There are many types of citrus fruits, kumquat, key lime, sweet orange, mandarin orange, pomelo, grapefruit…Wild boars will eat a sweet orange that has dropped onto the ground. Hornbills like fruits and may take kumquat. Never seen it. I’m just thinking it is possible. Many citrus varieties have been in cultivation for a very long time. Some citrus fruits do not have juice.
I get rid of a few sweet oranges every month, by cutting it in half and placing it at a wild place. I didn’t stick around. I guess the birds have been feeding on it. A few butterflies. Slugs and semislugs seen nearby sometimes. The fruit peel will be melting away. I did not take note if the slugs are eating everything. I think they like the white part of the peel. I did not observe too closely.