Correction factors used for estimating prey biomass in the diet of American minkMustela vison

Population assessment and habitat use by marine otter Lontra felina in southern Chile

“…Fish remains in collected spraints were identified using operculae and vertebrae, and their sizes were estimated by comparing the size of abdominal and caudal vertebrae with previously measured reference material (Medina 1997(Medina , 1998. The results were tabulated as: 'O' occurrence (number of spraints in which a species occurred) and 'RF' relative frequency (number of spraints in which a species occurred divided by the total occurrence of all the species tested; Brzezinski & Marzec 2003). Benthic freshwater invertebrate fauna were sampled five times in each subsystem using a Surber sampler dragged <1.2 m deep, no further than 4 m from the shore and for 3 m at a time.…”

Trophic niche comparison of American mink and Eurasian otter under different winter conditions

“…Today, as a result of escapes and deliberate releases from fur farms, the species is widely distributed across Europe (Bonesi and Palazon 2007). In Poland, the mink has already colonized over half of the territory, achieving the highest densities in northern and eastern parts of the country (Brzeziński and Marzec 2003). The mink is usually described as an opportunistic predator, characterized by variations in the diet composition between spring-summer and autumn-winter seasons, owing to differences in habitat-based prey distribution and abundance (e.g., Lode 1993, Sidorovich 2000, Jędrzejewska et al 2001, McDonald 2002, Bartoszewicz and Zalewski 2003.…”

“…and mammals (Mam.). The relative biomass (BIO) of each prey group in the diet was calculated on the basis of dry mass of prey remains and digestion coefficients for both predators (Jędrzejewska et al 2001, Brzeziński andMarzec 2003). We used the RFO (relative frequency of occurrence), the most frequently used method for diet comparison between otters living in various habitat conditions (e.g., Jędrzejewska et al 2001, Clavero et al 2003.…”

Feeding habits of American mink from Biebrza Wetlands affected by varied winter conditions

“…Prey remains were weighed (0.01 g accuracy) and divided into five groups: invertebrates, fish, amphibians, birds and mammals. The relative biomass of each prey group in the diet of mink was calculated on the basis of dry mass of prey remains and digestion coefficient (Brzeziń ski and Marzec 2003). To estimate differences in diet, we used niche breadth B (Levins 1968) and niche overlap a (Pianka 1973).…”