6 research outputs found
Behavior and activity of commensal roof rats around rodenticide bait stations in southern California, USA
No full textThe roof rat (Rattus rattus) is a highly invasive rat that poses a threat to humans and native species. In urban settings they are typically managed with bait stations containing chemical rodenticides, however, their behavior around bait stations is not well understood. We conducted field studies in 36 residential yards in Orange County, California, to determine whether different bait station designs or baiting approaches influence roof rat behavior around stations. Specifically, we tested whether the bait station's design, the presence of supplemental bait, and the addition of a scent lure in the station influenced rat behavior over three separate trials. Using digital game cameras, we monitored stations containing non-toxic bait for three weeks during each trial to estimate the time to discovery, entry, bait consumption, and nightly activity of rats around stations. We also determined whether landscape characteristics associated with each yard (presence of rodent management, pets/livestock, or fruits/vegetables) influenced rat behavior. Rats were detected in most yards (75 – 91 % of yards), and they discovered stations in most of these yards (59 – 89 % stations discovered). However, they did not enter many stations (24 – 63 % stations entered). Neither the station's design nor the addition of a scent lure in the station affected any of the measured response variables. Supplemental bait around stations decreased the time to entry and increased the nightly activity of rats at two types of stations, and increased bait consumption in all station designs. The presence of fruits and vegetables in the yard decreased the time to discovery of stations, but did not affect any other response variables. Rats in yards that were currently or recently (within last six months) managed for rodents were just as active as in unmanaged yards but were less likely to consume bait, indicating that neophobia is not the only factor contributing to bait avoidance -- previous exposure to management may also lead to bait avoidance by commensal rats. This underscores that new approaches may be needed to effectively control commensal rats with the tools currently available.106653https://doi.org/10.1016/j.applanim.2025.10665
Recommended from our members
Do Scent Lures Increase Visitation of Bait Stations by Urban Roof Rats?
No full textRoof rats (Rattus rattus) are invasive commensal rodents that pose a significant threat to both natural and manmade environments. Like other commensal rodents, roof rats are often controlled with rodenticides placed within bait stations, but rats can be slow to visit stations or avoid them altogether. We tested whether the addition of a scent lure (Airzonix; VM Products) would increase visitation and use of bait stations in 36 residential yards in Orange County, California. We placed two EZ-Secured (VM Products) stations, one containing a scent lure and non-toxic bait (treatment) and one containing bait only (control), in each yard, and monitored them continuously with digital game cameras for three weeks. We compared time to discovery and entry, bait consumption, and nightly roof rat activity between scent lure and control stations. The addition of a scent lure did not reduce time to discovery or entry significantly, nor did it increase bait consumption or rat activity, although rat behavior differed around scent lure and control bait stations. Overall, although roof rats discovered bait stations fairly quickly (median time to discovery 124-195 h), they entered and consumed bait in only a fraction (50-60%) of the stations, and were slow to enter stations (median time to entry 318-387 h), underscoring that additional techniques are still needed to improve the attractiveness and efficacy of bait stations
Relationship of Flood Peaks to 24-Hour Rainfall in the eastern Texas Hill Country, South-Central Texas
No full textThe eastern Texas Hill Country is noted for its extreme storm rainfall amounts and the resulting flood discharges. The resulting flash f loods contribute to Texas leading the U.S. in automobile-related, flood fatalities. These f loods produce considerable groundwater recharge to the Edwards Aquifer. A better knowledge of relations between precipitation and peak flood discharges can improve f lood hazard warning and provide estimates of groundwater recharge from ungauged ephemeral streams. The purpose of this study was to analyze the relationship between 24-hour precipitation amounts and peak discharge for four ephemeral streams, with drainage areas between 0.3 to 18.8 mi.2 on the Texas State University Freeman Ranch located approximately 6 miles west of downtown San Marcos, TX. We used the USGS Slope-area method (Dalrymple and Benson 1967) to calculate peak discharge and on-site as well as nearby and NWS, CoCoRaHS precipitation data. Reference unit runoff and flood volume runoff were determined from nearby USGS gauges for similar sized drainages. A precipitation minimum of 4 in in 24 hrs. was required to produce quickflow, a value that is affected by antecedent precipitation in the previous 1 to 3 days. Approximately 370 ac-ft of runoff would be produced by each 1,000 ft3 /sec peak stream flow with approximately fifteen percent becoming groundwater recharge in basins without dams, and a majority of which becomes recharge on streams with flood detention dams
Desenvolvimento de um método para o controle da utilização de gordura trans no processo produtivo de refeições
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-Graduação em Nutrição.Como resultado do aumento do consumo das gorduras trans e dos estudos que o associam a reflexos negativos na saúde dos indivíduos, a Organização Mundial da Saúde (OMS) lançou, em 2004, a Estratégia Global para Promoção da Alimentação Saudável, Atividade Física e Saúde, tendo a eliminação do consumo dessas gorduras como uma das metas. Nesse enfoque, este estudo objetivou desenvolver um método de controle da utilização de gorduras trans no processo produtivo de refeições - CGTR. Trata-se de uma pesquisa qualitativa descritiva em desenvolvimento, tendo sido o método delineado e testado por meio de um estudo de caso. As etapas da pesquisa foram: identificação de informações sobre a utilização e a formação de gorduras trans no processo produtivo de refeições na literatura científica; identificação de grupos e/ou subgrupos de preparações que podem vir a conter gorduras trans em sua composição, a partir de processos produtivos facilitadores para a adição e/ou formação dessas gorduras; concepção de um modelo de método de controle de gorduras trans na produção de refeições; definição do local do estudo de caso; aplicação do método no local escolhido; revisão do método a partir da experiência no estudo de caso e elaboração de estratégias para a aplicação do método desenvolvido. Os dados foram coletados em uma Unidade Produtora de Refeições de Florianópolis - SC, por meio do acompanhamento das refeições de desjejum, almoço e coffee break. Como resultados, foram definidas as etapas do processo produtivo que demandam controle para evitar um cardápio rico em gorduras trans. Dentre essas etapas destacam-se: a seleção de fornecedores que não utilizem produtos industrializados com gordura vegetal parcialmente hidrogenada, a conferência da lista de ingredientes dos rótulos dos alimentos, o controle de tempo e temperatura dos óleos vegetais utilizados para frituras de imersão. O CGTR é apresentado em etapas de aplicação, formulários com instruções para a coleta de dados, análise dos dados e glossário. Ressalta-se que este é um instrumento de gerenciamento do processo produtivo de refeições que pode facilitar a oferta de refeições mais saudáveis sob o ponto de vista nutricional, auxiliando para que as Unidades Produtoras de Refeições, comerciais e coletivas, cumpram o seu papel como promotoras de saúde
On a secant-like method for solving generalized equations
No full textsummary:In the paper by Hilout and Piétrus (2006) a semilocal convergence analysis was given for the secant-like method to solve generalized equations using Hölder-type conditions introduced by the first author (for nonlinear equations). Here, we show that this convergence analysis can be refined under weaker hypothesis, and less computational cost. Moreover finer error estimates on the distances involved and a larger radius of convergence are obtained
