Per- and poly-fluoroalkyl substances in Tawny Owl (Strix aluco) feathers from Trøndelag, Norway.

Per- and polyfluoroalkyl substances (PFASs) are contaminants of global concern due to their ubiquitous occurrence in the environment, bioaccumulation and the adverse effects on organisms. Tawny Owls (Strix aluco) are documented to be exposed to increasing concentrations of perfluoroalkyl carboxylic acids (PFCAs), and have been suggested in literature as a key raptor monitoring species. Therefore, non-destructive biomonitoring efforts are of high interest. Thus far, the use of feathers for biomonitoring PFASs in Tawny Owls has not been investigated. In this study, 32 PFASs were analyzed in 49 Tawny Owl body feather samples collected from 2017 to 2020 in Trøndelag, Norway. There were 30 PFASs detected in at least one feather, with the sum concentrations ranging from 31 to 203 ng/g (w.w.). Perfluoroheptanoic acid (PFHpA) (median: 33 ng/g) and perfluorooctane sulfonamidoacetic acid (FOSAA) (median: 18 ng/g) were the two compounds with the highest concentrations. Perfluorooctane sulfonic acid (PFOS), which is banned for production and use in Norway since 2007, was found in all samples (median: 4.14 ng/g), indicating its high persistence. 8 PFASs were detected in at least 50 % of the samples: FOSAA (11-127 ng/g), PFHpA (<0.04-115 ng/g), perfluorobutanesulfonic acid (PFBS) (<0.28-21 ng/g), PFOS (0.23-13 ng/g), perfluorotridecanoic acid (PFTrDA) (0.24-5.15 ng/g), perfluorododecanoic acid (PFDoDA) (<0.28-4.45 ng/g), perfluoroundecanoic acid (PFUnDA) (<0.28-2.33 ng/g), and 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2 FTSA) (0.07-1.01 ng/g). No significant differences were found for the concentrations of PFASs between calendar years and locations, but a slight increase could be observed in the sum concentration of PFASs (Æ©32PFASs) over the sampling years. As Tawny Owls are residential owls that usually do not cover great distances, their feathers can be used as a potential alternative matrix for future biomonitoring studies. To our knowledge, this is the first study on the occurrence of 32 PFASs investigated in feathers of a Tawny Owl population.

Primary Cell Lines From Feathers and Blood of Free-Living Tawny Owls (Strix aluco): A New In Vitro Tool for Non-Lethal Toxicological Studies.

The validation of the use of primary cell lines from non-lethal matrixes of feathers and blood of nestlings of a wild bird species, the tawny owl (Strix aluco) is described. Tawny Owl Feather Fibroblast (TOFF) cells and peripheral blood mononuclear cells (PBMCs) were isolated and cultured from the pulp of the secondary wing feathers and whole blood respectively from free-living tawny owl nestlings. Cell growth was registered up until 48 h for both the PBMC cells and the TOFFs. The validation of these primary cell lines in free-living birds has the potential to advance the assessment of immunotoxicological effects in wildlife via non-lethal manner. They provide a key tool with which to study cell toxicity and responses to environmental stressors on a cellular level in wild bird species of interest.

Population control by means of organised hunting effort: Experiences from a voluntary goose hunting arrangement.

Implementing management objectives may be challenging when decisions are made at different scales than where they are supposed to be carried out. In this study we present a situation where local goose hunting arrangements respond to objectives in an international management plan for pink-footed geese (Anser brachyrhynchus) and a local wish to reduce goose numbers as means to reduce grazing damage on farmland. A unique ten-year dataset provides an evaluation of the efficiency of voluntary actions at a local scale for implementing a policy of population control of geese, and general lessons are drawn for collaboration and co-production of knowledge for adaptive management. The study demonstrates how both the hunters and geese adapt in a situation where increasing the harvest of geese is the main objective. Introducing hunting-free days and safe foraging areas significantly increased goose numbers in the study area, with a corresponding increase in hunting success in terms of number of harvested geese. The geese's behavioural response to hunting also triggered the hunters to adapt accordingly by optimal timing and placement in the landscape. Based on the results of the present study we suggest a framework for local implementation of management actions. Bringing end-users on board, facilitates processes and strengthens the achievements, as they represent the actors where implementation occurs. Specifically, our findings demonstrate how optimal goose hunting can be practiced by the use of an adaptive framework with active stakeholder participation.