This pond is located in Superior Township, Michigan. According to Ebird.org, Trumpeters have been spotted in the pond since 2009 and Mutes have been seen since 2004. It seems that only Trumpeters have been reported on the pond during 2010-12.

On March 17, 2013, 2 Trumpeters were reported on the pond and 1 was flying over it. March 28, 2013, 2 Mutes were reported on the pond and no Trumpeters were in the report.

On April 1, I found 2 dead Mutes in the middle of the pond about 150 feet apart from one another. There were 2 Trumpeters in the pond. I had a suspicion that the Trumpeters could have caused the deaths of the Mutes. From my observations in the past, adult Mutes do not mess around with adult Trumpeters-especially if the Trumpeter is over 3 years old.

A week later, I was able to bag one of the dead Mutes and take it to Michigan DNR for a necropsy. The report showed that the cause of death was trauma. The Mute swan's testes were enlarged, due to the breeding season. The Mutes fought for a nesting area with the Trumpeters and lost. The Trumpeters started to nest on the pond a few weeks later. Unfortunately, they were not successful in producing any cygnets.

I have included the necropsy record here:
[ Ссылка ]

Picture of the dead Mute swan here:
[ Ссылка ]

Picture of the 2 Trumpeters on April 1st here:
[ Ссылка ]

свернуть