Monitoring of selected butterfly species in 2023
The report is part of the Monitoring of selected butterfly species in 2021, 2022 and 2023 and presents the results of the field survey for nine species of Slovenia in 2023.
- Slovenia
- 2014-2022
- Environmental impacts
Monitoring of selected butterfly species, which supports the Rural Development Programme (RDP) evaluation activities, has been carried out each year since 2008. This is a report for the year 2023 and is part of the monitoring project for the period 2021-2023. The purpose of monitoring is to establish the condition of selected butterfly species. Based on the monitoring results in 2021-2023, a summary conclusion of the species conservation status was prepared. In 2023, the following butterfly species were monitored in the field: Erannis ankeraria, Eastern Eggar (Eriogaster catax), the Lorkovic's Brassy Ringlet (Erebeia calcarius), the Scarce Fritillary (Euphydryas maturna), the False Ringlet (Coenonympha oedippus), the Apollo (Parnassius apollo), the Large Blue (Phengaris arion), the Scarce Large Blue (P. teleius) and the Dusky Blue Large (P. nausithous). Monitoring was carried out in selected areas of established distribution and areas of marginal and isolated populations across Slovenia. The fieldwork in 2023 was carried out in full compliance with the project task. In carrying out the monitoring, an already established methodology and results of previous research were followed. Three levels of monitoring the status of target butterflies were considered:
- Monitoring the size of selected populations.
- Monitoring in areas of established distribution.
- Monitoring in areas of marginal and isolated populations.
Different methods were used in the field: attracting adults to UV lamps and sampling them at night, searching for larval stages (nests of caterpillars and adult caterpillars) on nutrient plants, counting of adult specimens along a pre-selected census path (15 metre wide strip), counting of caught adult specimens, transect monitoring and MRR (method of catching and re-catching). For the assessment of the state of conservation of selected species, the limitations mainly include a shortage of data to assess trends. The conservation status of the following butterfly species in the period 2021-2023 is unfavourable: Erannis ankeraria, Lorkovic's Brassy Ringlet (Erebeia calcarius), Scarce Fritillary (Euphydryas maturna), False Ringlet (Coenonympha oedippus), Apollo (Parnassius apollo), Large Blue (Phengaris arion), Scarce Large Blue (Phengaris teleius), Dusky Large Blue (Phengaris nausithous), Fenton's wood white (Leptidea morsei) and Marsh Fritillary (Euphydryas aurinia). The conservation statuses of the Eastern Eggar (Eriogaster catax) and Jersey Tiger (Euplagia quadripunctaria) are unknown. In 2023, the highest number of nests of Eriogaster catax were found, equalling the numbers in 2018. For the Lorkovic's Brassy Ringlet (Erebeia calcarius) and Dusky Large Blue (Phengaris nausithous) the recorded number of species abundance were the lowest. A comparison of the Paranassius apollo populations in 2023 with previous years of monitoring shows large fluctuations in the abundance of adult specimens and the fewest red apollos observed in 11 years.
Author(s)
Centre for Cartography of Fauna and Flora: Barbara Zakšek, Nika Kogovšek, Ali Šalamun, Marijan Govedič. University of Ljubljana, Biotechnical Faculty: Rudi Verovnik, Valerija Zakšek
Resources
Documents
Monitoring of selected target species of butterflies in 2023
(PDF – 13.32 MB – 127 pages)