Differences in behavioral traits of tolerance, aggressivity and retreat in island and mainland population of Italian wall lizard (Podarcis siculus)

Otočni sindrom predstavlja pojavu gdje otočne populacije visoke gustoće imaju smanjenu agresivnost, smanjen spolni dimorfizam i smanjen utrošak energije za reprodukciju. Kod plavo obojene populacije Podarcis siculus klemmeri uočena je pojava obrnutoga otočnog sindroma gdje je kod otočnih populacija promjenjive gustoće prisutna viša razina agresivnosti te je spolni dimorfizam izraženiji. Cilj ovoga seminarskog rada bio je usporediti bihevioralne karakteristike tolerantnosti, agresivnosti i povlačenja kod otočne i kopnene populacije primorske gušterice (Podarcis siculus) pomoću analize videosnimki provedenih bihevioralnih testova u areni otvorenoga tipa. Otočnu populaciju činilo je 5 parova jedinki mužjaka s otočića Pijavice, a kopnenu 5 parova jedinki mužjaka iz Kaštela. Mužjaci populacije više gustoće s otoka Pijavice slabije su obojeni od jedinki kopnene populacije, koje pokazuju plavo i žuto obojenje trbušnoga dijela tijela i glave. Tijekom analize bilježene su interakcije te je svakoj određen unaprijed definirani tip i kategorija ponašanja. Jedinke otočne populacije pokazale su 100-postotnu tolerantnost, dok su 3 para jedinki kopnene populacije pokazala interakcije agresivnosti i povlačenja. Navedene karakteristike otočne populacije odgovaraju definiciji otočnoga sindroma, koji se može objasniti smanjenim pritiskom predatora i smanjenom interspecijskom kompeticijom.The island syndrome is a phenomenon in which high density island populations exhibit reduced aggression, decreased sexual dimorphism and decreased energy allocation to reproduction. The reversed island syndrome was observed in a fluctuating density, blue coloured population of Podarcis siculus klemmeri, which had higher levels of aggressivity and sexual dimorphism. The aim of this seminar paper was to compare the behavioral traits of tolerance, aggressivity and retreat in island and mainland population of Italian wall lizard (Podarcis siculus) by analyzing video-recordings of conducted behavioral trials in an open-type arena. The island population consisted of 5 pairs of males from the Pijavica island and the mainland population of 5 pairs of males from Kaštela. Males of high density population of the Pijavica island are normally coloured, while those of the land population have blue and yellow coloration of the ventral part of the body and head. During the analysis, all encounters were recorded and assigned to a predefined type and category of behavior. Males from the island population had 100 % tolerant encounters, while 3 pairs of land population showed encounters of aggressivity and retreat. Former characteristics of the island population correspond to the definition of island syndrome, which can be explained by reduced predation pressure and decreased interspecific competition