Do artificial nests simulate nest success of greater sage-grouse?

Artificial nests have been used to study factors affecting nest success because researchers can manipulate them more than natural bird nests. Many researchers have questioned the validity of generalizing the results from artificial nests onto naturally occurring nests. Other studies have assessed the validity of artificial nest studies by simultaneously comparing overall depredation or daily survival rates, depredation timing, predator species, or habitat characteristics of artificial and natural nests. To evaluate how well artificial nests simulated nest success of greater sage-grouse (Centrocercus urophasianus; hereafter, sagegrouse), we used the unique approach of monitoring artificial nests (n = 69) placed in the natural nest bowls of sage-grouse in southern Wyoming, USA, during 2010 to 2011. Brown chicken eggs were placed in natural sage-grouse nests 7 to 14 days after the hatch or depredation of natural sage-grouse nests to compare artificial nest fate to the fate of natural sage-grouse nests. As secondary objectives, we placed cameras next to a subset of artificial nests to identify which predator species were depredating nests, and we assessed the effects of corvid (black-billed magpie [Pica hudsonia] and common raven [Corvus corax]) density, nest-site characteristics (i.e., anthropogenic development, landscape variables, and microhabitat) date of depredation, and presence of a camera near nest bowls on the depredation rate of all artificial nests. We found that depredation of artificial nests paralleled the fate of natural sagegrouse nests. Depredations were more likely to occur earlier in the summer (June to early July rather than late July to early August). Depredation of artificial nests was negligible as time progressed past the typical sage-grouse nesting season, supporting the hypothesis of predators using a search image to detect eggs. We also found that shorter perennial grass height and greater magpie densities were positively associated with the depredation rates of artificial nests. Camera-recorded depredation events verified that 4 badgers (Taxidea taxus), 2 magpies, and 1 domestic cow depredated artificial nests. Artificial nests may give managers insight into the expected nest success rates of sage-grouse in areas of conservation interest. However, care must be taken regarding placement and timing of artificial nests for reliable conclusions to be drawn from artificial nest studies. Furthermore, identifying predators based on artificial nests likely leads to inaccurate assessment of local species composition of nest depredators

Microhabitat Selection by Greater Sage-Grouse Hens During Brood Rearing

Greater sage-grouse (Centrocercus urophasianus) populations have declined throughout the western United States over the past century. Loss of large stands of sagebrush is a major factor leading to the decline of sage-grouse populations. We captured, marked, and tracked hen sage-grouse in Wyoming during the summer of 2012 to study where sage-grouse hens keep their chicks given the dual needs to provide them with food and to keep them safe from avian predators. Vegetation surveys and avian point counts were performed at early season brood locations, late-season brood locations, and random locations. We conducted multinomial models to determine which habitat variables were most informative in predicting site selection by hen sage-grouse. Hens with and without broods selected sites that had more shrub cover during the early-brood season but not during the late-brood season. During the early-brood season, hens without broods avoided sites where there were American kestrels (Falco sparverius) and common ravens (Corvus corax), but brood hens did not avoid these sites. During late-brood season, brood hens chose sites with fewer small-avian predators (e.g., black-billed magpies [Pica hudsonia] and American kestrels), as well as medium-sized avian predators, such as common ravens, Buteo hawks (Buteo spp.), and northern harriers (Circus cyaneus). Our results suggest that habitat selection by sage-grouse hens is focused more on avoiding predators than on finding food

Predictors of pathologic outcome of focal FDG uptake in the parotid gland identified on whole-body FDG PET imaging

PURPOSE: To test whether patient's primary malignancy type and presence of FDG-avid cervical lymph node(s) are predictors of pathologic outcome of incidental focal FDG-avid parotid lesions. BASIC PROCEDURES: Retrospective cohort study of pathologically proven incidental cases. MAIN FINDINGS: Focal parotid FDG uptake in the setting of head and neck cancer/melanoma(OR=24.6,p<0.01), lymphoma(OR=7.2,p=0.02), or FDG-avid cervical lymph node(s)(OR=3.6,p=0.07) has a higher odds of representing metastases. No malignant primary parotid tumors were incidentally discovered. PRINCIPAL CONCLUSIONS: In patients with head and neck cancer/melanoma, lymphoma, or FDG-avid cervical lymph node(s) there was a higher odds that focal parotid FDG uptake was a metastasis

Implications of the full flexibility provision of the 1996 Farm Bill on regional planting

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 102-104).Issued also on microfiche from Lange Micrographics.From 1973 to 1996, for major program crops, the United States used a target price and a deficiency payment program to support farmers' incomes. Target prices were guaranteed levels of return on program acreage and yields. This "price'' was set by Congress and initially was estimated to be the average cost of production. The target price was used in conjunction with the market price and loan rate to set the amount of deficiency payment that a farmer would receive. The payment per unit was calculated as the lesser of the difference between target price and the market price or loan rate, whichever was lower. It soon became apparent to the Congress that budgetary pressures called for amendments to this program (Dobbs). Initial changes in policy separated the setting of the target price from the cost of production. In the 1985 Farm Bill, there were reductions in the target price, but for most years it was frozen. The effect of inflation was to lower the target price in real terms. The 1990 Farm Bill introduced the concept of flexibility. Framers were allowed to change their planting choice by utilizing the new Farm Bill provisions. However, previous to the 1996 Farm Bill, farmers had limited options for switching cropping patterns except to drop out of the program. One of the major innovations of the 1996 Farm Bill was that it allowed farmers to produce virtually any crop, hay, or pasture while receiving transition payments on their base contract acreage (Knutson and Smith, 1995 ). It was hypothesized that after more than 50 years of essentially fixed base acres, the flexibility provisions enabled farmers to change crop rotations, with substantial differences regionally. Findings verified that there were changes in regional crop rotations. While the emphasis in this study is on flexibility, it is recognized that it is difficult to segregate the precise cause of changes in cropping patterns. Weather, price expectations, government domestic and international policy all can play a part in producer's decisions regarding crop planting