There can be few more intriguing sights for a Garden BirdWatcher than to observe one species of bird feeding another on their patch. This unusual behaviour tends to cause a good degree of puzzlement. Why do parent birds do this? Is it a waste of energy? Can the parent not recognise their own young? A review paper by Marilyn Shy has explored this topic, revealing which species are most often observed involved in this behaviour and possible reasons why.

Click on the link to read the rest of the article: Cross-species feeding | BTO – British Trust for Ornithology