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ŠUMARSKI LIST 11-12/2011 str. 43     <-- 43 -->        PDF

N. Šprem, M. Piria, H. Novosel, T. Florijančić, B. Antunović, T. Treer: MORPHOLOGICALVARIABILITY... Šumarski list br. 11–12, CXXXV (2011), 575-583


Generally, a climatic, agricultural, and forestry vertical
gradient characterizes the Croatian territory, with a flat
Eastern region of the PannonianValley strongly influenced
by the Drava and Danube Rivers. This terrain
also includes large agricultural fields and predo minantly
oak and beech forests (N 45°43’28,2’’
EO 18°50’24,7’’). A Central hilly region with small
agriculture fields and mainly beech and chestnut
fo rests (N45°15’23,4’’ EO 16°15’26,7’’), the Western
region includes big mountains (N 44°46’28,4’’
EO 15°01’53,9’’)and the typical Mediterranean region
of the Adriatic Sea with small agriculture fields
(N 45°12’59,4’’ EO 14°13’21,5’’). These locations
were used because data of genetic analysis showed similarity
among same sampling sites (Šprem 2009). All
animals presented phenotypic characteristics of the
species. The hunted wild boars were sexed, weighed
and measured. All the animals included in the study
were hunted during the legal drive hunting season.The
age of the animals were estimated using patterns of
tooth eruption and replacement (Boitani &Mattei
1992). The animals were classified into three age
classes (Pedone etal. 1991): juvenile (less than one
year of age), yearling (between 1 and 2 years of age),
and adult (older than two years of age).Wild boars were
measured from the left side, and measurements were
carried out using a Lydthin stick, tape measure and
scale.A total of 181 individuals (97 males and 84 fema les)
from six month to seven years of age were scored
for the nineteen morphological measurements: height at
withers HW; height at sacrum HS; height of back HB;
the most caudal point of scapula mCPS; height at hip
HH; depth of chest DC; circumference at chest CC;
head length HL; ear length EL; ear width EW; tail
length TaL; trunk length TrL; bristles length (at wiethers)
BL; circumference of shin (tibia) CS; circumference
of testis (left) CTL; circumference of testis (right)


RESULTS
The average age of studied animals was under 24
months old, which indicated a relatively young population.
The sex ratio is slightly unbalanced in favor of
males, a similar unbalanced fetal sex ratio was also
found by (Massei etal. 1996). However, the sex ratio
did not attribute to the age or, weight. Morphological
data support the hypothesis that the wild boar populations
in some regions have hybridized with domestic
pigs. Some individuals in the data set displayed white
hair on the feet, stomach, tarsus and carpus; large and
fast growth; great intrapopulation morphological variability;
and, great accumulation of subcutaneous fat.
Mean values with standard deviation of the seventeen
analyzed morphological measurements under three different
geographical zones and three different age groups
of the animals are presented inTable 1.Statistical differ-


CTR; length of trunk with head TrHL; body weight
BW; color of bristles CB. Based on the age class data
where preliminary analyzed withANOVA(using GLM
procedure) for fixed effect of region, gender and their
interaction on each applicably measurement. For measurements
of CTLand CTRANOVAwas tested for effects
of region as fixed factor only on male part of
dataset. Significant effects of region were additionally
tested using Tukey HSD test. After determining variability
with ANOVA, data where merged and cluster
analysis (using CLUSTER procedure byWard method
and Euclidian distances) where preformed for determining
location groupings on averages of 14 relative morphological
measurements. Results of cluster analysis
are shown graphical (usingTREE procedure). Canonical
discriminant analysis (using DISCRIM procedure)
where preformed on region and relative morphological
measurements as given classification.ANOVA, cluster
analysis and canonical discriminate analysis where preformed
in SAS package (SAS Institute, 2007). For distinguishing
which morphological measurement allowed
different morphotypes constrained redundancy analysis
(RDA) by the CANOCO program (Braak & Smilauer
2002) which is used for sound statistical modeling
of ecological data. The Monte Carlo unrestricted
permutation test was performed to determine the significance
of the regression. For RDAanalysis, the measurement
was expressed in percentage of height at
withers.This is a very important parameter in morphological
studies of animals (Melaku 2003). Species
data (response variables) represents morphological me a
surements and environmental data (explanatory variables)
represents dummy variables.


– Rezultati
ences were observed between age classes, results put in
evidence that some variables were significantly different
(BW, TaL, TrL), but some of them were not homogenous
for all age classes (CS, mCPS, CC) and were unable
to highlight differences among the regions.
Additional effects of gender on differences between regions
were recorded on traits (BW, EL, TaL, TrL) only
in sub-adult age class.The correlation analysis shows a
significant link between measurements and age classes.
Results of RDA analysis throughout sampling sites
based on 16 morphological traits are showed in Fig 2.
There is a strong correlation between CB in Central and
West populations with the CS and TrL. West and East
populations are connected with HLand BL, but Central


and East populations are strongly correlated with HH,
EWand mCPS (Fig 2a).Analysis of young, adolescents