Blood smears from 259 birds of 12 species, representing four families of raptors, from New Jersey, Pennsylvania, Delaware, and Virginia were examined for blood parasites. Infected birds constituted 59.1% of the total. Birds were infected with one or more of the following genera of protozoa: Leucocytozoon (43.2%); Haemoproteus (21.6%); Plasmodium (1.2%); and Trypanosoma (1.2%). Blood culture of 142 raptors of 11 species for Trypanosoma revealed a prevalence of 41.5%. Plasmodium circumflexum is reported for the first time in Accipiter striatus, and Trypanosoma sp. in Buteo jamaicensis.

Epizootiologic studies conducted during the past few years showed the existence of widespread natural infection of the southern flying squirrel, Glaucomys volans, with epidemic typhus rickettsiae, Rickettsia prowazekii. The ecological findings strongly implicated transmission of the etiologic agent by an arthropod vector. Studies were conducted under controlled laboratory conditions to determine whether ectoparasites naturally associated with flying squirrels (squirrel fleas, lice, mites and ticks) were capable of acquiring, maintaining and transmitting the infection. Also studied were the cat flea, oriental rat flea and the human body louse. Flying squirrels inoculated with the GvF-16 strain of R. prowazekii circulated rickettsiae in their blood for 2-3 weeks, thus providing ample opportunity for arthropods feeding on them to become infected. The results with Dermacentor variabilis ticks indicated that the rickettsiae did not consistently survive in this insect and were not passed to the eggs of adult females that had been infected subcuticularly. Mites became infected by feeding on infectious blood but failed to sustain the infection. Also, mites fed on an infected flying squirrel did not transmit the infection to a normal squirrel. Squirrel, cat, and oriental rat fleas readily became infected by feeding on a rickettsemic host or on infectious blood through membranes, but failed to transmit the infection to susceptible flying squirrels. In the studies with flying squirrel lice, however, transmission of epidemic typhus from infected to uninfected flying squirrels was demonstrated. Infection of the human body louse with the GvF-16 flying squirrel strain of R. prowazekii was similar to that previously observed with classical human strains, viz., multiplication of the rickettsiae and excretion in the feces.

The ecology of the southern flying squirrel, Glaucomys volans (L i nn a e u s, 1758) was studied in 2 areas of central Virginia, using artificial tree shelter traps and baited live trapping. Within one year after their installation, 46.9% of the artificial shelters were used for nesting sites, 26.6% as feeding stations, and 17.2% as defecatoria; only 9.4% were without evidence of use. The animals utilized several shelters for nesting in addition to others used for food storage and defecatoria. In habitat selection, availability of bodies of fresh water was important, but the slope of the terrain was not significant. Foraging (average range 126.8 m ± 14.8 S.E.) was not significantly related to distance from aquatic habitat. Adult males foraged substantially farther than sexually inactive females or juveniles. Most females (94.2%) became pregnant within 6-8 months after birth. Birth of young occurred in early spring, March and April, and in late summer, from August to early October. Removal rate of young squirrels from the population by mortality was 50% within 5.5 months and 67% in 7 months. Population density, estimated by the Petersen index and regression analysis of recapture frequency, varied at different seasons from 4.5 to 10.1 flying squirrels/ha at one of the localities, and from 6.2 to 13.8/ha at the other.

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