Clear Lake’s wild bird population attracts photographers from across the country. There are literally hundreds of species of birds that inhabit the lake and one of the most popular is the Western Grebe. Grebes come to Clear Lake to nest and raise their young, but the past two years have seen few grebes on the nests. So far this year there have been few if any chicks sighted.
A bird photographer said he spent more than a day at Rodman Slough and saw very few grebes and no chicks. He didn’t see any grebe nests either. A few years ago, the quagmire was wall to wall with grebes and their young.
Normally May and June are when you will see most grebes on their nests, but not this year. Grebes fly at night and few people have actually seen one in flight. Each year, thousands of grebes migrate to Clear Lake. One of the reasons Clear Lake is attractive is the huge population of minnows. The lake also offers an abundance of aquatic grasses for nest building.
Western Grebes nest on floating mats of weeds and lay three to four eggs. The young hatch in 24 days. The chicks leave the nest soon after hatching and ride on their mother’s back until they are several weeks old. The mother grebe talks to her young while they are still in the egg. She does this so that the young recognize her cluck and can find her even when mixed with a flock of grebes.
Grebes feed mainly on minnows but also on clams and crayfish. They are the ultimate anglers. I saw them chasing little silver minnows and knocking them down one by one.
Studies have shown that grebes capture most of their prey by stabbing them with their long, sharp beaks. However, with smaller fish, such as silver minnows, they catch them with their beaks. Most of the time, grebes swallow their food underwater. Scientists believe they do this because it prevents other grebes from stealing their food. However, it is common for a grebe to surface with a minnow in its mouth and offer it to its mate or chicks.
A Western Grebe’s stomach is lined with fluffy feathers that form a ball. It is believed that the purpose of the feathery ball is to prevent sharp fish bones from penetrating the stomach lining.
It is the courtship dance of the grebe that most attracts the attention of ornithologists. The male approaches the female and does a series of head dives. She responds with similar dives, then they run across the surface of the water, necks arched in perfect unison. Their last act is to dive at the exact same time. This is called rushing.
Western grebes also perform what is called the “weed ceremony”, which takes place after the grebes have mated and just before they begin to build nests. Both birds dive and raise weeds in their beaks. They face each other and do a spiral dance and offer the weeds to their companions.
Of course, almost everyone knows that grebe chicks ride on their mother’s back. The way they climb there is unusual. The mother extends her foot as a platform on which the chick can climb and then onto her back. I didn’t believe this until one day I had the opportunity to observe a pair of chicks climbing on their mother’s back several times over a period of about 30 minutes. Each time they used his foot as a platform.
A limited hatch last year and a poor hatch this year could cause problems for the species. A number of ornithological organizations have reported a sharp decline in grebe populations around the world. No theory has been offered as to why this happens. It could be environmental causes or something else. Let’s hope one of Clear Lake’s favorite birds recovers quickly.