29 May 2024

Impacts of Invasive Species on Populations of Federally Listed Species on US Army Corps of Engineers Project Lands

Abstract: The US Army Corps of Engineers (USACE) is mandated to meet federal, state, and local environmental laws and organizational regulations pertaining to the protection and conservation of ESA (Endangered Species Act 1973)-listed species and associated critical habitats. USACE is also mandated under Executive Order 13112 to document the presence and status of invasive species on their lands. We examine the status of 50 ESA–listed species prioritized by USACE expenditures for ESA compliance from 2014 to 2018. We review the status of invasive species and assess any evidence from published US Fish and Wildlife Service (USFWS) or National Marine Fisheries Service recovery plans or other government documents that indicate whether invasive species are negatively impacting the status of ESA–listed species on USACE lands. We found that 18 of 50 (36%) USFWS recovery plans for these 50 listed species specifically mention invasive species as a primary factor leading to the species’ decline and listing, or they note the need for management and control of invasive species to meet proposed recovery goals. USACE will need to work collaboratively with other federal and state agencies, universities, and nongovernmental organizations to improve control of invasive species and management and recovery of ESA–listed species.

29 May 2024

Comparing Ecological Models for Assessing Rio Grande Silvery Minnow Response to Environmental Flows

Abstract: The proliferation of continuous streamflow monitoring and spatial data suitable for hydraulic modeling is increasing opportunities to use hydraulic habitat analysis to inform ecological models. However, species population and streamflow data exhibit high variability, making it challenging to identify hydrologic and hydraulic metrics that effectively correlate with ecological outcomes. Metric selection presents a challenge for informing environmental flow decisions and adaptive management of water infrastructure. This study applies models to characterize environmental flows with in-creasing model complexity, including the use of hydraulic models to estimate suitable habitat areas at a given flow. The results are compared to field-measured fish outcomes over the same period using functional data analysis. The variance in model correlation with ecological outcomes aids in identifying the most effective environmental flow parameters while also indicating potential pitfalls from increasing model complexity. This analysis demonstrates techniques that synthesize environmental flows with available habitat analysis and validates the approach. The case study is based on the Rio Grande silvery minnow (Hybognathus amarus, minnow), an endangered fish species in the Middle Rio Grande. Analysis focused on different methods to quantify spring runoff coinciding with the inundation of floodplain nursery habitat necessary for the minnow’s larval and juvenile life stages.

8 Aug 2022

The Use of US Army Corps of Engineers Reservoirs as Stopover Sites for the Aransas–Wood Buffalo Population of Whooping Crane

Abstract: This technical report summarizes the use of US Army Corps of Engineers (USACE) reservoirs as spring and fall migration stopover sites for the endangered Aransas–Wood Buffalo population of whooping cranes (WHCR), which proved much greater than previously known. We assessed stopover use within the migration flyway with satellite transmitter data on 68 WHCR during 2009–2018 from a study by the US Geological Survey (USGS) and collaborators, resulting in over 165,000 location records, supplemented by incidental observations from the US Fish and Wildlife Service (USFWS) and the USGS Biodiversity Information Serving Our Nation (BISON) databases. Significant stopover use was observed during both spring and fall migration, and one reservoir served as a wintering location in multiple years. Future efforts should include (a) continued monitoring for WHCR at USACE reservoirs within the flyway; (b) reservoir-specific management plans at all projects with significant WHCR stopover; (c) a USACE-specific and range-wide Endangered Species Act Section 7(a)(1) conservation plan that specifies proactive conservation actions; (d) habitat management plans that include potential pool-level modifications during spring and fall to optimize stopover habitat conditions; and (e) continued evaluation of habitat conditions at USACE reservoirs.

21 Jul 2022

Implementing Endangered Species Act (ESA) Section 7 (a)(1) Conservation Planning During US Army Corps of Engineers (USACE) Coastal Engineering

Purpose: This technical note was developed by the US Army Engineer Research and Development Center–Environmental Laboratory (ERDC-EL) to provide guidance to the US Army Corps of Engineers (USACE) on implementing Endangered Species Act* (ESA) Section 7(a)(1) conservation planning, in coordination with the US Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service (NMFS) during coastal engineering projects. USACE expends ~$200–$300 million each year on compliance, conservation, and other activities associated with the ESA (USACE 2022), and these expenditures often exceed those of other federal agencies (for example, US Bureau of Land Management) that have jurisdiction over far greater land holdings than USACE. To streamline the ESA compliance process, lower costs, and generate more positive outcomes for federally listed threatened and endangered species (TES), USACE was directed in June 2015 by the Deputy Commanding General (DCG) for Civil and Emergency Operations to proactively identify and incorporate conservation benefits into all projects when and where opportunities arise, under the authority of Section 7(a)(1) of the ESA (USACE 2015). The DCG identified Section 7(a)(1) conservation planning as a mechanism to efficiently achieve project purposes, create environmental value, and streamline the ESA Section 7(a)(2) consultation process

27 Sep 2021

Summary of Collaborative Wildlife Protection and Recovery Initiative (CWPRI) Conservation Workshop: Least Bell’s Vireo

Abstract: This special report summarizes the regional workshop held 24–26 April 2018 at the US Fish and Wildlife Service (USFWS) Ecological Services Office in Carlsbad, California on the importance of collaboration among federal, state, and nongovernmental agencies to facilitate the recovery of threatened and endangered species (TES). This workshop focused primarily on one species, the least Bell’s vireo (LBVI), and how to achieve full recovery and eventual delisting through agency partnerships. A major theme of the workshop was applying the Endangered Species Act (ESA) Section 7(a)(1) conservation planning process as a building block towards recovery of LBVI—as well as other threatened, endangered, and at-risk riparian species within the Southwest. The main objective of this workshop was to assemble an interagency and interdisciplinary group of wildlife biologists and managers to detail how the Section 7(a)(1) conservation planning approach, in consultation with the USFWS, can assist in the recovery of LBVI primarily on federal lands but also other public and private lands. Goals of this workshop were to (1) review Section 7(a)(1); (2) outline LBVI ecosystem processes, life history, threats, and conservation solutions; and (3) develop and organize agency commitments to collaborative conservation practices.

23 Apr 2020

PUBLICATION NOTICE: Conspecific Attraction as a Management Tool for Endangered and At-Risk Species on Military Lands

Abstract: Movements of wildlife species and associated colonization of habitats is often unpredictable, potentially leading to ineffective management and/or interference with military training. Habitat restoration for wildlife management on military lands is a common, yet expensive, response to federal conservation and mitigation mandates, yet viable wildlife populations often fail to become established on restored habitat. Conspecific attraction, using the tendency for individuals of the same species to settle near one another, can be a cost-effective means of attracting animals to newly created or restored habitats. This work demonstrated the use of conspecific attraction as an alternative tool for encouraging colonization of restored habitats by at-risk birds and amphibians. Conspecific attraction was relatively straightforward to employ, but its effectiveness varied among species. We demonstrated clear success in attracting some bird (northern bobwhite; Colinus virginianus) and frog (wood frogs; Lithobates sylvaticus) species into our target areas but other species showed a neutral response. Conspecific attraction presents a cost-effective alternative to current management practices such as translocation or colonization after habitat is created or restored. Only minimal equipment costs (<$300/broad-cast station) and nominal work-hours are required to set up the equipment, and total cost was ~$1,200 per demonstration plot annually.