Minnesota Department Of Natural Resources Research Articles

The Use and Performance of Sealed Bid versus Oral Timber Auctions by State Forestry Agencies: A Minnesota Case Study

Abstract State governments are responsible for the stewardship and management of more than 28 million ha of forest land in the United States. This study presents the findings of an in-depth examination of the characteristics and performance of sealed bid and oral auctions using records from more than a thousand tracts offered for sale by the Minnesota Department of Natural Resources, which administers one of the nation’s most robust state timber sale programs. The study found that although tracts offered for sale through oral and sealed bid auctions sold at the same rate and are undifferentiated with respect to nearly all characteristics, sealed bid tracts generated significantly higher winning prices and additional revenue per hectare than tracts sold using oral auctions. Logging businesses were more likely to win sealed auctions than oral auctions, and their portfolio of purchased tracts contained a higher proportion acquired through sealed bid auctions than the portfolio of sealed bid tracts purchased by mills. The study adds to the limited body of literature on public agency timber auctions and is the first to provide a detailed analysis of the auction methods used by a state forest management agency. Study Implications: Public agencies use sealed bid and oral auctions to sell timber rights. This study of the nation’s largest state timber sale program found that the auction method used affects winning bid prices, the likelihood certain categories of bidders will win the auction, the allocation of timber to mills and logging businesses, and revenue generated for each hectare of timber sold. State timber sale program administrators may be able to use these findings to better understand how the choice of auction method affects the financial performance of their timber sale program as well as the allocation of timber among the major types of bidders.

Quality Assurance Methods for Hourly Nonmotorized Traffic Counts

Growing numbers of public transportation and recreation agencies have implemented automated bicycle and pedestrian traffic monitoring programs. To support these initiatives, researchers and agency analysts have developed programs, methods, and measures to ensure data quality. These methods include statistical tests for identifying and flagging outliers and other invalid counts and procedures for imputing or managing missing and censored counts. Because statistics such as annual average daily bicyclists are used frequently in planning and engineering, analysts have focused on validation of daily counts using data from permanent monitors. Procedures for ensuring the validity of hourly counts have not been standardized. This paper presents quality assurance (QA) methods for hourly nonmotorized traffic counts at 115 short-duration and nine permanent monitoring sites on multiuse trails monitored by the Minnesota Department of Natural Resources (MnDNR) and the Minnesota Department of Transportation (MnDOT) between 2016 and 2021. These methods include statistical tests for flagging and censoring invalid hourly counts and procedures for imputing estimates for censored or missing counts. Differences in traffic flow estimates with and without QA are documented, and hourly patterns and factors are presented. Use of quality assurance methods for hourly counts can increase the validity of estimates of nonmotorized traffic.

Experience preferences and place attachment of Minnesota wildlife management area hunters

ABSTRACT Hunters in the United States are motivated to obtain and benefit from diverse experiences or experience preferences. Using a mail survey conducted during the 2015–2016 hunting season, we examined goal-oriented, introspective, and leadership experiences among hunters on Minnesota Department of Natural Resources’ Wildlife Management Area (WMAs). We used k-means cluster analysis to identify six clusters based on experience preferences. We defined these clusters using their ranked experience preferences and segregated them into categories of either participants or enthusiasts. These clusters showed differences in demographic characteristics, as well as support for management actions on WMAs. Hunters in clusters with lower importance ratings of experience preferences also reported less attachment to WMAs. High levels of support for management actions were closely related to high levels of place attachment. Using information gained from describing the heterogeneity of desired experiences, managers may be better able to understand their constituents and prioritize management goals to provide a variety of hunting experiences.

Modeling Potential Changes in Rare Species Habitat from Planned Timber Harvest in Minnesota, USA

In 2018, the Minnesota Department of Natural Resources conducted the Sustainable Timber Harvest Analysis that resulted in the 10-year Stand Exam List (SEL). The SEL includes stands that will be assessed for potential management action from 2021 to 2030, but the location, number, and impact of stands actually harvested remains unknown. This study sought to use modeling to assess potential habitat changes from the SEL for five threatened, endangered, or special concern wildlife species. Three simulation scenarios captured the potential range of harvest from the SEL, and the Wildlife Habitat Indicator for Native Genera and Species model assessed associated habitat changes. The most realistic simulation scenario resulted in statistically insignificant habitat changes of less than ±6%, while two scenarios providing the upper and lower extremes of harvest resulted in statistically significant changes for one species each. Scenarios that resulted in less harvest and more mature forests benefited the five species, reflecting their habitat preferences. The tempering of habitat change values in the most realistic simulation scenario provides evidence for forest management tradeoffs between different wildlife species habitat requirements, as well as other forest resource management objectives.

Assessing Minnesota’s Changing Yellow Perch Populations Using Length‐Based Metrics

AbstractCatch rates of Yellow Perch Perca flavescens in standard gill‐net surveys conducted by the Minnesota Department of Natural Resources have declined since 1970, but it is unclear whether this trend was due to reduced abundance or to changes in size structure affecting catchability. Because the minimum capture length of standard gill nets may limit effective sampling of some populations, the objectives of this study were to determine if length‐based metrics could be used to characterize populations and their susceptibility to standard gill nets, if these metrics were correlated with a suite of abiotic and biotic variables, and if temporal trends in these metrics were evident. Data were collected from a broad size distribution of Yellow Perch sampled with standard gill nets, boat electrofishing, and small‐mesh gill nets in 17 lakes. Estimated length at 50% maturity (L50) for females varied up to 100 mm across lakes, with values as small as 70 mm documented in some populations. Female L50 from supplemental gears was significantly positively correlated with the average length of the 15 largest fish (Lmax) from all gears, and both of these metrics were positively correlated with standard gill‐net catch. Exploratory analysis of female L50 indicated that this metric was positively correlated with latitude and lake size and negatively correlated with water clarity. Additionally, a statewide analysis of Lmax conducted with standard gill‐net data from over 1,000 lakes found significant declines during the past 25 years, indicating that populations in Minnesota have likely shifted towards a smaller size structure, reducing catchability in standard gill nets. These results indicate that standard gill nets were ineffective for sampling some Yellow Perch populations and that length‐based metrics such as L50 and Lmax can be used to infer catchability in standard gear and to monitor populations through time.

Comparing Channel Catfish Populations in the Fragmented Minnesota River

AbstractChannel Catfish Ictalurus punctatus provide important fisheries in lotic systems throughout much of North America, but few studies have evaluated the influence of dams and habitat fragmentation on their populations. The Minnesota River is an important recreational catfish fishery in Minnesota that is fragmented by Granite Falls Dam, located 395 km upstream from the confluence with the Mississippi River. Granite Falls Dam is a significant barrier to upstream fish passage; consequently, the upstream fish community is less diverse than the downstream community and habitat availability differs between reaches. For this study, hoop‐net assessments conducted by the Minnesota Department of Natural Resources during 2014–2017 were used to compare Channel Catfish catch rates, size structure, growth, and annual survival between the upstream and downstream reaches. Hoop‐net catch rates upstream (mean ± SE = 45.1 ± 5.2 fish/net‐night) were significantly greater by an order of magnitude compared to catch rates downstream (3.9 ± 0.4 fish/net‐night). Size structure of Channel Catfish also significantly differed between reaches: the percentage of stock‐length (≥280‐mm) fish that were preferred length or larger (≥610 mm) was 28.4% downstream compared to 5.8% upstream. Annual survival estimates and growth indices were generally similar between reaches, but there was evidence of greater longevity downstream, where the oldest aged fish were 24 years compared to 19 years upstream. This study demonstrates population differences that may be influenced and exacerbated by habitat fragmentation and provides support for considering each population individually when making future management decisions.

Game fish response to dredging of a eutrophic urban lake in Minnesota

Mundahl ND, Hoisington J. 2020. Game fish response to dredging of a eutrophic urban lake in Minnesota. Lake Reserv Manage. 37:170–185. We compared relative abundances, average weights, and growth rates of 6 game fish species before and after the 1999–2001 partial dredging of Lake Winona, a eutrophic, urban lake in Minnesota, to determine whether lake dredging sustainably changed fish population structure to the benefit of anglers. Relative catch rates (trap nets, gill nets, electrofishing) and growth rates were obtained from various fish population assessments and lake surveys conducted by the Minnesota Department of Natural Resources (MN DNR) from 1980 to 2016 for both Lake Winona and Lake Oscar, an ecologically similar lake that has not been dredged. Before-after control-impact (BACI) analyses revealed that compared to Lake Oscar, relative catch rates in Lake Winona after dredging declined significantly for bluegill (Lepomis macrochirus), black crappie (Pomoxis nigromaculatus), and northern pike (Esox lucius), and increased significantly for walleye (Sander vitreus) and largemouth bass (Micropterus salmoides). Average weights of yellow perch (Perca flavescens) and pike increased significantly after dredging. Only black crappie displayed improved growth after dredging. Largemouth bass catch rates for quality- and preferred-size fish increased in postdredging surveys. Although predredging data are lacking, population size structures and relative weights of bluegill, crappie, and bass post dredging were within ranges that meet MN DNR management objectives. Overall, dredging of Lake Winona was followed by improved quality and structure of game fish populations in this system, something that decades of previous biomanipulation and macrophyte management had not accomplished.

Minnesota landowners’ trust in their department of natural resources, salient values similarity and wildlife value orientations

Due to extensive land conversion over the last century, much of the native prairie pothole ecosystem has been converted to agricultural or other human uses. The prairie pothole ecosystem is found in the northern plains of Iowa, Minnesota, South Dakota, North Dakota, and Montana. Because most of the land in this region is privately owned and used for agricultural production, most impacts to wildlife habitat are the result of decisions by individual landowners. Landowner trust in natural resource management agencies is important for agencies to effectively accomplish their mission. We measured the nature (competence and fairness) and level of trust that western Minnesota landowners have in the Minnesota Department of Natural Resources (MnDNR) and landowners’ wildlife value orientations (WVO). Landowners rated MnDNR slightly higher in competence than fairness; however, these two dimensions were strongly correlated. We developed a MnDNR trust scale (six items) and a three-cluster model dividing landowners along the MnDNR trust scale, which we named Negative (28%), Neutral (43%), and Positive (29%). We provide evidence supporting the salient values similarity (SVS) model that states people have trust in agencies holding similar values; landowners reporting greater importance for wildlife consideration when making land-use decisions also reported greater trust in the MnDNR. In addition, mutualist landowners had the highest trust in the MnDNR and utilitarian landowners the lowest level of trust, which is opposite of the trust relationship reported for the general public with state wildlife agencies. Based on the SVS model, our results suggest that mutualist landowners perceive greater congruence with MnDNR goals related to wildlife habitat compared to utilitarian landowners.

Comparing survey and multiple recruitment-mortality models to assess growth rates and population projections.

Estimation of population trends and demographic parameters is important to our understanding of fundamental ecology and species management, yet these data are often difficult to obtain without the use of data from population surveys or marking animals. The northeastern Minnesota moose (Alces alces Linnaeus, 1758) population declined 58% during 2006–2017, yet aerial surveys indicated stability during 2012–2017. In response to the decline, the Minnesota Department of Natural Resources (MNDNR) initiated studies of adult and calf survival to better understand cause‐specific mortality, calf recruitment, and factors influencing the population trajectory. We estimated population growth rate (λ) using adult survival and calf recruitment data from demographic studies and the recruitment–mortality (R‐M) Equation and compared these estimates to those calculated using data from aerial surveys. We then projected population dynamics 50 years using each resulting λ and used a stochastic model to project population dynamics 30 years using data from the MNDNR's studies. Calculations of λ derived from 2012 to 2017 survey data, and the R‐M Equation indicated growth (1.02 ± 0.16 [SE] and 1.01 ± 0.04, respectively). However, the stochastic model indicated a decline in the population over 30 years (λ = 0.91 ± 0.004; 2014–2044). The R‐M Equation has utility for estimating λ, and the supporting information from demographic collaring studies also helps to better address management questions. Furthermore, estimates of λ calculated using collaring data were more certain and reflective of current conditions. Long‐term monitoring using collars would better inform population performance predictions and demographic responses to environmental variability.

A comparison of freshwater mussel assemblages along a land‐use gradient in Minnesota

Abstract Intensive agricultural land use may have adverse impacts on freshwater mussel assemblages. Before European settlement, the Minnesota River Basin (MRB) was home to dense and diverse assemblages of freshwater mussels. Of the 40 species that occurred there, 43% have been extirpated. the St. Croix Basin (SCB) in Minnesota/Wisconsin, in contrast, has maintained a dense and diverse mussel assemblage, probably owing to the maintenance of a higher‐quality ecosystem. Mussels were sampled in four rivers representing an agricultural land‐use gradient. Timed searches were conducted in each of three rivers of the MRB, and in one river in the SCB in 2015. These were previously sampled by the Minnesota Department of Natural Resources (1998–2008). Mussel abundance and richness were lower in the MRB compared with the SCB. There were negligible changes in mussel density in the SCB, whereas abundances declined 17–83% in the MRB over the same period. Rates of decline were greatest for rivers with higher agricultural land use. Individuals of species that inhabited both basins were larger in tributaries with higher agricultural land use. MRB rivers with increased agricultural land use harboured a greater proportion of individuals displaying opportunistic (low life‐span, age and high fecundity) and periodic life‐history traits (moderate to high growth rates, low to intermediate fecundity, life span and age at maturity), whereas SCB assemblages had a greater percentage of mussels displaying equilibrium life‐history traits (long life‐span, late maturity and low reproductive effort). Also, rivers with higher amounts of suspended sediment contained more individuals classified as disturbance tolerant. This study provides evidence that agricultural land use contributes to the loss of mussel diversity and abundance, especially in mussel species that are long lived or slow to reproduce. These life‐history traits may be correlated with increased sensitivity to disturbances commonly observed in agricultural basins, including more and larger flood events.

Effects of a rainbow trout stocking moratorium on the Daphnia species composition and water quality of Square Lake (Minnesota)

Hembre, LK. 2019. Effects of a rainbow trout stocking moratorium on the Daphnia species composition and water quality of Square Lake (Minnesota). Lake Reserv Manage. 35:127–139.Square Lake is among the clearest lakes in the Minneapolis–St. Paul (Minnesota) metropolitan area, but its water clarity has decreased over the past several decades despite levels of total phosphorus (TP) remaining relatively stable. Predation by zooplanktivorous rainbow trout annually stocked since the early 1980s was hypothesized to be the cause for this eutrophication trend. To evaluate this hypothesis, a 3-year moratorium on trout stocking was imposed by the Minnesota Department of Natural Resources (MNDNR) and water quality and zooplankton monitoring data from 2 years prior to the moratorium (2010 and 2012) were compared to data from the 3 moratorium years (2013–2015). Significant changes observed during the moratorium years that support the hypothesis include (1) an increase in biomass concentrations of the large-bodied Daphnia pulicaria, (2) a coincident decrease in biomass concentrations of the smaller bodied D. mendotae, and (3) more pronounced spring clear-water phases when D. pulicaria reached peak densities. In addition, the volume of hypoxic water (dissolved oxygen [DO] < 1 mg/L) that developed in deep water was less in moratorium years compared to the premoratorium years. Unexpectedly, surface water TP concentrations were significantly lower during the moratorium years than in premoratorium years. Greater sequestration of P in the biomass of Daphnia during the moratorium years is the likely cause for the decrease in surface water TP levels in those years. Natural resource managers from the MNDNR have extended the moratorium and are using the conclusions from this study to determine the future fisheries management plan for Square Lake.

Introduction to the Special Section on Recreation Surveys

Surveys to estimate characteristics associated with recreational activities in the United States are local, state-based, or national. While surveys of recreational fishing are well established, surveys to make estimates for populations such as visitors to recreation sites in the US National Forests or hikers on well-established trails are becoming more common. As described by the Minnesota Department of Natural Resources, creel or angler surveys are commonly conducted by state-based agencies to measure fish, determine the number of hours fished, and count boats, fish houses, recreational craft, etc. Nationally, the Marine Recreational Information Program of the National Oceanic and Atmospheric Administration (NOAA) is intended to “provide timely, scientifically sound estimates of recreational catch and effort that fishery managers, stock assessors, and marine scientists need to ensure the sustainability of ocean resources.” This is done by using a “suite of different surveys to capture recreational catch and effort from people who fish from the shore, private boat, for hire boats (including charter boats), headboats or party boats, and guide boats” (www.st.nmfs.noaa.gov/recreational-fisheries/index).

Imputing plant community classifications for forest inventory plots

Native plant community (NPC) classifications typically require on-site visits and in-depth observations by trained ecologists. The goal is to identify unique floristic and environmental characteristics indicative of a particular plant community, ecosystem, or demographic condition. Such data are often desired to inform management decisions on sustainable timber and ecosystem services production over local to large landscapes. Yet, the time and funding needed to identify, assess, catalogue, and map these communities is often limited. Lacking these classifications, we rely on imprecise determinations of the prevalence of various NPCs. Further, extrapolating statewide NPC extent from previously imputed classifications for state managed stands is difficult without a representative sampling design including all ownerships. As a solution to the NPC sample coverage limitation, we describe an extension of a previously reported imputation model to provide the desired statewide classifications and corresponding estimates of the ecological landscape state indicator provided by NPC extent.First, NPC observations from the Minnesota Department of Natural Resources (MNDNR) Division of Ecological and Water Resources for 1964–2015 were linked with MNDNR Forest Inventory Management (FIM) stand data to provide a set of observed polygons for training the imputation model. Then, USDA Forest Service Forest Inventory and Analysis (FIA) plot data, were associated with the observed stands to provide NPC classifications for a subset of plots (e.g., training plots) contained in the FIA database for Minnesota. NPC information was then linked to forest inventory and physiographic layers via spatial association techniques in a geographic information system. Soils data describing drainage, productivity, thickness of the rooting zone, and land position were also used. Finally, validation of resulting imputed classifications shows that application of the model to the statewide FIA inventory will result in an error rate between 8% and 30% with a mean of 83% of imputations correct at the class level.We then updated the publicly accessible FIA database for Minnesota with imputed NPC classifications and scripted labeling schemes integrated with the EVALIDator report building tool to produce estimates of forestland extent. Here, we focus on estimates of NPC class by FIA Survey Unit and inventory year. Finally, quantified estimates of landscape state (e.g., NPC extent and condition) are enabled for inventories ending between 1977 and 2014. Imputed data from this series of statewide inventories enables the analysis of landscape change, and facilitates strategic planning to move the bioregional landscape in a desired ecological direction, or to provide specific ecosystem services.

Effects of restrictive harvest regulations on rehabilitation of coaster brook trout in Minnesota's portion of Lake Superior

Abstract Adfluvial brook trout in Lake Superior, commonly referred to as coasters, were once widely distributed among tributaries and supported trophy fisheries. The Minnesota Department of Natural Resources recently enhanced efforts to rehabilitate brook trout in Minnesota waters by imposing restrictive harvest regulations intended to produce more large individuals adopting a coaster life-history. The agency evaluated effects of the regulation changes by conducting electrofishing stream surveys concurrently with changes and three additional times over the next 16 years. Catch per unit effort of brook trout across all streams was similar among sampling periods. Generalized linear mixed models indicated a greater proportional size structure (number ≥ 330 mm/number ≥ 200 mm) and proportion of older fish (≥ age 3) after the regulation change. Genetic analyses indicated that individuals from coaster hatchery strains, which were stocked in nearby jurisdictions, made up only 5.6% of all individuals in Minnesota streams and 12% of individuals ≥ 330 mm, although the two largest fish were hatchery strain. Our results indicated that conservative regulations can contribute to rehabilitation of coaster populations and that stocked coasters could not account for the improved size and age structure.

Public outreach at the Soudan Underground Laboratory

There are many facets to the outreach program at the Soudan Underground Laboratory, currently host to the MINOS neutrino oscillation experiment and the Cryogenic Dark Matter experiment, plus a number of smaller experiments in the Low Background Counting Facility. The main focus is on twice daily public tours, operated in coordination with the Soudan Underground State Park and Minnesota Department of Natural Resources, who also operate undergound tours of the historical iron mining area. Another important component is the undergraduate interns and high school teachers who lead the tours. They also participate in the operation and/or analysis of the experiments hosted at the mine.

The January 8-9, 2015 Frozen UAS Tour Blows into Grand Forks, North Dakota

AbstractASPRS attendees from the University of Minnesota, the Minnesota and Wisconsin Departments of Transportation, the Minnesota Department of Natural Resources, the U.S. Fish & Wildlife Service, USGS, KMB, Inc. and others all want to thank the University of North Dakota, the Customs Air and Marine Operations and the USAF 69th Observation Squadron for hosting a bunch of frozen remote sensors gain a better understanding of high tech UAS platforms.

Changes in Relative Abundance of Several Minnesota Fishes from 1970 to 2013

AbstractLarge‐scale ecological stressors such as climate change, habitat degradation, and invasive species increasingly affect fisheries across watershed or political boundaries within which they are typically managed. Though broad‐scale analyses of trends in fish populations and changes in aquatic communities can be useful for detecting the effects of these stressors, they are rarely possible due to a lack of long‐term data sets. The Minnesota Department of Natural Resources has used gill nets and trap nets to monitor fish communities in lakes since 1940, and the techniques have been standardized since 1970. We applied a random‐coefficient mixed‐effects model to mean CPUE data to describe statewide and local population trends of eight key fish species (Black Crappie Pomoxis nigromaculatus, Bluegill Lepomis macrochirus, Largemouth Bass Micropterus salmoides, Northern Pike Esox lucius, Smallmouth Bass M. dolomieu, Walleye Sander vitreus, White Sucker Catostomus commersonii, and Yellow Perch Perca flavescens) sampled from 1970 to 2013 in 119–1,499 lakes. We found increasing statewide trends in gill‐net CPUE of Black Crappie, Bluegill, Largemouth Bass, Smallmouth Bass, Northern Pike, and Walleye and decreasing trends for Yellow Perch and White Sucker. Statewide trends in average trap‐net CPUE were positive for Bluegill, negative for Black Crappie, Walleye, White Sucker, and Yellow Perch, and stable for Largemouth Bass, Northern Pike, and Smallmouth Bass. We compared the CPUE trends across lake types developed for Minnesota lakes and found some differences, especially in medium and large mesotrophic lakes, suggesting that some species display changes in abundance more in those lakes types than in others. This study quantifies temporal changes in Minnesota's fish community structure and can help managers focus future research and management activities in the state and in similar waters across central North America.Received May 14, 2014; accepted September 9, 2014

PREZENTACE DIGITÁLNÍCH LESNICKÝCH MAP POMOCÍ WEBOVÝCH MAPOVÝCH SLUŽEB

The Web Mapping Services (WMS) are very useful means for presentation of digital geospatial data in the Internet environment. Typical Open Source example of these services is development environment MapServer, which was originally developed by the University of Minnesota ForNet project in cooperation with NASA and the Minnesota Department of Natural Resources. MapServer is not a full-featured Geographical Information System (GIS), but provides the core functionality to support a wide variety of web applications. Complex and open information system about forest (and cultural) land is presented in real example of MapServer application with data from the Mendel University Training Forest. MapServer is used in effective representing of data for the University Forest staff, students and general public from October 2002. MapServer is usually applied in education process of GIS and Remote Sensing and for sharing of the Faculty of Forestry and Wood Technology Departments geospatial data.

Semi-automated analysis of high-resolution aerial images to quantify docks in glacial lakes

Lake resources can be negatively affected by environmental stressors originating from multiple sources and different spatial scales. Shoreline development, in particular, can negatively affect lake resources through decline in habitat quality, physical disturbance, and impacts on fisheries. The development of remote sensing techniques that efficiently characterize shoreline development in a regional context could greatly improve management approaches for protecting and restoring lake resources. The goal of this study was to develop an approach using high-resolution aerial photographs to quantify and assess docks as indicators of shoreline development. First, we describe a dock analysis workflow that can be used to quantify the spatial extent of docks using aerial images. Our approach incorporates pixel-based classifiers with object-based techniques to effectively analyze high-resolution digital imagery. Second, we apply the analysis workflow to quantify docks for 4261 lakes managed by the Minnesota Department of Natural Resources. Overall accuracy of the analysis results was 98.4% (87.7% based on K^) after manual post-processing. The analysis workflow was also 74% more efficient than the time required for manual digitization of docks. These analyses have immediate relevance for resource planning in Minnesota, whereas the dock analysis workflow could be used to quantify shoreline development in other regions with comparable imagery. These data can also be used to better understand the effects of shoreline development on aquatic resources and to evaluate the effects of shoreline development relative to other stressors.

A comparison of models using removal effort to estimate animal abundance

This paper compares methods for modeling the probability of removal when variable amounts of removal effort are present. A hierarchical modeling framework can produce estimates of animal abundance and detection from replicated removal counts taken at different locations in a region of interest. A common method of specifying variation in detection probabilities across locations or replicates is with a logistic model that incorporates relevant detection covariates. As an alternative to this logistic model, we propose using a catch–effort (CE) model to account for heterogeneity in detection when a measure of removal effort is available for each removal count. This method models the probability of detection as a nonlinear function of removal effort and a removal probability parameter that can vary spatially. Simulation results demonstrate that the CE model can effectively estimate abundance and removal probabilities when average removal rates are large but both the CE and logistic models tend to produce biased estimates as average removal rates decrease. We also found that the CE model fits better than logistic models when estimating wild turkey abundance using harvest and hunter counts collected by the Minnesota Department of Natural Resources during the spring turkey hunting season.