magistrsko delo
Tomaž Jagar (Author), Lilijana Bizjak-Mali (Reviewer), Cene Fišer (Mentor)

Abstract

Navadni gad (Vipera berus) je polimorfna vrsta, za katero so značilni osebki s kontrastnim cikcak vzorcem ter popolnoma črni (melanistični) osebki. Dosedanje raziskave so pokazale prednost melanistične obarvanosti pri termoregulaciji ob višjem tveganju za predacijo, zato pogosto prevladujejo v okoljih z slabšimi pogoji za termoregulacijo kot so višje nadmorske višine. Barvnega polimorfizma navadnega gada v Sloveniji ni še nihče obravnaval sistematično. V tej nalogi obravnavamo prostorsko razporeditev barvnih fenotipov navadnega gada glede na ekološke razmere v naravi. Predvidevali smo, da je v Sloveniji v odprtem prostoru z nizko in slabo prekrivno vegetacijo močnejši pritisk s strani plenilcev, predvsem ptic. Predvidevali smo, da so v takem okolju uspešnejši bolj prikriti osebki z vzorcem. V takih okoljih so melanistični osebki lahko prisotni, a redki. Nasprotno smo v zaprtem, bolj zastrtem habitatu, kot je gozd, pričakovali več melanističnih osebkov oz. njihovo prevlado. Ti so v zasenčenem prostoru zaradi boljše termoregulacije v prednosti pred fenotipi z vzorcem, poleg tega pa je v takšnem življenjskem okolju pogosto manj oportunističnih plenilcev in selekcijski pritisk plenilcev manjši. Analize 76 živali z skupno 5 lokalitet so potrdile naša pričakovanja.

Keywords

navadni gad;Vipera berus;polimorfizem;aposematizem;habitatni tipi;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [T. Jagar]
UDC: 591.9
COBISS: 128529155 Link will open in a new window
Views: 34
Downloads: 8
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Other data

Secondary language: English
Secondary title: Correlation between morphology of the common European adder and habitat type in Slovenia
Secondary abstract: The common adder (Vipera berus) is a polymorphic species characterized by specimens having a contrasting zigzag pattern as well as completely black (melanistic) specimens. Previous research has shown that melanistic coloration conferes a thermoregulatoty advantage and a higher risk of predation, so it is often the dominant phenotype in environments with suboptimal thermoregulatory conditions, such as higher altitudes. The color polymorphism of the common adder in Slovenia has not yet been systematically studied. In this work, we analyzed the spatial distribution of color phenotypes of the common adder in relation to ecological conditions in nature. We assumed that in Slovenia, in open space with low and poorly covering vegetation, there is stronger pressure from predators, especially birds. We hypothesized that in such an environment, more covert individuals with the contrast zigzag pattern would be more successful. In such environments, melanistic individuals may be present but rare. In contrast, in a shaded, more covered habitat, such as a forest, we expected more melanistic individuals or their dominance. In a shaded area, they have an advantage over patterned phenotypes because of better thermoregulation, and furthermore, there are often fewer opportunistic predatorsin such habitats, so there is less selection pressure from predators. We analyzed 76 animals from 5 localities and found support for our predictions.
Secondary keywords: common adder;polymorphism;aposematism;habitat types;master thesis;Kače;Univerzitetna in visokošolska dela;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za biologijo
Pages: 1 spletni vir (1 datoteka PDF (VII, 25 str., [1] str. pril.))
ID: 16888960