Kanjirankulam Bird Sanctuary is a Protected area near Mudukulathur Ramanathapuram District, Tamil Nadu. India, declared in 1989. It is notable as a nesting site for several migratory heron species that roost in the prominent growth of babul trees there. The sanctuary vegetation is mostly tropical dry deciduous forest. It is dominated by babul along with Prosopis juliflora and the grasses Bermuda grass and Eremopogon foveolatus. The invasive Prosopis is slowly encroaching on much of the sanctuary area, retarding growth of babuls. The irrigation tank bund and the area outside the tank have tamarind trees, fig trees, neem trees, portia trees, silk trees (Albizzia amara), drumstick trees, and palmyra palms. The breeding population of migratory waterbirds arrive here between October and February and include: painted stork, white ibis, black ibis, little egret, great egret. The site qualifies as an IBA as the threatened Spot-billed Pelican Pelecanus philippensis breeds here. There are five sluices that drain water to the agricultural lands. The wetland is irregular in depth and retains water for 3 to 5 months if rain is normal. Excess flood water is let out towards Chitrangudi village through a sluice gate about 0.5 km from the inlet aqueduct. The wetland performs three main ecosystem services to the fringe population in particular including hydrological regulation of floods and droughts, carbon sequestration and climate regulation, and storm protection,

A wetland should be considered internationally important if it contains a representative, rare, or unique example of a natural or near-natural wetland type found within the appropriate biogeographic region.

A wetland should be considered internationally important if it supports vulnerable, endangered, or critically endangered species or threatened ecological communities.

A wetland should be considered internationally important if it supports populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region.

A wetland should be considered internationally important if it supports plant and/or animal species at a critical stage in their life cycles, or provides refuge during adverse conditions.

A wetland should be considered internationally important if it regularly supports 20,000 or more waterbirds.

A wetland should be considered internationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of waterbird.

A wetland should be considered internationally important if it supports a significant proportion of indigenous fish subspecies, species or families, life-history stages, species interactions and/or populations that are representative of wetland benefits and/or values and thereby contributes to global biological diversity.

A wetland should be considered internationally important if it is an important source of food for fishes, spawning ground, nursery and/or migration path on which fish stocks, either within the wetland or elsewhere, depend.

A wetland should be considered internationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of wetland-dependent nonavian animal species.