Diet and fish choice of Eurasian otters (Lutra lutra L.) in fish wintering ponds in Hungary
Tóm tắt
The diet composition and fish preference of piscivorous Eurasian otters (Lutra lutra) were studied in two fish farm systems in Hungary using spraint (otter faeces) analysis during two wintering periods. The primary food source of otters in both fish farms was fish (97–99% of biomass). The main fish prey was small-sized, below 100 g in weight (96% in both areas), while fish prey above 500 g comprised only 0.1–0.4% of the diet. The bulk of the otters’ diet consisted of less-valued species, especially non-native Prussian carp (Carassius auratus gibelio). Consumption of commercial fish species ranged between 15 and 31% of the total diet. Otters preferred fish below 100 g in weight (Ivlev’s electivity index, E
i
= 0.65–0.70), and showed a lesser preference for (or avoided) fish above 100 g in weight (E
i
= −0.37–1.00). With regard to species distribution, otters preferred small (below 100 g) grass carp (Ctenopharyngodon idella), zander (Sander lucioperca), pike (Esox lucius), Prussian carp, topmouth gudgeon (Pseudorasbora parva), while they consumed common carp (Cyprinus carpio), the most important commercial species, proportionally to its abundance in the environment (E
i
= −0.18–0.29).
Tài liệu tham khảo
Adámek Z, Kortan D, Lepic P, Andreji J (2003) Impacts of otter (Lutra lutra) predation on fish ponds: A study of fish remains at ponds in the Czech Republic. Aquac Int 11:389–396
Berinkey L (1966) Halak—Pisces. Akadémiai Press, Budapest
Brown R, Ferguson J, Lawrence M, Lees D (1993) Federn, Spuren und Zeichen der Vögel Europas: Ein Feldführer. Aula-Verlag, Wiesbaden
Clavero M, Prenda J, Delibes M (2003) Trophic diversity of the otter (Lutra lutra L.) in temperate and Mediterranean freshwater habitats. J Biogeogr 30:761–769
Conroy JWH, Chanin PRF (2002) The status of the Eurasian otter (Lutra lutra). IUCN OSG Bull 19(A):24–48
Copp GH, Roche K (2003) Range and diet of Eurasian otters Lutra lutra (L.) in the catchment of the River Lee (south-east England) since re-introduction. Aquat Conserv: Mar Freshw Ecosyst 13:65–76
Dulfer R, Foerster K, Roche K (1998) Habitat use, home range and behaviour. In: Dulfer R, Roche K (eds) First Phase Report of the Trebon Otter Project. Scientific background and recommendations for conservation and management planning, vol 93. Council of Europe Publishing, Strasbourg, pp 31–46
Erlinge S (1969) Food habits of the otter Lutra lutra L. and the mink Mustela vison Schreber in a trout water in southern Sweden. Oikos 20:1–7
Geidesis LC (2002) Diet of otters (Lutra lutra) in relation to prey availability in a fish pond area in Germany. IUCN OSG Bull 19(A):72–76
Jedrzejewska B, Jedrzejewski W (1998) Predation in vertebrate communities. The Bialowieza Primeval Forest as a case study. Springer, Berlin
Jedrzejewska B, Sidorovich VE, Pikulik MM, Jedrzejewski W (2001) Feeding habits of the otter and the American mink in Bialowieza Primeval Forest (Poland) compared to other Eurasian populations. Ecography 24:165–180
Kemenes I, Demeter A (1995) A predictive model of the effect of environmental factors on the occurrence of otters (Lutra lutra L.) in Hungary. Hystrix 7:209–218
Kemenes KI, Nechay G (1990) The food of otters Lutra lutra in different habitats in Hungary. Acta Theriol 35:17–24
Kloskowski J (1999) Otter Lutra lutra predation in cyprinid-dominated habitats. Z Säugetierkunde 64:201–209
Knollseisen M (1996) Fischbestimmungsatlas, als Grundlage für nahrungsökologische Untersuchungen. Boku-Reports Wildl Res Game Manage, Wien
Kranz A (2000) Otters (Lutra lutra) increasing in Central Europe: from the threat of extinction to locally perceived overpopulation? Mammalia 64:357–368
Krebs CJ (1989) Ecological methodology. Harper Collins, New York
Kruuk H (1995) Wild otters. Predation and populations. Oxford University Press, Oxford
Kruuk H, Moorhouse A (1990) Seasonal and spatial differences in food selection by otters (Lutra lutra) in Shetland. J Zool 221:621–637
Kruuk H, Conroy JWH, Moorhouse A (1991) Recruitment to a population of otters (Lutra lutra) in Shetland, in relation to fish abundance. J Appl Ecol 28:95–101
Lanszki J, Körmendi S, Hancz C, Martin TG (2001) Examination of some factors affecting selection of fish prey by otters (Lutra lutra) living by eutrophic fish ponds. J Zool 255:97–103
Lanszki J, Molnár T (2003) Diet of otters in three different habitats in Hungary. Folia Zool 52:378–388
Lanszki J, Molnár M, Molnár T (2006) Factors affecting the predation of otter (Lutra lutra) on European pond turtle (Emys orbicularis). J Zool 270:219–226
Lanszki J, Sallai Z (2006) Comparison of the feeding habits of Eurasian otters on a fast flowing river and its backwater habitats. Mamm Biol 71:336–346
März R (1972) Gewöll- und Rupfungskunde. Akademie Verlag, Berlin
Pintér K (2006) Fish production of Hungary in 2005. Halászat 2:48–53
Roche K (1998) The diet of otters. In: Dulfer R, Roche K (eds) First phase report of the Trebon otter project. Scientific background and recommendations for conservation and management planning, vol 93. Council of Europe Publishing, Strasbourg, pp 57–71
Ruiz-Olmo J, Lopez-Martin JM, Palazon S (2001) The influence of fish abundance on the otter (Lutra lutra) populations in Iberian Mediterranean habitats. J Zool 254:325–336
Taastrøm HM, Jacobsen L (1999) The diet of otters (Lutra lutra L.) in Danish freshwater habitats: comparison of prey fish populations. J Zool 248:1–13
Wise MH, Linn IJ, Kennedy CR (1981) A comparison of the feeding biology of mink Mustela vison and otter Lutra lutra. J Zool 195:181–213