The Great Valley of California is a great place to see a lot of birds in one place. In pre-colonist days, the 400-mile-long valley was a prairie that was watered by a series of rivers flowing from the adjacent Sierra Nevada. There was enough water that even in historical time there were two immense lakes between Bakersfield and Fresno, Tulare Lake and Buena Vista Lake. Before water diversions for irrigation caused it to dry up, Tulare Lake was the largest freshwater lake west of the Mississippi.
|The ecological role of grazer in the refuges is occupied by a handful of deer and lots of sheep and cows to make up for the now-extinct megafauna|
But historical accounts and paleontology can provide us some idea. In addition to birds, the vast prairies supported huge herds of tule elk, deer, antelope, and even bison. Prior to 12,000 years ago, the plant-consuming animals included giant ground sloths, mammoths, mastodons, horses, and camels. The birds and grazing animals were the prey of an imposing array of predators including the recently departed California Grizzly Bear, black bears, wolves, mountain lions, coyotes, and foxes. The pre-12,000-year crew included saber-toothed cats, dire wolves (bigger than wolves of today), American Lions, jaguars, and the immense Short-faced Bear, an animal that would have made a Grizzly think twice about a confrontation. The reason for the almost simultaneous extinctions of the species of the so-called 'mega-fauna' is a subject of contention among geologists, paleontologists and anthropologists (the role of humans has not been ruled out).
|This cuddly little Short-faced Bear can be seen at the Fossil Discovery Center near Madera|
|Snow Geese at the San Luis National Wildlife Refuge|
So that is where are today. The refuges provide forage for millions of migratory cranes, geese, swans and ducks (in many they grow fields of corn for the singular purpose of feeding the birds). The birds are too crowded, and diseases can spread if the flocks are not managed properly, but it is a better situation than having no refuges at all. Some species, especially the Aleutian Cackling Goose, have been brought back from the brink of extinction (once down to just 300 or so birds, the population is more than 100,000; they mostly shelter at the San Joaquin NWR just west of Modesto). And yearly, more and more abandoned farmlands are being converted to the original riparian habitat to allow for population growth.
I don't do video often, but the one at the top seemed necessary because I was looking at what I believed was the largest single grouping of birds I've ever seen (and I've been exploring these refuges for 7-8 years now). It required about a 180-degree pan. On the other hand, there is nothing in the world quite like watching thousands of geese taking flight all at once. When we were at the San Luis NWR last week, the serene view was of several thousand Snow Geese and Tundra Swans. It's not really a good thing for the birds to be scared into the air, as it uses precious energy, and they could get hurt. But a helicopter flew overhead at a low elevation, and it spooked the geese (the swans seemed like they could care less) and several thousand took flight. I caught the flight on video, and you can clearly hear the helicopter. I took a picture of the craft thinking to report it, but it turned out to be medi-flight out on an emergency call.
The number of birds and the variety of birds at the local refuges is truly astounding. We saw 50 species at the San Luis Refuge last week and 46 at the Merced Refuge yesterday. The really good birders will report 60-65 in a single trip. And the birds are beautiful. Here are some that caught my eye this last week.
|Sunset at the Merced NWR|