نشریه محیط زیست طبیعی

بررسی حضور و تعیین رژیم غذایی شنگ (Lutra lutra) در ناحیة مصبی رودخانه‌های شرق استان گیلان: پل رود، خشک‌رود و آچارود

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه محیط زیست، دانشکده منابع طبیعی، دانشگاه گیلان، صومعه‌سرا، ایران

2 سازمان تحقیقات و آموزش کشاورزی، موسسه تحقیقات علوم شیلاتی کشور، پژوهشکده آبزی پروری آبهای داخلی (بندر انزلی)، ایران

چکیده

شنگ اوراسیایی (Lutra lutra) از جمله پستانداران ساکن گسترة زیستگاهی آب‌های داخلی ایران به‌‌شمار می‌رود که در رأس هرم غذایی و در خطر انقراض قرار دارد. مطالعات رژیم غذایی، برای درک بوم‌شناسی حیات­وحش و حفظ جمعیت آن‌ها حیاتی است. اهداف این مطالعه شامل بررسی حضور و تعیین رژیم غذایی شنگ در رودخانه­ های آچارود، خشک‌رود و پل ­رود واقع در شرق استان گیلان، و نیز بررسی میزان وابستگی این گونه به ماهیان دریای کاسپین بوده است. طول پنج کیلومتر انتهایی هر رودخانه­، در قالب سه بخش با طول تقریبی 1700 متر، بر حسب دوری یا نزدیکی به دریا مورد بررسی قرار گرفتتد. نتایج بررسی نشان داد که از طول پنج کیلومتری مورد بررسی رودخانه ­ها، شنگ تا 4/3 کیلومتری مصب حضور داشته است. در مجموع، 511 نمایة حضور با تغییرات فصلی مشخص در هر یک از بخش­ های رودخانه‌ها، مشاهده ­شد. بیشترین نمایة مشاهده ­شده در فصل پاییز و کمترین آن در فصل تابستان بود. بر اساس تجزیه و تحلیل و بررسی مدفوع‌­ها، 955 مورد طعمه شامل ماهی­ ها، سخت ­پوستان، خزندگان، دوزیستان، پرندگان و حشرات مشاهده شد. بالاترین شاخص تغذیه‌ای در سه رودخانة مورد بررسی، مربوط به ماهیان و کمترین شاخص تغذیه ­ای مربوط به حشرات بوده است. تغییرات فصلی در اقلام غذایی میان بخش ­ها نیز مشاهده شد. به‌‌طوری‌که در دو فصل پاییز و زمستان در هر سه بخش رودخانه ­ها، بیشترین شاخص تغذیه ­ای مربوط­ به ماهیان بود. در فصل بهار و پاییز، شاخص تغذیه ­ای ماهیان تغذیه ­شده عمدتاً مربوط ­به دسته ماهیان رودخانه ­ای و ماهیان مشترک رودخانه‌ای-دریایی بود. در فصل‌های تابستان و زمستان، درصد ماهیان دریایی نسبت ­به بهار و پاییز بیشتر بود. شاخص تغذیه ­ای اقلام غیرماهی نیز در فصل تابستان نسبت ­به فصول دیگر افزایش داشته است.

کلیدواژه‌ها

عنوان مقاله [English]

Investigating the presence and diet of otter (Lutra lutra) in the estuary region of eastern rivers of Guilan province: Polrood, Khoshkrod and Acharod

نویسندگان [English]

  • Saeid Eshagh Nimvari 1
  • Saeid Naderi 1
  • Alireza Mirzajani 2

1 Department of Environment , Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Iran

2 Inland Water Aquaculture Research Center,, Iranian Fisheries Science Research, Institute, Agricultural Research Education and Extension Organization (AREEO), Bandar Anzali,, Iran

چکیده [English]

The Eurasian otter (Lutra lutra) as one of the mammals of the inland waters of Iran is at the top of the food pyramid and encounter to endanger of extinction. The diet studies are critical to understanding the ecology of wildlife and preserving their populations. The objectives of this study were the presence and diet of otter in estuary region of Acharod, Khoshkrod and Polrood rivers, in the east of Guilan province, and also the study of the level of dependency of this species on fish species of the Caspian Sea. The length of the last five kilometers of each river, as three sections with an approximate length of 1700 meters, was examined in terms of distance or proximity to the sea. The results showed that of the five km length studied of the rivers, the Eurasian Otter was present up to 4/3 km of the estuary. In total, 511 presence indices with specific seasonal changes were observed in each of the river sections. The highest index was observed in the autumn season and the lowest in the summer season. Based on the analysis and investigation of spraints, 955 prey items including fishes, crustaceans, snakes, frogs, birds and insects were observed. The highest feeding index (FI) in three studied rivers was for fish and the lowest FI was for insects. Also, the seasonal changes in food items between sections were observed. So that in the two seasons of autumn and winter in all three sections of the rivers, the highest FI was for fish. In the spring and autumn, the feeding index of the fed fish was mainly related to river fish and common river-sea fish. In summer and winter, the percentage of sea fish was higher than in spring and autumn. The feeding index of non-fish items has also increased in the summer compared to other seasons.

کلیدواژه‌ها [English]

  • Eurasian otter
  • Feeding index
  • Presence
  • Caspian Sea
  • Guilan province
Ansari, N., 2021. Habitat quality evaluation for the Eurasian Otter (Lutra lutra) (Class: Mammalia, Family: Mustelidae) in Markazi Province. Journal of Animal Research (Iranian Journal of Biology) 34(2), 135-149 (In Persian).
Armitage, K.B., Buikema Jr, A.L., Willems, N.J., 1972. Organic constituents in the annual cycle of the crayfish Orconectes nais (Faxon). Comparative Biochemistry and Physiology Part A: Physiology 41(4), 825-842.‏
Blanco-Garrido, F., Prenda, J., Narvaez, M., 2008. Eurasian otter (Lutra lutra) diet and prey selection in Mediterranean streams invaded by centrarchid fishes. Biological Invasions 10(5), 641-648.
Buglione, M., Petrelli, S., Troiano, C., Notomista, T., Rivieccio, E., Fulgione, D., 2020. The diet of otters (Lutra lutra) on the Agri river system, one of the most important presence sites in Italy: a molecular approach. Peer J 8, e9606.
Chanin, P., 2003. Ecology of the European Otter. Conserving Natura 2000 Rivers Ecology Series No. 10. English Nature, Peterborough, 64 p.
Clavero, M., Prenda, J., Delibes, M., 2005. Amphibian and reptile consumption by otters (Lutra lutra) in a coastal area in southern Iberian Peninsula. The Herpetological Journal 15(2), 125-131.
‏Conroy, J.W.H., French, D.D., 1987. The use of spraints to monitor populations of otters (Lutra lutra). Symposia of the Zoological Society of London 58, 247-262.
Cosby, H.A., 2013. Variation in diet and activity of river otters (Lontra canadensis) by season and aquatic community (Master's thesis, Humboldt State University).
Crimmins, S.M., Roberts, N.M., Hamilton, D.A., 2009. Effects of prey size on scat analysis to determine river otter Lontra canadensis diet. Wildlife Biology 15(4), 449-453.
Day, C.C., Westover, M.D., McMillan, B.R., 2015. Seasonal diet of the northern river otter (Lontra canadensis): what drives prey selection? Canadian Journal of Zoology 93(3), 197-205.
Farid Mojtahedi, N., 2017. Rivers of Guilan. Farhang Ilia Publishing. 148 p. (In Persian)
Flint, R.W., 1977. Seasonal activity, migration and distribution of the crayfish, Pacifastacus ieniusculus, in Lake Tahoe. The American Midland Naturalist 97(2), 280-292.
Gorgadze, G., 2013. Seasonal diet of the otter (Lutra lutra) on the Alazani River (Georgia). Hystrix-the Italian Journal of Mammalogy 24(2), 157-160.
Groves, D., Smith, R.J., 2021. The diet of Eurasian otters (Lutra lutra) around the coastal fringe of Cornwall. Mammal Communications 7, 11-16.
Hadipour, E., Karami, M., Abdoli, A., Borhan, R., Goljani, R., 2011. A study on Eurasian Otter (Lutra lutra) in amirkelayeh wildlife refuge and international wetland in Guilan Province, Northern Iran. IUCN Otter Specialist Group Bulletin 28(2), 84-98.
Harna, G., 1993. Diet composition of the otter Lutra lutra in the Bieszczady Mountains, south-east Poland. Acta Theriologica 38(2), 167-174.‏
Hysaj, E., Bego, F., Prigioni, C., Balestrieri, A., 2013. Distribution and marking intensity of the Eurasian otter, Lutra lutra, on the River Drinos (southern Albania). Journal of Vertebrate Biology 62(2), 115-120.
Jêdrzejewska, B., Sidorovich, V.E., Pikulik, M.M., Jêdrzejewski, 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.
Jordaan, R.K., McIntyre, T., Somers, M.J., Bester, M.N., 2015. An assessment of spatial and temporal variation in the diet of Cape clawless otters (Aonyx capensis) in marine environments. African Journal of Wildlife Research 45(3), 342-353.
Karami, M., Dehdar Dargahi, M., Hamzehpour, M., 2012. Habitat Suitability Index Model of Common Otter (Lutra lutra) in Prohibited Hunting Area, Deylaman–Dorfak. Journal of Natural Environment 65(1), 127-137. (In Persian)
Karami, M., Dehdar Dargahi, M., Islami, A., Hamzehpour, M., 2009. Study of distribution (distribution map) of Common Otter (Lutra lutra) using standard method in Shenroud River (Prohibited Hunting Area, Deylaman–Dorfak). Environmental Science and Technology 10(4), 85-99. (In Persian)
Karami, M., Mirzaei, R., Hamzehpour, M., 2006. Status of Eurasian Otter (Lutra lutra) in Iran. IUCN Otter Specialist Group Bulletin 23(1), 27-33.
Kawakami, E., Vazzoler, G., 1980. Método gráfico e estimativa de índice alimentar aplicado no estudo de alimentação de peixes. Boletim do Instituto Oceanográfico 29, 205-207.
Kean, E.F., Muller, C.T., Chadwick, E.A., 2011. Otter scent signals age, sex, and reproductive status. Chemical Senses 36(6), 555-564.
Kiabi, B., 1993. Otter. Aquatic Species Magazine 6, 10-15. (In Persian)
Kruuk, H., 1995. Wild Otters: Predation and Populations. Oxford University Press. 304 p.
Kruuk, H., 2006. Otters: ecology, behaviour and conservation. Oxford University Press, Cambridge. 265 p.
Lanszki, J., Lehoczky, I., Kotze, A., Somers, M. J., 2016. Diet of otters (Lutra lutra) in various habitat types in the Pannonian biogeographical region compared to other regions of Europe. PeerJ 4, e2266.
Leuchtenberger, C., Rheingantz, M.L., Zucco, C.A., Catella, A.C., Magnusson, W.E., Mourão, G., 2020. Giant otter diet differs between habitats and from fisheries offtake in a large Neotropical floodplain. Journal of Mammalogy 101(6), 1650-1659.
Litvaitis, J.A., 2000. Investigating Food Habits of Terrestrial Vertebrates. In: Boitani, L. & Fuller, T.K. (Eds.); Research Techniques in Animal Ecology: Controversies and Consequences. Columbia University Press, New York, pp: 165-190.
Macdonald, S.M., Mason, C.F., 1987. Seasonal marking in an otter population. Acta Theriologica 32(27), 449-462.
Martínez-Abraín, A., Mari-Mena, N., Vizcaíno, A., Vierna, J., Veloy, C., Amboage, M., Guitian-Cammano, A., Key, Ch., Vila, M., 2020. Determinants of Eurasian otter (Lutra lutra) diet in a seasonally changing reservoir. Hydrobiologia 847(8), 1803-1816.
Mason, C.F. Macdonald, S.M., 1986. Otters: ecology and conservation. Cambridge University Press, 236 p.
‏Mirzaei, R., Conroy, J., Yoxon, P., 2010. Otters in the Hawr al Azim wetland, Iran. Hystrix-the Italian Journal of Mammalogy 21(1), 83-88.
Mirzaei, R., Danehkar, A., Abdoli, A., 2014. The diet of Eurasian otters in the Jajrood River system, Iran. Mammal Study 39(1), 33-41.‏
Mirzaei, R., Karami, M., Danehkar, A., Abdoli, A., 2009. Habitat selection of the Eurasian Otter, Lutra lutra, in Jajrood river, Iran: (Mammalia: Carnivora). Zoology in the Middle East 47(1), 13-19.
Mirzajani, A., Ganeh, A., Khodaparast, H., Gorbanzadeh Zaferani, S.G., Sedigi Savadkohi, O, 2014. Study of Caspian Sea river estuaries in Guilan province base on benthic organisms. Journal of Natural Environment 67(4), 461-474.‏
Mirzajani, A., Naderi, S., Ganeh, A., Hadipour, E., Salahi, M., Javidpour, J., 2021. Trophic flexibility of Eurasian otter (Lutra lutra) in Anzali Wetland, Iran, assessed by fecal and stable isotope analysis. Aquatic Ecology 55(2), 401-415.
Mohtasebi, S., Tabatabaei, F., 2018. Evidence of the presence of Lutra lutra in Taleqan, Alborz Province Iran. IUCN Otter Specialist Group Bulletin 35(3), 156-158.
Naderi, S., Mirzajani, A., Hadipour, E., 2017 a. Distribution of and threats to the Eurasian Otter (Lutra lutra) in the Anzali Wetland, Iran. IUCN/SCC Otter Specialist Group Bulletin 34(2), 84-94.
Naderi, S., Mirzajani, A., Rajabi Maham, H., Hadipour, E., 2017 b‏. The mammals of Anzali Wetland in the Southern Caspian Sea. Caspian Journal of Environmental Sciences 15(3), 223-235.
Natarajan, A., Jhingran, A., 1961. Index of preponderance - a method of grading the food elements in the stomach analysis of fishes. Indian Journal of Fisheries 8, 54-59.
Nolet, B.A., Wansink, E.H., Kruuk, H., 1993. Diving of otters (Lutra lutra) in a marine habitat: use of depths by a single-prey loader. Journal of Animal Ecology 62(1), 22-32.
Ottino, P., Giller, P., 2004. Distribution, density, diet and habitat use of the otter in relation to land use in the Araglin valley, Southern Ireland. In Biology and Environment: Proceedings of the Royal Irish Academy (pp. 1-17). Royal Irish Academy.
Parry, G.S., Burton, S., Cox, B., Forman, D.W., 2011. Diet of coastal foraging Eurasian otters (Lutra lutra L.) in Pembrokeshire south-west Wales. European Journal of Wildlife Research 57(3), 485-494.
Penland, T.F., Black, J.M., 2009. Seasonal variation in river otter diet in coastal northern California. Northwestern Naturalist 90, 233-237.
Prenda, J., López-Nieves, P., Bravo, R., 2001. Conservation of otter (Lutra lutra) in a Mediterranean area: the importance of habitat quality and temporal variation in water availability. Aquatic Conservation: Marine and freshwater Ecosystems 11(5), 343-355.
Prigioni, C., Remonti, L., Balestrieri, A., 2006. Otter Lutra lutra movements assessed by genotyped spraints in southern Italy. Hystrix-the Italian Journal of Mammalogy 17(1), 91-96.
Prigioni, C., Remonti, L., Balestrieri, A., Sgrosso, S., Priore, G., Misin, C., Anania, R., 2005. Distribution and sprainting activity of the otter (Lutra lutra) in the Pollino National Park (Southern Italy). Ethology Ecology & Evolution 17(2), 171-180.‏
Rasooli, P., Kiabi, B.H., Abdoli, A., 2007. On the status and biology of the European Otter, Lutra lutra (Carnivora: Mustelidae), in Iran. Zoology in the Middle East 41, 25-29.
Romero, R., Guitián, J., Ruiz‐Olmo, J., 2012. Changes in the diet of coastal otters after the Prestige oil spill (Galicia, north‐west Spain). Journal of Zoology 286(1), 22-29.
Ruiz-Olmo, J., López-Martin, J.M., Palazón, S., 2001. The influence of fish abundance on the otter (Lutra lutra) populations in Iberian Mediterranean habitats. Journal of Zoology 254(3), 325-336.
Sulkava, R., 1996. Diet of otters Lutra lutra in central Finland. Acta Theriologica 41(4), 395-408.
Theng, M., Sivasothi, N., Tan, H.H., 2016. Diet of the smooth-coated otter Lutrogale perspicillata (Geoffroy, 1826) at natural and modified sites in Singapore. Raffles Bulletin of Zoology 64, 290-301.
Verwoerd, D.J., 1987. Observations on the food and status of the Cape clawless otter, Aonyx capensis, at Betty’s Bay, South Africa. South African Journal of Zoology 22(1), 33-39.
Wise, M.H., Linn, I.J. Kennedy, C.R., 1981. A comparison of the feeding biology of mink Mustela vison and otter Lutra lutra. Journal of Zoology 195(2), 181-213.
نشریه محیط زیست طبیعی
دوره 75، شماره 4 - شماره پیاپی 4
آبان 1401
صفحه 716-732