The impact of fire on habitat use by the short-snouted elephant shrew ('Elephantulus brachyrhynchus') in North West Province, South Africa

Several studies have investigated the response of small mammal populations to fire, but few have investigated behavioural responses to habitat modification. In this study we investigated the impact of fire on home range, habitat use and activity patterns of the short-snouted elephant shrew (Elephantulus brachyrhynchus) by radio-tracking individuals before and after a fire event. All animals survived the passage of fire in termite mound refugia. Before the fire, grassland was used more than thickets, but habitat utilization shifted to thickets after fire had removed the grass cover. Thickets were an important refuge both pre- and post-fire, but the proportion of thicket within the home range was greater post-fire. We conclude that fire-induced habitat modification resulted in a restriction of E. brachyrhynchus movements to patches of unburned vegetation. This may be a behavioural response to an increase in predation pressure associated with a reduction in cover, rather than a lack of food. This study highlights the importance of considering the landscape mosaic in fire management and allowing sufficient island patches to remain post-fire ensures the persistence of the small mammal fauna

The impacts of natural flood management approaches on in-channel sediment quality

Natural Flood Management (NFM) techniques aim to reduce downstream flooding by storing and slowing the flow of stormwater to river channels. These techniques include a range of measures, including setback stormwater outfalls and the physical restoration of channels and floodplains, to improve the natural functioning of catchments. An additional benefit of NFM measures is the potential reduction in sediment and pollutant delivery to the channel. Urban development releases a variety of heavy metal and nutrient pollutants that enter rivers through stormwater outfalls with adverse effects on the aquatic ecosystem. In this study, the influence of channel modification and quality of the river habitat on the sediment quality surrounding stormwater outfalls was assessed. Sediment samples were taken at several outfalls within the Johnson Creek catchment, Oregon, USA, and analysed for a variety of urban pollutants. The level of river habitat quality and modification at each site were assessed using a semi-quantitative scoring methodology. Significant increases in pollutant levels were observed at outfalls, with a greater and more variable increase at direct compared to setback outfalls. Removal efficiency of certain pollutants was found to be significantly correlated to the level of habitat quality or modification (for Fe, Ba, Sn, Mg, P, K) indicating that more natural reaches had greater potential for pollutant removal. The findings highlight the multiple benefits associated with NFM and river restoration approaches in relation to sediment quality and pollutant content

State Fish Stocking Programs at Risk: Takings Under the Endangered Species Act

Part I of this article provides a brief background to fish stocking practices in the United States, including a discussion of beneficial fish stocking practices, as well as some of the allegations surrounding the detrimental effects. Part II of this article provides some necessary background on section 9 of the ESA, the “actual injury” prong, the “significant impairment” prong, and their application to fish stocking. Part III of this article sets forth recommendations for future clarification and increased consistency on these issues. Specifically, this article supports the use of two rules that can help reconcile the uncertain landscape surrounding a taking based on habitat modification. First, “actual injury” should be found where there is injury to either an individual or a population of protected species. Second, the degree of proof required to establish an “injury” where essential behaviors are impaired should be bifurcated into two tests, depending on which behavioral pattern is being adversely affected. Together, these rules can bring resolution not only to scenarios like fish stocking, but also to other future fact patterns scrutinized under the habitat modification analysis. Part IV of this article demonstrates how application of these rules to states can further the goals of the ESA, both through voluntary reevaluation of fish stocking programs, and through application for an Incidental Take Permit and corresponding Habitat Conservation Plan. These rules can provide two different paths to the same goal: to minimize adverse impacts to endangered and threatened species

\u3ci\u3eNeurocordulia (Platycordulia) Xanthosoma\u3c/i\u3e (Williamson) in Texas (Odonata: Libellulidae: Corduliinae)

(excerpt) The rarity of a species is usually judged by the number of specimens in collections, both private and institutional, and the number of places where it has been found or seen. On this basis, Neurocordulia xanthosoma (Williamson) is rare. Its crepuscular habits, its brown coloration, and its habitat requirements, coupled with the habits of most collectors, have been its protection. Nevertheless, because of its apparent special requirements and man\u27s modification of, and encroachment on, its environment, it may soon be a species of the past

Ecological values of Hamilton urban streams (North Island, New Zealand): constraints and opportunities for restoration

Urban streams globally are characterised by degraded habitat conditions and low aquatic biodiversity, but are increasingly becoming the focus of restoration activities. We investigated habitat quality, ecological function, and fish and macroinvertebrate community composition of gully streams in Hamilton City, New Zealand, and compared these with a selection of periurban sites surrounded by rural land. A similar complement of fish species was found at urban and periurban sites, including two threatened species, with only one introduced fish widespread (Gambusia affinis). Stream macroinvertebrate community metrics indicated low ecological condition at most urban and periurban sites, but highlighted the presence of one high value urban site with a fauna dominated by sensitive taxa. Light-trapping around seepages in city gullies revealed the presence of several caddisfly species normally associated with native forest, suggesting that seepage habitats can provide important refugia for some aquatic insects in urban environments. Qualitative measures of stream habitat were not significantly different between urban and periurban sites, but urban streams had significantly lower hydraulic function and higher biogeochemical function than periurban streams. These functional differences are thought to reflect, respectively, (1) the combined effects of channel modification and stormwater hydrology, and (2) the influence of riparian vegetation providing shade and enhancing habitat in streams. Significant relationships between some macroinvertebrate community metrics and riparian vegetation buffering and bank protection suggest that riparian enhancement may have beneficial ecological outcomes in some urban streams. Other actions that may contribute to urban stream restoration goals include an integrated catchment approach to resolving fish passage issues, active reintroduction of wood to streams to enhance cover and habitat heterogeneity, and seeding of depauperate streams with native migratory fish to help initiate natural recolonisation

The Effects of Critical Habitat Designation on Housing Supply: An Analysis of California Housing Construction Activity

Under the Endangered Species Act, the U.S. Fish and Wildlife Service is required to designate critical habitat for listed species. Designation could result in modification to or delay of residential development projects within habitat boundaries, generating concern over potential housing market impacts. This paper draws upon a large dataset of municipal-level (FIPS) building permit issuances and critical habitat designations in California over a 13-year period to identify changes in the spatial and temporal pattern of development activity associated with critical habitat designation. We find that the proposal of critical habitat results in a 20.5% decrease in the annual supply of housing permits in the short-run and a 32.6% decrease in the long-run. Further, the percent of the FIPS area that is designated as critical habitat significantly affects the number of permits issued. We also find that the impact varies across the two periods in which critical habitat is designated and by the number of years relative to when critical habitat was first proposed.

Deer reduce habitat quality for a woodland songbird: evidence from settlement patterns, demographic parameters, and body condition.

Understanding avian responses to ungulate-induced habitat modification is important because deer populations are increasing across much of temperate Europe and North America. Our experimental study examined whether habitat quality for Blackcaps (Sylvia atricapilla) in young woodland in eastern England was affected by deer, by comparing Blackcap behavior, abundance, and condition between paired plots (half of each pair protected from deer). The vegetation in each pair of plots was the same age. The Blackcap is an ideal model species for testing effects of deer on avian habitat quality because it is dependent on dense understory vegetation and is abundant throughout much of Europe. We compared timing of settlement, abundance, age structure (second-year vs. after-second-year), and phenotypic quality (measured as a body condition index, body mass divided by tarsus length) between experimental and control plots. We used point counts to examine Blackcap distribution, and standardized mist netting to collect demographic and biometric data. Incidence of singing Blackcaps was higher in nonbrowsed than in browsed plots, and singing males were recorded in nonbrowsed plots earlier in the season, indicating earlier and preferential territory establishment. Most Blackcaps, both males and females, were captured in vegetation prior to canopy closure (2–4 years of regrowth). Body condition was superior for male Blackcaps captured in nonbrowsed plots; for second-year males this was most marked in vegetation prior to canopy closure. We conclude that deer browsing in young woodland can alter habitat quality for understory-dependent species, with potential consequences for individual fitness and population productivity beyond the more obvious effects on population density

Choosing Your Ground on the Endangered Species Act: How Do the Ninth, Tenth, and District of Columbia Circuit Courts of Appeal Evaluate Water Management Decisions Made by Federal Water Agencies?

The purpose of this article is twofold. First, federal agencies are responsible for the development and implementation of ESA documents, and knowing what a court will look for and at when that document is challenged can help the agencies to develop a document that can better survive court review. Second, a plaintiff who challenges such a document can benefit from that same knowledge, by knowing which elements of the document to best challenge. The intent of this article is to provide practitioners, both agency and non-, with an introduction to that knowledge, to identify some of those difficulties, dangers, and distances, with the ultimate goal of adding clarity to an often confusing battlefield. This article first provides, in Part II, an overview of how the ESA applies to federal actions, and then discusses in Part III how the Ninth, Tenth, and District of Columbia Circuit Courts of Appeal analyze, under the ESA, the decisions made by the federal agencies. The discussion includes specific analytic tests the courts have developed. Finally, in Part IV, the article describes a hypothetical decision on a large river system with multiple dams operated by Reclamation and the Army Corps as a hypothetical case study to illustrate the Courts’ tests. Different federal circuits utilize different tests to determine whether or not the decisions made under the ESA satisfy the statute and court precedent. The intent of this article is to illustrate the particular criteria some of the courts use in those tests, and thus to provide information for federal agencies and litigants to use in crafting their documents and, if necessary, their arguments

Construction of data-driven models to predict the occurrence of planktonic species in the North-Sea

Marine habitat suitability models typically predict the potential distribution of organisms based on basic abiotic variables such as salinity, oxygen concentrations, temperature fluctuations (Gogina & Zettler, 2010) or sediment class information (Degraer et al., 2008; Willems et al., 2008). Recently, Dachs & Méjanelle (2010) claimed that the modification of biota composition due to marine pollution is a factor to be taken into account in marine habitat suitability models. Although the anthropogenic pressure on the environment has been exponentially increasing during the last six decades (Dachs & Méjanelle, 2010), the global effect of human inputs on oceanic phytoplankton remains unknown (Echeveste et al., 2010). A limited number of studies have assessed the impact of anthropogenic stressors on phytoplankton in marine environments at a global level (Faust et al., 2003; Magnusson et al.,2008). In order to fill this knowledge gap, this research tries to determine to what extent pollution data can be used to predict the occurrence of the phytoplanktonic organisms compared to basic abiotic variables. Here we explored this issue by developing classification trees relating physical-chemical variables with the occurrence of the potential harmful toxic algae Odontella sinensis