Rose-ringed parakeet (Psittacula krameri) and starling (Sturnus vulgaris) syntopics in a Mediterranean urban park: evidence for competition in nest-site selection?

Giuseppe Dodaro, Corrado Battisti


Introduced species may compete with indigenous ones, e.g. for space resources, but evidence for syntopic cavity-nester birds is limited, at least for Mediterranean urban parks. In this work we report data on nest-site habitat use, availability and selection in two species: the introduced rose-ringed parakeet (Psittacula krameri) and the autochthonous starling (Sturnus vulgaris) nesting in ornamental tree (Cedrus libanotica) patches occurring in an historical urban park (Rome, central Italy). In particular, in our study we hypothesize that parakeets negatively affect starling nest-site selection. On 55 trees, we detected 73 available holes for nesting (38.4 % of which hosted nests: 9 of rose-ringed parakeet, 16 of starling, 3 of house sparrow). Birds utilized for nesting only a limited number (< 20%) of the ornamental trees (all larger than 80 cm in diameter). Compared to the total number of available trees, nesting trees had a significantly larger diameter at breast height. We observed a shift in the frequency distribution of nest hole height classes between starlings and parakeets suggesting competition for nesting sites between these two species. Starlings located their nests significantly lower than did rose-ringed parakeets, resulting in a higher specialization for starlings (as measured by the Feinsinger index) than for rose-ringed parakeets. The analysis of co-occurrence highlights a spatial segregation in nest holes. We argue that these differences in preferred nest height are indicative of parakeet dominance over starlings in cavity selection for nesting.


height habitat selection; niche overlap; competition; introduced species; central Italy

Full Text:



Adams LW (1994). Urban wildlife habitats. University of Minnesota press, Minneapolis.

Angelici FM (1984). Il Parrocchetto dal collare Psittacula krameri (Scopoli) è presente in libertà anche a Roma. Avifauna, 7: 179-180.

Angelici FM & Pazienti A (1985). Tre nuove colonie di Storno Sturnus vulgaris nella città di Roma. Rivista italiana di Ornitologia, 55: 181-182.

Battisti C (1986). Censimento degli uccelli nidificanti in un parco urbano (Villa Doria Pamphili, Roma). Avocetta, Italian Journal of Ornithology, 10: 37-40.

Bauer H-G & Woog F (2008). Non-native and naturalized bird species (neozoa) in Germany, part I: occurrence, population size and status. Vogelwarte, 46: 157–194.

Bauer G & Woog F (2011). On the ‘invasiveness’ of non-native bird species. Ibis, 153: 204-206.

Bennett WA (1990). Scale of investigation and the detection of competition : an example from the house sparrow and house finch introductions in North America. The American Naturalist, 135: 725-747.

Blackburn TM, Lockwood JL & Cassey P (2009). Avian Invasions. The Ecology and Evolution of Exotic Birds. Oxford: Oxford University Press.

Braun M, Czajka C & Wink M (2009). Gibt es eine Brutplatzkonkurrenz zwischen Star und Halsbandsittich? Vogelwarte, 47: 361–362.

Beissinger SR & Osborne DR (1982). Effects of urbanization on avian community organization. Condor, 84: 75-83.

Bellamy PE, Hinsley SA & Newton I (1996). Factors influencing bird species numbers in small woods in south-east England. Journal of Applied Ecology, 33: 249-262.

Bibby CJ, Burgess ND, Hill DA & Mustoe SH (2000). Bird census techniques. II Ed., Academic Press, Londra, UK.

BirdLife International (2004). Birds in Europe: population estimates, trends and conservation status. BirdLife Conservation Series, 12, BirdLife International, Canbridge, UK.

Blair RB (2001). Birds and butterflies along urban gradients in two ecoregions of the United States. In: Lockwood JL & McKinney ML (Eds.), Biotic homogenization . Kluwer, Norwell, MA: 33-56.

Blanc A & Walters JR (2008). Cavity excavation and enlargement as mechanisms for indirect interactions in an avian community. Ecology, 89: 506-514.

Brunelli M, Sarrocco S, Corbi F, Sorace A, Boano A, De Felici S, Guerrieri G, Meschini A & Roma S (2011). Nuovo Atlante degli Uccelli Nidificanti nel Lazio. Edizioni ARP (Agenzia Regionale Parchi), Roma.

Butler, CJ (2005). Feral parrots in the Continental United States and United Kingdom: past, present, and future. Journal of Avian Medicine and Surgery, 19:142–149.

Cassey P, Blackburn TM, Russel GJ, Jones KE & Lockwood JL (2004). Influences of the transport and establishment of exotic bird species: an analysis of the parrots (Psittaciformes) of the world. Global Change Biology, 10: 417-426.

Cecere JC, Sorace A & De Santis E (2005). Distribuzione dello Storno Sturnus vulgaris nella città di Roma. Alula, 12: 85-86.

Celesti Grapow L (1995). Atlante della flora di Roma. La distribuzione delle piante spontanee come indicatore ambientale. Comune di Roma, Argos edizioni, Roma.

Cieslak M (1985). Influence of forest size and other factors on breeding bird species number. Ekologia Polska, 33: 103-121.

Cignini B & Zapparoli M (1996). Atlante degli uccelli nidificanti a Roma. F.lli Palombi Editore, Roma.

Clergeau P, Croci S, Jokimäki J, Kaisanlahti-Jokimäki M-L & Dinetti M (2006). Avifauna homogenization by urbanisation: Analysis at different European latitude. Biological Conser-vation, 127: 336-344.

Cramp S & Perrins CM (1993). The Birds of the Western Palearctic. Vol. VII. Oxford Univ Press, Oxford.

Czaijka C, Braun MP & Wink M (2011). Resource use by non-native Ring-Necked Parakeets (Psittacula krameri) and native Starlings (Sturnus vulgaris) in Central Europe. The Open Ornithology Journal, 4: 17-22.

Davis MA (2003) Biotic Globalization: Does Competition from Introduced Species Threaten Biodiversity? BioScience, 5: 481-489.

Dorney JR, Guntenspergen GR, Keugh JR & Sterns F (1984). Composition and structure of an urban woody plant community. Urban Ecology, 8: 69-90.

Dytham C (2011). Choosing and using statistic. A Biologist’s guide. Wiley-Blackwell, UK.

Ebenhard T (1988). Introduced birds and mammals and their ecological effects. Swed. Wildlife Research, 13: 1–107.

Edelman AJ, Koprowski JL & Bertelsen S (2009). Potential for nest site competition between native and exotic tree squirrels. Journal of Mammalogy, 90:167–174.

Essl F, Klingenstein F, Nehring S, Otto C, Rabitsch W & Stöhr O (2008). Schwarze Listen invasiver Arten – ein Instrument zur Risikobewertung für die Naturschutz-Praxis. Natur Landschaft, 83: 418–424.

Falk JH (1976). Energetics of suburban lawn ecosystems. Ecology, 57: 141-150.

Feare CJ (1984). The starling. Oxford University Press, New York.

Feinsinger P, Spers EE & Poole RW (1981). A simple measure of niche breadth. Ecology, 62: 27-32.

Gotelli NJ (2000). Null model analysis of species co-occurrence patterns. Ecology, 81: 2606-2621.

Gotelli NJ & Entsminger GL.(2001). EcoSim: Null models software for ecology. Version 7.0. Acquired Intelligence Inc. & Kesey-Bear.

Helle P (1985). Effects of forest fragmentation on bird densities in northern boreal forests. Ornis Fennica, 62: 35-41.

Hinsley SA, Bellamy PE, Newton I & Sparks TH (1995). Habitat and landscape factors influencing the presence of individual breeding bird species in woodland fragments. Journal of Avian Biology, 26: 94-104.

Kerpez, TA & Smith NS (1990). Competition between European starlings and native woodpeckers for nest cavities in Saguaros. Auk, 107: 367-375.

Kestenholz M, Heer L & Keller V (2005). Non-indigenous bird species established in Europe – a review. Ornithologische Beob.102: 153–180.

Koenig WD (2003). European Starlings and their effect on native cavity-nesting birds. Conserv. Biol. 17: 1134–1140.

Kotaka, N & Matsuoka, S (2002). Secondary users of great spotted woodpecker (Dendrocopos major) nest cavities in urban and suburban forests in Sapporo City, northern Japan. Ornithol. Sci. 1: 117-122.

Krebs CJ (1989). Ecological methodology. Harper Collins Publishers, New York.

Juniper T & Parr M (1998). Parrots: a guide to the Parrot of the World. Pica press.

Lövei GL (1997). Global change through invasion. Nature, 388: 627–628.

Martin K & Eadie JM (1999). Nest webs: A community-wide approach to the management and conservation of cavity-nesting forest birds. Forest Ecology and Management, 115: 243-257.

Martin K, Aitken KEH & Wiebe KL (2004). Nest sites and nest webs for cavity-nesting communities In Interior British Columbia, Canada: nest characteristics and niche partitioning. The Condor, 106: 5-19.

Martin TE & Li P (1992). Life history traits of open- vs. cavity-nesting birds. Ecology, 73: 579-592.

Matthysen E, Lens L, Van Dongen S, Verheyen GR, Wauters LA, Adriaensen F & Dhondt AA (1995). Diverse effects of forest fragmentation on a number of animal species. Belgian Journal of Zoology, 125: 175-183.

McKinney ML (2002). Urbanization, biodiversity, and conservation. BioScience, 52: 883-890.

Mennechez G & Clergeau P (2006) Effect of urbanisation on habitat generalists: starlings not so flexible? Acta Oecologica, 30: 182-191.

Mikusinski G, Gromadzki M & Chylarecki P (2001). Woodpeckers as Indicators of Forest Bird Diversity. Conservation Biology, 15: 208-217.

Mori E, Di Febbraro M, Foresta M, Melis P, Romanazzi E, Notari A & Boggiano F (2013). Assessment of the current distribution of free-living parrots and parakeets (Aves: Psittaciformes) in Italy: a synthesis of published data and new records. Italian Journal of Zoology, 80: 158-167.

Newson SE, Johnston A, Parrott D & Leech DI (2011). Evaluating the population-level impact of an invasive species, Ring-necked Parakeet Psittacula krameri, on native avifauna. Ibis, 153: 509-516.

Nilsson, SG (1984). The evolution of nest-site selection among hole-nesting birds: the importance of nest predation and competition. Ornis Scandinavica, 15: 167-175.

Opdam P, Rijsdijk G & Hustings F (1985). - Bird communities in small woods in an agricultural landscape: effects of area and isolation. Biological Conservation, 34: 333-352.

Pell, AS & Tidemann, R (1997). The impact of two exotic hollow-nesting birds on two native parrots in savannah and woodland in eastern Australia. Biological Conservation, 79: 145-153.

Pranty B (2002). The use of Christmas Bird Count data to monitor populations of exotic birds. American Birds, 56: 24–28.

Rebele F (1994). Urban ecology and special features of urban ecosystems. Global Ecology and Biogeographic letters, 4: 173-187.

Robinson RA, Siriwardena GM & Crick HQP (2005) Status and population trends of Starling Sturnus vulgaris in Great Britain: Bird Study 52: 252-260.

Smith, KW (2006). The implications of nest site competition from starlings Sturnus vulgaris and the effect of spring temperatures on the timing and breeding performance of great spotted woodpeckers Dendrocopus major in southern England. Annales Zoologici Fennici, 43: 177-185.

Snow DW & Perrins CM (1998). The Birds of the Western Palearctic. Concise edition. Vol. I, Non Passerines. Oxford University Press, Oxford.

SPSS Inc. (2003) SPSS for Windows – Release 13.0 (1 Sep 2004), Leadtools (c), Lead Technologies Inc.

Spanò S & Truffi G (1986). Il parrocchetto dal collare, Psittacula krameri, allo stato libero in Europa, con particolare riferimento alle presenze in Italia e primi dati sul pappagallo monaco, Myiopsitta monachus. Rivista italiana di Ornitologia, 56: 231-239.

Stone L & Roberts A (1990). The checkerboard score and species distributions. Oecologia, 85: 74-79.

Strubbe D & Matthysen E (2007). Invasive ring-necked parakeets Psittacula krameri in Belgium: habitat selection and impact on native birds. Ecography, 30: 578-588.

Strubbe D & Matthysen E (2009a). Establishment success of invasive ring-necked and monk parakeets in Europe. Journal of Biogeography, 36: 2264-2278.

Strubbe D. & Matthysen E. (2009b). Experimental evidence for nest-site competition between invasive Ring-necked Parakeets (Psittacula krameri) and native Nuthatches (Sitta europaea). Biological Conservation, 142: 1588–1594.

Strubbe D, Matthysen E & Graham CH (2010). Assessing the potential impact of invasive ring-necked parakeets Psittacula krameri on native nuthatches Sitta europaea in Belgium. Journal of Applied Ecology, 47: 549-557.

Summer-Smith JD (2003). The decline of the House Sparrow: a review. British Birds, 96: 439-446.

Zangari L, Ferraguti M, Luiselli L, Battisti C & Bologna MA (2013). Comparing patterns in abundance and diversity of hole-nesting birds in Mediterranean habitats. Revue d’Écologie (Terre Vie), 68: 275-282.



  • There are currently no refbacks.

The Royal Belgian Society of Zoology acknowledges the Universitarian Foundation of Belgium and the National Fund of Scientific Research for their financial support in publishing the Belgian Journal of Zoology.