Lethal Roost Toxicants for Control of Starlings and Blackbirds

Roosting congregations of starlings (Sturnus vulgaris) and several blackbird species (Icteridae) cause several millions of dollars in losses to agricultural crops throughout the United States. In addition, they are responsible for a variety of nuisance problems, human and livestock diseases, and human safety hazards. Dozens of tools have been developed for alleviating these problems, some of which are nonlethal techniques aimed at either roost dispersal or site specific protection of the problem site. Lethal baiting techniques for use at staging areas or at the problem site have also been developed. However, the most controversial solution involves the use of lethal techniques for killing the birds at the roost site. The seriousness of the controversy is fueled by several factors that are unique within the set of problems associated with wildlife damage management. First, there is the public\u27s familiarity and appreciation of birds in general. They are ubiquitous and more often associated with urban environments than, say coyotes or field rodents. In addition, pest birds are not usually secretive or nocturnal like many other vertebrate pest species and therefore maintain a high profile in the public\u27s mind. Moreover, when roost control is conducted, individuals killed within a short one or two day period can number in the hundreds of thousands, which is many. times greater than numbers associated with lethal control of problem species of mammals

A Framework for Reproductive Models of Mourning Doves

Population models can be used to aid in development and evaluation of harvest management strategies for game species. No current models are available for the Mourning Dove (Zenaida macroura), which is considered a migratory game bird in 37 states. A predictive model for annual reproduction is a necessary component of such a model. I used a simple construct based on parameters of the Mourning Dove breeding cycle to develop probability distributions of annual per capita reproduction for each of five geographical regions in the U.S. Confidence intervals for model predictions included average estimates from published studies in all regions except the southeastern U.S. Additional field studies will be required to produce contemporary estimates of model parameters and their spatial and temporal variation. A large-scale survey to estimate age ratios using wings from hunter-harvested doves could be used to evaluate and improve model predictions and structure, but additional research will first be necessary to calibrate harvest age ratios with realized annual productivity. Stochastic computer simulations of population models can be used to evaluate the sensitivity of predicted population trends to individual reproductive parameters

Assessing the Role of Conspecific Attraction in Habitat Restoration for Henslow’s Sparrows in Iowa

The presence of conspecific individuals may provide important cues about habitat quality for territorial songbirds. We tested the ability of a conspecific song playback system to attract Henslow’s sparrows to previously unoccupied restored habitat. We successfully attracted Heslow’s sparrows to 3 of 7 treatment plots using conspecific song playbacks and we found no Henslow’s sparrows in control plots. The addition of social cues using playback systems in restored grassland habitats may aid conservation efforts of Henslow’s sparrows to available habitat

EFFECT OF AVITROL BAITING ON BIRD DAMAGE TO RIPENING SUNFLOWER WITHIN A 144-SECTION BLOCK OF NORTH DAKOTA

The chemical frightening agent 4-aminopyridine (4-AP) has been repeatedly tested as a means of protecting both ripening corn (De Grazio et al. 1971, 1972; Besser et al. 1973; Besser 1976; Dolbeer et al. 1976; Stickley et al. 1972, 1976; Woronecki et al. 1979) and sunflower (Besser and Guarino 1976; Besser and Pfeifer 1978; Henne et al. 1979; Besser et al. in press) from depredating blackbirds. It was reported that less than one percent of a flock need ingest the treated baits and respond with distress symptoms in order to move birds from a corn field (De Grazio et al. 1972) or even shift roosting aggregations from night roosts (Cummings 1979). However, there is still conflicting evidence as to whether frightened blackbirds will subsequently avoid nearby fields, or even the same treated fields, resulting in efficient protection. The efficacy of 4-AP has not been resolved because of questions about the presentation and formulation of the treated baits and the difficulty of conducting a valid, unambiguous field test. This study was a large-scale evaluation of AvitroⓇ (HCI) FC-Corn Chops-99S1, where all commercial sunflower fields were monitored within a 144-sq mi block centered around a major concentration of roosting blackbirds; and all those fields with significant bird pressure were baited. The test was designed to answer two questions: can selective baiting (1) reduce damage overall when compared with pre-treatment damage from 1981, and (2) disperse it within the block? In other words, can the treatment keep blackbirds out of preferred fields? If so, is the result an overall reduction in damage within the surrounding area, or is it a redistribution of the damage

Psychological and cultural factors in the process of occupational achievement

An eight-equation model embodies the hypothesis that cultural differences among ethnic-religious groups give rise to differences in psychological dispositions, which, though not directly observable, influence occupational achievement, directly or via educational attainment, while being subject to feedback from one or the other of these endogenous variables. Dispositions are reflected in three fallible indicators, constructed from items in a survey interview of native white men in the Detroit area; the survey also secured socioeconomic measures and an estimate of intelligence. The model is block recursive and over-identified. Parameter estimates are secured by a sequence of ordinary least squares and two-stage least squares procedures, after solving out the structural equations to eliminate the unobservable variables. Numerical results do not strongly support the "Protestant Ethic" theory of achievement, but do suggest that the influence of education on occupation is mediated by motivational as well as cognitive and institutional factors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34086/1/0000367.pd

The Lantern Vol. 54, No. 1, Fall 1987

• Darkside • Reflections on a Subway Ride • Demand for Love • Music Man • Something Wild • The Nice Guy\u27s Story • The Picnic • Internalize • Days When You Feel Like Wonder Bread • II • A Tear • In Pursuit of Beauty • A Walk Down Sycamore Lane • A Wish • Sins of Omission • Pessimism • And the Sky Cracked • The Clock Strikes • Invinciblehttps://digitalcommons.ursinus.edu/lantern/1131/thumbnail.jp