Voor de liefhebber: 4 rapporten om te downloaden over de toestand van de lynxen in Zwitserland.
https://www.kora.ch/index.php?id=214&tx_ttnews%5Btt_news%5D=814&cHash=3d7613d2653748d75f2588d5e5395254 Ik lees nu al een aantal jaren deze rapporten en de zwitsers maken hun reputatie volledig waar: zeer gedegen onderzoek. Een methode die gekopieerd kan worden. Is wel duur. In een bepaald gebied worden automatische camera's opgehangen op de meest ideale plaatsen. De camera's hangen in de paringstijd, wanneer de dieren zich verplaatsen op zoek naar partners. Lynxen kunnen ruim 10 jaar oud worden en aangezien deze onderzoeken zich om de 3 jaar herhalen worden vaak bekende dieren weer waargenomen. Door hun individuele vlekken patroon kunnen individuele lynxen onderscheiden worden. Lynxen hebben een territorium dat zij jarenlang bezetten. Hierdoor weet men wat er in 3 jaar gebeurt in een bepaald gebied. Meestal is er een groei in het aantal dieren.
Er is onderzoek in twee gebieden gedaan.
Over het eerste gebied wordt gezegd:
Abstract
Camera-trapping of Eurasian lynx (Lynx lynx) was carried out during 60 nights, from 20th December 2018 to 18th February 2019 in western central Switzerland IIIa. Camera-traps were set pairwise at 74 sites. The camera traps operated during 4323 of the theoretically 4440 capture nights (97.4%). In the whole reference area of 951 km, 112 events at 26 camera trap sites (one to several lynx events per site) of 9 independent lynx and 7-9 juveniles from 3 litters were recorded along trails. The capturerecapture estimate of abundance (95% confidence interval) under model Mh was 9 (9-9) independent lynx, which corresponds to a density of 1.44 (1.371.50) per 100 km2 suitable habitat. Compared to the value observed three years ago during winter 2015/16 (2.09 (1.762.43)) the density decreased significantly, mainly due to the absence of lynx detections along the north-western side of the reference area. The density estimated per 100 km2 suitable habitat is significantly lower compared to the latest estimates in all other reference areas, except for the south of the Lower Valais IVd, where no lynx was detected.
En over het tweede gebied:
Abstract
Camera-trapping of Eurasian lynx (Lynx lynx) was carried out during 60 nights, from 5 th December 2018 to 3 rd February 2019 in the northern Jura. Camera-traps were set pairwise at 61 sites. The camera traps operated during 3607 of the theoretically 3660 capture nights (98.6%). In the whole reference area of 882 km2, 85 events at 42 camera trap sites (one to several lynx events per site) of 14 independent lynx and one juvenile were recorded along trails. The capture-recapture estimate of abundance (95% confidence interval) under model Mh was 16 (15-24) independent lynx, which corresponds to a density of 2.55 (1.913.19) per 100 km2 suitable habitat. Compared to the value observed three years ago during winter 2015/16 (1.75 (1.322.19)) there was not significant increase of the density. The density estimated per 100 km2 suitable habitat does not differ significantly from the latest estimates in the other reference areas, except for western central Switzerland IIIa and south of Lower Valais IVd where the densities were significantly lower.
Beetje teleurstellend, meestal nemen de aantallen lynxen toe. Ik weet ook niet wat hier aan de hand is. In het tweede gebied weren ook vrijwel geen jonge dieren waargenomen.