Tagus Estuary Natural Reserve breed on adjacent farmland. Little bustard ("Tetrax tetrax") occurs all year but is more numerous in winter. Raptors which may be seen over the fields include black-winged kite ("Elanus caeruleus"), short-toed eagle ("Circaetus gallicus") and booted eagle ("Aquila pennatus") Nearby patches of woodland hold short-toed treecreeper ("Certhia brachydactyla"), European nightjar ("Caprimulgus europaeus"), red-necked nightjar ("Caprimulgus ruficollis"), Iberian magpie ("Cyanopica cooki") and many passerines. During the Spring and Autumn many species stopover on the Tagus during their migration these include curlew sandpiper ("Calidris ferruginea") in large numbers with many other shorebirds in smaller numbers, Common redshank and Balck-tailed Godwits reach their
Edwardsiella tarda along with maintaining suitable sanitation of water. Other stress factors include drastic changes in temperature, pH, and dissolved oxygen levels in the water. In order to manage properly for edwardsiellosis water must be checked constantly in order to keep fish stocks completely free of pathogens. Some of the most recent research done on "Edwardsiella tarda" was performed by Griffin et al. (2013) to assess what the literature refers to as "the intra-specific variability of "E. tarda" isolates from 4 different fish species in the eastern United States." These intra-specific variations that they were looking for occur in other parts of