It is really fun to make dramatic silhouettes like this shot of a red-winged blackbird in song. One of the challenges of making an image like this is dealing with flare. Flare is highlights created by the bright light of the light source reflecting off the elements within your lens. Flare will show up as bright polygonal hot spots in your image or as a bright haze across a portion of the image.
There are quite a few things you can do to help reduce the appearance of flare in your images. Without a doubt the number one thing you can do is to use a lens hood. This will virtually eliminate the haze type of flare since this haze is caused by light skimming across the front element of the lens.
For the other type of flare the highlights are caused by light bouncing off the elements within the lens. Some things you can do to minimize this type of flare is to reduce the number of elements by using a prime lens as opposed to a zoom which has more elements. Also be sure to remove any unnecessary filters such as a skylight or UV filter. If the composition allows it you can also use part of your subject to block part of the light source within the image.
In the case of the red-winged blackbird shot shown here I waited for a nice hazy sunset. The haze cut back enough of the light from the sun to virtually eliminate flare.
Good Luck and Good Light!
Steve
Image: Red-winged Blackbird in Song, Kensington Metropark Milford, MI