Habitat conservation plans under the endangered species act: A comprehensive three-decade analysis
Abstract
Development can pose a substantial threat to imperiled species listed under the US Endangered Species Act (ESA), particularly as two-thirds of these species rely on private lands. Habitat Conservation Plans (HCPs) outlined in Section 10(a)(1)(B) of the ESA have emerged as crucial instruments for harmonizing conservation and development needs. Yet, despite being established for over 30 years, the HCP program's impact remains inadequately understood. Consequently, we evaluated 629 HCPs—covering 38 states and territories, and 748 species—to assess the program's transparency, organization, and impact by examining three key factors: (1) the presence of required documents, (2) the adequacy of monitoring, and (3) the consistency of conservation measures. A lack of required documents made it difficult to quantitatively assess the overall impact of the program, including the adequacy of monitoring. Conservation measures outlined in the plans were also often inconsistent. Our findings indicate that enhancements are needed to modernize data management, increase transparency, strengthen oversight to improve the monitoring and evaluation of both individual HCPs and the program overall, and establish or update species conservation standards. These changes could significantly improve program functionality, streamline development and implementation processes, and offer greater opportunities to gauge success in the program.
1 INTRODUCTION
The US Endangered Species Act (ESA) is one of the most protective laws in the world for imperiled species, with the explicit purpose to recover species listed under the ESA to the point where they no longer need its protections (16 U.S.C. §1531(b)). One of the strongest provisions of the ESA is the prohibition of “take” for all species designated as endangered and most species designated as threatened. “Take” encompasses a broad range of actions that impact the species' health or behavior—including not only killing but also harassment and disruption of activities such as breeding or feeding. The prohibition against take extends beyond intentional harm; individuals who take a protected species incidentally while carrying out other activities—such as commercial activities—could face legal liability for that take. “Incidental” take therefore refers to unintentional take of protected species that occurs while engaging in other activities. Concerned that strict take prohibitions could significantly inhibit economic activity, Congress amended the ESA in 1982 to add Section 10 (“Exemptions”) to the law. Under Section 10 the US Fish and Wildlife Service (“FWS”) and National Marine Fisheries Service (“NMFS,” or collectively “the Services”) are authorized, among other things, to issue permits that can allow non-federal entities who incidentally “take” a protected species while carrying out other activities (e.g., land development, natural resource extraction, energy generation) to avoid legal liability so long as permit conditions are met.
To receive an “incidental take permit” (ITP) under Section 10, applicants must create—and have approved by the relevant Service(s)—a planning document known as a Habitat Conservation Plan (HCP). The ESA requires that an HCP must set forth how the applicant will “minimize and mitigate” their impacts on the listed or non-listed species covered under the plan to the “maximum extent practicable” (16 U.S.C. §1538(a)(2)(A)(ii)), and only HCPs that meet this standard can be approved under the law. Additionally, applicants are required to include reporting which “determine[s] whether [incidental take permit] terms and conditions are being complied with” (Section 10(a)(2)(B)(v)). With the guidance of FWS, applicants often develop and implement monitoring programs within their plans which must provide “information necessary to assess compliance and project impacts and verify progress toward the biological goals and objectives” (US FWS & NOAA, 2016). These permitting exemptions are available to any non-federal entity including private companies, state, local, and Tribal governments.
Over the past few decades, HCP program participation has increased significantly, as have funding opportunities for states and landowners to conserve species through the Cooperative Endangered Species Conservation Fund (Section 6 of the ESA) (US FWS, 2024). This is particularly true in the aftermath of the 1994 “No Suprises Policy,” which ensured that once an HCP was approved, land-use alterations, mitigation, or financial requirements would not be added beyond those agreed to within the HCP document (50 C.F.R. §17.3, §17.22(b)(5) and §17.32(b)(5)). The “No Surprises Policy” does not prevent the Services from requiring HCP provisions that incorporate adaptive management or require permittees to carry out activities if future conditions change so long as they are set forth in the HCP. As of this writing, HCPs have been approved by FWS for more than 1300 ITPs (US FWS, 2021, 2022, 2023).
Two-thirds of federally listed species reside on and utilize non-federal lands (US FWS, 2021), and while section 10(a)(1)(B) does not require, at least at the individual project level, recovery of the relevant species, the Services state that the “goal of every HCP, should be, at minimum to fully offset the impacts of covered activities and ideally to contribute to the recovery of the species” (US FWS & NOAA, 2016). This is consistent with Congress's stated intent that “all Federal departments and agencies…shall utilize their authorities” to recover threatened and endangered species (16 U.S.C. §1531(c)), as well as section 7(a)(1)'s requirement that federal agencies use their authorities to recover listed species (16 U.S.C. §1536(a)(1)). In its Conference Report to the 1982 amendments which created the HCP program, Congress stated that when determining whether to issue a long-term permit for an HCP, the government should consider whether that HCP “is likely to enhance the habitat of the listed species or increase the long-term survivability of the species or its ecosystem” (Conf. Rep. 97–835, 1982). This suggests that while individual permittees may not have an obligation to move a species toward recovery, Congress envisioned the HCP process as a tool for such recovery in the aggregate. And occasionally HCPs have been shown to be significant in species recovery efforts (Haines et al., 2021; Langpap, 2012).
However, despite the importance of HCPs, there is limited information on the program overall, including its effectiveness in meeting the statutory requirements of minimizing and mitigating the impacts of HCP-covered projects “to the maximum extent practicable,” or the broader recovery goals of the ESA. Because of a lack of transparency and the limited availability of public data, large-scale evaluations of the program have been rare. To the best of our knowledge, there has been only one prior, publicly available, large-scale analysis of HCPs, involving 92% of HCPs existing at the time (Kareiva et al., 1998). That study found data limitations, including widespread lack of quantitative take estimates, substantial uncertainties as to whether given mitigation measures would be successful, and lack of clearly outlined monitoring programs (Kareiva et al., 1998). In addition, several other critiques of the program have been published, highlighting various data deficiencies including a lack of: recordkeeping or a centralized data system (Callihan et al., 2009; Kareiva et al., 1998; Owley, 2015a; Surrey et al., 2022), monitoring data and adaptative management mechanisms (Hall, 1997; Kareiva et al., 1998; Owley, 2015a; Wilhere, 2002), adequate baseline data on species impacts (Hood, 1998; James, 1999; Kareiva et al., 1998; Shilling, 1997; Thomas, 2001), and data on enforcement (Callihan et al., 2009; Owley, 2015a). Consequently, our goal was to enhance the understanding of HCPs in the United States by building on previous research and improving transparency and data availability within the program.
We evaluated the statutory standards and requirements of the Services and aimed to answer three major questions: (1) What is the current landscape of the HCP program? Specifically, how many species are covered by HCPs, which FWS regions and states have the highest concentration of HCPs, and which industries are included under these plans? (2) Is FWS adequately monitoring the HCP program so that it can measure success? We gauged this by evaluating both the completeness of the data and the extent of monitoring requirements stipulated within the HCPs; and (3) Is the statutory requirement to minimize and mitigate impacts to species to the maximum extent practical being fulfilled? To answer this, we evaluated species-specific conservation data to measure minimization and mitigation ratio offsets from HCPs for five species, which represented roughly half of all plans in the assessment.
2 METHODS
To further our goal of improving transparency and to minimize duplication of previous studies on HCPs (Callihan et al., 2009; Kareiva et al., 1998), we acquired data for our analysis through a US Freedom of Information Act (FOIA) request submitted in 2017 to FWS, which manages almost all HCPs (with a small number managed by NMFS or jointly by both Services). Pursuant to this request, by 2021 FWS had provided us with 12,414 documents (the vast majority of which were not publicly available) associated with 629 HCPs; this represents 57% of the total HCPs approved between 1986 and 2016 (US FWS & NOAA, 2016). Over the subsequent 3 years, we manually cataloged, digitized, and reviewed all of these documents.
More specifically, our FOIA request asked for documents falling into seven categories (Figure 1) from separate HCP entries as identified in FWS's Environmental Conservation Online System (ECOS) website, created in December of 2017 (US FWS, n.d.-a). We used FWS's delineation of individual HCPs as contained on their ECOS database, though recordkeeping is not consistent. For example, for some HCPs, the original HCPs/ITPs and amended HCPs/ITPs are grouped under one entry while in others original HCPs/ITPs and subsequent amended versions are separated. We also assessed individual permits issued under general conservation plans (GCPs)—HCPs designed by FWS biologists for residential projects—as separate entities, despite their often similar or identical content. GCPs can serve as interim plans, such as those for the Houston toad (Bufo houstonensis), or apply to small-scale developments, as seen with the Alabama beach mouse (ABM) (Peromyscus polionotus ammobates). The FOIA request omitted, to the extent practicable, HCP entries for which adequate documents were available online, as well as HCP entries that were determined to be amendments to an HCP for which documents (including amendments) were already requested. Our inquiry also included a request for a random sample of 25% of programmatic or umbrella HCPs which encompass large swaths of land, usually county or city-managed lands, where individual landowners join into the existing plan. According to conversations with FWS, individual regions and offices were asked to collect and digitize documents responsive to the request and send them to headquarters. Documents were then reviewed by FWS, and some confidential information was redacted or omitted. Based on the scope of our FOIA request, we have no reason to suspect that the documents we received were biased toward any particular species, industries, regions, or otherwise.
We surveyed the program at a broad level to assess the landscape of the HCP program over the past 30 years. Alaska (region 7) was excluded from the analysis because of the absence of any HCPs in that area during the time studied. We centered our analysis on four key areas: (1) species attributes, (2) permit holder/industry composition, (3) regional variations in HCP usage by FWS, and (4) types of conservation measures utilized within plans to minimize and mitigate impacts. For species, we assessed which covered species were included within the conservation plans including federally ESA-listed and non-listed species, their taxonomy, and their listing status. We also pulled information on geographical variations in HCP implementation and usage between different FWS regions. Distinct attributes of the program include the number of conservation plans per region, the number of species covered in plans (single species vs. multiple species plans) and the type of development (residential, commercial, or mixed) within FWS regions. Furthermore, permittee demographics were assessed (private entity, local or municipal government, programmatic, state agency, private and government partnership, multiple government entities) as well as types of activities represented within the program (residential, commercial, recreation or mixed-use). Lastly, we characterized and listed the types of conservation measures (minimization and mitigation) contained across all HCPs analyzed within each plan. Conservation measures, which may include avoidance, minimization, and mitigation strategies, can vary widely (Table S2) but are mandated to reduce and fully offset, to the maximum extent practicable, the direct, indirect, and cumulative adverse effects on covered species. We categorized mitigation and minimization to closely match the examples laid out in the 2016 HCP Handbook (US FWS & NOAA, 2016). Although avoidance is typically considered part of the mitigation hierarchy, we did not specifically include this tier in our analysis because the avoidance measures mentioned in both Handbooks lack the defining characteristic of avoiding impacts altogether (Bull et al., 2022). We felt those conservation measures were better defined as minimization measures (Table S2).
To gauge in more detail how HCPs were meeting the statutory requirement to minimize and mitigate impacts to covered species to the maximum extent practicable, we evaluated conservation measure data for the five species with the most HCPs. The golden-cheeked warbler (GCW) (Setophaga chrysoparia), Florida scrub-jay (FSJ) (Aphelocoma coerulescens), Houston toad (HT), ABM, and coastal California gnatcatcher (CAGN) (Polioptila californica californica) encompassed nearly half of all the permits included in our dataset. The bald eagle (Haliaeetus leucocephalus) also would have been included in this list based on the number of HCPs that represented it, but we excluded it because of the lack of conservation measures for the species in half of the HCPs (amended HT plans resulting in harassment of bald eagle with no additional measures for the species). In addition to categorizing conservation measures we also tabulated mitigation ratios (how many units of habitat protected/restored per unit lost). We also considered the consistency of mitigation measures across HCPs by determining how often certain measures or ratios were used in plans for each of our case study species. If measures were inconsistent for a species, for example, usage of certain minimization measures or mitigation ratios for compensatory mitigation, and especially if no measures were used at all, it is possible some projects may not be reducing and offsetting impacts “to the maximum extent practicable.” To confirm our findings, we contacted FWS biologists with expertise on matters to gain insight into standards and guidance information for the five case study species. Biologists provided us with information on species conservation measure standards and documentation. The identity of biologists will be kept anonymous, and they will be identified only by number, for example, Biologist 1.
3 RESULTS
3.1 The landscape of HCPs
Our dataset of 629 HCPs covered seven FWS regions across 38 states and territories, and 748 species (Table S4) and allowed us to conduct the largest-scale assessment of the HCP program to date. HCPs can cover properties ranging from less than two acres, as typically seen with individual housing permits for residential development, to millions of acres (e.g., Edwards Aquifer Authority: 10,758,976 acres) and some spanning multiple states (e.g., Lower Colorado River Multi-species plan in Arizona, California, Nevada). HCP characteristics varied between regions in terms of the number of plans, species, and industries involved. FWS regions 2 (Southwest), 4 (Southeast) and 8 (Pacific Southwest) accounted for 84.2% of plans, with the majority originating in California, Texas, and Florida (Figure 1). Species representation varied, but HCPs in regions 1 (Pacific) and 8 covered more species than the other regions combined, especially non-listed species. Importantly, the high presence of non-listed species in HCPs (65.0%) came from large multispecies plans in FWS regions 1 and 8, but most plans covered take for a single species (67.8%) compared to multi-species HCPs (32.2%) (Figure 1). In addition, 251 federally listed species (threatened: 30.6%, endangered: 69.3%) and nine recovered species are covered under ITPs. Species covered under these HCPs comprise approximately 15% of all domestically listed ESA species. Approximately half of the species covered in the HCP program were vertebrates (55.7%), followed by plants (29.1%) and invertebrates (15.1%) (Figure 2). Most HCP plant species (67.4%) were not federally listed but had some state-level protections, with the majority located in California. Of the 748 species, six were covered for incidental take within roughly half (51.3%) of the HCPs in the analysis: GCW, FSJ, HT, ABM, CAGN, and the bald eagle.
HCP development has experienced fluctuations over time, likely in response to the 1998 “no surprises” amendment, surges in regional development, and economic recessions (Figure 3). While the program covered many actions and industries on non-federal lands, private entities or individuals represented the largest proportion of permit holders (82.7%), which can include commercial or residential developers, companies, and individual homeowners (Figure 4). The next largest demographics were local city or county municipal governments (9.1%) followed by large-scale programmatic HCPs (4.5%) (multiple applicants including private and government entities). Lastly, state-wide, multi-state HCPs including state natural resource agencies (2.4%), public–private partnerships (1.3%) and interagency collaboration (0.02%) made up the smallest percentage of permit holders of the program (Figure 4).
Residential development comprised half of the HCPs (52%) in our evaluation, with Florida, California, Alabama, and Texas representing the highest prevalence of residential development HCPs (Figure 4). Commercial development (any activity outside of residential living) represented 36.6% of HCPs, followed by mixed development (8.4%) (residential and commercial development) and recreation-based impacts (3.0%) (Figure 4). The most prevalent commercial industries included natural resource extraction (timber, water authority, and mining) (30.9%), energy generation and transmission (wind farms, powerplants, transmission, and pipelines) (22.2%), and services industry (hotels, retail, and schools) (22.6%) (Figure 4).
Unfortunately, our FOIA request was missing many documents, constraining our analysis. In fact, of the required HCP documents (i.e., HCP main document, ITP, Biological Opinion, Findings,) 19.8% were missing from the responses to our FOIA request. Furthermore, most HCPs (97.7%) were missing one or more optional categories of requested documents (i.e., Implementation Agreement, GIS files). In addition to missing documents, some documents were incomplete or missing key information. This was because of scanning inaccuracy of older documents and a lack of labeling and fragmentation of received documents from FWS.
3.2 Monitoring data
As noted above, our request for information was missing many documents and thus limited our analysis of monitoring data. FWS requires most HCP applicants (73.2%) to provide some form of monitoring or compliance reports, with a majority (60.0%) requiring submission on an annual basis. Unfortunately, we only received copies of less than half (48.8%) of those required reports through the FOIA request. Because we had few documents to analyze, it was difficult to determine the status of the monitoring program. Our challenges in evaluating the monitoring data constrain our capacity to ascertain whether permit holders are fulfilling their obligations to minimize and mitigate impacts to the greatest extent. This issue also underscores a broader lack of transparency within the HCP program.
3.3 Conservation measures
Within an HCP, the impacts resulting from the take of a covered species must be minimized and mitigated to the maximum extent practicable (50 CFR 17.22(b)(2)(i) and 50 CFR 17.32(b)(2)(i) for FWS; and (ii) and (iii) found at 50 CFR 222.307(c)(2) for NMFS). Almost all permit holders (81.6%) were using multiple minimization measures for their plans, with a smaller percentage using either one measure (9.2%) or no minimization measures (7.8%) (Figure 5). In addition, a large proportion of HCPs were utilizing multiple mitigation measures (76.6%) with on-site preservation, restoration, or enhancement utilized in 29.4% of HCPs, off-site mitigation in 42.9% of HCPs, and a mixture of both in 23.6% of plans. Land management measures were usually paired with other mitigation measures such as ecological threat management and translocation procedures for some select species. The data highlight the wide array of tools that permit holders are utilizing to minimize and mitigate their impacts on covered species.
A detailed examination of the five case study species revealed varying levels of consistency in conservation measures across plans for the same species (Table 1). The rationale for including or excluding specific measures was often unclear within the HCP documents. This lack of clarity was particularly noticeable regarding mitigation ratios, which determine how many units of area must be offset (i.e., restored and/or protected) for each unit of take or degraded habitat. Mitigation ratios are set to account for differences in habitat quality and uncertainty. Inconsistent conservation measures and limited evidence behind certain actions can lead to uneven outcomes where similar plans (species, activity, and region) are not reaching the “maximum extent practicable” requirement. FSJ had a consistent mitigation standard across HCPs, but other species mitigation strategies seem to be determined, at times, ad hoc, with little indication of how they were calculated. Through reviews of the HCPs and other documents (including recovery plans), and through discussions with FWS staff (who have worked on these species), we found that only a few species have some documented form of conservation measure standards, and most measures are assessed on a case-by-case basis. Only FSJ and ABM have conservation guidance documents for HCP conservation measure implementation (Alabama Ecological Services Field Office, 2012; Field Supervisor, Jackson Field Office, & Field Supervisor, South Florida Ecological Services Office, 2004; Southern Florida Ecological Services, 2004). Despite the ABM guidance being a GCP and not an official guidance document, it is still used as a standard by FWS. The remaining three case study species did not have conservation measure standards. Instead, when drafting conservation measures, applicants and/or FWS staff used “proxy” documents which were not drafted for the purpose of guidance for HCPs but had some segments of information that could be used by FWS or applicants to determine conservation options for their plans (California Department of Fish & Game & California Resources Agency, 1993; Hopkins, 2004; US Fish and Wildlife Service Austin Ecological Services Field Office, 2021; US FWS & Austin Ecological Services Field Office, 2017; US FWS & Southwest Region, 2013). It is unclear how often these documents are utilized for HCPs as most are regional planning, mitigation bank, and habitat management guidance documents.
| Standard mitigation ratio | Predominant minimization measure | |||||
|---|---|---|---|---|---|---|
| Species | Yes/No | Explanation | Widely used ratio | Seasonal | Spatial | Prohibitions |
| Houston Toad | No | “In the process” | 59%—1.5:1 21.2%—1:1 | 4.5% | 100% | 3% |
| Alabama beach mouse | Yes | $2.30 per sq. ft | 90%—on site avoidance | 81.4% | 98.5% | 97.1% |
| Florida scurb-jay | Yes | 2:1 | 72%—2:1 | 84% | 40% | 25.3% |
| Golden-cheeked warbler | No | “Goal” Indirect Impacts 0.5:1 Habitat Quality 1:1–3:1 | 78.8%-used goal 21.2% used other ratios | 100% | 94.1% | 19.7% |
| Coastal California gnatcatcher | No | “General Range” 1:1–3:1 | 37% used range 63% used other ratios | 77.7% | 70.3% | 29.6% |
- Note: Shown are the top conservation measures and standards used within conservation plans for the five case study species: Houston toad, Alabama beach mouse, Florida scrub-jay, golden-cheeked warbler, and coastal California gnatcatcher. The three predominant minimization measures aimed at reducing impacts are seasonal restrictions, spatial restrictions, and prohibition of certain activities in the plan area. Because most HCPs use multiple measures for a single plan, these percentages will overlap for a given species. Mitigation (offsets on-site or off-site) are detailed in the table, categorized according to FWS offset standards and their usage. The ratio is preservation/restoration: Impact of take.
We also found that a majority (60%) of the case study species did not have a standard mitigation ratio amongst HCP applicants to offset their impacts. The FSJ and ABM were the only species in our study that had documented mitigation standards (Alabama Ecological Services Field Office, 2012; Field Supervisor, Jackson Field Office, & Field Supervisor, South Florida Ecological Services Office, 2004). Though the mitigation standard for ABM was designed in 2012, it post-dates the pool of ABM ITPs in our analysis (Table 1). Currently, FWS is drafting a mitigation standard for the HT, but nearly all HCPs (95.5%) were using an undocumented habitat quality-based ratio designed through an informal in-lieu program (Table 1) (Biologist 1). Similarly, GCW and CAGN do not have standard mitigation ratios but utilize several ratios based on habitat quality, direct and indirect impacts, and the use of several in-lieu and regional conservation banks (Table 1) (Biologist 2 and Biologist 3). The predominant mitigation mechanisms are species conservation banks and in-lieu fee programs aimed at protecting and managing lands and waters in perpetuity, essential for specific species conservation needs.
Similarly, minimization measures have varied usage and inconsistencies. For example, information provided by FWS biologists stated that, currently, the most common measure used for HT HCPs is seasonal land clearing restrictions during the breeding season (Biologist 1). In the pool of HCPs evaluated, however, only 4.5% of plans used that measure. In contrast, FWS biologists stated that seasonal restrictions on land clearing are a primary measure for GCW (Biologist 2) with 100% usage in our evaluation. For other avian species like the FSJ, seasonal land clearing restrictions can greatly reduce impacts during the nesting season; however, rather than see universal usage of this measure like with the GCW, 84.0% of HCPs use this measure and a smaller portion of HCPs (40.0%) use a spatial restriction around nesting sites (Table 1).
4 DISCUSSION
Section 10 (a)(1)(B) is one of the most valuable tools to balance species conservation and development needs in the United States, but its effectiveness relies on applicants meeting the statutory requirements under the ESA. Our goal was to gauge the impact of the program by examining several factors, including the scope of the program and if key requirements such as fully offsetting impacts of covered species and monitoring and compliance of HCPs were being met. Below, we discuss some of the strengths and weaknesses of the HCP program based on our assessment.
4.1 Opportunities for expansion
Although Congress envisioned the HCP program as a comprehensive and collaborative initiative involving both the private and public sectors, its implementation has been limited in terms of species coverage and regional and industrial application. A mere 15% of United States listed species were covered under HCPs in 2017, which is a shocking number considering two-thirds of imperiled species utilize non-federal lands for habitat, breeding, and/or foraging behaviors. This analysis did not address the overlap between geographical areas of activities and development where incidental take occurs and the species excluded in HCPs, but future assessments should investigate this overlap more thoroughly. Possible exclusions may stem from a lack of regional engagement with Section 10 by FWS, as observed in Alaska and several states throughout the South and Southeast, or alternative usage of other ESA consultation processes.
The limited scope of species covered in individual plans can be attributed to various factors, including a lack of scientific data on certain species, constraints imposed by federal laws, and notably insufficient engagement from some regional or field offices as well as a lack of resources for FWS staff. The confluence of these elements underscores the challenges in achieving a more comprehensive and inclusive conservation strategy for species. Species coverage limitations are especially prominent for plants, which account for 56% of United States listed species but, outside of federal lands, are exempt from take on private lands, and unless states enact ESA protections for plants within their boundaries, the presence of plants within the HCP program will be limited overall. ESA-listed species including pollinating insects, aquatic vertebrates, and invertebrates make up a small portion of species covered in our analysis but need immediate conservation efforts and have fewer resources than most terrestrial vertebrate species (Haines et al., 2021; Levin, 2013; NatureServe, 2022; Rosa et al., 2023; Strayer, 2006).
States such as Florida, Texas, and California demonstrated a high prevalence of HCPs, but disparities persist as other states grapple with an inadequacy in the number of plans or no plans at all to address development in biodiverse-rich areas within their boundaries. This is especially true for states in the Midwest, South, and Southeast given their biodiversity and opportunities for private land conservation. Notably, regions with historically low HCP participation are now utilizing the program to address incidental take, including the Midwest, where the number of HCPs has doubled in recent years, primarily because of the expansion of wind energy generation. In 2022, Missouri implemented a multi-species plan encompassing 41 million acres (US FWS, n.d.-b). And since our analysis, hundreds of ITPs have been approved (US FWS, 2022, 2023). The demand for ITPs is expected to grow with increases in urban development and resource use. Section 10 plays a critical role in balancing economic development and those impacts on species, yet significant gaps remain, including the underutilization by sectors like agriculture, fisheries, and ranching, where activities may lead to the incidental take of listed species. Despite the potential for improvement, challenges persist, including fragmented data availability, inconsistent conservation outcomes, and issues with oversight and compliance. These concerns must be addressed to enhance the effectiveness of the program moving forward.
4.2 Limitations in monitoring and compliance
Routine review and monitoring are crucial to assessing the effectiveness of conservation measures and their ability to meet goals and objectives of an HCP. They balance development and species conservation efforts and lend valuable information to species recovery planning. We acknowledge that in some cases monitoring may be going unreported, but from our FOIA request we only received half of the required monitoring documents. Even when monitoring reports were provided, we often received reports covering a few years, rather than the full breadth of required documentation. Without a centralized data system, FWS used regional systems and practices to store documents like routine monitoring reports. It is unclear if missing documents never existed, were misplaced over time, or if applicants were not providing the required documents to FWS biologists for review. Attached to plans we found a few correspondence documents between FWS staff confirming assertions by Callihan et al. (2009) and Owley (2015a) that because of the difficult nature of administering programs, especially given limited resources, upkeep of documentation and paperwork, as well as routine review of plans after it was finalized, was not always a priority, with some emails highlighting compliance issues after permit issuance (Biologist's email communication, April 18, 2000). In contrast, several monitoring reports in our FOIA request highlight swift compliance action by FWS. While the extent to which these issues unfolded remains uncertain, as we only obtained fragmented documents, it is evident that the management of these HCPs exhibited significant variability over time as also found by Callihan et al. (2009). The fluctuation may be attributed to various factors—such as increased workload and inadequate staffing—which lead to selective resolution of certain issues while others remain unaddressed. FWS staff are dedicated individuals working under conditions that have been both understaffed and underfunded for some time (Greenwald et al., n.d.; Callihan et al., 2009; Defenders of Wildlife, 2024; Evansen, 2022; Malcom, 2021; Malcom & Evansen, 2020). A biologist's workload is a myriad of other responsibilities outside of Section 10 and, given high demands and ever-shifting constraints, limitations on oversight can be rampant even outside of the HCP program (GAO, 2009). To address some of these issues, FWS began the process of modernizing the ECOS website to transition to ECOSPHERE, providing a central point of access to data on ESA-listed species including updates to HCP document storage and information. Along with ePermits, this new system is poised to create an improved framework for applicants and FWS staff and may also promote easier monitoring and storage of compliance documents, as well as greater transparency through public access to relevant species documentation. As of April 2025, to the best of our knowledge, FWS still intends to transition to the ECOSPHERE platform; however, the timeline for this transition remains uncertain. In the interim, certain components of the ECOS system are no longer being updated, resulting in limited public access to current information and documents. We note that difficulties in monitoring and enforcing mitigation measures are not uncommon generally. For example, under the Clean Water Act and its No Net Loss policy, developers need to offset their impacts on protected wetlands through compensatory mitigation, with an aggregate goal of no net loss of such wetlands in the United States. However, there have been significant questions about whether required mitigation is being implemented and adequately enforced (Banks et al., 2014; National Research Council et al., 2001; Owley, 2015b). Similar problems can be seen globally (Zu Ermgassen et al., 2019).
4.3 Species conservation standards lack consistency and may not be meeting statutory requirements
Individual plans employ various conservation measures to minimize and mitigate the impacts of take, but our investigation revealed greater variability than anticipated between plans for the same species, especially given proximity and similar activities. This variability arises because conservation measures required to offset impacts are applied on a case-by-case basis. While flexibility is an essential part of the HCP program, as every HCP “has its own set of unique circumstances,” (US FWS & NOAA, 2016) this method of implementation may not be the most effective or efficient way to establish offsetting metrics. A species-oriented baseline standard or strategy for conservation under Section 10 of the ESA would offer a clear path for applicants navigating the complex consultations between FWS biologists. This could also increase transparency, resulting in greater buy-in from stakeholders, and improve the speed of the HCP design and implementation process, something which is greatly valued in the HCP community (California Habitat Conservation Planning Coalition, 2014; California Habitat Conservation Planning Coalition et al., 2013). This would in turn benefit species by ensuring measures are universal, tested, and structured to meet the fully offset (minimum no net loss) impacts “of resources or individual animals or plants” requirement (Camacho et al., 2023; US Fish and Wildlife Service, 2023; US FWS & NOAA, 2016). Strategy documents could be species specific as demonstrated with the FSJ or could be regionally focused outlining conservation guidance for multiple species in a particular location as seen with the highly collaborative East Alameda County Conservation Strategy, which was established to “streamline and increase predictability of the permit process both for applicants and local resource agencies- and contribute to species recovery” (East Alameda County, 2010). Most of our case study species did not have a documented standard for conservation measure efforts within the HCP program. In addition, during our analysis, conservation strategies were at times verbal, and we were often unable to find updated or current documentation or guidance that provides the scientific validity of conservation measure options. This lack of documented guidance made it difficult for not only us, but presumably also the FWS biologists to decipher if measures, especially mitigation, were sufficient at offsetting impacts. The establishment and documentation of conservation standards would allow the Services to better determine if they are meeting their obligations under Section 10, monitoring and improving the impact of the HCP program over time, and potentially increase species' chances of survival.
Of the few documents we found, the 2:1 mitigation ratio standard set for the FSJ was based on an unpublished 1994 scientific study and framework establishing a ratio that “would preserve two thirds of the unprotected population statewide” at the 1993 baseline (Field Supervisor, Jackson Field Office, & Field Supervisor, South Florida Ecological Services Office, 2004; Fitzpatrick et al., 1994; Southern Florida Ecological Services, 2004). The preservation assessment is based off the “not likely to jeopardize the existence of” standard of Section 7, which is a different requirement than Section 10's “to the maximum extent practicable.” And while Section 7 is another tool to further species conservation on non-federal lands and often requires similar conservation measures, such as breeding season restrictions (Biologist 1), it can hold less stringent protections and requirements. In other words, the mitigation ratio necessary to avoid the jeopardy threshold may not meet the “maximum extent practicable” threshold.
In contrast to the FSJ mitigation strategy, in 2012, FWS revised the ABM conservation measure guidance noting lessons learned over the past decade from the initial general HCP (Alabama Ecological Services Field Office, 2012). The updated mitigation standard utilizes the neighboring Perdido key beach mouse (PKBM) (Peromyscus polionotus trissyllepsis) mitigation strategy and data from their business plan designed to address mitigation offsets with restricted land area and high real estate values (FWC et al., 2005; RCF Economic and Financial Consulting, Inc., 2005; Biologist 4). For the case study species, status updates highlight key aspects of the HCP program's contributions to conservation, particularly through monitoring and habitat preservation (Table S3). However, for species still declining because of ongoing habitat loss and fragmentation (Table S3), it remains unclear whether conservation measures are adequately evaluated and adjusted to effectively offset these impacts.
- Greater understanding is needed of the current and historical barriers faced by FWS staff who manage and oversee the HCPs, as well as the resources required to support their efforts.
- Establishing conservation measure standards or conservation strategy guidance documents for HCP applicants will provide clear benchmarks for meeting the ESA's “maximum extent practicable” requirements. These documents will improve plan development and implementation while supporting species recovery efforts.
- Strengthening the integration of information from other programs into the HCP program, and vice versa, including conservation measure usage and monitoring data in species recovery plans and reviews. Centralized databases (i.e., ECOSPHERE, Conservation Evidence) can aid in sharing species research to better evaluate conservation actions over time.
- Improving transparency on record keeping and monitoring through the new e-Permits platform, extending the ECOSPHERE to allow publicly available access to HCPs and their documents, and updating the website to have accurate up-to-date information on certain attributes of the program.
5 CONCLUSIONS
Our assessment of the HCP program's impact was limited because of the absence of critical documents and data needed to evaluate its overall success. The variability in conservation measure implementation, lack of structured standards, inadequate scientific documentation, and absence of monitoring reports in our FOIA request made it difficult to determine whether applicants are meeting the goals and objectives of their plans. While it is evident that HCPs play an important role in conservation, HCP implementation has been challenging because of species complexity on non-federal lands, the lack of Service-wide guidance, and particularly the significant funding and resource limitations faced by FWS. We believe the proposed improvements outlined in this paper will enhance conservation outcomes, provide more robust metrics for measuring success, and streamline the program to help it achieve the full potential envisioned by Congress.
ACKNOWLEDGMENTS
The authors are extremely grateful for the dedication of US Fish and Wildlife Service personnel who helped fulfill the FOIA request and especially to biologists who responded to requests for species specific information. We also appreciate the insightful feedback provided by the reviewers, and thank Laura Nunes, Lindsay Rosa, and Talia Niederman for their assistance and guidance with this article, and Ya-Wei (Jake) Li and Jacob Malcom for their early initiation of the project.
FUNDING INFORMATION
Financial and institutional support for this manuscript was provided by Defenders of Wildlife.
CONFLICT OF INTEREST STATEMENT
The authors declare no conflict of interest.
ETHICS STATEMENT
While identities of participants cannot readily be ascertained from the reported information, in an abundance of caution the authors also requested and received written approval from all the government employees that were surveyed for certain clarifying information in the analysis. All documents provided by US Fish and Wildlife Service were either publicly available documents and/or provided through a Freedom of Information Act request.
Open Research
DATA AVAILABILITY STATEMENT
A repository of documents for all 629 HCPs provided by FWS through our FOIA request and our analysis data can be found online at OSF PREPRINTS: https://osf.io/2a4vb/.
