Last week we talked about how Jersey Zoo keepers have hand-reared chough chicks for release into the wild. We mentioned that there is sometimes a risk of chicks imprinting on humans. One way round this is to call in the help of a foster parent. Meet Gianna, our foster mum at Jersey Zoo.
Gianna came to Jersey from Turin in Italy. She was rescued from a balcony of a block of high rise flats by staff at the University of Turin’s Faculty of Veterinary Medicine. Once in their care they realised she was a very tame and suspected she might have been kept as a pet. They contacted Jersey Zoo and wondered if she could help with our reintroduction project. She certainly has.
Gianna is happy to share an aviary with other choughs, but she does not play with them. She much prefers the company of the zoo keepers. As a way of showing that you are best friends, a chough will preen another chough. Preening also means that your feathers are kept clear of feather mites and dirt. That is why Gianna enjoys tickles from the keepers. Sometimes we she does it back!
This is how we knew that together we would make a good team. In 2015 we started using Gianna as a foster mum. We treat her the same as we treat all our breeding choughs when the season arrives. We move her into her own aviary. It looks very similar to the other choughs aviaries except the nest box is placed lower down so keepers can easily reach in.
We provide her with nesting material at the same time as the others.
Once they start laying eggs we give Gianna a fake egg, also known as a dummy egg. This stimulates her to start laying her own infertile eggs and incubate them.
If staff end up having to rescue an egg or chick we can hand-rear it for the first five days - the critical period. We then swap Gianna's egg for a chick. The chick does not look too different from a newly hatched chick so Gianna just thinks that her egg has hatched. Last year Gianna looked after four chicks at once.
In the wild, mum and dad take turns feeding the chicks. This means that keepers have to help Gianna feed the chicks. She doesn't mind and even allows us to weigh the chicks to collect data about their health and development.
When the chicks were old enough we moved them to the release aviary at Sorel. They were kept locked in a separate section of the aviary to the released choughs who were free to come and go as they pleased. We didn't the young chicks to be scared too much. It is a bit like the first day of school. Everything is new and exciting, but the big kids can seem scary.
Once the foster chicks had fledged and learnt to feed for themselves we prepared them for being released. When the day finally came to leave the aviary they didn't want to! They did not feel confident enough to join the other choughs. Instead they followed the other keeper and myself. We had to stay with them when they were outside of the aviary. In the evenings they would fly back to the aviary to roost.To get them to socialise and forage for food with the rest of the group we would walk with them slowly towards the group and stay with them. Imagine being in the playground at school. You can see other children you want to play with, but you don't feel confident enough to walk up and say "hey want to play?".
After a week or so they became more confident and more independent. They developed an amazing skill of being able to see me arriving from 50 metres away and fly over to demand food. Today these chicks are a year old. They still recognise me and fly quite close. They no longer land on me which is a good thing.
These foster chicks behaved exactly how you would expect wild chicks to behave around their parents. The bonus is that, just like wild choughs, they see other humans as potential threats and don't fly to them. In a way I became an honourary chough when I was hand-feeding them alongside Gianna.
If you have any questions you would like to ask about the choughs or to find out more about the project go to www.BirdsOnTheEdge.org We would love to hear from you.