Cannot remove default sidebar menu

For all pages which have a parent>child relationship, there is a default sidebar menu that shows up which lists all pages under the parent page. Example: http://humanitiesinitiative.org/faculty-graduate-student-fellowships/faculty-fellowships/

Notice on the left, how the sidebar has duplicated items. The upper menu lists all pages under the parent page (I want to remove this menu), and the lower menu is the actual (correct) menu I have created.

Please let me know how to remove this default menu.

Thanks,

Chris