Vijabilnost populacija tekunice Spermophilus citellus (L., 1766) na području Srbije
Viability of European ground squirrel Spermophilus citellus (L., 1766) populations in Serbia
2015
Authors:
Ćosić, NadaContributors
Ćirović, DuškoJarić, Ivan
Đan, Mihajla
Kataranovski, Dragan
Ćirović, Duško
Document Type:
Doctoral thesis (Published version)
Metadata
Show full item recordAbstract:
The European ground squirrel (Spermophilus citellus, L. 1766) is endemic species
to the Central and Southeastern Europe. Its recent range is divided in two main parts by
the Carpathian Mountains. The northern part of the range is characterized by uniform
steppe habitats at low altitudes, while the southern part is situated on the Balkan
Peninsula, where different types of habitats, with different environmental conditions and
at different altitudes are present. The majority of Serbian populations is located in the
northern part of the country, i.e. in Vojvodina, while only a few small and isolated
mountain populations are present in the east and southeastern part of the country.
The European ground squirrel inhabits steppes, meadows and pastures covered with
short grass. These once widely distributed habitats, which were commonly inhabited by
European ground squirrels, had disappeared due to their intensive transformation into
agricultural land during the past few decades. Today, species survives only in very
isolated steppe-meadow fragments which are preserved within the dominant agricultural
matrix.
Given that a number of populations is continually declining throughout the range
and that the future survival of the species is put in danger, the European ground squirrel
has been protected since 2008 under the IUCN Red List of threatened species as a
vulnerable species (VU). Its status in Europe is governed by the EU Habitats and Species
Directive (Annexes II and IV) and the Convention on the Conservation of European
Wildlife and Natural Habitats, known as the Bern Convention (Annex II). Also, 414 of its
habitats are under protection regime within the Natura 2000 network. At the national
level, European ground squirrel is protected by law as a strictly protected species.
In order to analyze the genetic diversity and the structure of the European ground
squirrel in Serbia, a total of 180 tissue samples from 11 localities (Krušedol, Neradin,
Mala Remeta, Sremska Mitrovica, Banatska Palanka, Šušara, Mokrin, Lok and
Tomislavci from area of Vojvodina, one locality from Vlasina and one from Stara Planina
Mountain were collected during the 2007-2009. Density and abundance of the European
ground squirrel populations were estimated during the period 2004-2014 on the localities
Krušedol and Neradin, which are located on the periphery of Fruška Gora Mountain, as
well as on the locality Banatska Palanka, which is located on the periphery of the
Deliblato Sands. Finally, the minimum viable population size (MVP) was estimated using
the Vortex software.
The results gained in this study clearly indicated that the genetic diversity of
populations from Vojvodina is significantly higher than those from the periphery of the
species range, and similar to the genetic diversity of surrounding Pannonian populations
which are occupying a central position within the Northern phylogenetic group. On the
other hand, the results showed that the genetic diversity of mountain populations from
Vlasina and Stara Planina Mountain is significantly lower compared to the populations
from Vojvodina. All analyzed populations from Serbia showed high level of genetic
differentiation, indicating the presence of isolation and the absence of gene flow between
existing populations.
According to the cluster analysis, eleven studied populations from Serbia are
optimally grouped into four clusters. Populations from Vojvodina made first three
clusters, while two far mountainous populations from Vlasina and Stara Planina made the
fourth cluster. Arrangement of populations from Vojvodina by clusters indicates that the
Danube River, but not the Tisza River, represents a significant barrier to gene flow among
populations.
Observed populations showed high fluctuations in density and abundance during the
eleven studied years, both within and between localities. During this period, positive
population growth was observed only in the locality Neradin, while large fluctuations
were recorded on the localities Krušedol and Banatska Planka, followed by dramatic
decline in density and abundance.
According to the MVP analysis, for the survival of isolated populations of European
ground squirrel, preservation of 90% of genetic diversity and avoidance of the harmful
effects of inbreeding, it is necessary to ensure the presence of at least 300 individuals over
50 years. However, if we take into account different levels of demographic and
environmental stochasticity, MVP would be considerably larger. This pointed out the
need to establish more optimal habitat conditions and thus minimize large fluctuations in
the abundance caused by extremely adverse factors and increase the likelihood of
population survival.
The loss of suitable habitats, as well as the formation of barriers that prevent the
migration and gene flow between populations, currently represent the most important
factors that directly and indirectly affect the survival of populations of the European
ground squirrel.
The results from this study represent a good conservation basis and provide
guidance for an active approach to the protection and preservation of the European ground
squirrel in Serbia, development of the Action and Management Plans, as well as a basis
for the future fundamental ecological and conservation research of this endangered
species. Future conservation of the European ground squirrel in Serbia has not only the
national relevance. Namely, populations from Serbia and Bulgaria are of key importance
for the future preservation of the whole species, as these areas served as refugia from
which the species spread to the Central Europe during favorable climatic conditions in the
past. Therefore, we have a great obligation to preserve viable populations of the European
ground squirrel with a minimum loss of the existing genetic diversity.
Keywords:
European ground squirrel; European ground squirrel; Viability; Genetic diversity; Genetic structure; Microsatellites; Density; Abundance; MVP; Probabilities of extiction; Threatening factors; viability; genetic diversity; genetic structure; microsatellites; density; Abundance; MVP; probabilities of extiction; threatening factorsSource:
University of Belgrade, Faculty of Biology, 2015, 1-111URI
http://eteze.bg.ac.rs/application/showtheses?thesesId=2377https://fedorabg.bg.ac.rs/fedora/get/o:10350/bdef:Content/download
http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=1025023154
http://nardus.mpn.gov.rs/123456789/4181
https://radar.ibiss.bg.ac.rs/handle/123456789/2811