A hybrid also has the electric motors that kick in to help with getting the trailer moving. Getting something moving requires a lot of energy, and with electric motors, you have instant torque. The Alex on Auto's Youtube RAV4 Hybrid tow test should give you an idea of how it behaves and its fuel economy, but expect worse fuel economy than the RAV4. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.