Goats, birds, and emergent diseases: apparent and hidden effects of exotic species in an island environment

• DOI: 10.1890/07-2134.1
• Publication Date: 2009-05-21T20:21:12Z
• Authors: Martina Carrete; David Serrano; Juan C. Illera; Guillermo López; Matthias Vögeli; Antonio Delgado; JoséL. Tella
• Keywords: Population Density; 0106 biological sciences; 2. Zero hunger; Goats; Feeding Behavior; Poxviridae Infections; Plants; 15. Life on land; 01 natural sciences; Diet; Songbirds; Spain; Prevalence; Animals; Ecosystem

Exotic species can have devastating effects on recipient environments and even lead to the outbreak of emergent diseases. We present here several hidden that introduction goats has had Lesser Short-toed Lark, Calandrella rufescens, commonest native bird inhabiting island Fuerteventura (Canary Islands). Vegetation structure varied with grazing pressure, indeed, vegetation was all but eradicated from locality greatest goat densities, which also where lowest density Larks recorded. The impact habitat impoverishment, however, partially compensated for by changes in foraging behavior birds, benefited abundant food provided farms. Capture-resighting methods showed birds visiting farms outnumbered estimates obtained surrounding natural habitat, suggesting there recruitment a much larger area. Stable isotope analyses feathers indicated feed largely maize supplied at farms, showing poorer body condition than populations not associated (peninsular Spain Morocco). Moreover, larks very high prevalence poxvirus lesions compared other worldwide may increase risk contracting disease feeding they aggregate coexist atypically domestic birds. lower average productivity, be consequence and/or poor nutritional state resulting low-protein diet. Diseased non-diseased similar annual survival rates. However, isotopic traces delta 13C indicate diet diseased more uniform being based Our results show how combination frequently introduced onto islands (goats, poultry, pathogens) create ecological traps are always easy identify. we stress nutrition infectious diseases important determinants well-being dynamics animal populations, thus health research must included design monitoring programs conservation strategies.