Ecology of the Black-Footed Ferret and the Black-Tailed Prairie Dog

Research involving the black-footed ferret (Mustela nigripes) and black-tailed prairie dog (Cynomys ludovicianus) was conducted during 1968 and 1969. Eighteen prairie dog burrows were excavated in 1968 and 1969. Burrow systems ranged from 13 to 109 feet long and 3 to 14 feet deep. Fifteen of the burrows exhibited dome-shaped entrances leading to a gradually descending passageway which made an abrupt vertical ascent to a crater-shaped entrance. Nest chambers were found in 6 burrows. Earthen plugs created by prairie dogs in burrows after ferret departure ranged from 9 to 33 feet long. Eighty-two ferret scats were recovered. Animal remains found in ferret scats were mouse (86 percent) and prairie dog (14 percent). Mouse remains occurred in 32 percent of scats in 1968 on a town which had four young ferrets and 9 percent in 1969 with one young ferret on the town. Rabbit hair was recovered from the intestine of one roadkilled ferret. Although prairie dog activity appeared to peak at 8:00 a.m. and 8:00 p.m. during the last two weeks of July, least variation among counts occurred in midafternoon. Counts throughout the summer of 1969 indicated optimum censusing conditions existed on a still, overcast afternoon within a temperature range of 74 to 76°F. Five to 41 counts were required to detect changes of 10 percent in population weith a probability of 0.95 under these optimum conditions. The number of prairie dogs on a town with five ferrets in 1968 and two in 1969 decreased 16 percent from 1968 to 1969 while counts on three other town increased 19, 42, and 28 percent. One ferret was reported seen one morning in 1968 on the town the increased 28 percent. The town decreasing in prairie dog population differed significantly (P\u3c0.01) in population change from the others. Prairie dogs were observed creating curved trough-like formations on their mounds that could be confused with earthen trenches created by ferrets. Unlike the prairie dog troughs, ferret trenches were usually straight and often extended off the burrow mound. Two ferrets were captured with snares and three were live trapped for ear marking by notches and tags; live trapping proved more convenient. Both markings were readily observable at a distance of 30 yards with aid of 7x50 binoculars

Computed Normal Range of Iowa Statewide July Precipitation

Iowa summer rainfall distributions are examined to identify small-scale anomalies. Examination of extremely wet and dry summer months shows that large rain amounts fall mainly in small, cellular areas for both extremely wet and dry months. These configurations result from individual rainfall events. Analysis of the distribution of mean July rainfall across the state reveals significant anomalous wet and dry regions that contrast with the background, east-west rainfall gradient. Because of the skewed nature of summer rainfall distributions, the median value is used to represent a more realistic expected rainfall amount for any given year. Some parts of the stare have a more variable distribution and are more sensitive to the expected annual swing of one standard deviation. On the basis of statistical probabilities, these areas can expect summers of more severe moisture deficiencies to occur more often than in the rest of the stare

Current Status of the Woodcock in Iowa

Iowa is at the western edge of the continental range of woodcock. Because of their scarcity in the state, little interest has been shown in them. They are a prized game bird in many states in the eastern half of the country. In 1961, Iowa began participating in the annual U.S. Fish and Wildlife Service spring woodcock census, which has increased efforts to learn more about this species in the state. The spring singing-ground census of courting males revealed that a low population of breeding woodcock exists in suitable habitat, primarily limited to the eastern one-third of the state. Thirty verified records of nesting woodcock in Iowa, most from brood sightings, were recorded during the 1960\u27s and 1970\u27s. These bracketed the state from the Mississippi to the Missouri rivers. Other sightings have been reported from various locations in the state during spring and fall migration. A composite of information available showed that woodcock are not abundant but are widely distributed over Iowa

Surging Versus Continuous Turbidity Currents: Flow Dynamics and Deposits in an Experimental Intraslope Minibasin

Small intraslope basins (~100 km^2), or "minibasins," such as those found on the continental slope of the Gulf of Mexico, have been filled predominantly by turbidity currents. Each minibasin is the result of local subsidence and is partially or completely isolated from neighboring basins by ridges formed from compensational uplift. We undertook a series of experiments to investigate the relationship between the flow dynamics of turbidity currents entering a minibasin and the stratal architecture of their deposits. The experiments were performed using continuous-feed turbidity currents and surge-feed turbidity currents. A dimensionless ponding number is developed to compare the geometry of the deposits with the dynamics of the flows that filled the basins. The experimental surging turbidity currents created a deposit that was notably more ponded than the deposits of continuous turbidity currents

Faculty versus Student Repeatability on Evaluating Translucency of the Anterior Dentition

The objective was to compare the repeatability between dental faculty, whose clinical practice was primarily restorative dentistry, and final year dental students in categorizing the inherent translucency of images selected at random using either a 3- or 7-point scale (translucent to opaque). Digital images of anterior dentition were randomly selected based on inherent translucency. Thirty images (five were repeated) were randomized and categorized by 20 dental students and 20 faculty on their inherent translucency. Statistical analysis was performed using an F test for analysis of variance at 95% confidence interval. A covariance parameter estimate (CPE) was accomplished to compare the inter-rater variability of the dental faculty and dental students. Statistically, more variability occurred between Slides (CPE of 0.185 (p = 0.001)) and between Subject and Slide (CPE of 0.122 (p = 0.0002)) than within subjects (CPE of 0.021 (p = 0.083)). Viewing repeat Slides, Students (CPE = 0.16) were more consistent (p \u3c 0.05) than faculty (CPE = 1.8) using the 3- point scale, while the CPE was the same (CPE = 0.669) using 7-point scale. Dental students and faculty were consistent using the 7-point scale to judge repeat slides, while dental students in this limited pilot study were more consistent when viewing a repeat slide using the 3-point scale

Allometric trajectories of body and head morphology in three sympatric Arctic charr (Salvelinus alpinus (L.)) morphs

A study of body and head development in three sympatric reproductively isolated Arctic charr (Salvelinus alpinus (L.)) morphs from a subarctic lake (Skogsfjordvatn, northern Norway) revealed allometric trajectories that resulted in morphological differences. The three morphs were ecologically assigned to a littoral omnivore, a profundal benthivore and a profundal piscivore, and this was confirmed by genetic analyses (microsatellites). Principal component analysis was used to identify the variables responsible for most of the morphological variation of the body and head shape. The littoral omnivore and the profundal piscivore morph had convergent allometric trajectories for the most important head shape variables, developing bigger mouths and relatively smaller eyes with increasing head size. The two profundal morphs shared common trajectories for the variables explaining most of the body and head shape variation, namely head size relative to body size, placement of the dorsal and pelvic fins, eye size and mouth size. In contrast, the littoral omnivore and the profundal benthivore morphs were not on common allometric trajectories for any of the examined variables. The findings suggest that different selective pressures could have been working on traits related to their trophic niche such as habitat and diet utilization of the three morphs, with the two profundal morphs experiencing almost identical environmental conditions