1,720,989 research outputs found
Demographic dynamics of wild boar (Sus scrofa) populations in a National Park to management purpose
No full text
WILD BOAR INVASION TREATS BIODIVERSITY IN MEDITERRANEAN NATIONAL PARKS
No full textThe Wild Boar (Sus scrofa) is the most-widely distributed ungulate of the world. Since
the 1960s, wild boars went through a worldwide population expansion that increased
their overall geographic distribution as well as their population density in many areas
in Europe. For example
studies documented an increase of wild boar hunting bag by
540% during 1960
-
2002 in Northern Germany, meanwhile in France by 500% during
the 1973
-
1993, and in the next five years by an additional 900%. The widespread
increase in numbers and geographica
l range of this species might have a remarkable
impact on many plant communities and animal species, habitat structure and crop and
livestock production. The Cilento and Vallo di Diano National Park has instituted in the
1995 in the hotspot of Mediterranea
n region. From this period the administration of
Park has refunded, to the local communities, some of the damage declared for the
agricultural or traditional manufacture constructions imputable to wild boar actions.
Just at the end of 2009 National Park go
vernance started an organic plan to manage
the wild boar problem, in collaboration with University of Naples Federico II. Here we
report this action plan, arisen from an interdisciplinary approach in consideration of all
the components that are associated
to this problem. We developed simulation of
population dynamics in the national park, as well as to verify the effectiveness of the
management operations in progress throughout the action planed. We analysed the
population genetic characteristic, in the li
ght of European wild boar phylogenesis and
human translocation, hybridization with the domestic form and their effect on the wild
populations. We evaluated also population structure arising from this overpopulation.
The lack of natural predators, the eleva
ted environmental plasticity, and peculiar
reproductive biology of some hybrid populations would seem concomitant causes of
the high density both in natural and anthropic areas. Moreover wild boar ecological
invasion can create problem to some critical spe
cies like as orchids, birds nesting on
ground (i.e.
Alectoris graeca
) or lizards (
Podarcis sicula
). Wild boar problem involves
progressively many protected areas in Italy and the divulgation of a scientific
management can represent key factor for an
organic approach and a prompt for
research in conservation biology
La Coturnice, Stato e Conservazione delle Popolazioni del Parco Nazionale del Cilento, Vallo di Diano e Alburni
No full textThe Rock Partridge (Alectoris graeca) is a gamebird belonging Galliformes (gallinaceous birds), a wide order of heavy-bodied ground-feeding birds including a lot of well-known species, like turkey, grouse, chicken, and pheasant. Galliformes count about 275 species, divided in 73 genus and 5 families. These are generally medium size to large terrestrial birds, with a short and generally strong bill, short wings and strong legs. They usually prefer to run rather than fly, but if necessary they fly on short distance. Sometimes, male has brightly coloured plumage as well as facial ornamentations such as wattles or crests. Galliformes have a varied diet, with foods taken ranging from vegetarian items (roots, leaves, tubers, fruits, seeds) and to small animals including insects.
Phasianidae are the largest family of Galliformes and they include 155 species, among which the Rock Partridge.
The Rock Partridge is linked to dry agro-pastoral mountains with heathland, grass and low scrub, rocky escarpments or crags and small agglomerations bushy (10-20% of the total surface area) used as shelters, or repairs from adverse weather conditions and predators. This species tends to avoid bare soil, probably for the greater difficulty in such contexts to find the trophic resources (seeds, sprouts, etc.). The presence of the Rock Partridge is negatively correlated to the wooded areas, probably for their minor trophic importance and the increased presence of predators (such as foxes and wild cat).
The Rock Partridg is a typical mountain species that can be found between 800 and 2700 m with a maximum between 1000 and 1200 m in Apennine range. It prefers the mountain south side with a slope between a minimum of 30% to a maximum of 70% (higher values for the slopes with a gradient of 50-59%). Palearctic range of this bird involve Central and Eastern Europe; it is found throughout the Alps, from France to Austria, Central and Southern Apennines, and Sicily in Italy, in the Balkans, in Albania and in Greece.
Three living subspecies are usually recognized , which differ in some aspects of their coloration and somewhat more according to molecular studies: A. graeca saxatilis (central rock partridge) in Southern half of the Alps to Bosnia and Appenines; A. g. whitakeri (Sicilian rock partridge) restricted to Sicily; A. g. graeca (eastern rock partridge) distributed from Bosnia to Greece and Bulgaria.
The Rock Partridge has undergone a large decline since about 1950 throughout its entire distribution range and in some areas it seems to be even extinct.
The IUCN (International Union for the Conservation of Nature) classifies this species as Threatened or Near Threatened in Red Data Books in most of its range. In Italy, A. graeca is evaluated as Vulnerable and it is listed in the first attachment of the Birds Directive (79/409/CEE) by European Union. Furthermore, BirdLife International includes it in SPEC 2 (Species of European Conservation Concern) category (species which have an unfavorable conservation status in Europe).
Various phenomena are considered responsible for the decline of the Rock Partridge. The hunting pressure affects this species, so throughout districts of Campania it was forbidden, although there are in act several forms of poaching.
The Rock Partridge is also affected by climate change, studies on French Alps suggest that the partridges experienced a rapid decline since 1994, with a minimum 1997-98, caused by freezing winters between ‘94 and ’96.
Moreover, hybridization between different subspecies is one of the factors which seriously threatens the genetic integrity of the populations. It was recorded especially in the areas of transition between ranges of different species; for example, hybrids between A. rufa x A. greca (in Southern French) and A. chukar x A. greca (in Bulgaria and Romania) were recognized.
Finally, human depopulation of rural mountain areas and the consequent abandonment of traditional land management represent a treat for partridges. In fact, tree and shrub encroachment leads to a decrease in fragmentation of the agro-pastoral landscape, patches suitable for partridges reduce in size and increase in mutual distance. The Rock Partridge, linked to the agro-pastoral habitat, has suffered negative effects through a reduction in connectivity. The opportunity for individuals to move between suitable patches is severely limited causing the development of small and isolated populations. The small size associated with the isolation state can be a serious threat for a lot of populations. Small populations, if reproductively isolated, are the most exposed to inbreeding. In general, raise in inbreeding creates unfavorable conditions (inbreeding depression) and affect reproductive capacity, adaptation to environmental changes, and disease resistance. Inbreeding can indeed lead to disadvantageous or lethal traits causing even extinction of population.
The A. graeca decline is particularly pronounced in the Central and Southern Apennines, where it survives in small and fragmented populations. This species is present from Umbrian-Marchigiano Appennines to the Aspromonte (Marche, Umbria, Lazio, Abruzzo, Molise, Campania, Basilicata e Calabria regions) while it seems to be extinct in Northen Appennines, where it was considered present until the first decades of the last century. The total population is estimated to 1939 - 2436 couples, most of which (about 1500, accounting for 69-77% of the total) concentrated in Abruzzi.
In Campania, the Rock Partridge has undergone a rapid decline since about 1960. Currently, the Cilento and Vallo di Diano National Park (a protected mountain area in Southern Italy) is the only area where the conspicuous Rock Partridge populations can be found. These populations, waiting for further analyses of the Matese mountains, may be considered the only autochthonous ones in Campania. Thanks to their geographical position they may be an important link between the central Apennines populations and those of Basilicata and Calabria.
Also in Cilento, the status of A. graeca is affected by impact of human settlement: poaching and intensive hunting stress the few remaining populations; the introduction of congeneric allochthonous species could be the causes of interspecific competition or hybridization.
In the mountain of Cilento, the abandonment of traditional agricultural practices and depopulation of rural areas cause profound changes in the landscape structure and function. The resulting isolation condition could lead the Rock Partridge population toward a bottleneck. It is a sharp reduction in the size of a population due to environmental events or human activities that can reduce the variation in the gene pool of a population. After a bottleneck event, the chance of inbreeding and genetic homogeneity increases and unfavoured alleles can accumulate. In consequence of population size reductions and the loss of genetic variation, the ability to survive for population at the mercy of environmental changes, is reduced. Our research, using molecular genetic marker, have shown that A. graeca populations of Cilento have signature of past bottleneck. Continuous monitoring of this population is essential to define a conservation strategy.
Since 1998, a lot of studies were conducted by the Cilento and Vallo di Diano National Park Authority aimed to increase knowledge about the Rock Partridge and delineate suitable management and conservation plans. In the page of this book we tell about this long period research. We start from the estimation of size and distribution of this bird populations. Survey have started in the Park thanks to the involvement of academic researchers, birdwatchers, shepherds, hunters and their dogs. The Rock Partridge is an elusive animal and sniffer dogs are an efficient support for the census activities during the winter. In spring survey, in order to avoid any disturbance to breeding couples, was performed using a play-back method.
Geographic Information System was implemented to identify suitable areas in the Park. Multivariate, spatially explicit model based on ecological niche factor analysis (ENFA) was used to predict the habitat suitability (HS) of the A. graeca and to examine the connectivity of the habitat in the study area. ENFA revealed about 42 areas (landscape patches) with 100% suitability for the species, corresponding to approximately 40,000 acres of study area. However, only 15 patches was equal or greater than the minimum vital extension for the bird and 9 of these 15 patches are characterized by the presence of stable units of A. graeca.
In this patched landscape live a population scattered on nine mountain: M. Alburni, M. Motola, M. Serra Nuda, M. Cocuzzo delle Puglie, M. San Giacomo, M. Cerasuolo, M. Cervati, M. Faiatella and M. Raia del Pedale.
In each mountain we performed about 10 km transect long, with fixed listening points for receiving the acoustic signal. At each point, calls were launched for 4 minutes; the following five minutes were spent to listening to the responses.
The data collected in 1998 reveal the presence of small populations of Rock Partridge with an average density of less than 2 individuals/kmq in M. Alburni, M. Motola, M. Serra Nuda, M. St. Giacomo, M. Cervati, M. Faiatella and M. Raia Pedale. Analyses of population in the 2004 showed a slow but worrying demographic decline (1.63 ind/kmq). The number of breeding pairs were about 84 in 2006 when the densities increase to 2.17 ind/kmq remaining so until 2014. In fact, census in the spring and autumn seasons of 2014 has led to prove the presence of the species with he same densities of 2006 in the areas of M.ti Alburni, M.te Motola, M.te San Giacomo, Cervati, M.te Faiatella e Raia del Pedale. The population of Serra Nuda e M.te Cerasuolo seem to disappear.
The connectivity analysis shows that there are a isolated unit localized to north (mountains of Alburni) and other remained populations of Partridge to south (mountains of Motola, Serra Nuda, Cerasuolo, Cervati, Faiatella, Raia del Pedale).
One of the main management activities of the species in the Park is to preserve and enhance the connectivity among available areas that ensures species survival through maintaining gene flow, genetic variability and providing a source for individuals to offset losses caused by poaching, predation or natural disasters.
Identifying and protecting threatened habitats, while balancing the requirements of faunal management policies, economic stability and other human needs, is a key conservation objective. However, the identification and protection of suitable areas are not sufficient to ensure long-term species conservation; we believe that applying management strategies based on the restoration of connectivity through financial support and promotion of traditional agro-pastoral practices is essential for the preservation of Rock Partridge
HISTORICAL CHANGES OF LANDSCAPE AFFECT POPULATION SIZE AND CONNECTIVITY OF ITALIAN ROCK PARTRIDGE
No full textAfter the Second World War, agro
-
pastoral practices in
Italian mountain areas were
progressively abandoned due to the
development
of industry and intensive crop.
Human depopulation of rural mountain areas
and the consequent abandonment of
traditional land management are among the
greatest driving forces behind changes in
this ecosystem in whole Western
Europe. This change
involves a specific ecological
succession, in which
grassland gradually turns into scrubland and, ultimately, into
forest,
increasing in agro
-
pastoral landscape fragmentation, reducing patches size
and increasing in mutual distance. The animal associated
with agro
-
pastoral
habitat
may suffer from decreased connectivity as a consequence. The Rock
Partridge
(
Alectoris graeca
) is a mountain species endemic to Europe here
used as a model for
investigating the impact of habitat loss, fragmentation,
hunting and
climate change.
We compared the habitat suitability of the
Apennine Rock Partridge prior
to
abandonment of traditional agro
-
pastoral
activities with the current landscape, in
order to investigate the effect of
secondary succession on the distribution and v
iability
of the species. We
aimed to understand the type and extent of habitat loss that the
Apennine
population has experienced. We assessed the past landscape throughout
historical aerophotography an
d species distribution (c. 1900
-
1950) by
quantifying
anecdotal evidence from interviews. Current landscape and
distribution were assessed
from GIS resource and survey data respectively.
We applied ecological niche factor
analysis and connectivity approaches to
obtain historical and current Rock Partridge
hab
itat suitability. Results
indicated that in just five decades our study area has
experienced profound
changes in landscape structure and function. We observed a
drastic decrease
in connectivity as a result of a reduction in numbers and size of high
suitabi
lity patches. We suggest
to maintain a viable populatio
n it
requires an ensemble
of ecological conditions along corridors connecting the
actual residual populations. In
the Rock Partridge, we also showed that,
during this time period, species experienced
a
shift of niche and an
increase of marginality. However, if
the increased population’
s
fragmentation recorded since the 1900s persists, the
extinction of some of
the
subpopulations appears inevitabl
Landscape fragmentation and interspecific interaction can affect status of Italian hare
No full textHabitat fragmentation, caused by expanding of human activities through landscape,
has heavy effects on the status of natural populations. It causes: the reduction of total
biodiversity, the loss of reactivity of the whole ecosystem, and the increase of
ecological distances between populations. During the last decade, the endemic Italian
hare (Lepus corsicanus) shows a endangered conservation status due to the
fragmentation and scarcity of its populations. Globally, this species is classified as
vulnerable due to its variable conservation status across its restricted
geographic range. Italian hare decreasing can be also imputable to others different
factors: harvest, poaching, and the probable interspecific competition with congeneric
European hare (Lepus europaeus, introduced in the last decades by man for hunt).
However, the creation of several protected areas in southern and central Italy will help
the populations to recover. The goal of our work was provide a descriptive model to
explain actual distribution of Italian hare in relation to landscape fragmentation
and interaction with sympatric European hare. In order to suggest starting
point for management actions in the conservation planning of Italian hare. Cilento and
Vallo di Diano National Park is home of the greater population of Italian hare, of
peninsula, and here we validated ecological model and populations genetic analysis
from two species. Genetic approach can be a good tool to quantify status, probable
hybridisation, and dispersal, especially if it can be correlated with the connectivity of
the landscape. The results suggest that the Italian hare shows an ecological
requirement close to average of available resources in the considered landscape. The
genetic structure of this autochthonous species can be explained from habitat
suitability pattern, and it highlights the differences between the two species. By our
first results we can not exclude the inter specific hybridisation events. A lot of
conservation actions can be carried out to improve connectivity between Italian hare
subpopulations actually characterised by low gene flow: finding new corridors or
moving artificially the hare populations
Variazioni cromatiche nel geco (Tarentola mauritanica): causalità diretta e adattamenti evolutivi
No full text- …
