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Increasing numbers of reports of clinical falcon herpesvirus infection (Falconid herpesvirus-1; FHV-1) have been seen in the UK since 1996. The aim of this epidemiological study was to investigate the seroprevalence of FHV-1 and owl herpesvirus (Strigid herpesvirus-1; StHV-1) infection in the UK, using virus neutralization tests, and to evaluate the prevalence of herpesvirus infection in captive and wild raptor populations. The results, using the English FHV-1 CVL 32/93 isolate, revealed a seroprevalence of 3.97% (10/252). The seroprevalence for StHV-1 was 12.3% (8/65). Analysis of the data by captivity status, age and species revealed that the family Falconidae showed the highest seroprevalence with 6.7% (5/75), while only one of 104 captive Accipitridae was positive for FHV-1 (0.96%). The incidence of FHV-1 neutralizing antibodies in owls was 5.5% (4/73), representing only wild individuals. Eighty-nine serum samples were additionally tested using two other FHV-1 isolates, the German isolate Merlin 1869/92 and the Dutch isolate Peregrine Z100. The seroprevalences of FHV-1 were 28.1% (25/89) and 32.6% (29/89), respectively. All these samples, however, were negative using the CVL 32/92 isolate.