Birds need varied activities during avian flu lockdowns, new research shows.
Scientists studied a flock of Chilean flamingos that were kept indoors due to a government order to stop the spread of avian influenza.
Flamingos were very inactive during the lockdown and just after release, and were more alert while kept indoors.
They also displayed unusual behaviour during and after the lockdown.
"This project started because keepers noticed the birds performing an unusual behaviour - dropping their heads as if filter-feeding when they weren't in the water," said Dr Paul Rose, from the University of Exeter.
"Chilean flamingos perform this sweeping action to filter-feed in water, and they had access to a pool while kept indoors, but for some reason they were making this motion on dry land.
"We can't say exactly why they did this, but it shows that birds need a variety of foraging and bathing opportunities to allow them to perform their natural behaviours."
This "mock" filter-feeding continued after the flamingos were allowed back outside, suggesting it takes time for natural behaviour patterns to reestablish after lockdowns.
The higher level of alertness indoors is thought to be due to the proximity of humans - the flock being locked inside meant keepers had to be closer than usual to feed and care for them.
Dr Rose added: "Our study shows the difficulty of trying to decipher animal wellbeing just by observing their behaviour.
"To assess birds' welfare, it's better to consider a range of information - including social behaviour, resting and plumage condition."
Plumage is an especially important sign of flamingo health - they spend much of their time preening, and a flamingo with rich pink feathers is likely to be very healthy.
Dr Rose was surprised to find plumage condition improved when flamingos were inactive - but this may be explained by the birds experiencing less disturbance after lockdown, meaning feathers were less likely to get ruffled.
Commenting on the study's wider implication for bird keepers - from zoos to people who keep pet chickens - Dr Rose said: "Lockdowns prevent the spread of disease but birds also have behavioural requirements.
"Know your animal. They are hard-wired to do certain things, so you should try to provide opportunities - whether that means roosting, feeding in certain ways, or whatever else they do."
The flamingos in the study were at Banham Zoo in Norfolk, UK.
