Search results for "Endangered Species"
showing 10 items of 173 documents
Living Together: The Parasites of Marine Mammals
2002
The reader may wonder why, within a book of biology and conservation of marine mammals, a chapter should be devoted to their parasites. There are four fundamental reasons. First, parasites represent a substantial but neglected facet of biodiversity that still has to be evaluated in detail (Windsor, 1995; Hoberg, 1997; Brooks and Hoberg, 2000. Perception of parasites among the public are negative and, thus, it may be hard for politicians to justify expenditure in conservation programmes of such organisms. However, many of the reasons advanced for conserving biodiversity or saving individual species also apply to parasites (Marcogliese and Price, 1997; Gompper and Williams, 1998). One fundame…
The headstarting technique is an ineffective method for conservation of the European pond turtle – elasticity analysis
2008
The European pond turtle ( Emys orbicularis ) is endangered in many areas within its distribution range. Thus, protection programmes for the turtle populations are in place. However, the efficiency of some techniques (including a highly manipulative one - headstarting) is questionable. Elasticity analysis was conducted using the life history data gathered in central Poland during the period 1986 - 2002. The analysis revealed that headstarting is a fairly ineffective method. The most effective methods are those that protect adult individuals. Thus, methods that can sustain a decreasing adult mortality rate should be recommended for turtle conservation.
Estimating the onset of dispersal in endangered Bonelli's Eagles Hieraaetus fasciatus tracked by satellite telemetry: a comparison between methods
2007
This project was funded by the Terra Natura Foundation. L.C. and P.L.-L. are supported by FPU grants of the Spanish Ministerio de Educacion y Ciencia (references AP2001-1444 and AP2005-0874, respectively).
Density and distribution patterns of the endangered species Pinna nobilis within the harbour bay of Favignana (Egadi Islands MPA)
2015
The fan shell P. nobilis (Linnaeus, 1758) is the largest marine bivalve in the Mediterranean Sea which acts as ecosystem engineer, offering an adequate substratum to several associated benthic species. P. nobilis is threatened by the reduction and loss of its natural habitat and by increased anthropogenic inputs into coastal waters. The knowledge on the population of this species are scarce, especially as concerns Sicily and its coasts. This study focused on the density of population, spatial distribution, level of burial and orientation of the population of P. nobilis in the harbour area of Favignana island (western coast of Sicily, Italy). The fan shell surveys were carried out by SCUBA d…
Measurement and Conservation of Species and Habitat Biodiversity at Different Scales on Small Mediterranean Islands
2021
In this paper we discuss current methodologies for measuring biodiversity, analyse pros and cons at different scales, and finally propose distribution mapping as the most suitable method for measuring floristic biodiversity on small Mediterranean islands. These territories often host endangered flora and habitats, and have peculiarities that distinguish them from the mainland and the larger islands.
Genetic diversity in Cytisus aeolicus Guss. (Leguminosae), a rare endemite of the Italian flora
1998
ABSTRACT Cytisus aeolicus Guss, is an endemic plant restricted to the isles of Vulcano, Stromboli and Alicudi in the Aeolian archipelago. All known populations were assayed for genetic variability using enzyme polymorphism. Allozyme variation at 16 loci coding for 10 enzyme systems was examined. The great majority of loci turned out to be monomorphic or fixed heterozygous. The observed genetic depauperation is indicative of historical factors, such as the bottleneck effect associated with migration, and the founder effect in population re-establishment. The low genetic diversity is largely partitioned within rather than among populations, indicating that extant populations have not been est…
A report on the conservation status of segetal weeds in Tajikistan
2014
Summary Intensification of agriculture has significantly diminished the populations of segetal weeds worldwide in recent decades. Remarkable changes to the entire flora and vegetation of man-made habitats are being observed in agroecosystems. The present study analyses, for the first time, the threat status of segetal weeds in Tajikistan. A group of 871 weed species were evaluated against IUCN criteria. The assessment of threat status revealed that 214 weed taxa have to be regarded as threatened in Tajikistan, including 18 endemic and four subendemic plants. Five species have been classified as extinct, 27 as critically endangered, 27 as endangered, 39 as vulnerable, 34 as near threatened a…
The contribution of forest restoration to the conservation of woody endangered species in Sicily
2017
Sicilian forest ecosystems are, in general, numerically poor in terms of their floristic composition. As many studies on Sicilian dendroflora have highlighted, such poorness is not intrinsic to forest formations, but it is due to the millenary human pressures. Repeated passage of fire, continuous wood usage and reforestations by single or few species dra- matically reduced the plant biodiversity of Sicilian forest ecosystems, often suffering of monodominance. The Sicilian dendroflora includes several endangered species, such as Abies nebrodensis, Betula aetnensis, Celtis tournefortii subsp. asperrima and subsp. aetnensis, as the wild pears, which in Sicily are represented by 4 endemic speci…
Parasites in sympatric populations of native and invasive freshwater bivalves
2021
An increasing threat to local, native freshwater mussels (Unionida)—an ecologically important but globally alarmingly declining group— is the invasion by exotic bivalves. The Enemy Release Hypothesis predicts that introduced species should benefit from enemy-mediated competition because they are less likely to be harmed by natural enemies, such as parasites, than their native competitors. We investigated within-site differences in parasitism between sympatric native (tot. five spp.) and invasive (tot. three spp.) bivalves in eight northern European waterbodies, which harboured totally 15 parasite taxa. In paired comparisons using within-site averages, the mean number of parasite species in …
Analysis of population genetic structure and variability using RAPD markers in the endemic and endangered Limonium dufourii (Plumbaginaceae)
1998
Limonium dufourii (Plumbaginaceae) is a triploid species, with apomictic reproduction, endemic to the east mediterranean coast of Spain, where it is present in only six populations with a few individuals in most of them. L. dufourii is included in the Red List of Endangered Species by the IUCN. Genetic variation and population structure in this species has been studied using RAPDs. Twelve different primers provided 124 reliable bands of which 33 were polymorphic among the 165 individuals analysed. Those polymorphic bands were able to define 44 different patterns, of which all but six were present in only one population. Several methods for statistical evaluation have been used for intra- an…