Selective predation on common voles by Tawny Owls and Long-eared Owls in winter and spring

We studied size preferences of Tawny (Strix aluco) and Long-eared (Asio otus) Owls preying on common voles (Microtus arvalis) in the winter and spring seasons in Central Lithuania. Regression equations were used for body mass estimations. We found that both A. otus and S. aluco preferred larger M. arvalis than the average available in the population (the average body mass of predated individuals was 21.45 ± 0.12 g compared to 16.42 ± 0.16 g of snap-trapped individuals). Irrespective of the owl species, most of the predated Microtus voles were adults. In S. aluco prey, the winter proportion of young voles was significantly higher than in the prey of A. otus, 33.3% versus 5.2%. By contrast, the proportion of subadult and adult voles with a body mass in the range between 19 and 23 g was significantly higher in the prey of A. otus. Our results may indicate that the selection of the differently sized prey allows the 2 species of owls to coexist sympatrically.

Anahtar Kelimeler:

Key words: Owl diet, prey size, diet selectivity, body mass prediction

Selective predation on common voles by Tawny Owls and Long-eared Owls in winter and spring

Keywords:

Key words: Owl diet, prey size, diet selectivity, body mass prediction,

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Balčiauskas L, Balčiauskienė L (2011). Estimation of Root Vole body mass using bone measurements from prey remains. NorthWest J Zool 7: 143–147.
Balčiauskas L, Balčiauskienė L, Janonytė A (2012). Reproduction of the root vole (Microtus oeconomus) at the edge of its distribution range. Turk J Zool 36: 668–675.
Balčiauskienė L (2007). Cranial growth of captive bred common voles (Microtus arvalis). Acta Zool Lit 17: 220–227.
Balčiauskienė L, Balčiauskas L (2011). Data on morphometry of the Root Vole (Microtus oeconomus) from Lithuania. Acta Zool Lit 21: 24–31.
Balčiauskienė L, Balčiauskas L, Čepukienė A (2009). Winter growth depression of common vole (Microtus arvalis). Acta Zool Lit 19: 85–92.
Balčiauskienė L, Jovaišas A, Naruševičius V, Petraška A, Skuja S (2006). Diet of Tawny Owl (Strix aluco) and Long-eared Owl (Asio otus) in Lithuania as found from pellets. Acta Zool Lit 16: 37–45.
Dickman CR, Predavec M, Lynam AJ (1991). Differential predation of size and sex classes of mice by the barn owl, Tyto alba. Oikos 62: 67–76.
Fulk GW (1976). Owl predation and rodent mortality: A case study. Mammalia 40: 423–427.
Gliwicz J (2008). Body size relationships between avian predators and their rodent prey in a North-American sagebrush community. Acta Ornithol 43: 151–158.
Goszczyński J (1977). Connection between predatory birds and mammals and their prey. Acta Theriol 22: 399–430.
Goszczyński J (1981). Comparative analysis of food of owls in agrocenosis. Ekologika Polska 29: 431–439.
Granjon L, Traoré M (2007). Prey selection by barn owls in relation to small-mammal community and population structure in a Sahelian agro-ecosystem. J Trop Ecol 23: 199–208.
Halle S (1988). Avian predation upon a mixed community of common voles (Microtus arvalis) and wood mice (Apodemus sylvaticus). Oecologia 75: 451–455.
Jędrzejewski W, Jędrzejewska B (1993). Predation on rodents in Białowieża primeval forest, Poland. Ecography 16: 47–64. Karell P, Lehtosalo N, Pietiäinen H, Brommer JE (2010). Ural owl predation on field voles and bank voles by size, sex and reproductive state. Ann Zool Fenn 47: 90–98.
Kirk DA (1992). Diet changes in breeding tawny owls (Strix aluco). J Raptor Res 26: 239–242.
Korpimäki E (1985). Rapid tracking of microtine populations by their avian predators: possible evidence for stabilizing predation. Oikos 45: 281–284.
Lagerström M, Häkkinen I (1978). Uneven sex ratio of voles in the food of Aegolius funereus and Strix aluco. Ornis Fennica 55: 149–153.
Longland WS, Jenkins SH (1987). Sex and age affect vulnerability of desert rodents to owl predation. J Mammal 68: 746–754. Markov G, Csorba G, Kocheva M, Gospodinova M (2012). Skull features of the common vole (Microtus arvalis sensu lato) from Hungary: craniometrical evidence for its taxonomic detachment. Turk J Zool 36: 283–290.
Marks JS, Marti CD (1984). Feeding ecology of sympatric Barn Owls and Long-eared Owls in Idaho. Ornis Scand 15: 135–143. Marti CD, Bechard M, Jaksic FM (2007). Food habits. In: Bird DM, Bildstein KL, editors. Raptor Research and Management Techniques. Electronic edition. Hancock House Publishers. Available at http://raptors.hancockwildlife.org/index. php?topic=RRMT.
Marti CD, Hogue JC (1979). Selection of prey by the size in screech owls. Auk 96: 319–327.