CHANGES OF RED DEER (CERVUS ELAPHUS, L.) PEDICLES WITH AGE AT BARANJA DANUBE`S REGION

Antles of deer family (Cervidae) is an example of fast growing bones and the only bony structure form of mammals, capable of complete regeneration. Every year, antlers are cast and a set of new antlers are growing every year. This is called the antler growth cycle and is closely related to the reproduction cycle, hormonal processes and photoperiodism in the Cervidae family. The antlers, that are changing every year, grow on the pedicles that last for a lifetime and that do not become bone, but are leather-coated for a lifetime.

Pedicles grow during the first year of life, when a male calf comes into puberty. Usually it is during the fifth or sixth month of life, but beside the age, for the growth of the pedicles and the first antlers, it is more important that a male calf reach a certain threshold of body mass. Physical mass allows entry into puberty and involves the work of male sex glands (testis) that leads to male sex hormone (testosterone) and stimulate the growth of the pedicles (Figure 1).

Thus under the growth of testosterone the pedicles grow, but antlers under the influence of tertosterone cease to grow and enter the stage of mineralization and nourishing. The evidence of the effect of testosterone on the growth of the pedicles is still found in the development of the fetus.

Between the 50th and 100th days of the development of the fetus, fetal development of the gonadal (sexual glands) in the Red deer occurs. At that time, male fetuses may notice thickening at the sites of future forward projections – the pedicles and the appearance of thickening of the neck muscles.

Both characteristics are the secondary sexual characteristics of males in Red deer and occur at the time of development of male sex glands, which then yield enough testosterone to briefly develop the development of these characteristics (Figure 2). During the life of male Red deer, pedicles change their form, so the aim of the paper was to observe changes in the males’ pedicles and to associate them with the male age class. Simply to offer a model for population management classification of male deer at age classes.

The value of the diameter of the pedicles increases with age (Graph 1), while the height of the pedicles with the age decreases (Graph 2). The practice of hunting management strives for simplicity, so this research has been carried out to simlify the classification of stags in to age classes

In addition to the height and diameter of the pedicles, a significant change in the height and diameter of the pedicles in relation to the age was found. Thus the regression coefficient of the height of the pedicles and age is significant and is R = 0.65 (AGE = 15.25 – 0.18 x height of the pedicles) (the height of the pedicles decreases with age), also the regression coefficient of the diameter of the pedicles and age is significant is R = 0.85 (AGE = 0.25 x pedicles diameter – 4.72) (the diameter of the pedicles increases with age).

Changes in the height and the diameter of the pedicles are significant and are in such a good relationship with each other as compared to the age to be counted in hunting management. These mean values ​​as well as mathematical expressions for age determination, considering the degree of significance, can be used to determine age and classification in the age classes (young males in 3, 4 and 5 years of old males, middle-aged males in 6, 7 and 8 years of old males and mature 9-year-old males) in practice of hunting management in this area of ​​research.

RED DEER ANTLER DEVELOPMENT

Red deer antlers are an example of fast-growing tissue and are the only mammal organ capable of complete regeneration. Each year set of an antlers are cast, and each year a set of a new one are grown. This is called antler growth cycle and is closely associated with reproductive cycle, hormonal processes, climate and hydrological factors. Climate and hydrological factors act directly through the air temperature, precipitation (rain, snow), snow, ice, insolation (photoperiod), frost and water levels. Habitat or the living environment is defined as a set of natural resources and conditions presented in a given area to ensure the stability of the population that inhabits it. The aim of this paper is to present climate and hydrological impacts on the value of red deer antlers on the example of hunting ground along the Danube River.

The hereditary basis, the habitat conditions and the age class are the primary determinants of the RED DEER antler development. But that is not sufficient for the development of good antlers, because the heredity cannot be displayed if the environmental conditions are not good enough during the crucial time of the year. Depending on the environmental conditions, different phenotypic effects can be expected. The reason for significantly higher values of measured traits of antlers during one period in relation to another can be found either in the factors of a population (abundance, density, sex and age structure, birth rate, mortality, etc.) or in the habitat factors (climatic factors, size, depth, fragmentation, the distribution of food, water and shelter, etc.)

Temperature as a climatic element acts directly on antler development during the autumn – winter period (November, December, January and February) and spring period (March, April, May) (Graph 1). Temperature is the one that starts and stops the development of the vegetation so during the autumn – winter period temperature is essential in the sense of longer duration of vegetation while in spring the temperature is important for early initiation of vegetation. During the autumn – winter period males with this longer lasting vegetation maintain their body weight while the early start of vegetation in spring allows males to refresh their body early and to grow a new set of antlers with full genetic capacity. It is evident from Graph 1. that the purple line (2007/2008. hunting year) is continuously above average and it is particularly important to emphasize temperature values above average during December, January and February. During these months the average temperature is around 0 0C (mostly below) as it was case in most years during the study. Antler growth in that year had an early start and longer growth period which resulted in significantly higher values of observed traits. Growth and development of antlers lasts from 120 to 150 days and the duration of growth among other factors depends of the habitat conditions (climate) during that particular year.

Precipitation (rain), as an element of the climate on growth and development of red deer antlers acts in a way that with good temperature values (above average) precipitation initiate the growth of vegetation. Precipitation together with poor temperature conditions require more energy to maintain body processes but also precipitation is together with high water level of river Danube responsible for a burst of a wetland insect population. Precipitation together with water level and temperature during April may and June determines the number of insects whose biology is related to wetlands. Insects that may affect the growth and development of red deer antlers in Danube region are mosquitoes. The intensive activity of insects (in particular mosquitoes) interferes with the normal daily rhythm (feeding – resting and chewing – looking for food) instead the animals are nervous from bites and often forced into rush sprints and cold water as a safe refuge and all that during the day and June at the time when five and more years old red deer stags begin to develop royal rich with points. It is obvious that during years with greater mosquito numbers the royals are poorer with points

All physiological processes in both plants and animals depend on sunlight. Seasonal changes are induced by the length of the day compared to night. The sun light runs so called „biological clock“which have all animals including Cervidae family. The critical day length (photoperiod) sets the length of day which when is crossed either above or below acts as a trigger for a specific physical or physiological processes. At red deer everything is programmed and occurs exactly at a certain time of the year like mating, calving, migration, changes of hair, antler growth and development.

Graph 4. clearly shows a jump in the number of sunshine hours during April of 2007/08. hunting year (purple line) and it amounted 307,2 hours, which is one third greater than the ten year average for April (205,2 hours). Number of sunshine hours during May and June are about ten year average so this study showed that the most important month for growth and antler development was April when the matter is sunshine. Von Raesfeld and Reulecke (1991) stated that according to the author Rohring the red deer antlers grow about 12 % during march, 30 % in April, 31 % during may and the rest during June and July depending of the completion of the process. How fast or how many days will one growth phase last it depends on the light impulse (the number of sunshine hours) during the time of antler growth. Therefore Bubenik (1990) states that the new antlers can grow up to 2 centimeters per day and that the whole process lasts from 120 to 150 days.

Water is the crucial environmental factor for the development of forest ecosystems in floodplain forest. In these ecosystems water appears as precipitation, flood and underground water. Floods (maximum water levels) in these ecosystems and because of snow melting and heavy rainfall occurred mostly in late winter and early spring. The amount and duration of floods occurs as a crucial factor for the survival of such ecosystems in the spring while precipitation and underground water often play a crucial role for the survival of such ecosystems during summer. The Danube water level affects nutritional base of game but also it acts as a source of stress with high water levels in spring when it overlaps with the time of antler growth and development. The high water level reduces the size of habitat area that deer population can use and that is connected with food but also with a much needed peace and the possibility of increasing parasitic diseases.

Habitat key factor is the one factor whose influence is crucial for the population parameter that is a subject of evaluation. Equally important is the presence or absence of the key habitat factor in the crucial time during the development of this parameter. When one tries to link the growth and development of antlers with one key factor in this habitat, one is confronted with a mission impossible. The natural dynamics of habitat is a collection of environmental and anthropogenic factors that cannot be observed separately.

For the practice of wildlife management it is important to monitor the climate and other habitat elements so that with this knowledge one can predict the future antler value, population growth rate, body weight of calves at the start of a hunting year. All this is important because of possible interventions in the management plans in a way that the cull will be reduced in some age classes and it will be increased in some other age classes and all with the aim of long term sustainable management both in biological and economic sense.

The story of logo design

The logo design represents two paws of European pine Marten labeled “WILDCRO” at the base of the logo. The company is headquartered in the continental part of the Republic of Croatia, formerly the Kingdom of Slavonia (15th century). The coat of arms of the kingdom from the end of the 15th century contains: in blue shield two transverse silver beams, representing the rivers Sava and Drava. Between the rivers is a red field, with European pine Marten turned to the right. Above is a six-pointed star (the designation of the god Mart (Mars), as a symbol of the great heroism of Slavonic nobles. Until then, the figure of the European Pine Marten was never used on the coat of arms, and it was significant for Slavonia at that time because the means of payment were precisely the skin of the European pine Marten, and later the name of the European pine Marten was taken over as the currency of payment in the territory of the Republic of Croatia. Confirmation that on the coat of arms is exactly the star of the god of Mars and the animal European Pine Marten is found in the words of the chronicler “and in the upper field is one star which we will call the Martian star, because of the continuous wars led by the mentioned Kingdom of Slavonia and its inhabitants … in the middle there is a European pine Marten, a beast as wild and belligerent as the god of war Mars himself.”

      The logo design is a blend of the tradition, culture and legends of the company headquarters region and the origin of the owner. The paws of the European pine Marten leading the way into the wilderness.