Nicarbazin has no effect on reducing feral pigeon populations in Barcelona

• Published in: Pest management science Vol. 77; no. 1; pp. 131 - 137
• Main Authors: Senar, Juan Carlos, Navalpotro, Helena, Pascual, Jordi, Montalvo, Tomás
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-01-2021; Wiley Subscription Services, Inc
• Subjects: Animals; Census; Cities; Columba livia; Columbidae; Contraceptives; Control methods; Feeders; Feeding; feral pigeon; Feral populations; Nicarbazin; Pest control; Pigeons; Population; Population Density; Population number; population size control; Populations; Stations; Cities; feral pigeon; contraceptives; nicarbazin; population size control; Columba livia
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.6000

BACKGROUND
Nicarbazin is an anti‐coccidial product sometimes used as a contraceptive to reduce the size of feral pigeon populations. However, its effectiveness in reducing pigeon population size in cities has caused some controversy. Here, we evaluate its effectiveness in the city of Barcelona.
RESULTS
In 2017, the Barcelona City Council set 23 feeding stations with nicarbazin and ten with placebo (untreated corn). Censuses were undertaken before and after one year of treatment, within a 200‐m radius around each feeder. We also censused 28 circles of 200 m radius distributed randomly 200 m from the feeders and 28 circles > 500 m from the feeders, which acted as controls. Population size across the whole city was also evaluated pre‐ and post treatment. We found that feral pigeon density did not change after one year of treatment, either in the circles around feeding stations with nicarbazin or in the areas around control stations at 200 and > 500 m from the feeders. Population size in placebo circles rose after a year by 10%. A pigeon census for the whole of Barcelona showed a 10% increase.
CONCLUSION
Overall, our results indicate that the nicarbazin treatment had no effect on feral pigeon population size, and we advise against its use as a pigeon control method, at least in large cities.
Feral pigeon density in Barcelona did not change after one year of treatment with Ovistop, either in circles of 200 m diameter around feeding stations or in areas around control stations 200 and > 500 m from the feeders. The pigeon census for the whole city of Barcelona showed a 10% increase. Results indicate that Ovistop treatment had no effect on feral pigeon population size.
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