In my experience so far in Poland, many of the plants and animals are very similar to those found in the United States. One of the most surprising animals that I've found in both places is swans. In Poland, these large birds are called Polish mute swans. While mute swans are found in the U.S. as well as in much of Europe, the birds in Poland have a difference that makes them particularly special.
Polish swans look very similar to the swans that we have back home. When fully grown, they are all white with a black stripe next to their eyes. Young swans are grey until they grow to maturity. Normal swans have black feet, but some of the swans in this group where I visited had pink feet. When doing research about why some of these swans looked different, I discovered that in Poland, some swans have a genetic defect tied to their sex chromosomes. For some birds, there is a pigment deficiency that causes the feet to remain white, but it does nothing else to the bird.
When I first saw the Polish mute swans, I felt a rush of familiarity. In my home town in the U.S., I live next to a pond where two swans have babies each year. Seeing these familiar birds made me miss home immediately. However, after watching them closely for a few minutes, I noticed how the feet were a different color.
