Connecticut statewide sTEP wave evaluation

INTRODUCTION: Selective Traffic Enforcement Programs (sTEPs) are a proven method to change motorists' behavior. Since 1997, the Connecticut DOT's Division of Highway Safety has organized a statewide seat belt enforcement program, with sTEP waves every three or four months. To date, 28 waves have been implemented. METHOD: Pre-wave and post-wave seat belt observation surveys are conducted by both state and municipal police across the state. Survey results, as well as a summary of all enforcement activity during the wave, are submitted for evaluation. RESULTS: Connecticut seat belt use has continued to rise from one wave to the next in a predictable "saw blade" pattern. CONCLUSIONS: The data clearly demonstrate that agencies that have participated in a greater number of waves have experienced the greatest increase in belt use. Belt use has not yet plateaued and additional sTEP enforcement seems indicated. However, evidence from other states suggests that a plateau may occur somewhere in the mid 80% range. IMPACT ON INDUSTRY: Should this occur, Connecticut will work toward strengthening the round the clock model, emphasizing the importance of aggressive primary enforcement.     

Effects of Washington, D.C. law on drivers' hand-held cell phone use

OBJECTIVE: To assess the effects of Washington, D.C. law prohibiting drivers' use of hand-held cell phones on such use. METHODS: Daytime observations of drivers were conducted at signalized intersections in D.C. in March 2004, several months before the law took effect on July 1, 2004, and again in October 2004. As a comparison, observations also were conducted in areas of Virginia and Maryland located close to the D.C. border. Maryland and Virginia placed no limitations on drivers' phone use. Use was observed for 36,091 vehicles in D.C., 25,151 vehicles in Maryland, and 28,483 vehicles in Virginia. RESULTS: The rate of talking on hand-held cell phones among drivers in D.C. declined significantly from 6.1% before the law to 3.5% after. Phone use declined slightly in Maryland and increased significantly in Virginia so that, relative to the patterns of hand-held phone use in the two states, phone use in D.C. declined 50%. Hand-held phone use in D.C. declined comparably among drivers of vehicles registered in all three jurisdictions. D.C. police issued 2,556 citations and 1,232 warnings for cell phone violations during July-November 2004. There were spates of media coverage when the law was passed and when it took effect. CONCLUSIONS: D.C.'s law prohibiting drivers' hand-held phone use had a strong effect on such use among drivers in D.C. Without ongoing publicized enforcement of the law, long-term compliance may be difficult to achieve.     

Mortality in rural locations after severe injuries from motor vehicle crashes

BackgroundMortality from traffic crashes is often higher in rural regions, and this may be attributable to decreased survival probability after severe injury.MethodsData were obtained from the National Automotive Sampling System – General Estimates System (NASS-GES) for 2002–2008. Using weighted survey logistic regression, three injury outcomes were analyzed: (a) Death overall, (b) Severe injury (incapacitating or fatal), and (c) Death, after severe injury. Models controlled for (pre-crash) person, event, and county level factors.ResultsThe sample included 883,473 motorists. Applying weights, this represented a population of 98,411,993. Only 2% of the weighted sample sustained a severe injury, and 9% of these severely injured motorists died. The probability of death overall and the probability of severe injury increased with older age, safety belt nonuse, vehicle damage, high speed, and early morning crashes . Males were less likely to be severely injured, but more likely to die if severely injured. Motorists in southern states were more likely to have severe injuries, but not more likely to die if severely injured. Motorists who crashed in very rural counties were significantly more likely to die overall, and were more likely to die if severely injured.ConclusionsMotorists with severe injury are more likely to die in rural areas, after controlling for person- and event-specific factors.     

Risk-aversion,relative abundance of resources and foraging preference

Summary Foraging theory depicts dietary choice as a function of prey quality and absolute abundance. Ecological processes, however, can depend on the way foragers respond to the relative abundances of available prey types; several models for frequency-dependent foraging adequately describe these responses. Our laboratory experiments with white-throated sparrows investigated preferential choice of two food rewards as we manipulated both reward quality and relative abundance. In any single experiment the two rewards provided the same mean food quantity, but the variances differed. Average energy budgets predicted risk-aversion, so that foraging preference should decrease as reward variance increases. We presented each two-reward pairing at availability ratios of 1:2, 1:1, and 2:1 for three consecutive days. By the third day risk-aversion exceeded preference for reward variance significantly. When relative abundances of the low and high variance rewards were not equal, the birds tended to prefer the rare over the common reward. This response began before the birds had thoroughly sampled the reward distributions. Preference for rarity apparently constrained the birds' economic response to reward variance levels.     

Habitat Improvements and Fish Community Response Associated with an Agricultural Two‐Stage Ditch in Mower County,Minnesota

Water quality and stream habitat in agricultural watersheds are under greater scrutiny as hydrologic pathways are altered to increase crop production. Ditches have been traditionally constructed to remove water from agricultural lands. Little attention has been placed on alternative ditch designs that are more stable and provide greater habitat diversity for wildlife and aquatic species. In 2009, 1.89 km of a conventional drainage ditch in Mower County, Minnesota, was converted to a two‐stage ditch (TSD) with small, adjacent floodplains to mimic a natural system. Cross section surveys, conducted pre‐ and post‐construction, generally indicate a stable channel with minor adjustments over time. Vegetation surveys showed differences in species composition and biomass between the slopes and the benches, with changes ongoing. Longitudinal surveys demonstrated a 12‐fold increase in depth variability. Fish habitat quality improved with well‐sorted gravel riffles and deeper pool habitat. The biological response to improved habitat quality was investigated using a Fish Index of Biological Integrity (FIBI). Our results show higher FIBI scores post‐construction with scores more similar to natural streams. In summary, the TSD demonstrated improvements in riparian and instream habitat quality and fish communities, which showed greater fish species richness, higher percentages of gravel spawning fish, and better FIBI scores. This type of management tool could benefit ditches in other regions where gradient and geology allow.     

Population structure,northern range limit,and recruitment variation in the intertidal limpet Lottia scabra

The northern range limit of the intertidal limpet Lottia scabra is Cape Arago, Oregon (43°N), where adult survival is excellent, the population is small (<300), and recruitment is low; the range limit may be set by limited recruitment. Between June 2012 and March 2013, 25 sites from the middle of the species range (33°N) to Cape Arago were sampled and population size frequency distributions, densities, and nearest neighbor distances were compared to the amount of rocky and sandy shore and kelp bed size. North and south of 37°N, the densities of new recruits averaged 22 and 86 m^?2, respectively. This shift was associated with the range limit of Macrocystis pyrifera kelp beds; we hypothesize that slower currents in M. pyrifera beds may limit larval dispersal leading to higher recruitment. North and south of 40°N, adult density averaged <1 and 458 m^?2, respectively, with the species absent from many sites to the north. This shift was associated with a sharp drop in the amount of rocky shoreline and an increase in uninhabitable sandy shore. Near the northern range limit, >80 % of the individuals were solitary and may be unable to spawn successfully. Recruitment at Cape Arago was infrequent and likely due to self-recruitment. This study suggests that the range limit was set by the absence of M. pyrifera and too little rocky shore leading to high larval wastage, low settlement, low population densities, and, due to an Allee effect, very small effective population sizes.     

Public sector perspectives and policy implications for the Pitons Management Area World Heritage Site,St. Lucia

St. Lucia faces numerous challenges associated with striking a balance between its economic and conservation goals with respect to the Pitons Management Area (PMA) World Heritage Site. Among the various stakeholders, the public sector, which largely constitutes the administrative authorities representing the general public, plays an instrumental role in site management. They are primarily responsible for policy formulation as well as the provision of fiscal incentives and funds to assist in the maintenance of the site. Based on a qualitative inquiry approach, this study explored the perspectives of key persons among pertinent public and non-profit organizations. Semi-structured interviews were conducted among local and national representatives from the public sector. Results revealed that the designation of the PMA as a World Heritage Site has presented both opportunities and challenges to the management of the site. Findings strongly indicate that the integrity and sustainability of the site is at stake due to a lack of commitment, coordination and political will in the public sector.     

Air‐Water Temperature Relationships in the Trout Streams of Southeastern Minnesota's Carbonate‐Sandstone Landscape

Carbonate‐sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface‐water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater‐fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air‐water temperature relationships for 40 GWFS in southeastern Minnesota. A 40‐stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R² of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface‐water dominated streams. Regression models for streams with high R² values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater‐fed systems, but will do so at a slower rate than surface‐water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.     

Cavity excavation and enlargement as mechanisms for indirect interactions in an avian community

Direct and indirect species interactions within ecological communities may play a strong role in influencing or maintaining community structure. Complex community interactions pose a major challenge to predicting ecosystem responses to environmental change because predictive frameworks require identification of mechanisms by which community interactions arise. Cavity-nesting communities are well suited for mechanistic studies of species interactions because cavity nesters interact through the creation of and competition for cavity-nest sites. In this study, we use a cavity-nest web as a predictive framework for identifying potential indirect species interactions within a cavity-nesting community. From 2002 to 2005, we monitored abundance and nests of cavity-nesting birds in the longleaf pine (Pinus palustris) ecosystem. Using a nest-web approach, we identified a potential indirect interaction between the Red-cockaded Woodpecker (Picoides borealis) and large secondary cavity nesters, mediated by the Northern Flicker (Colaptes auratus). We used structural equation modeling to test a path model of this interaction, using cavity excavation and enlargement as mechanisms which drive the relationship between these species. Through experimental manipulation of cavity availability, we blocked links described in our model, confirming cavity creation and enlargement as processes that influence community structure. We found that a single-species management technique could potentially disrupt this indirect relationship by affecting Northern Flicker cavity-excavation behavior. This study is the first demonstration of how experimental cavity manipulation can be used to test inferred processes derived from a nest web and highlights the need to understand how mechanisms underlying species interactions can complicate ecosystem responses to environmental change.