Here are some tips on taking wildlife pictures in very high contrast situation. In this example we have bright snow and a much darker subject. Most of the time my camera is on one of the automatic mode settings, and an image such as this will turn out much darker than expected. The light meter tries to adjust the exposure to the equivalent of light grey. The result a severely underexposed squirrel.
Many photographers like to use the automatic mode called “Aperture Preference”. This is mainly used for “Depth of Field” control. This is fine in most situations where contrast is not extreme, but not in this special high contrast situation. In this case there is a simple solution. With a little bit of preparation before taking these type of wildlife pictures, you can control Depth of Field, Exposure and Shutter Speed, by putting your camera on manual and adjusting aperture, shutter speed and ISO beforehand.
Professional photographers are very aware of how different surfaces can affect (fool) the camera exposure meter. They often carry an 18% grey card or special color chart with them so they can adjust the manual settings before taking the picture.
In this case there is a very simple solution without an 18% grey card. Put your camera on manual, walk up to a surface approximately the same color and brightness value as the wildlife you are planning to photograph. Make sure the entire viewfinder of your camera is filled and then adjust the aperture, shutter speed and ISO combination to achieve your Depth of Field and Shutter Speed appropriate for your subject. Note: your ISO cannot be on Auto, you have to select a value, otherwise the exposure meter will adjust your ISO automatically defeating the Manual settings. Then forget about metering, and just pay attention to focusing and snapping images.
Here is a link to an in-depth article on exposure and its adjustments