Fledgling behaviour and movement patterns throughout the post-fledging dependence period (PFDP), especially in relation to changing environmental conditions, have been rarely studied, despite the fact that this period is recognized as of crucial significance in terms of high mortality of juveniles. The PFDP can extend over quite a protracted period, particularly in birds of prey, and a knowledge of the movement patterns of individuals is fundamental for understanding mechanisms underlying survival, habitat use and dispersion. We radiotracked 39 fledglings of the Tengmalm's owl (Aegolius funereus) in two years with different availability of prey: 2010 (n = 29) and 2011 (n = 10) and obtained 1455 daily locations. Fledglings reached independence on average in 45 days after fledging in 2010 (n = 22) and 57 days in 2011 (n = 6). Within years, the most important measures influencing the distance moved from the nest box were age of fledglings and number of surviving siblings present. Individual home range size and duration of PFDP in particular were dependent on maximal number of siblings seen outside the nest box. In the season with low prey availability fledglings were observed at greater distances from the nest box than in the year with higher prey availability (mean distance: 350 m in 2010 and 650 m in 2011) and occupied larger home ranges (mean: 30.3 ha in 2010 and 57.7 ha in 2011). The main factor causing these differences between years was probably the different availability of prey in these two years, affecting breeding success and post-fledging survivorship of the Tengmalm's owls.

Department of Ecology Faculty of Environmental Sciences Czech University of Life Sciences Prague Prague Czech Republic

Zobrazit více v PubMed

Blackwell PG (1997) Random diffusion models for animal movement. Ecol Model 100: 87–102.

Schick RS, Loarie SR, Colchero F, Best BD, Boustany A, et al. (2008) Understanding movement data and movement processes: current and emerging directions. Ecol Lett 11: 1338–1350. PubMed

Bengtsson G, Nilsson E, Ryden T, Wiktorsson M (2004) Irregular walks and loops combines in small-scale movement of a soil insect: implications for dispersal biology. J Theor Biol 231: 299–306. PubMed

Kennedy PL, Ward JM (2003) Effects of experimental food supplementation on movements of juvenile northern goshawks (Accipiter gentilis atricapillus). Oecologia 134: 284–291. PubMed

Bowler DE, Benton TG (2005) Causes and consequences of animal dispersal strategies: relating individual behaviour to spatial dynamics. Biol Rev 80: 205–225. PubMed

Vásquez RA, Ebensperger LA, Bozinovic F (2002) The influence of habitat on travel speed, intermittent locomotion, and vigilance in a diurnal rodent. Behav Ecol 13: 182–187.

Gurarie E, Ovaskainen O (2011) Characteristic spatial and temporal scales unify models of animal movement. Am Nat 178: 113–123. PubMed

Newton I (1979) Population ecology of raptors. Berkhamsted: Poyser.

Weathers WW, Sullivan KA (1989) Juvenile foraging proficiency, parental effort, and avian reproductive success. Ecol Monogr 59: 223–246.

Delgado MD, Penteriani V, Nams VO (2009) How fledglings explore surroundings from fledging to dispersal. A case study with Eagle Owls Bubo bubo . Ardea 97: 7–15.

Kenward RE, Marcström V, Karlbom M (1993) Post-nestling behavior in goshawks, Accipiter gentilis: 1. The causes of dispersal. Anim Behav 46: 365–370.

McFadzen ME, Marzluff JM (1996) Mortality of prairie falcons during the fledging-dependence period. Condor 98: 791–800.

Todd LD, Poulin RG, Wellicome TI, Brigham RM (2003) Post-fledging survival of burrowing owls in Saskatchewan. J Wildlife Manage 67: 512–519.

Sunde P (2005) Predators control post-fledging mortality in tawny owls, Strix aluco . Oikos 110: 461–472.

Bendel PR, Therres GD (1993) Differential mortality of Barn Owls during fledging from marsh and off-shore nest sites. J Field Ornithol 64: 326–330.

Coles CF, Petty SJ (1997) Dispersal behavior and survival of juvenile Tawny owls (Strix aluco) during the low point in a vole cycle. In: Paul, Minnesota: USDA Forest Service, General Technique Report Duncan JR, Johnson DH, Nicholls TH, eds. Biology and Conservation of Owls of the Northern Hemisphere. St. NC-190: 111–118.

Ganey JL, Block WM, Dwyer JK, Strohmeyer BE, Jenness JS (1998) Dispersal movements and survival rates of juvenile Mexican Spotted Owls in northern Arizona. Wilson Bull 110: 206–217.

Todd LD (2001) Dispersal patterns and post-fledging mortality of juvenile Burrowing Owls in Saskatchewan. J Raptor Res 35: 282–287.

Wiens JD, Reynolds RT, Noon BR (2006) Juvenile movement and natal dispersal of Northern Goshawks in Arizona. Condor 108: 253–269.

Petty SJ, Thirgood SJ (1989) A radio tracking study of post-fledging mortality and movements of Tawny Owls in Argyll. Ring & Migra 10: 75–82.

Overskaug K, Bolstad JP, Sunde P, Øien IJ (1999) Fledgling behavior and survival in northern Tawny Owls. Condor 101: 169–174.

Wiens JD, Noon BR, Reynolds RT (2006) Post-fledging survival of northern goshawks: The importance of prey abundance, weather, and dispersal. Ecol Appl 16: 406–418. PubMed

Belthoff JR, Sparks EJ, Ritchison G (1993) Home ranges of adult and juvenile Eastern Screech-owls: size, seasonal variation and extent of overlap. J Raptor Res 27: 8–15.

Konrad PM, Gilmer DS (1986) Post fledging behavior of Ferruginous Hawks in North Dakota. J Raptor Res 20: 35–39.

Miller GS (1989) Dispersal of juvenile Northern Spotted Owls in western Oregon: M.Sc. thesis, Oregon State University, Corvallis.

Whitmore S (2009) Habitat use of juvenile California spotted owls (Strix occidentalis occidentalis) during the post-fledging dependency period in northeastern California: M.Sc. thesis, California State University, Chico.

Southern HN, Vaughan R, Muir RC (1954) The behaviour of young Tawny owls after fledging. Bird Study 1: 101–110.

Penteriani V, Delgado MM, Maggio C, Aradis A, Sergio F (2005) Development of chicks and predispersal behaviour of young in the Eagle Owl Bubo bubo . Ibis 147: 155–168.

Trivers RL (1974) Parent-offspring conflict. Am Zool 14: 249–264.

Harper AB (1986) The evolution of begging - sibling competition and parent-offspring conflict. Am Nat 128: 99–114.

Godfray HCJ (1995) Signaling of need between parents and young - parent-offspring conflict and sibling rivalry. Am Nat 146: 1–24.

Mock DW, Parker GA (1997) The evolution of sibling rivalry. Oxford: Oxford University Press.

Mock DW, Parker GA (1998) Siblicide, family conflict and the evolutionary limits of selfishness. Anim Behav 56: 1–10. PubMed

Sunde P (2008) Parent-offspring conflict over duration of parental care and its consequences in tawny owls Strix aluco . J Avian Biol 39: 242–246.

Arroyo BE, De Cornulier T, Bretagnolle V (2002) Parental investment and parent-offspring conflicts during the postfledging period in Montagu's harriers. Anim Behav 63: 235–244.

Cramp S (1985) The birds of the western Palaearctic, Vol. IV. Oxford: Oxford University Press.

Drdáková M (2004) Sýc rousný - úspěšný druh imisních holin. Živa 3: 128–130.

Korpimäki E (1981) On the ecology and biology of Tengmalm’s Owl (Aegolius funereus) in southern Ostrobothnia and Soumenselkä, western Finland: Acta Univ Oul A 118 Biol. 13: 1–84.

Mikkola H (1983) Owls of Europe. Calton: Poyser.

Vacík R (1991) Hnízdní biologie sýce rousného, Aegolius funereus, v Čechách a na Moravě. Sylvia 28: 95–113.

Eldegard K, Sonerud GA (2009) Female offspring desertion and male-only care increase with natural and experimental increase in food abundance. Proc R Soc B-Biol Sci 276: 1713–1721. PubMed PMC

Eldegard K, Sonerud GA (2010) Experimental increase in food supply influences the outcome of within-family conflicts in Tengmalm's owl. Behav Ecol Sociobiol 64: 815–826.

Eldegard K, Sonerud GA (2012) Sex roles during post-fledging care in birds: female Tengmalm's Owls contribute little to food provisioning. J Ornithol 153: 385–398.

Zárybnická M (2009) Parental investment of female Tengmalm's Owls Aegolius funereus: correlation with varying food abundance and reproductive success. Acta Ornithol 44: 81–88.

König C, Weick F (2008) Owls of the world. Second edition. New Haven and London: Yale University Press.

Hakkarainen H, Mykra S, Kurki S, Korpimaki E, Nikula A, et al. (2003) Habitat composition as a determinant of reproductive success of Tengmalm's owls under fluctuating food conditions. Oikos 100: 162–171.

Hakkarainen H, Korpimäki E, Laaksonen T, Nikula A, Suorsa P (2008) Survival of male Tengmalm's owls increases with cover of old forest in their territory. Oecologia 155: 479–486. PubMed

Sunde P, Bolstad MS, Moller JD (2003) Reversed sexual dimorphism in tawny owls, Strix aluco, correlates with duty division in breeding effort. Oikos 101: 265–278.

Wood PB, Collopy MW, Sekerak CM (1998) Postfledging nest dependence period for bald eagles in Florida. J Wildlife Manage 62: 333–339.

Vergara P, Fargallo JA, Martinez-Padilla J (2010) Reaching independence: food supply, parent quality, and offspring phenotypic characters in kestrels. Behav Ecol 21: 507–512.

Minguez E, Angulo E, Siebering V (2001) Factors influencing length of the post-fledging period and timing of dispersal in Bonelli's Eagle (Hieraaetus fasciatus) in southwestern Spain. J Raptor Res 35: 228–234.

Balbontin J, Ferrer M (2005) Factors affecting the length of the post-fledging period in the Bonelli's Eagle Hieraaetus fasciatus . Ardea 93: 189–198.

Withey JC, Bloxton TD, Marzluff JM (2001) Effects of tagging and location error in wildlife radiotelemetry studies. In: Millspaugh JJ, Marzluff JM, eds. Radio tracking and animal populations. San Diego: Academic Press. 43–70.

Kenward RE (2001) A manual for wildlife radio tagging. London: Academic Press.

Hayne DW (1949) Calculation of size of home range. J Mammal 30: 1–18.

Kouba M, Šťastný K (2012) Home ranges of Tengmalm’s Owl (Aegolius funereus) fledglings during post-fledging dependence period in polluted areas of the Krušné hory Mts., (In Czech with English summary). Sylvia 48: 115–125.

Hurlbert SH (1984) Pseudoreplication and the design of ecological field experiments. Ecol Monogr 54: 187–211.

De SollaSR, Bonduriansky R, Brooks RJ (1999) Eliminating autocorrelation reduces biological relevance of home range estimates. J Anim Ecol 68: 221–234.

Cushman SA, Chase M, Griffin C (2005) Elephants in space and time. Oikos 109: 331–341.

Börger L, Franconi N, De Michele G, Gantz A, Meschi F, et al. (2006) Effects of sampling regime on the mean and variance of home range size estimates. J Anim Ecol 75: 1393–1405. PubMed

Tao J, Littel R, Patetta M, Truxillo C, Wolfinger R (2002) Mixed Model Analyses Using the SAS System Course Notes. Carry, NC, USA: SAS Institute Inc.

Korpimäki E (1992) Fluctuating food abundance determines the lifetime reproductive success of male Tengmalm’s Owls. J Anim Ecol 61: 103–111.

Korpimäki E (1988) Diet of breeding Tengmalm’s Owls Aegolius funereus: long-term changes and year-to-year variation under cyclic food conditions. Ornis Fenn 65: 21–30.

Korpimäki E, Hakkarainen H (1991) Fluctuating food suplly affects the cluch size of Tengmalm’s owl independent of laying date. Oecologia 85: 543–552. PubMed

Kloubec B, Vacík R (1990) Náčrt potravní ekologie sýce rousného (Aegolius funereus) v Československu. Tichodroma 3: 103–125.

Pykal J, Kloubec B (1994) Feeding ecology of Tengmalm’s owl Aegolius funereus in the Šumava National Park, Czechoslovakia. In: Meyburg B-U, Chancellor RD, eds. Raptor Conservation Today. Berlin, Germany: WWGBP/The Pica Press. 537–541.

Pokorný J (2000) Potrava sýce rousného (Aegolius funereus) v imisemi poškozených oblastech Jizerských hor a Krkonoš. Buteo 11: 107–114.

Ellsworth EA, Belthoff JR (1999) Effects of social status on the dispersal behaviour of juvenile western screech-owls. Anim Behav 57: 883–892. PubMed

Nilsson JA (1990) Family flock break-up - spontaneous dispersal or parental aggression. Anim Behav 40: 1001–1003.

Sonerud GA (1988) Two nestings of a Tengmalm’s owl Aegolius funereus female in one season. Fauna norv Ser C, Cinclus 11: 47–48.

Korpimäki E (1989) Mating system and mate choice of Tengmalm’s Owls Aegolius funereus . Ibis 131: 41–50.

Korpimäki E, Salo P, Valkama J (2011) Sequential polyandry by brood desertion increases female fitness in a bird with obligatory bi-parental care. Behav Ecol Sociobiol 65: 1093–1102.

Belthoff JR, Ritchison G (1989) Natal dispersal of Eastern Screech-Owls. Condor 91: 254–265.

McClaren EL, Kennedy PL, Doyle DD (2005) Northern Goshawk (Accipiter gentilis laingi) post-fledging areas on Vancouver Island, British Columbia. J Raptor Res 39: 253–263.

Frye GG, Jageman HR (2012) Post-fledging ecology of Northern Pygmy-Owls in the Rocky Mountains. Wilson J Ornithol 124: 199–207.

Molecular Identification of Sarcocystis sp. (Apicomplexa, Sarcocystidae) in Offspring of Tengmalm's Owls, Aegolius funereus (Aves, Strigidae)

Long-term trends in the body condition of parents and offspring of Tengmalm's owls under fluctuating food conditions and climate change

Interactive influences of fluctuations of main food resources and climate change on long-term population decline of Tengmalm's owls in the boreal forest

Home range size of Tengmalm's owl during breeding in Central Europe is determined by prey abundance

Factors Affecting Growth of Tengmalm's Owl (Aegolius funereus) Nestlings: Prey Abundance, Sex and Hatching Order

Factors affecting the duration of nestling period and fledging order in Tengmalm's owl (Aegolius funereus): effect of wing length and hatching sequence

Perching of Tengmalm's owl (Aegolius funereus) nestlings at the nest box entrance: effect of time of the day, age, wing length and body weight

Factors affecting vocalization in Tengmalm's owl (Aegolius funereus) fledglings during post-fledging dependence period: scramble competition or honest signalling of need?