I have a pair of 2 year old Black Australian Swans, Gracie and Gunther that have grown up in a captive back yard environment. They have a large yard with water trough to use during the day but due to predators have to be put in their safe house/run at night that is quite large but has no swimming water. They have 2 standard buckets, one with water, other with water and floating Mazuri waterfowl feed in the house. They also have a 5 gallon bucket in the run (roofed). All water and food is fresh changed daily, sometimes more often. They are nocturnal I'm assuming but what concerns me is they scream through the night. I used to run out there thinking they were being murdered but know nothing can penetrate the walls and welded wire or roof above. Precautions were taken so nothing can dig under in the run. Why do they scream out several times during the night? The house floor is concrete covered with straw and run is sand with straw. All is kept clean. Soiled straw removed daily.

Thank you so much,

Darlene