How do you know if you have a silver marten or an otter?
There are a few key factors to telling the two similar colors apart. The biggest (and easiest) way to tell is by looking behind the base of the ear. Otters will have tan coloring in this triange, while silver martens will have white. Another, sometimes less obvious, way to tell the two apart is the tan coloring otters have around their side ticking. Silver martens will have white around their side ticking. Some otters do not have much tan, or tan coloring that is very light, and can look like a silver marten. If you aren't sure which color you're looking at, look at the trianges behind the ear base!
This picture shows (starting left): blue otter, blue silver marten, and blue. The blue coloring all three have are the same. Already the trianges behind the ears should give away the otter and the marten.
This is a blue otter. Again, the tan [although lighter in dilutes (blues, lilacs)] coloring behind the ear base is a good indication of an otter.
This is a blue silver marten. The white behind the ear base should clearly be white (don't be fooled by staining!).
This is a solid blue. There is no coloring other than blue anywhere. This is just for comparitive purposes.