| Abstract | Grivasti skakač alohtona je životinjska vrsta u Hrvatskoj koja obitava na planini Mosoru. Iz
ograđenog prostora 2002. godine pobjeglo je pet jedinki grivastih skakača od čega je
nastala današnja populacija koja se procjenjuje na oko 140 jedinki. Dok je u autohtonom
staništu populacija ugrožena zbog krivolova i gubitka staništa te je vrsta uvrštena na Crvenu
listu IUCN-a, većina introduciranih populacija pokazala je visoku prilagodljivost novim
staništima i visok potencijal za širenje na nova staništa.
Budući da papkari igraju ključnu ulogu u ekosustavima, poznavanje morfoloških, bioloških i
ekoloških osobina nužno je za ispravno gospodarenje istima. Alohtoni papkari mogu
predstavljati ozbiljnu prijetnju autohtonoj biološkoj raznolikosti. Poznato je da neke alohtone
vrste papkara imaju negativan utjecaj na područja u koja su unesene.
Da bismo bolje razumjeli ekologiju grivastih skakača, posebice njihovu dnevnu aktivnost,
izbor staništa te potencijal za daljnje prostorno širenje, uhvatili smo i označili jedanaest
životinja GPS-GSM ogrlicama.
Rezultati su pokazali tipičan bimodalni obrazac aktivnosti s dva vrhunca – prvi, jutarnji,
između 5:00 i 9:00 sati ujutro te drugi, popodnevni, između 16:00 i 19:00 sati. Praćene
životinje prosječno su se kretale 1,46 km na dan, a područje obitavanja iznosi 1872 ha.
Podatci upućuju da je disperzija grivastih skakača ograničena na područje planine Mosora
i malo je vjerojatno da će se proširiti.
Za potrebe morfometrijskih analiza prikupljene su mjere tijela i roga 30 grivastih skakača
(20 M, 10 Ž) legalno odstrijeljenih na Mosoru te je napravljena deskriptivna analiza
kvantitativnih mjera tijela i roga. Rezultati kvantitativnih morfoloških osobina grivastih
skakača s Mosora sugeriraju da je ova populacija dobro prilagođena sredozemnom
staništu. Uspoređujući dobivene podatke populacije s Mosora s ostalim populacijama,
vidljivo je da se bitno ne razlikuju.
Analizirajući prehrambene navike utvrdili smo da je vrsta pašnjačkog tipa, vrlo fleksibilna u
vidu prehrane te pokazuje velike sezonske varijacije. Glavninu hrane sačinjavale su različite
trave i lišće listopadnih stabala.
Rezultati ovog istraživanja upućuju na nova saznanja o životnim navikama ove vrste u
slobodnoj prirodi mediteranskog staništa te će pridonijeti boljem gospodarenju alohtonim
vrstama u Hrvatskoj, čime će se očuvati biološka raznolikost i ekosustav u izvornom obliku. |
| Abstract (english) | Barbary sheep is a nonnative animal species in Croatia that lives on the Mosor Mountain.
In 2002, five Barbary sheep individuals escaped from captivity, resulting in today's
population, which is estimated at around 140 individuals. While in the native habitat the
population is endangered due to poaching and habitat loss , and the species is listed on the
IUCN Red List, most of the introduced populations have shown high adaptability to new
habitats and a high potential for spreading to new habitats.
Since ungulates play a key role in ecosystems, knowledge of their morphological, biological
and ecological characteristics is necessary for their proper management. Non-native
ungulates can pose a serious threat to native biodiversity. Some non-native species of
ungulates are known to have a negative impact on the areas into which they have been
introduced.
These include predation, competition with native wildlife, diseases and their associated
consequences, hybridization and habitat alteration.
Due to the high growth rate and the ability to adapt to the diet, the results from the areas
where the Barbary sheep was introduced (Spain and the USA) show a rapid process of
dispersion and population increase, which is not the case on Mosor Mountain.
The motive of the research was to obtain the first information about the non-native ungulate
species that has been present on Mosor Mountain in open nature for twenty years using
modern and appropriate methods.
Although so far there is no empirical evidence related to any negative impact on native
fauna or flora from Barbary sheep, due to general and scientifically unconfirmed theses,
there is a negative opinion about this species in society.
Insights into autochthonous and nonnative populations of Barbary sheep with an emphasis
on their ecological, biological and morphological characteristics present the current
knowledge about the species. The chronology of the arrival of the Barbary sheep in Croatia
is shown, and the habitat where they were introduced, Mosor Mountain, is discussed
through the relief and climatic features of the plant community. To determine the daily
activity, habitat choice and dispersion estimation using two different methods, we caught
and marked one of the animals with GPS-GSM collars. No mortality was recorded while
capturing and tagging animals with collars. The total monitoring of marked animals lasted
from 2015. to 2019.
Daily activity in the research was measured using an accelerometer built into GPS-GSM
collars and a separate measurement of the collar's movement speed in 2 rectangular
directions. The information obtained from the two-axis sensor is not a binary activity status
(active-passive), but a numerical value, the result of the intensity and duration of the collar's
movement. The accelerometer measures activity using the x-axis and the y-axis. From the
x-axis and y-axis values, we obtained the total activity (VA) in the formula VA=sqrt(x2 +y2).
The collars we placed on the animals were programmed to record the location of the tracked
animal (GPS coordinates) every two hours. All the data from the GPS-GSM collars was
presented within the ArcGIS PRO program and further enriched using GIS analyzes and
publicly available data. We analyzed daily movements, habitat area, habitat characteristics
and changes in space use during the warm and cold part of the year.
For the purposes of determining dietary habits, samples of rumen content were taken from
animals that were legally shot on Mosor Mountain. Analyzes of rumen content samples of
Barbary sheep were made according to the methodology of Klansek et al. (1995).
The morphological characteristics of the body and horn growth were determined on 30
samples of Barbary sheep (20 M, 10 F) that were legally caught from 2014. to 2019. on
Mosor Mountain. The measurements were taken just after the individual was shot in the
mountain. All measurements were made by the same person using standard methodology.
We analyzed females and males separately, due to pronounced sexual dimorphism.
The results of daily activity showed a typical bimodal pattern of activity with two peaks, the
first in the morning between 5:00 and 9:00 a.m., and the second in the afternoon between
4:00 and 7:00 p.m. Afternoon activity is more pronounced than morning activity and lasts
longer. The peak of activity changed in accordance with the seasonal dynamics of the
photoperiod.
period of the lowest activity is in winter before dawn.
The home range of Barbary sheep on Mosor Mountain is the mountain ridge and
southeastern exposure. The monitored animals moved an average of 1.46 km per day, and
the area of their annual home range is on average 1872 ha. Data suggest that the dispersal
of Barbary sheep is limited to the Mosor Mountain area and is unlikely to spread. The activity
was mostly circular and vertical in home range and during the research, not a single tracked
animal moved away from the Mosor Mountain, and they very rarely stay on the northern
slopes.
Barbary sheep prefer and use extremely steep, rough and sunny terrains of the Mosor
Mountain with altitudes above 650 m/s. They spend most of their time on rocks and in
deciduous forests. They show the greatest tendency to use rock creep, where there are
very few in the habitat, while they use the forest habitat types a lot, but do not prefer them.
During the cold part of the year, Barbary sheep use terrains with a lower altitude and sunnier
exposures with a greater slope.
The species is of the pasture type, very flexible in terms of diet and shows large seasonal
variations. The main part of the diet consisted of various grasses and leaves of deciduous
trees. During the summer, they consumed much more leaves of deciduous trees than in
other seasons, which may indicate that they use it as a substitute for water. The results of
the quantitative morphological characteristics of Barbary sheep from Mosor Mountain
suggest that this population is well adapted to the Mediterranean habitat and indicate that
they do not differ significantly from other populations either in autochthonous or non-native
habitats. Males had significantly higher mean values of all quantitative variables, which
explains the pronounced sexual dimorphism of this species.
The results of this research indicate new knowledge about the life habits of this species in
the free nature of the Mediterranean habitat, and will contribute to better management of
nonnative species in Croatia, which will preserve biological diversity and the ecosystem in
its original form. |
