
So the birds that belong to this order are medium to large size water birds that have worldwide distribution.
Their diet consists of fish and aquatic/marine life (such as salamanders, frogs, squids and so forth, depending on the species and location).
They all have colonial nesting habits, and the young when hatched are helpless and fort the most part also naked.
In terms of the classification–classically it was based on morphological characteristics, which led to other bird families also being grouped in this order. With the advances of DNA sequencing, it was determined that the other families while sharing morphological characteristics–genetically they were different enough to be moved to thier own orders.
The families that make up the order Pelecaniformes include:
Family Pelecanidae (the pelicans)

Family Balanicipitidae (the shoebill)
Family Scopidae (the hamerkop)
Family Threskiornithidae (ibises and spoonbills)

Family Ardeidae (herons, egrets, and bitterns)

Reference: https://en.wikipedia.org/wiki/Pelecaniformes
Unless noted all pictures have been taken by the owner of the blog: Jessica Matts