Waterfowl Losses in the Surf along the Northern California Coast

Abstract

For many years residents of Humboldt County in northern coastal California have witnessed waterfowl perishing in the surf in large numbers. In the vicinity of Humboldt Bay and the Eel River the phenomenon is observed commonly and residents refer to these waterfowl victims as From November 1 to December 31, 1952, a preliminary study of this unusual condition was made and pertinent facts are reported here. The area where occur extends for a distance of approximately 25 miles from Centerville Beach north to Clam Beach, California. This includes the mouths of the Eel and Mad Rivers, North and South Spit of Humboldt Bay, and the Clam Beaches north of Arcata, California. The shore line in most of this area consists of steeply sloping beaches which cause short but forceful wave action during heavy seas. During a severe storm this wave action digs into the shore and for a distance of 200 to 400 feet from the beach the surf is saturated with sand. Immediately behind the beach is a series of small, sparsely vegetated sand dunes, and extending back from the sand dunes for several miles the land is largely agricultural. Several thousand acres are planted to permanent pasture with interspersed barley fields. On the pasture area of low rolling terrain, low spots fill with water in winter, thus making ideal resting and feeding areas for waterfowl. Many natural streams and sloughs pass through the farming area. The pasture areas are utilized primarily for grazing of dairy cattle and sheep. During hunting season waterfowl feed on ponds in the pastures from late afternoon until shooting begins in the morning, when they leave the farming area and fly to the ocean. They settle down one-half to one mile from shore in rafts of 200 to 3,000 birds. During the day smaller flocks may be seen continually flying from ocean to fields. Excessive losses of birds usually occur in moderately rough seas immediately following severe storms and with heavy fog off shore. At these times winds are usually from the southwest or in an easterly direction. Sanded birds occur on the beaches immediately following low tide. Observed losses were heaviest among surface-feeding ducks, and in order of decreasing prevalence the following species of waterfowl appeared to be most affected by sanding: baldpate (Mareca americana), pintail (Anas acuta tzitzihoa), mallard (Anas p. platyrhynchos), green-winged teal (Anas carolinense), lesser scaup (Aythya affinis), canvasback (Aythya valisineria) and redhead (Aythya americana). Other sanded birds included the western grebe (Aechmophorus occidentalis) and Baird's cormorant (Phalacrocorax pelagicus resplendens). At numerous times during past years a limited number of black brant (Branta nigricans) also have been affected by sanding but none were observed during the period of this study. Th heaviest concentrations of ducks and, in turn, the greatest losses occur near the m uth of the Eel River. During heavy seas this area is particularly rough, with occasional w v s breaking as far as a mile from shore. The birds sleep in concentrated groups and drift shoreward with the wind. Occasionally a high wave breaks far from shore and engulfs a group of resting ducks. They are then rolled into the area of heavy sand, and once their feathers become saturated with sand and water the seem helpless to maintain themselves in rough water. Birds attempting to re-enter open water are picked up by the surf and rolled back into the sand. Loss of waterfowl in this manner usually occurs several times during the year but is prevalent mainly during the hunting season. At these times the birds seek sanctuary in the ocean as an escape from hunters who harass them regularly on inland feeding