Geology topics
T.J. Floyd
Publications and source records attributed to T.J. Floyd.
An improved method of censusing deer in deciduous-coniferous forests
Aerial censusing has been used to determine densities of many large mammals, including deer ( Odocoileus virginianus ) in agricultural areas or deciduous forests (Saugstad 1942, Morse 1946, Petrides 1953, Sanderson 1953, Berner pers. comm.). However, observability of deer from the air remains a problem in northern coniferous forests. LeResche and Rausch (1974) determined that even with the much larger and more observable moose ( Alces alces ) during ideal snow conditions, experienced observers counted only 68% of a known number of animals; inexperienced observers counted 43%. Caughley (1974) and Caughley et al. (1976) suggested that the best solution to the problem of observability in aerial censuses is to measure the magnitude of the biases that exist, and correct estimates accordingly. This paper describes an attempt to measure observability bias in an aerial census of deer in deciduous coniferous habitat and to produce an accurate estimate of numbers.
Relating wolf scat content to prey consumed
In 9 trials, captive wolves ( Canis lupus ) were fed prey varying in size from snowshoe hares ( Lepus americanus ) to adult deer ( Odocoileus virginianus ), and the resulting scats were counted. Field-collectible scats were distinguished from liquid, non-collectible stools. I n collectible scats, the remains of small prey occurred in greater proportion relative to the prey's weight, and in lesser proportion relative to the prey's numbers, than did the remains of larger prey. A regression equation with an excellent, fit to the data (r2 = 0.97) was derived to estimate the weight of prey eaten per collectible scat for any prey. With this information and average prey weights, the relative numbers of different prey eaten also can be calculated.