The results showed fostering had no negative effects, with fostered flamingos still forming stable social ties – making "friends" and behaving like parent-reared birds. "Slimbridge's Andean flamingos hadn't nested for about 20 years," said Dr Paul Rose, of the University of Exeter.
"But in the hot summer of 2018 – probably due to the high temperatures – they made nests and laid eggs.
"Unfortunately, the eggs turned out to be infertile, possibly due to the age of the birds – some of them are approaching their 60s.
"To give them enrichment (allowing them to behave naturally), keepers placed six eggs from the Chilean flamingo flock to be raised by the Andean flamingos.
"This gave us a rare opportunity to study the effects of fostering – although it should be noted that these species are remarkably similar, and this would not have been attempted otherwise."
Peter Kidd, then a student on Exeter's MSc Animal Behaviour course, observed and recorded the chicks' behaviour from April to July 2019 (after their return to their own flock).
