Fine-scale habitat use by black-footed ferrets (Mustela nigripes) released on black-tailed prairie dog (Cynomys ludovicianus) colonies in New Mexico

2010 Spring.Includes bibliographic references (pages 47-62).Covers not scanned.Print version deaccessioned 2022.Black-footed ferrets (Mustela nigripes) are among the most endangered animals in North America. The dependency of ferrets on diminishing prairie dog {Cynomys spp.) colonies for prey and shelter has been detrimental to their persistence in the wild. Reintroductions of captive-born ferrets into remaining prairie dog complexes have become crucial to the conservation of the species. Gaps in knowledge of ferret behavior hinder the success of these reintroductions. In this study, fine-scale prairie dog burrow density use by captive-born ferret kits was analyzed to inform future management. In September 2007, captive-born ferrets were released on a black-tailed prairie dog (C. ludovicianus) colony on the Vermejo Park Ranch in northern New Mexico. Locations {n = 46) from 16 ferret kits experimentally released in areas of comparatively low and high prairie dog burrow densities were obtained via spotlight surveys. Ten kits were subsequently translocated to low and high burrow density areas on other Vermejo colonies and located thereafter (« = 53). For two months, habitat use was quantified by mapping all burrow openings within a 30 m radius of where ferrets were located. Spatial autoregressive models and spatially-explicit t-tests were used to account for autocorrelation in the used burrow densities. It was hypothesized that ferrets released in, or translocated to, areas of low burrow densities would move so as to increase their localized burrow densities as they spent more nights in the wild. It was also hypothesized that ferrets released in, or translocated to, high burrow density areas would maintain high used burrow densities. There was an inverse relationship between used prairie dog burrow densities and nights in the wild for ferrets released in high burrow density areas. For ferrets translocated to high burrow density areas, a pattern was not detected in burrow densities over time, which does not contradict the hypothesis for these ferrets. However, burrow densities used by ferrets released in, and translocated to, low burrow density areas did not increase over time as expected. With the number of nights in the wild converted to release or translocation burrow densities versus ferret-used burrow densities, average used burrow densities increased for ferrets placed in low burrow density areas, and average used densities decreased for ferrets placed in high burrow density areas. Used burrow densities on most inhabited colonies were similar to available densities, except for one colony, where used densities were lower than available densities. Because newly-released ferrets in this study used burrow densities similar to densities available at the colony level, releasing ferrets on colonies offering overall high burrow densities might increase reintroduction success rates. Furthermore, burrow densities directly correlated with prey densities in this study. Ferrets used higher burrow densities before midnight; future research on ferret habitat use should consider within night variation. Other studies on ferret habitat use after release are necessary; kits monitored for more than two months, or with experience in the wild at a younger age, might select high burrow density areas within colonies as predicted

Use optimization of natural antioxidants in refined, bleached, and deodorized palm olein during repeated deep-fat frying using response surface methodology

An optimization study on the use of oleoresin rosemary extract, sage extract, and citric acid added into refined, bleached, and deodorized (RBD) palm olein in deep-fat frying of potato chips was carried out using response surface methodology (RSM). Results showed that oleoresin rosemary extract was the most important factor affecting the sensory acceptability of potato chips. For taste and odor, its effects were highly significant (P<0.01), while for crispiness and overall acceptability, the effects were significant (P<0.05). As for sage extract, the level of this antioxidant had a highly significant (P<0.01) effect on appearance and taste and a significant effect (P<0.05) on odor and overall acceptability, but had no effect on crispiness. Although there was no significant synergistic correlation between citric acid and oleoresin rosemary extract or sage extract at the first order, its second order was significantly (P<0.05) related to taste, crispiness, and overall acceptability. An interaction between oleoresin rosemary and sage extracts also significantly (P<0.05) improved the score of overall acceptability of the potato chips. Contour maps of the sensory scores of potato chips indicated that the optimal points for appearance were achieved using 0.062% oleoresin rosemary extract, 0.066% sage extract, and 0.023% citric acid, while optimal task was achieved with 0.063% oleoresin rosemary extract, 0.075% sage extract, and 0.025% citric acid. With the same sequence of ingredients added into oil, the combinations required to achieve the optimal odor, crispiness, and overall acceptability scores were 0.058-0.046-0.026, 0.060-0.071-0.022, and 0.060-0.064-0.026%, respectively

Effects of natural and synthetic antioxidants on changes in refined, bleached, and deodorized palm olein during deep-fat frying of potato chips

The effects of antioxidants on the changes in quality characteristics of refined, bleached, and deodorized (RBD) palm olein during deep-fat frying (at 180°C) of potato chips for 3.5 h/d for seven consecutive days in five systems were compared in this study. The systems were RBD palm olein without antioxidant (control), with 200 ppm butylated hydroxytoluene (BHT), 200 ppm butylated hydroxyanisole (BHA), 200 ppm oleoresin rosemary, and 200 ppm sage extract. Fried oil samples were analyzed for peroxide value (PV), thiobarbituric acid (TBA) value, iodine value (IV), free fatty acid (FFA) content, polymer content, viscosity, E1% 1 cm at 232 and 268 nm, color, fatty acid composition, and C18:2/C16:0 ratio. Sensory quality of the potato chips fried in these systems prior to storage was also evaluated. The storage stability of fried potato chips for 14 wk at ambient temperature was also determined by means of the TBA values and sensory evaluation for rancid odor. Generally, in the oil, oleoresin rosemary gave the lowest rate of increase of TBA value, polymer content, viscosity, E1% 1 cm at 232 and 268 nm compared to control and three other antioxidants. The order of effectiveness (P BHA > sage extract > BHT > control. Prior to storage, the sensory evaluation of fried potato chips for each system showed that there was no significant (P>0.05) difference in terms of flavor, odor, texture, and overall acceptability. The same order of effectiveness (P 0.05) difference in sensory evaluation for rancid odor during storage periods