30,000 ha of land near Aglou, south of the park, is also included in the site because it is sometimes used as a feeding area by the northern bald ibis.

[2] The park's main conservation importance is that it holds three of the four Moroccan colonies of the northern bald ibis (Geronticus eremita).

Together with the fourth site at nearby Tamri, it holds 95% of the world's truly wild breeding birds of this endangered species.

[5] The Oued Massa holds water throughout the year and has breeding marbled ducks, a globally threatened species.

Other notable breeding bird species are red-necked nightjar, thick-billed lark, Tristram's warbler and Moussier's redstart.