The San Luis National Wildlife Refuge (NWR) has played a key role in the recovery of the tule elk, a non-migratory elk subspecies found only in California.
Interpretive panels like these, along the Tule Elk route, tell the story of this unique subspecies, endemic to California, that nearly went extinct in the late 1800s1. As this sign states “The mosaic of wetlands, wooded sloughs and grasslands before you represents a small, altered remnant of a diverse ecosystem that existed throughout the [California] Central Valley 150 years ago. That ecosystem supported a variety of wildlife – millions of waterfowl, hundreds of thousands of elk and pronghorn and the now extinct California grizzly bear. The San Joaquin River and its tributaries ran clear and were filled with spawning salmon.”
“Settlement of the Central Valley reduced this extensive ecosystem. Wolves and grizzly bear were exterminated as pests; market hunters and gold miners hunted antelope and elk for meat and hides. Native grasses could not withstand the constant cattle and sheep grazing and introduction of competitive non-native grasses. Valley Oaks whose acorns fed wildlife and people, were cleared off for farmland and building material. Dams, dikes and irrigation canals, established as water control and delivery systems, eliminated millions of acres of marsh and floodplain forests.”
Prior to the mid-1800s, an estimated 500,000 tule elk lived in California. Due to over-hunting and loss of natural habitat the population, by some accounts, was reduced to as few as 20-30 individuals. In 1974 a herd of 18 animals was established in a large enclosure at the San Luis NWR and has since thrived1. The elk at the refuge are visible throughout the year.
“The tule elk enclosure encompasses 761 acres of grassy uplands, wooded sloughs and freshwater marshes. To keep a high quality habitat, the elk population must be maintained at or below what the land can sustain. San Luis Refuge’s enclosure supports 40 to 50 elk, above that, they are relocated to improve other California herds or establish new populations.”
As noted in the previous post from San Luis NWR, I took this auto tour when the refuge was just beginning to be flooded so the waterfowl had not yet arrived in large numbers. Wetland resource management is one of the most important aspects of our National Wildlife Refuge System, especially in California where over 90% of our native wetlands have been lost between 1780 and 1985.
San Luis NWR manages over 150 individual wetland units or ponds at the Complex. These wetland units support a tremendous variety and abundance of waterbirds. Most of the Complex’s wetlands are managed as moist soil units where important wetland food plants, in particular smartweed, watergrass, sedge, and swamp timothy are grown as forage for waterbirds. Seasonal wetlands are drained in spring, irrigated once or twice during the early summer, and flooded in late summer and early autumn1.
However, even though the ponds were just beginning to be flooded, I did spot large flocks of Northern Shovelers, Great Blue Heron and this Great Egret (Ardea alba)
and numerous Mourning Doves (Zenaida macroura).
Near the final stretch of the five mile Tule Elk auto tour, I spotted what appeared to be a first year Western Kingbird looking all fluffy and fairly nondescript. It was followed closely by the Tule Elk seen in the top photo.
Then, as I bid adieu to this section of the refuge complex, I was given the once over by nearly a dozen Turkey Vultures (Cathares aura) perched, one per post. More than half of them flew before I could get my lens on them.
Next on the San Luis National Wildlife Refuge Complex tour is the Merced National Wildlife Refuge which hosts the largest wintering concentration of Lesser Sandhill Cranes on the Pacific Flyway!
References: 1San Luis National Wildlife Refuge Complex