Hersek Lagoon also offers a suitable living space for summer migrants who come for breeding during the summer months. In the area, there are important bird species that breed in colonies, especially on the coastline between the sea and the lake. These are Sandwich tern, common tern, Mediterranean gull, Eurasian oystercatcher, Little ringed plover and Caspian gull. With at least 20 farm populations breeding in the Sandwich tern area, Hersek Lagoon has an important bird area (IBA) feature. This species breeds only in Hersek Lagoon apart from Gediz Delta in our country.
Another species that breeds in the area is Black-winged stilt. It adds importance to the lagoon with 25 pairs breeding in such a small area.
During the summer season, many resident and migratory bird species find breeding and sheltering area in the maquis and forest around the wetland and the Lagoon.
Hersek Lagoon has an important position in the Marmara region with the number of Flamingos it hosts in the winter season. More than 1000 Flamingos were counted in the area in the winter of 2013-2014.
Again, 6 individual common eiders were observed in winter and spring is an important number for our country.
Slender-billed gull is also a type of seagull that uses the area in high numbers in winter and spring.
A total of 201 species have been identified through mid-winter water bird counts (KOSKS) and other observations in the area. Although the area is small, this number carries the Hersek Lagoon to the front ranks among the wetlands in our country.