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Crossosoma 34(2), Fall- Winter 2008 
Wilson C. Hanna (1883-1982) was a neighbor and an early mentor to Oscar. 
Hanna was a chemist for the Colton Portland Cement Company by vocation, 
but an avid amateur ornithologist and oologist (egg collector) by avocation. 
Hanna was a major figure in Southern California ornithology in the first half 
of the 20 th century. A great deal of what we know today about bird biology in 
the field (e.g., clutch sizes, nesting dates, nest parasitism, and historic breeding 
distributions) is based on the work of the old-time egg collectors (see W.L. 
Dawson’s masterful “ The Birds of California ” [South Moulton Co., 1923] as an 
example of the oologists’ contributions). Hanna’s well-documented egg and nest 
collections are an important baseline for modern ornithology and conservation 
biology, representing a major part of the historical record of the local avifauna. 
As a teenager, Oscar helped Hanna with his egg collections, particularly serving 
as his tree climber, but also building and installing nest boxes for cavity-nesting 
species, and processing the eggs as they arrived from the field. Fresh eggs had to 
be drilled, their contents drained, and labeled with a fine brush, in ink, with the 
species’ American Ornithologists Union checklist number and number of eggs 
in the original set. Oscar worked at this processing in the evenings after school. 
He developed an early interest in botany as he studied the plant materials from 
which various birds made their nests. Hanna’s egg specimens now comprise the 
bulk of the San Bernardino County Museum’s oology collection, the 5 th largest 
such collection in the world. The Museum’s collection was curated through the 
1990s by another of Hanna’s informal students, Oscar’s friend and younger 
contemporary, Eugene A. Cardiff. 
Edmund Jaeger (1887-1983) was another important early mentor, who Oscar met 
when Jaeger brought some bird specimens to Hanna for identification. Jaeger 
was a charismatic naturalist, best known for his books on natural history of the 
California deserts and for the annual “Palavers” (field trip/seminar/camp-outs) he 
organized, and which continue to the present. Oscar participated in many Palavers, 
frequently as a keynote naturalist or as leader for botanical activities. Jaeger 
introduced Oscar to Dr. Howard Fawcett (1877-1948), plant pathology professor 
at the University of California’s Citrus Experiment Station in Riverside (which 
became UCR in 1 954), who hired Oscar as a lab technician in 1 941 . Among many 
other tasks, he worked with the botanical collection Fawcett had assembled to aid 
in plant identification for the Station’s research work. Oscar’s work at UCR was 
interrupted within a year when he was drafted into the US Army where he served 
in the Medical Corps from 1942-1946. While in the army, stationed in Medford, 
Oregon, he met and married Joanne Riesch (1919-1996), a teacher. The couple 
had four children. 
Oscar returned to the Citrus Experiment Station in 1946, again working as a 
