Western Grebe Supersp #3 Aechmophorus occidentalis Lawrence       Field Guide IDs: NG-20; G-20; P-34; AW-pl 174; AM (I)-46 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy MF I: 23 DAYS PRECOCIAL 4 MF 3-4 (2-7) MONOG? F: 63-77 DAYS MF AQUATIC INVERTS BREEDING: Marshes, lakes. 1 brood. DISPLAYS: Elaborate mutual displays performed by 2 or more birds in predictable sequences: "rushing" by 2 males, male and female, or several males and a female; "weed dance" with male and female holding plants in bills; "greeting" by pairs rejoining after separation. NEST: Floating platform in shallow water; compact mass of fresh and decayed veg, oft coated with aquatic veg, usu anchored to or built up over live veg. Open or concealed. EGGS: Bluish-white, chalky, nest-stained buff/brown. 2.3" (58 mm). DIET: Mostly fish, aquatic inverts, few amphibians, feathers. Young fed adults' feathers. CONSERVATION: Winters s to c Mexico. Blue List 1973-82, Special Concern 1986. Plume hunters devastated populations. NOTES: Colonies of tens to hundreds of nests; gregarious year-round. Recently split into two species Western and Clark's; Western is the dark-faced form); double-noted advertising call prevents hybridization. Tend to feed nearer to shore than Clark's Grebe, suggesting possibility of reduced foraging overlap Bare skin patch on head of young flushes dark red when begging or in distress. Chicks carried on adults' backs; young fed while carried. STANFORD. NOTES: ESSAYS: Eating Feathers; Visual Displays; Transporting Young; Plume Trade; Species and Speciation; Blue List. REFERENCES: Nuechterlein, 1981a, 1985; Nuechterlein and Storer, 1982..