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Abstract: There is limited information available on how New Zealand wetland bird communities respond to removal of mammalian predators, and reintroduction of locally extinct species. The forested Zealandia Te Māra a Tāne sanctuary in Wellington is surrounded by a mammal predator-exclusion fence, and contains two small lakes (2.7 and 1.1 ha). Counts of all visible wetland bird species were used to assess changes in the Zealandia wetland bird community over 28 years. This included a 3-year block of counts before the fence was built in 1999. Flocks of up to 143 southern black-backed gulls (karoro, Larus dominicanus) bathed on the larger lake before the catchment was opened to the public after 1999. Brown teal (pāteke, Anas chlorotis) and New Zealand scaup (pāpango, Aythya novaeseelandiae) both established resident breeding populations following releases of captive-reared birds between 2000 and 2003. Little shag (kawaupaka, Microcarbo melanoleucos), black shag (māpunga, Phalacrocorax carbo) and pied shag (kāruhiruhi, P. varius) all colonised naturally, and started breeding in 2003, 2008, and 2009 respectively. Paradise shelducks (pūtangitangi, Tadorna variegata) increased after the sanctuary was created, although numbers remained small (mean counts of c. 5 birds). Numbers of mallards (Anas platyrhynchos) were unaffected by creation of the sanctuary; however, there was an unexplained decline after 2016. Overall, the wetland bird community in Zealandia has become more diverse over time, and with a higher proportion of native and endemic species. However, we suggest that some of these changes (particularly the establishment of a large breeding colony of pied shags) might well have occurred even if the sanctuary had not been created.