Nest box contentions: Are nest boxes used by the species they target?

Nest boxes have grown in popularity as a habitat management tool in Australia during the last decade. This management use remains contentious because some studies suggest nest boxes are ineffective. There are three recent contentions: (i) nest boxes mostly benefit common species, (ii) exotic species may be dominant users of nest boxes, and (iii) species of conservation concern use nest boxes infrequently. We address these contentions using data from 1865 nest boxes involving eight nest box designs. These nest boxes were installed predominantly <200 m from a road in association with highway duplication and re‐alignment across 16 projects in New South Wales. The Common Brushtail Possum (Trichosurus vulpecula) is the species of most relevance to contention 1. It used 9% of boxes overall including 26% of ‘possum’ designated boxes. The most frequent nest box users were small petaurid gliders (mostly Sugar Gliders, Petaurus breviceps) which used 63% of ‘small glider’ designated boxes. This nest box and another suited to the Sugar Glider comprised 40% of all boxes installed, so it is not surprising that this species might be a common user. Exotic species were uncommon users of the nest boxes enabling contention 2 to be rejected. Active hives of Feral Honeybees (Apis mellifera) occupied just 1% of boxes, and another 1% of boxes were used by introduced rodents and birds. The Squirrel Glider (Petaurus norfolcensis) is the species most relevant to contention 3. It was seen in 80 boxes across 11 projects, representing 7% of the three types most frequently used. These observations are not consistent with the third contention. Nest boxes can provide many important insights about the requirements and interactions of hollow‐dependent fauna. However, they are not intended as an alternative to retaining hollow‐bearing trees.     

Mule Deer Migrations and Highway Underpass Usage in California,USA

Roadways may pose barriers to long-distance migrators such as some ungulates. Highway underpasses mitigate wildlife-vehicle collisions and can be an important management tool for protecting migration corridors. In northern California, 3 underpasses were built on United States Route 395 (Route 395) in Hallelujah Junction Wildlife Area (HJWA) in the 1970s for a migratory mule deer (Odocoileus hemionus) herd that had been negatively affected by highway traffic. To determine whether these underpasses were still reducing mule deer mortalities >40 years after construction, we investigated deer use of the underpasses from 2006–2019 using cameras, global positioning system (GPS) collars, and roadkill records. We used occupancy models, approximations of GPS-collared mule deer movement paths, and roadkill locations to estimate the highway crossing patterns of deer. From camera data, there was higher use of the underpasses by deer during migration (spring [Mar–Jun], fall [Oct–Dec]) than in summer (Jul–Sep), when only resident deer were present. Higher underpass usage occurred in the spring compared to fall migrations. Eleven of 21 GPS-collared migrating mule deer crossed Route 395. We estimated 30% of the crossings (by 7 of the 11 deer) occurred south of the underpasses where deer could easily access the highway because of short (1-m high) and deteriorating highway fencing. Roadkill data confirmed that deer-vehicle collisions were occurring south of the underpasses and at the underpasses. This was likely due to deteriorating infrastructure at the underpasses that allows wildlife access to the highway. Overall, our study indicated that although underpasses can provide safe passage for migratory deer decades (>40 yr) after their construction, deteriorating infrastructure such as fencing and gates can lead to wildlife mortalities on highways near underpasses. © 2021 The Wildlife Society.     

Using Video Surveillance to Estimate Wildlife Use of a Highway Underpass

ABSTRACT Roads pose many threats to wildlife including wildlife-vehicle collisions, which are a danger to humans as well as wildlife. Bridges built with provisions for wildlife can function as important corridors for wildlife passage. We used video surveillance to record wildlife passage under a bridge near Durham, North Carolina, USA, to determine whether it functioned as a wildlife underpass. This is particularly important for white-tailed deer (Odocoileus virginianus) because forests associated with the bridge created a corridor between 2 natural areas. We calculated detection probabilities and estimated the number of crossings as observed crossings divided by detection probability. We observed 126 crossings by >10 species of mammals. Detection probability was 42%; therefore, an estimated 299 wildlife crossings occurred. We observed 75 deer: 17 deer approached the underpass and retreated. We estimated sighting 40% of deer crossings and 92% of deer approaches. Thus, an estimated 185 deer crossings and 18 approaches occurred. As an index of road mortality, we conducted weekly surveys of vehicle-killed animals on a 1.8-km section containing the underpass. We discovered only 5 incidences of animals killed by vehicles. The size and design of the bridge promoted wildlife use of the underpass, providing landscape connectivity between habitats on opposite sides of the highway and likely increasing motorist safety. Thus, bridges in the appropriate landscape context and with a design conducive to wildlife use, can function as a corridor to reduce the effects of fragmentation.     

Traffic Volume Alters Elk Distribution and Highway Crossings in Arizona

ABSTRACT We used 38,709 fixes collected from December 2003 through June 2006 from 44 elk (Cervus elaphus) fitted with Global Positioning System collars and hourly traffic data recorded along 27 km of highway in central Arizona, USA, to determine how traffic volume affected elk distribution and highway crossings. The probability of elk occurring near the highway decreased with increasing traffic volume, indicating that elk used habitat near the highway primarily when traffic volumes were low (<100 vehicles/hr). We used multiple logistic regression followed by model selection using Akaike's Information Criterion to identify factors influencing probability of elk crossings. We found that increasing traffic rates reduced the overall probability of highway crossing, but this effect depended on both season and the proximity of riparian meadow habitat. Elk crossed highways at higher traffic volumes when accessing high quality foraging areas. Our results indicate that 1) managers assessing habitat quality for elk in areas with high traffic-volume highways should consider that habitat near highways may be utilized at low traffic volumes, 2) in areas where highways potentially act as barriers to elk movement, increasing traffic volume decreases the probability of highway crossings, but the magnitude of this effect depends on both season and proximity of important resources, and 3) because some highway crossings still occurred at the high traffic volumes we recorded, increasing traffic alone will not prevent elk-vehicle collisions. Managers concerned with elk-vehicle collisions could increase the effectiveness of wildlife crossing structures by placing them near important resources, such as riparian meadow habitat.     

Can Cone Scales and Bark of Aleppo Pine Be Used in the Biomonitoring of Some Heavy Metals?

The highest levels of Pb in soils and needles were detected in the Lisbon Botanical Garden, reflecting the intense car circulation since the end of the late nineteenth century, and the presence of tetraethyl lead in petrol. Levels of Pb in Aleppo bark were at or above the threshold values for plant tissues as defined by the UN-ECE/EC (>4–30 μg/g). Nickel was easily washed by distilled water from the bark, indicating a predominant adsorption due to atmospheric deposition, while only Pb was water-extracted from cone scales, but no more than 0.88 μg/g (4.3% of the total). If we take into account the dry weight of each cone, we can assess the amount of extractable lead present in a given time (ranges between 3.0 and 15.5 μg), although its eventual transfer to the ground through rainfall will be hampered by the cone architecture. The average levels of total Pb in the cones (12.7–35.4 μg/g) fall within the range defined by the UN-ECE/EC, generally; only the reference value is below 4 μg/g. Due to the high capabilities of allocating Pb inside the structure and through adsorption, Aleppo bark and cones can be very interesting tools in the monitoring of Pb.     

Behavior of Moose Relative to a Road Network

Abstract Roads often negatively affect terrestrial wildlife, via habitat loss or fragmentation, noise, and direct mortality. We studied moose (Alces alces) behavior relative to a road network, in an area with a history of moose-vehicle accidents, to determine when moose were crossing roadways or using areas near roads and to investigate if environmental factors were involved in this behavior. We tracked 47 adult moose with Global Positioning System collars in a study area crossed by highways and forest roads. We hypothesized that moose would avoid crossing roads but would make occasional visits to roadsides to feed on sodium-rich vegetation and avoid biting insects. Further, we expected moose avoidance to be greater for highways than forest roads. We recorded 196,710 movement segments but only observed 328 highway and 1,172 forest-road crossings (16 and 10 times lower than expected by chance). Moose usually avoided road proximity up to ≥500 m on each side but 20% of collared moose made visits to areas within 50 m of highways, which might have resulted from moose searching for sodium in vegetation and roadside salt pools. In fact, vegetation along highways had higher sodium concentrations and was browsed in similar proportions to vegetation in adjacent forest, despite moose avoidance of these zones. Moose, however, did not use areas near roads more during periods of biting insect abundance. Our results supported the hypothesis of scale-dependent selection by moose; avoidance of highways at a coarse scale may confer long-term benefits, whereas selection of highway corridors at finer scales may be part of a strategy to overcome short-term limiting factors such as sodium deficiency. We found a positive relationship between home-range size and the proportion of road axes they contained, suggesting that moose either compensated for habitat loss or made specific movements along highways to gather sodium. The presence of sodium along highways likely increases moose-vehicle accident risks. Removal of salt pools or use of a de-icing salt other than sodium chloride should render highway surroundings less attractive to moose.     

The legacy lead deposition in soils and its impact on cognitive function in preschool-aged children in the United States

Surface soil contamination has been long recognized as an important pathway of human lead exposure, and is now a worldwide health concern. This study estimates the causal effects of exposure to lead in topsoil on cognitive ability among 5-year-old children. We draw on individual level data from the 2000 U.S. Census, and USGS data on lead in topsoil covering a broad set of counties across the United States. Using an instrumental variable approach relying on the 1944 Interstate Highway System Plan, we find that higher lead in topsoil increases considerably the probability of 5-year-old boys experiencing cognitive difficulties such as learning, remembering, concentrating, or making decisions. Living in counties with topsoil lead concentration above the national median roughly doubles the probability of 5-year-old boys having cognitive difficulties. Nevertheless, it does not seem to affect 5-year-old girls, consistent with previous studies. Importantly, the adverse effects of lead exposure on boys are found even in counties with levels of topsoil lead concentration considered low by the guidelines from the U.S. EPA and state agencies. These findings are concerning because they suggest that legacy lead may continue to impair cognition today, both in the United States and in other countries that have considerable lead deposition in topsoil.     

高速公路生态景观质量评价指标体系和评价方法:以江苏南通为例

公路生态景观建设不仅是公路建设的重要组成部分,也是美丽乡村建设和生态园林城市建设的重要标志,对于实现社会经济的可持续发展具有重要作用.公路生态景观质量的评价指标和方法是衡量公路及其外部环境建设质量的重要依据.本研究以江苏省南通市5条主要干线高速公路G15、G228、G204、S334和S335为例,建立了定量和定性评价指标相结合的公路生态景观质量评价指标体系,包括景观功能、生态效能和安全设计3大类12个评价指标.通过现场调查和计算,建立了12个评价指标的变量矩阵,并进行了主成分(PC)分析.结果表明: 公路绿化景观生态评价综合得分模型为: H=0.694PC1+0.191PC2+0.115PC3, 5条高速公路得分排序结果为: G204>G15>S334>G228>S335.本研究结果将为高速公路生态景观质量评价提供方法和参考.     

表土在彭湖高速公路低缓边坡生态恢复中的应用

选取江西省彭泽至湖口高速公路沿线5个典型低缓边坡试验点,利用表土生态恢复,采用样线法调查1年后的试验边坡植物的生长情况。结果表明:在彭湖高速公路低缓边坡利用表土资源进行边坡生态恢复是可行的,各种利用表土的试验设计均取得了较好的恢复效果,其中,边坡覆盖7～10cm中层厚度表土后采取人工撒播恢复方式,边坡植物群落的Simpson多样性指数(平均0.80)及Pielou均匀度指数(平均0.84)相对较高,恢复效果较好;同时,此试验条件下生物量的积累值(平均446g.m-2)和木本植被的群落重要值(平均14.5)都显著高于其他恢复方式,这有利于群落结构的稳定和延续。