Botulism in Wild Birds and Changes in Environmental Habitat: A Relationship to be Considered

• Published in: Animals (Basel) Vol. 9; no. 12; p. 1034
• Main Authors: Circella, Elena, Camarda, Antonio, Bano, Luca, Marzano, Giacomo, Lombardi, Roberto, D'Onghia, Francesco, Greco, Grazia
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.12.2019; MDPI
• Subjects: Animal diseases; Animals; Aquatic birds; Artificial ponds; Bird migration; Birds; Botulism; Canals; Carcasses; Case Report; Disease; Diseases; Distribution; Drainage canals; Ducks; Environmental aspects; Environmental management; Environmental protection; Epidemics; Fishes; Food; Food contamination; Food supply; Habitats; Health aspects; Herons; Human influences; Human-environment interactions; Mortality; Mosaics; Mugil; Mugil cephalus; Mullet; Nature; Nature reserves; Outbreaks; Paralysis; Ponds; Protection and preservation; Sandpipers; Summer; Toxins; Waterfowl; Wetlands; Wildlife; Wildlife conservation; Wildlife habitats; Wildlife management; Wildlife refuges; Italy; United Kingdom > UK; United States > US; Ireland; Europe; botulism; human activities; wildlife conservation; wetland; nature reserve
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani9121034

Any human activity, even if aimed at the improvement of a natural area, can potentially affect wildlife, leading to possible short-term or long-term changes due to the human-wildlife interaction. In this study, a botulism outbreak which occurred in waterfowl in a nature reserve after a conservative environmental action is reported. More than 180 different species of wild birds, including seventy waterfowl species, live in the area. The wildlife reserve rangers built an artificial pond equipped with draining canals in the wetland in order to improve the environment of waterfowl species and to facilitate their supply of food. Then, presumably due to tidal rides, gray mullets ( ) arrived from the sea and settled in the pond. The number of fishes gradually increased, and several fishes died with a peak of mortality in the summer of 2017, creating a great amount of decaying organic material and the optimal conditions for growth and toxin production. A botulism outbreak then occurred rapidly and was characterised by flaccid paralysis and sudden mortality of the birds. Seven mallard ducks ( ), 4 common teals ( ), 1 garganey ( ), 2 wood sandpipers ( ), 1 little egret ( ), 1 little grebe ( ), and 4 Eurasian coots ( ) were found dead. Interestingly, the toxin identified as responsible for the disease outbreak was the mosaic of type C and D toxins (C/D type). The prompt removal of the fish carcasses led to a rapid resolution of the outbreak of the disease, highlighting the relevance of a correct management for any action in environmental contexts. The conclusion is that any human activity in wildlife habitats should be carefully considered in order to assess the possible impacts and to quickly identify the possible risks of changes in wildlife population.