Life–history and ecological distribution of chameleons
... WILD, 1993, 1994), many species are known to suffer from the multiple conservation problems in the area (WILD, 1993, 1994), to the extent that the conservation status of a lot of these species herein is unknown (see NARESCON, 1992 for Nigeria). At Niger Delta, the various species of chameleons are n ...
... WILD, 1993, 1994), many species are known to suffer from the multiple conservation problems in the area (WILD, 1993, 1994), to the extent that the conservation status of a lot of these species herein is unknown (see NARESCON, 1992 for Nigeria). At Niger Delta, the various species of chameleons are n ...
Habitat and Niche
... A species’ niche must be specific to that species; no two species can fill the same niche. They can have very similar niches, which can overlap, but there must be distinct differences between any two niches. When plants and animals are introduced, either intentionally or by accident, into a new envi ...
... A species’ niche must be specific to that species; no two species can fill the same niche. They can have very similar niches, which can overlap, but there must be distinct differences between any two niches. When plants and animals are introduced, either intentionally or by accident, into a new envi ...
Impact of maximum sustainable yield on competitive community
... The above examples show that TMSY exists if species have similar biotic potentials, carrying capacities and competition coefficients and if they do not compete intensively. All of these conditions are hardly ever met in nature. With the difference among parameters increasing, TMSY may become smaller ...
... The above examples show that TMSY exists if species have similar biotic potentials, carrying capacities and competition coefficients and if they do not compete intensively. All of these conditions are hardly ever met in nature. With the difference among parameters increasing, TMSY may become smaller ...
reprint
... Gilbert, 1991), which would seem to support a model of hostshift-mediated diversification. For example H. cydno is, by Heliconius standards, a generalist that feeds on five Passiflora species at La Selva, Costa Rica. Its sympatric sister species, H. melpomene (Brown, 1981; Gilbert, 1991; Brower, 199 ...
... Gilbert, 1991), which would seem to support a model of hostshift-mediated diversification. For example H. cydno is, by Heliconius standards, a generalist that feeds on five Passiflora species at La Selva, Costa Rica. Its sympatric sister species, H. melpomene (Brown, 1981; Gilbert, 1991; Brower, 199 ...
building a regional species pool: diversification of the
... from New Jersey to Maine, and the other in the southeastern United States. The northeastern center of diversity is dominated by the ‘‘bluet’’ species within the genus (i.e., species having adults that are generally pale blue in base color). The southeastern diversity center is dominated by the group ...
... from New Jersey to Maine, and the other in the southeastern United States. The northeastern center of diversity is dominated by the ‘‘bluet’’ species within the genus (i.e., species having adults that are generally pale blue in base color). The southeastern diversity center is dominated by the group ...
Diversity, productivity and temporal stability in the economies ARTICLE IN PRESS
... contributes to many valuable ecosystem services such as carbon sequestration. Both models are capable of predicting the long-term persistence or stable coexistence of a large number of competing species if the species have the appropriate tradeoffs in their requirements for limiting resources and/or ...
... contributes to many valuable ecosystem services such as carbon sequestration. Both models are capable of predicting the long-term persistence or stable coexistence of a large number of competing species if the species have the appropriate tradeoffs in their requirements for limiting resources and/or ...
Geographic range of West African freshwater fishes
... Tabou catchments were not retained even though they are located in the region in question because of their low species richness (clearly underestimated). Although this set of 20 rivers does not truly form the Nilo-Sudanian region, it is referred to as such henceforth. Figure 1 shows the geographic z ...
... Tabou catchments were not retained even though they are located in the region in question because of their low species richness (clearly underestimated). Although this set of 20 rivers does not truly form the Nilo-Sudanian region, it is referred to as such henceforth. Figure 1 shows the geographic z ...
Latitudinal gradients and geographic ranges of
... et al., 1994; Blackburn & Gaston, 1996). There are a few exceptions, but these occur primarily at small taxonomic scales. For example, birds and trees both show the pattern, but nonrandom subsamples, such as penguins and pines, do not (Araya & Chester, 1993; Stevens & Enquist, 1998). A second robust ...
... et al., 1994; Blackburn & Gaston, 1996). There are a few exceptions, but these occur primarily at small taxonomic scales. For example, birds and trees both show the pattern, but nonrandom subsamples, such as penguins and pines, do not (Araya & Chester, 1993; Stevens & Enquist, 1998). A second robust ...
Cryptic species, cryptic endosymbionts, and geographical variation
... 1208 T A M A R A M . M C G O V E R N and M I C H A E L E . H E L L B E R G and with their environments in different ways (Haylor et al. 1984; Knowlton et al. 1992; Mokady & Brickner 2001), and by definition have independent population dynamics. Ecological differences that previously might have been ...
... 1208 T A M A R A M . M C G O V E R N and M I C H A E L E . H E L L B E R G and with their environments in different ways (Haylor et al. 1984; Knowlton et al. 1992; Mokady & Brickner 2001), and by definition have independent population dynamics. Ecological differences that previously might have been ...
Gauging the impact of fishing mortality on non
... of converting the total catch-at-length distribution (or its proxy) from a steady-state fishery into estimates of population size and fishing mortality at size. Properly, its use requires an estimate of the steady-state catch-atlength distribution of the total catch together with model parameters de ...
... of converting the total catch-at-length distribution (or its proxy) from a steady-state fishery into estimates of population size and fishing mortality at size. Properly, its use requires an estimate of the steady-state catch-atlength distribution of the total catch together with model parameters de ...
Status of the World`s Tortoises and Freshwater Turtles
... most of these were giant tortoise species on Mauritius and other Indian Ocean Islands. Several species feared extinct only a decade ago have been rediscovered in recent years through targeted coordinated surveys, and heroic efforts are made to secure and expand the remnant populations of these and o ...
... most of these were giant tortoise species on Mauritius and other Indian Ocean Islands. Several species feared extinct only a decade ago have been rediscovered in recent years through targeted coordinated surveys, and heroic efforts are made to secure and expand the remnant populations of these and o ...
Connectance in stream food webs
... The power–law relationship between links and web size (L = αS β) not surprisingly confirmed that the number of links increases with web size, but we obtained an exponent (β) of S of 1·3, a value that differs significantly from the link-species scaling ‘law’ (β = 1) and the constant connectance hypot ...
... The power–law relationship between links and web size (L = αS β) not surprisingly confirmed that the number of links increases with web size, but we obtained an exponent (β) of S of 1·3, a value that differs significantly from the link-species scaling ‘law’ (β = 1) and the constant connectance hypot ...
PREDATOR IDENTITY AND ECOLOGICAL IMPACTS
... degree of similarity depends on the specific response variable. In our study we found no predominance of weak or strong interactors, as predators appear to be evenly distributed along a gradient of interaction strengths. Knowledge of the identity of the species occupying a particular trophic positio ...
... degree of similarity depends on the specific response variable. In our study we found no predominance of weak or strong interactors, as predators appear to be evenly distributed along a gradient of interaction strengths. Knowledge of the identity of the species occupying a particular trophic positio ...
The metacommunity concept
... Clusters of oceanic islands exemplify the first category, with oceans providing barriers to dispersal to different degrees depending on the taxa considered (Mehranvar & Jackson 2001). The vast literature on island biogeography is a starting point for finding many potential examples of communities wh ...
... Clusters of oceanic islands exemplify the first category, with oceans providing barriers to dispersal to different degrees depending on the taxa considered (Mehranvar & Jackson 2001). The vast literature on island biogeography is a starting point for finding many potential examples of communities wh ...
Title: Fine-scale and Microhabitat Factors Influencing Terrestrial
... habitat types, a broad-quadrat sampling (large quadrats; 8m x 8m) technique would be most appropriate for this study (Jaeger and Inger 1994). However, thoroughly sampling and classifying habitat in such a large area may prove infeasible, therefore an enlarged pointsampling technique is posed, in whi ...
... habitat types, a broad-quadrat sampling (large quadrats; 8m x 8m) technique would be most appropriate for this study (Jaeger and Inger 1994). However, thoroughly sampling and classifying habitat in such a large area may prove infeasible, therefore an enlarged pointsampling technique is posed, in whi ...
This article discusses the various hypotheses proposed to explain
... found that 5 to 8 years after the clear-cut, the species richness was increased by 30 to 35%. Haeussler pointed out that this increase in diversity came at a price: the clear-cut disturbance stripped the land of important soil organic layers causing a shift in the type of plants colonizing the regio ...
... found that 5 to 8 years after the clear-cut, the species richness was increased by 30 to 35%. Haeussler pointed out that this increase in diversity came at a price: the clear-cut disturbance stripped the land of important soil organic layers causing a shift in the type of plants colonizing the regio ...
the vegetation history of snowdonia since the late glacial period
... is some evidence for this in the genetics of the Snowdon lily, since the genetic distance between the Welsh populations and their nearest Alpine neighbours, from which the Welsh plants presumably descended, was found to be greater than would be expected based on geographical distance alone, (Jones e ...
... is some evidence for this in the genetics of the Snowdon lily, since the genetic distance between the Welsh populations and their nearest Alpine neighbours, from which the Welsh plants presumably descended, was found to be greater than would be expected based on geographical distance alone, (Jones e ...
Leibold et al. 2004
... Clusters of oceanic islands exemplify the first category, with oceans providing barriers to dispersal to different degrees depending on the taxa considered (Mehranvar & Jackson 2001). The vast literature on island biogeography is a starting point for finding many potential examples of communities wh ...
... Clusters of oceanic islands exemplify the first category, with oceans providing barriers to dispersal to different degrees depending on the taxa considered (Mehranvar & Jackson 2001). The vast literature on island biogeography is a starting point for finding many potential examples of communities wh ...
Values & Ethics in Conservation
... A. INSTRUMENTAL VALUE cont. 1. Goods - - direct economic benefits derived from uses of individual species 2. Services - indirect economic benefits derived "free" from functioning ecosystems 3. Information - content of the genetic code represents a resource of knowledge ...
... A. INSTRUMENTAL VALUE cont. 1. Goods - - direct economic benefits derived from uses of individual species 2. Services - indirect economic benefits derived "free" from functioning ecosystems 3. Information - content of the genetic code represents a resource of knowledge ...
Some historic landmarks
... asks how well community-level patterns conform to predictions under the simplifying assumption that all individuals are equal (in terms of probability of recruiting, dying, and replacing themselves through ...
... asks how well community-level patterns conform to predictions under the simplifying assumption that all individuals are equal (in terms of probability of recruiting, dying, and replacing themselves through ...
Morphology and Niche Partitioning of Fish Assemblage in the Tonle
... mammals that hold high diversity after examining the length of the culmen in birds and the skull length in mammals was found in Hutchinson (1959). A conclusion was made that niche partitioning resulted from competition pressures that made closely-related warbler species to divide up a niche to coexi ...
... mammals that hold high diversity after examining the length of the culmen in birds and the skull length in mammals was found in Hutchinson (1959). A conclusion was made that niche partitioning resulted from competition pressures that made closely-related warbler species to divide up a niche to coexi ...
Biological Diversity - Punjab Biodiversity Board
... Maintaining genetic diversity within a group of plants or animals is extremely important because it allows populations to adapt when changes occur in their environment. If populations become too small, genetic diversity is lost. Populations that have little genetic diversity are often more vulnerab ...
... Maintaining genetic diversity within a group of plants or animals is extremely important because it allows populations to adapt when changes occur in their environment. If populations become too small, genetic diversity is lost. Populations that have little genetic diversity are often more vulnerab ...
Abstracts
... types (i.e., Bromus tectorum, Poa secunda, Sisymbrium altissimum and L. papilliferum) located within 20 m of ant colonies. We found that Owyhee harvester ants exhibited distinct seasonal patterns in seed resource use. Poa secunda seeds were overrepresented in the diet of ants early in the season. Ho ...
... types (i.e., Bromus tectorum, Poa secunda, Sisymbrium altissimum and L. papilliferum) located within 20 m of ant colonies. We found that Owyhee harvester ants exhibited distinct seasonal patterns in seed resource use. Poa secunda seeds were overrepresented in the diet of ants early in the season. Ho ...
On size and area: Patterns of mammalian body size extremes
... landmasses have a higher probability of picking up species with extreme values of body size. In statistical terms, the pattern presented in Fig. 1 is qualitatively predicted by the theory of order statistics (Balakrishnan and Cohen, 1991). The smallest and largest body sizes present in a landmass wi ...
... landmasses have a higher probability of picking up species with extreme values of body size. In statistical terms, the pattern presented in Fig. 1 is qualitatively predicted by the theory of order statistics (Balakrishnan and Cohen, 1991). The smallest and largest body sizes present in a landmass wi ...
Bifrenaria
Bifrenaria, abbreviated Bif. in horticultural trade, is a genus of plant in family Orchidaceae. It contains 20 species found in Panama, Trinidad and South America. There are no known uses for them, but their abundant, and at first glance artificial, flowers, make them favorites of orchid growers.The genus can be split in two clearly distinct groups: one of highly robust plants with large flowers, that encompass the first species to be classified under the genus Bifrenaria; other of more delicate plants with smaller flowers occasionally classified as Stenocoryne or Adipe. There are two additional species that are normally classified as Bifrenaria, but which molecular analysis indicate to belong to different orchid groups entirely. One is Bifrenaria grandis which is endemic to Bolívia and which is now placed in Lacaena, and Bifrenaria steyermarkii, an inhabitant of the northern Amazon Forest, which does not have an alternative classification.