An outbreak of bird flu in La Code Oura last May, which has now been eradicated, resulted in the deaths of some 3,000 birds. The most serious are the nestlings of Sand Tern (Thalasseus sandvicensis), Black-headed Gull (Ichthyaetus melanocephalus) and Black-billed Tern (Gelochelidon nilotica), which may lose about 2,000 chicks in total. For adults, the number is three times lower, with around eight hundred samples, according to data managed by the Ministry of Environment.
The General Administration of Agriculture, Animal Husbandry and Fisheries at that time took strict protective measures to prevent further expansion. Despite this, the number of black-headed gulls has increased from 1,000 pairs in 2022 to 1,700 pairs this year, according to a census conducted by SEOBirdlife. However, the numbers of remaining affected species remain about the same as in previous years.
On May 30, technicians at the Valencia City Council’s Devesa-Albufera service center suspected an outbreak when they discovered four animals showing symptoms of the disease. After animal analysis and health authorities confirmed the presence of the virus, controls were tightened and carcasses and sick animals were removed to reduce the deadly spread.
The epidemic did not begin to subside until August and was considered extinct after the breeding season ended. Experts point out that high temperatures are always helpful in “clearing out” viruses that may be vectors.
The department, now headed by Salomé Pradas, points out that avian influenza ultimately affected only 2.7% of the birds in the enclave, while the mortality rate in the Nordic seabird habitat was as high as 74%. According to statistics conducted by SEOBirdlife, the number of seagulls and terns showed positive signs during the event.
Some 20,000 pairs of 39 different species are capable of breeding, and 121,341 specimens have been counted during the winter. In fact, the number of Audouan’s gulls (Ichthyaetus audouinii), which is listed as vulnerable on the Valencian Endangered Species List, has tripled from last year, with the number approaching 800 pairs. Among the terns classified as some threat, Little Terns have seen an increase in their numbers, from 50 to 62 pairs, while Common Terns have a breeding population of more than 250 pairs, slightly below their 2022 numbers .