Land‐use changes and monk parakeet expansion in the Pampas grasslands of Argentina

• Published in: Journal of biogeography 2014-06, Vol.41 (6), p.1160-1170
• Main Authors: Bucher, Enrique H, Aramburú, Rosana M, Patten, Michael
• Format: Article
• Language: English
• Subjects: agricultural land; Agriculture; Agronomy. Soil science and plant productions; Animal and plant ecology; Animal nesting; Animal, plant and microbial ecology; Applied ecology; Argentina; beak; Biogeography; Biological and medical sciences; biological invasions; Bird nesting; cattle; Conservation, protection and management of environment and wildlife; Ecological invasion; Ecoregions; Eucalyptus; food availability; Fundamental and applied biological sciences. Psychology; General agroecology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; General aspects; Generalities. Agricultural and farming systems. Agricultural development; government agencies; grasslands; information sources; Internet; Invasive species; land use change; Myiopsitta monachus; Pampas; Parakeets; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Parrots; Pine trees; Psittacidae; questionnaires; railroads; railways; range expansion; Shifting distributions; Synecology; Terrestrial ecosystems; thistles; trees; urban development; weeds
• ISSN: 0305-0270; 1365-2699
• DOI: 10.1111/jbi.12282

AIM: The monk parakeet, Myiopsitta monachus (Boddaert, 1783), is a successful invasive species that has established viable populations on four continents, including North America and Europe. Of particular interest is the little known, large‐scale expansion of monk parakeet within its native range on the Pampas grasslands of Argentina during the 20th century. To understand the key factors involved in this large‐scale expansion and their implications in terms of current hypotheses on bird introductions, we investigated in detail the expansion process and related changes in land use during the period 1860–2010. LOCATION: The Pampas grassland ecoregion of Argentina. METHODS: Range expansion was assessed using the following information sources: museum specimens, published scientific literature, reports from government agencies, postal questionnaires, internet public media, and data obtained during extensive travelling by the authors. RESULTS: The range of the monk parakeet has expanded by about 327,958 km² in 150 years. The linear range expansion rate was between 2.1 and 7.6 km year⁻¹. Range expansion followed a neighbourhood diffusion pattern. Key land‐use changes included expansion of eucalyptus trees (the preferred nesting tree), introduction of European cattle, weed (thistle) invasion, conversion of grassland to cropland, and urban development. MAIN CONCLUSIONS: Eucalyptus was a key factor favouring parakeet range expansion. Food availability increased as a result of changes in grassland structure, weed invasion and cropland expansion. Urban environments operated as expansion stepping stones along the routes of railways. The invasive potential of monk parakeet and other parrots appears to be related to behavioural flexibility and dietary opportunism favoured by high intelligence and morphological adaptations (beak and foot structure).