Sand lizard (Lacerta agilis) sighting frequency in a 20-year period on the northern edge of its range: The effect of management actions and habitat variables
2024 (English)Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE credits
Student thesisAlternative title
Observationsfrekvens av sandödlor (Lacerta agilis) under en 20-årsperiod på den norra utbredningsgränsen : Effekten av skötselåtgärder och habitatvariabler (Swedish)
Abstract [en]
The sand lizard (Lacerta agilis) is a characteristic reptile in open, sandy habitats. The sand lizard is declining at the northern edge of its range. The main threats in Sweden are afforestation and lack of natural disturbances, creating a need for habitat management. In this study, a visual count survey of the lizards was made in 13 habitats in the region of Jönköping. The results were compared to sighting frequency data from the past 20 years. Managed and non-managed habitats were compared, as well as habitats managed one or several times. The results showed an increase in the total sighting frequency compared to previous surveys. One possible reason could be the regional temperature increase. There was no difference between managed and non-managed habitats. Anthropogenic impacts with positive effects in the non-managed habitats are a plausible reason. The lack of difference between habitats managed one and several times could be because vegetation succession is faster than the management rate, causing interruptions in the continuity of essential habitat resources, such as exposed sand. The percental coverage of characteristic sand lizard habitat variables, open ground and heather, did not affect the sighting frequency. The coverage of trees and bushes, with an assumed negative effect, did not affect the sighting frequency neither. This may be because the lizard prefers complex, mosaic environments, making it harder to connect single variables to sighting frequency. More frequent and extensive monitoring with updated methods is needed to better understand the sand lizard dispersion and status in the region.
Place, publisher, year, edition, pages
2024. , p. 25
Keywords [en]
Lacerta agilis, sand habitat, habitat management
Keywords [sv]
sandödla, habitatrestaurering, naturvårdsskötsel
National Category
Ecology
Identifiers
URN: urn:nbn:se:umu:diva-231725OAI: oai:DiVA.org:umu-231725DiVA, id: diva2:1912556
External cooperation
Länsstyrelsen i Jönköpings län
Educational program
Bachelor of Science in Biology and Earthscience
Supervisors
Examiners
2024-11-152024-11-122024-11-15Bibliographically approved