Red-billed Caspians make a huge splash fishing for food
Published at
A huge splash took my attention away from the Chipping sparrow I was photographing as it collected hatching damsel nymphs along the shore of Silver Lake at Harriman State Park. I was lucky enough to capture the Caspian tern as it surfaced with a minnow in its beak.
The Caspian, the largest tern in the world, adjusted the minnow so that the head was facing the open throat and down the hatch it went. Quickly the big bird skimmed the top of the water to help wash the fish down.
These birds are commonly found throughout the Upper Snake River Valley with the most viewed in Fremont County at Henrys Lake, the Henrys Fork of the Snake River and at Harriman. On most mid-summer days, the terns can be seen cruising over the river near Last Chance, occasionally harvesting small fish.
Market Lake, Mud Lake and the Snake River from Rigby to Roberts are also favorite areas for these red-billed fishers. The small catfish and chubs from the Market Lake ponds provide a ready supply of food for the few that nest there.
Their nests are a primitive divot in the dirt with very little nesting material for the one to four eggs that are incubated by both parents. Most Caspians like to nest in colonies of up to 40 pair, but many will nest individually away from other nesting birds. As a colony, they are extremely aggressive to other birds and even people who approach the nesting area; but if an eagle appears all of the nesting birds take to the air. This is devastating to the nests as it exposes the chicks and eggs to gulls and the attacking killer and scavenger.
It is believed that young Caspians have a difficult time of learning to harvest fish, their main source of food. They stay with their parents for at least a year and even at two years of age are often seen following adults begging for food. Most do not breed until their third year. Many do not migrate from their winter areas, enjoying the single life, lounging on a fish-rich sea shore sunbathing.
That is okay; they deserve it because they have an average lifespan of about 12 years with the longest recorded wild banded tern living for 29 years.
Because of their unpredictable nesting habits, it is difficult to get a solid population estimate for them and to determine how healthy their population may be. The largest breeding colony of Caspians is about 6,000 pair on an artificial island created in the Columbia River between Oregon and Washington. The North American Waterbird Conservation Plan estimates there are about 35,000 breeding pair in the Continental United State.
The Idaho Department of Fish and Game believe that the state population is somewhat stable even though two of the largest nesting populations at Magic and Mormon Reservoirs disappeared in 2004. Other small colonies have cropped up or increased on other bodies of water around the state to make up for their loss.
Being as large as many gulls who they compete with for food, the fishing-harvesting Caspians make a huge splash as they dive into the water head first for lunch. They are not dainty like their small cousins with a gruff voice that will help you identify them.
PREVIOUS BILL SCHIESS COLUMNS
An outdoor peep show that will entertain you for hours
Birds and people hunting Kokanee at Ririe Reservoir
What started as a rude awakening turned into a beautiful day at City of the Rocks
Fish aren’t surviving in Henrys Lake, looks to be a ‘very bad season’
Living the Wild Life is brought to you by The Healing Sanctuary.