceed several million individuals, challenging that threat category. Our genetic analysis, based on allozymes, has shown that in spite of the large population sizes, very low levels of genetic variation were found in P. pungens . Genetic variation was similar in most populations, but the largest, Gallocanta lagoon as a whole, had less variation (35% polymorphic loci, 1.4 alleles/locus, H T = 0.038) than the more restricted Royuela range (45% polymorphic loci, 1.5 alleles/locus, H T = 0.056), suggesting a recent population expansion of the Gallocanta populations from few founder lines. The low genetic distances among populations also suggest a recent divergence. The low genetic variation observed cannot be explained fully by eventual clonal spread and rare seedling establishment in the hypersaline environment. This low variation seems to result from extreme recent population bottlenecks as a consequence of habitat conversion to agricultural fields. In the light of our data, it seems unlikely that reinforcement of populations could increase the genetic diversity of the populations. Hence, conservation efforts should focus on avoiding further habitat loss of this endangered steppe grass species.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 269–281.  相似文献   

14.
15.
The degree of influence of environment, location and geography on the distribution of closely-related Jekelius nitidus and Jekelius hernandezi , coleopteran species endemic to the Iberian Peninsula, was examined. Niche envelope model predictions of probable absence points were based on available presence information. Presence–absence information for each of the two species was logistic-regressed against climate, altitude, lithology, spatial and river basin variables from each of 100 km2 UTM Iberian Peninsula squares. Models predict that environmental conditions are suitable for both species in an area larger than that in which they have been found. The best-fitting environment model for J. nitidus , based on summer precipitation, area underlain by siliceous rocks, area with siliceous sediments and aridity index, explains more than 81% of total deviance. The final model, which includes spatial and river basin variables, accounts for nearly of 89% of total deviance. The best-fitting environment model for J. hernandezi, based on the area underlain by calcareous rocks, summer precipitation, aridity index, altitude and minimum annual temperature, explains 63% of total deviance. The final model based on both spatial and river basin variables accounts for nearly 70% of total deviance.
  Our results suggest that climate influences the distribution of both species similarly and that the acidic or basic nature of the substrate is the environment variable that most influences the occurrence of both species. The major degree of influence of river basin variables, together with lithologic variables, on the current distribution of both species may be due to the limited mobility of these flightless species.  相似文献   

16.
The development ofM. gale oil as an insect repellent has created a requirement for cultivation of the plant. Botanical evidence indicates thatM. gale is likely to thrive on well—aerated acid peatland and could become a valuable crop on land of low agricultural value. Plant growth would be enhanced by the prevention of grazing and could be combined with softwood forestry since the trees would benefit from soil nitrogen enrichment thanks to the symbiotic association ofM. gale andFrankia. The economics of oil production would be improved if additional compounds of value such as pharmacologically active fiavonoids could be extracted from the by-products.  相似文献   

17.
Using a large database on the spatial distribution of European springtails (Collembola) we investigated how range sizes and range distribution across European countries and major islands vary. Irrespective of ecological guild, islands tended to contain more endemic species than mainland countries. Nestedness and species co‐occurrence analysis based on country species lists revealed latitudinal and longitudinal gradients of species occurrences across Europe. Species range sizes were much more coherent and had fewer isolated occurrences than expected from a null model based on random colonization. We did not detect clear postglacial colonization trajectories that shaped the faunal composition across Europe. Our results are consistent with a multiregional postglacial colonization. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 498–506.  相似文献   

18.
19.
Abstract

During the 19th century, sail whalers hunted right whales throughout the southern oceans north of 50 degrees. This review seeks to document the recovery of southern right whales by comparing the northernmost recent sightings with older sightings that survive “fossilised” in historical records of the sail whaling era. Despite a steady expansion northwards in recent years, the present distribution of right whales is still far short of that recorded by sail whalers over a century ago.  相似文献   

20.
The decomposition of urea by Nitellopsis obtusa from Characeae was investigated. The intact cells were exposed to the inhibition by two typical urease inhibitors: boric acid and fluoride ion, used as a criterion to define if urease or UAL-ase is responsible for the ureolytic activity of the algae. It was found that boric acid and fluoride ion are simple competitive and slow-binding competitive inhibitors of Nitellopsis obtusa enzyme respectively, which is the response characteristic of urease. The inhibition constants equal to 2.3 and 0.1 mM for boric acid and fluoride ion, when compared to those of jack bean urease, indicate that in the observed kinetic behaviour of Nitellopsis obtusa urease partake transport processes taking place in the intact cells.  相似文献   

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