Ocena velikosti populacije in izbor habitata podhujke Caprimulgus europaeus na Pivškem

Kljun, Ivan (author), Tome, Davorin (mentor)

Podhujka (Caprimulgus europaeus) je naravovarstveno pomembna vrsta, ki se ji je v prejšnjem stoletju izrazito skrčil areal ter ji je upadla številčnosti v večjem delu Evrope. Z raziskavo smo ocenili velikost populacije in pripravili model izbora habitata v zahodnem delu IBA Snežnik – Pivka, ki je drugo najpomembnejše območje za vrsto pri nas. Za opis habitata smo izbrali 16 okoljskih spremenljivk, ki smo jih razdelili na tri kategorije: raba tal, značilnosti gozda in topografske značilnosti. Travnike smo s terenskim pregledom klasificirali v tri razrede glede na rabo: intenzivni, ekstenzivni in pašniki. Model logistične regresije za napoved verjetnosti pojavljanja podhujke na točki smo pripravili v programu RStudio. Za popis podhujk smo uporabili točkovno metodo s predvajanjem posnetka teritorialnega oglašanja samca. Na 125 popisnih točkah smo zaznali 129 podhujk. Ocena navadne gostote pojočih samcev je bila 2,08 / km2, največja gostota pa 4,24 / km2. Ocena populacije pojočih samcev podhujke je bila 432 (rang: 389 – 510), kar predstavlja okrog tretjino populacije v Sloveniji. Model napoveduje večjo verjetnost prisotnosti podhujke z večanjem površin zemljišč v zaraščanju, iglastih gozdov, ekstenzivnih travnikov in dolžine gozdnega roba. Njive in intenzivni travniki predstavljajo neugodno okolje za podhujko.

• Language: Slovenian
• Keywords: Caprimulgus europaeus/podhujka/izbor habitata/logistična regresija/velikost populacije
• Work type: Master's thesis/paper
• Organization: BF - Biotechnical Faculty
• Year: 2017
• PID: 20.500.12556/RUL-94544
• COBISS.SI-ID: 4410959
• Publication date in RUL: 02.09.2017

KLJUN, Ivan, 2017, Ocena velikosti populacije in izbor habitata podhujke Caprimulgus europaeus na Pivškem [online]. Master’s thesis. [Accessed 11 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=94544

Secondary language

• Language: English
• Title: Population size estimation and habitat use of Nightjar (Caprimulgus europaeus) in Pivka area (Slovenia)

Abstract

The Nightjar (Caprimulgus europaeus) has experienced a reduction in range and numbers over much of Europe and is, as such, a species of conservation concern. We performed a survey of singing males and a research of habitat selection in the western part of IBA Snežnik – Pivka, which is the second most important area for the Nightjar in Slovenia. We selected 16 habitat parameters, based on the Nightjar’s ecology. The parameters were different land uses, types of forest and topographic characteristics. We carried out a field survey of meadows and categorized them into three classes based on the management type: intensive, extensive and pastures. We performed the logistic regression model using the program RStudio. We surveyed the Nightjars by the point-count method using the playback of the male song. We registered 129 Nightjars at 125 survey points. The estimated crude density was 2.08 singing males per km2; the highest estimated density was 4.24 singing males per km2. The estimated population size was 432 singing males (range: 389 – 510), which constitutes about a third of the entire population in Slovenia. The logit model predicts a higher probability of the Nightjar occurrence in areas covered by overgrowing grasslands with trees, coniferous forests, extensive meadows and a long forest edge. Arable land and intensive meadows were found unsuitable for the Nightjar.

• Keywords: Caprimulgus europaeus/Nightjar/habitat use/logistic regression/population size