<P> The first day of Christmas my true love sent to me a partridge and a pear - tree; </P> <P> The second day of Christmas my true love sent to me two turtle - doves, a partridge, and a pear - tree; </P> <P> The third day of Christmas my true love sent to me three fat hens, two turtle - doves, a partridge, and a pear - tree; </P> <P> The fourth day of Christmas my true love sent to me four ducks quacking, three fat hens, two turtle - doves, a partridge, and a pear - tree; </P>

How many different types of birds are mentioned in the twelve days of christmas song