She bought the yellow birds during a shopping trip in California this week.

A source said: 'Britney had just picked up some dog food when she spotted the parakeets and decided to buy a pair. She settled on yellow parakeets and bought a big, white cage and several toys for the birds.'

Britney purchased the winged creatures at the California Pet Center in Calabasas, and impressed staff by questioning how to care for them properly.

Workers didn't initially realise it was the 27-year-old singer – who has sons Sean Preston, four, and three-year-old Jayden James with ex-husband Kevin Federline - who was enquiring about the pets.

Store worker Brieanna Kirby told gossip website X17online: 'She came in just to buy the birds. She walked in, picked out a cage and set it down on my desk and then took off her glasses and I realised who she was. She was really, really, really nice, asking lots of questions about the upkeep of the birds and how much time and effort it takes to take care of them.

'She talked about the bird needing to be compatible with her family and she wanted a bird that would be easy to handle for her boys - one that wouldn't bite a finger off. And she liked all the colors.'