Demography of the Burrowing Owl in Badlands National Park

Martell, Mark; Redig, Patrick; Nibe, Jill

The burrowing owl (Speotyto cunicularia) is native to the shortgrass plains of North America. They often nest in prairie dog towns and their response to various management practices is unknown. This study was conducted in Badlands National Park (BNP) and surrounding grasslands. The objectives of this study were to: 1) develop a census technique to allow monitoring of the Park's owl population, 2) determine the number and distribution of owls in the Park, and 3) document the degree of natal and nest-site fidelity of burrowing owls in southwestern South Dakota. The work was conducted on ten prairie dog towns in BNP and fourteen in the Conata Basin between June 1991 and July 1992. Point-transect surveys were done on towns and repeated to establish statistically valid comparisons. We used the "area occupied" method to analyze survey data. Adult and juvenile owls were trapped, banded, and color-marked on both the Conata Basin and in BNP. In 1991, 12 broods with a total of 31 young were found on 5 towns in BNP. In 1992, we located 20 broods with 62 young on those 5 towns, and 11 broods with 37 young on 3 additional towns. The proportion of the area occupied was 0.34 (SE = 0.07, n = 75) in 1991 and 0.57 (SE = 0.07, n = 129) in 1992. Eighty-eight owls (10 adult, 78 young) were banded in BNP and Conata Basin during the 2 year study. No banded owls were seen or recovered in the years after their banding. We were able to design a reliable, repeatable survey technique which should allow BNP biologists to monitor the long term stability of the Park's burrowing owl population. This will help form framework for future management actions.