Trukhanova I.S., Chirkova O.A., Shakhnazarova V.Yu., Gromov V.V., Bakunovich P.M., Kouprianov P.A., Kouprianov A.V., Fedeneva Y.V., Sokolovskaya M.V. 2023. Non-invasive monitoring of endangered Ladoga ringed seal (Pusa hispida ladogensis) (Carnivora: Phocidae) using photo-identification // Russian J. Theriol. Vol.22. No.2. P.172–181 [in English].
Irina S. Trukhanova [irina_trukhanova@yahoo.com], Olga A. Chirkova [chirr.dec@yandex.ru], Vladimir V. Gromov [gromov@vladimir.one], Polina M. Bakunovich [polina.bakunovich@yandex.ru], Platon A. Kouprianov [alexei.kouprianov@gmail.com], Alexei V. Kouprianov [alexei.kouprianov@gmail.com], Yulia V. Fedeneva [fedeneva.yy@mail.ru], Interregional Charitable Public Organization “Biologists for nature conservation”, 1st lane of V.O., 36-10, Saint Petersburg 199004, Russia; Vlada Yu. Shakhnazarova [shahnazarova-v@mail.ru], Saint-Petersburg State University, Universitetskaya emb., 7/9, Saint Petersburg 199034, Russia; Maria V. Sokolovskaya [ladoganerpa@mail.ru], Palace of Children’s (Youth) Creativity of the Frunzensky District, Budapeshtskaya st., 30, bldg. 2, Saint Petersburg 192071, Russia.
doi: 10.15298/rusjtheriol.22.2.10
ABSTRACT. Based on imagery taken at summer coastal haul-out sites on the islands of the Valaam Archipelago in northern Lake Ladoga in 2019 and 2020, a photo-identification database for the endangered Ladoga ringed seal (Pusa hispida ladogensis) has been developed. We based individual identification on unique patterns visible on the seal pelt and demonstrated the utility of this approach to ringed seal monitoring. The current version of the database contains 537 individual seals. When possible, the sex and age class of individuals were recorded, as well as individual resightings within one day, intra- and inter-seasonal resightings. At the haul-outs, the female-to-male ratio was about 1:1.16, and 2.3% of the animals were young-of-the-year. The intra-season resighting percentage was 2% in 2019 and 2.3% in 2020, whereas the inter-annual resighting rate was only 1.3%, indicating low haul-out site fidelity and substantial rotation across seal groups using the islands during the open-water season.
KEY WORDS: Ladoga ringed seal, Ladoga Lake, endangered species monitoring, photo-identification, photo-ID, database.