A field Study of the slender glass lizard, Ophisaurus attenuatus, in northeastern Kansas

early a year after initiating ecological studies on the University of Kansas Natural History Reservation (UKNHR) in July 1948, 1 saw for the first time a slender glass lizard (Ophisaurus attenuatus) on the area.As in most other areas where the species occurs, it was rare and few records of it accrued with the passing years for nearly a decade.However, as ecological succession progressed on the UKNHR with protection (after 1948) from cultivation, grazing, and other direct and indirect effects of man's activities, it became evident that the habitat changes were benefitting the glass lizard.Its numbers increased as did the area occupied.Nevertheless, because of relatively slow growth and low reproductive potential in the glass lizard compared with other small vertebrates, the population increased gradually, and seemed to reach peak numbers about 18 years after the policy of protection had initiated rapid successional change.At that stage much interest and effort were directed to the study of glass lizards.On one occasion in 1966, 70 individuals were captured in a single day.Although numbers have gradually decHned during the second half of the 35-year observation period, a total of 2116 slender glass lizards has been recorded 3353 times (including recaptures of marked individuals).All of these sightings were on UKNHR, on the Rockefeller Experimental Tract, or near the boundaries of these two contiguous areas owned by the University of Kansas.