Large portions of the Refuge have been maintained in a near pristine state. The marsh, with its intersecting tidal streams and rivers, provides excellent natural habitat for the birds and mammals of the area and also serves as a nursery and breeding area for marine organisms, many of which are of sporting and commercial interest. Though wildlife can be seen year round at Bombay Hook, fall and spring offer the best opportunity for observing peak concentrations of migratory birds. The period from October 1 through November 30 is generally the most interesting to the Refuge visitor as this is the season during which waterfowl populations are at their peak. Over 100,000 ducks and geese utilize the Refuge at this time.
Spring is another preferred season for the visiting public.
March is the second peak for waterfowl as they travel through on their return to northern breeding grounds. April brings early shorebird migrants and the emergence of reptiles and amphibians from winter hibernation. Shorebirds are at their highest concentrations during May and June, primarily due to the arrival of horseshoe crabs laying eggs along the bay shore and mud flats. These eggs provide the shorebirds with needed energy to complete their northward migration. Wading birds such as herons, egrets, and glossy ibis, reach their peak numbers during the summer months.