January
Numbers peak for geese, cranes, and ducks
Wetlands fully flooded
Foggy weather prevails
Bald eagles often observed hunting on refuges
Waterfowl hunting season ends
February
Tule elk bulls shed antlers at the San Luis NWR
Great-horned owls hatching
Hawks exhibiting aerial courtship displays
Large numbers of wintering waterfowl and cranes visible
March
Waterfowl begin migrating north
Vernal pool wildflowers begin blooming
Hawks and herons nesting
Tule elk bulls at the San Luis NWR sprouting new antlers covered in velvet
Shorebird numbers building
April
Songbirds are migrating
Wildflowers are abundant around vernal pools
Tule elk cows begin giving birth to calves at the San Luis NWR
Seasonal wetlands are drained to allow waterbird food plants to grow
Peak number of shorebirds
May
Shorebirds are migrating in breeding plumage
Songbirds are very vocal defending nesting territories
Wildflowers still spectacular
June
Tule elk antlers fully grown with velvet falling off
Shorebirds migrate north
Seasonal wetlands are dry
Songbird and raptor fledglings are visible
July
Tule elk breeding rut begins at the San Luis NWR
Seasonal wetlands are irrigated to encourage waterbird food plants to thrive
Fall shorebird migration begins
August
Swainson's hawks have fledged and will form "kettles" over grasslands
Irrigated pastures attract ibis and long-billed curlews
Tule elk rut and bugling peaks
September
The tule elk rut continues
Sandhill cranes begin returning mid-month
Songbirds and cinnamon teal migrate south
Valley oaks drop their acorns
October
Aleutian cackling geese arrive at the San Joaquin River NWR
Waterfowl hunting season opens
Tule elk still in harems and bachelor herds
Crane Day at the Merced NWR
November
Over 15,000 Sandhill cranes are in the Grasslands by Thanksgiving
Ross’ and white-fronted geese arrive
December
Snow geese begin to arrive at Merced NWR
Swans may arrive in small numbers by month's end
Watch for eagles, falcons, and ferruginous hawks
Black-tailed deer can be spotted at the San Luis NWR throughout year, most often at the West Bear Creek Unit