Original scientific paper
Factors that Determine Sex of Red Deer Calves (Cervus elaphus L.): Verification of Current Knowledge
Dražen Degmečić
; Hrvatske šume Šumarija Tikveš
Krešimir Krapinec
orcid.org/0000-0002-8815-7568
; Šumarski fakultet Sveučilišta u Zagrebu
Tihomir Florijančić
; Poljoprivredni fakultet Osijek
Abstract
One of the key factors of hunting economy is the question of reproduction, i.e. quality and sex ratio of the calves. This is especially impor tant for those kinds of game, the males of which have a trophy. The density of population, dominance of hinds in the population and the amount of precipitation during winter (November-January), are definitely factors that influence the amount of food available (the first is negatively dependant, whereas the other two factors have a positive dependency on food availability), i.e. on the nourishment of the hinds. According to Flint et al. (1997) and Enright et al. (2001), the hinds that are better nourished give birth to a higher percentage of male calves, regardless if we are talking about red deer (Cervus elaphus L.) or fallow deer (Dama dama L.). Kojola’s research (1997) has confirmed similar results for reindeer (Rangifer tarandus L.), and Wauters et al. (1995) for roe deer (Capreolus capreolus L.).
The research of the factors that may influence the sex of a red deer calf (Cervus elaphus L.) has been conducted in the State hunting ground number XIV/9 “PODUNAVLJE – PODRAVLJE”. The hunting ground is situated in Baranja alongside the rivers Danube and Drava. The hunting ground is ma naged by the company Hrvatske šume d.o.o. Zagreb, Uprava šuma podružnica Osijek. This paper is based on the cull data of the hinds in the hunting ground during the hunting seasons 2007/2008 (42 head) and 2008/2009 (23 head). The following data has been recorded and analyzed: net body weight of the hinds (body weight of eviscerated head with skin, without head and feet (car pal and tarsal parts of the extremities)); also during evisceration, embryos or foetuses were removed from uterus, weighed on a gram scale and their sex was determined in utero (Figure 2. and 3.).
The research did not find differences that would point to this particular factor, although there is a change in ratio of male and female foetuses. For the hunting season 2007/2008 sex ratio was 1:21 (45:55 %) for the female foetu ses, and a year after 1,09:1 (52:48 %) for the male foetuses (Table 1.). The cause of the irregular sex ratio in the hunting season 2007/2008 could be an extremely hot and very dry summer in 2007, or the difference could simply be caused by the sample examined. It was found that the sex ratio of the culled hinds in two consecutive hunting seasons (2007/2008 and 2008/2009) was dif ferent (1:21, and 1.09:1 respectively). The results of the net body weight tests for the hinds, as one of the key parameters for the population, did not show a significant relevance for determining the sex of future calves. However, alt hough statistically insignificant, a climate difference in the summers of the two hunting seasons was recorded.
Keywords
Cervus elaphus; hind body weight; in utero; red deer; sex of the foetus
Hrčak ID:
39465
URI
Publication date:
30.6.2009.
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