The revised EFSA 2023 Guidance on the risk assessment of plant protection products for birds and mammals emphasises vulnerability as a relevant criterion for focal species (FS) selection rather than prevalence. The EFSA 2023 Guidance suggests to rank FS candidates for each dietary group according to their expected exposure by estimating a species-specific daily dietary dose (DDD). Species experiencing higher exposure would be ranked as potentially more vulnerable and can be identified as FS candidates. The DDD is calculated using an estimated "proportion of diet an individual obtains from the (treated) crop" (PT). A PT is derived from a radio-tracking field study in the crop of interest, but such data are not available for all species. We introduce the frequency of occurrence in surveys (FOsurvey) in each study field from FS field studies as a proxy for PT in theoretical DDD calculations. The presence of a species during a high proportion of surveys, resulting in a high FOsurvey, could indicate a high proportion of foraging time spent in this crop. To evaluate whether FOsurvey is an appropriate proxy for PT, empirical PT values from radio-tracking studies for different bird species were correlated to respective FOsurvey values from FS studies in the same crop and growth stage. Based on 10 case examples covering different species and crops, a positive correlation was shown between PT and FOsurvey, supporting the suitability of the proposed approach. Based on a positive correlation between the species' prevalence and the new theoretical DDD, the list of the most relevant FS resulting from the new ranking approach is not expected to differ significantly from the FS selection, according to the methodology proposed in EFSA 2009. However, in a few cases, additional species were identified as potential FS, therefore requiring further consideration in the risk assessment.