Population Trend Data Research Articles

A test of niche centrality as a determinant of population trends and conservation status in threatened and endangered North American birds

Abundance and other aspects of population ecology have long been known to con- tribute to shaping the geography of species' distributions. In particular, abundance patterns have recently been shown to negatively correlate with environmental distance from conditions in the center of a species' abiotic niche, rather than vary with distance from the geographic center of a species' distribution. We tested for such associations across 8 species of endangered or threatened bird species in North America using population trend data derived from >4 decades of North Amer- ican Breeding Bird Surveys. Although we found no consistent overall pattern, we did observe nega- tive population trends at conditions that were the most extreme within species' niches. This suggests that niche peripherality is a relevant factor to consider in conservation planning. Specifi- cally, environmentally peripheral sites may be poor places in which to protect populations of endan- gered and threatened species, irrespective of how centrally they may occur within species' geo- graphic distributions.

A successful model for citizen scientist involvement in building a statewide at-risk butterfly database

Long-term population trend data are not available for most butterfly species in many areas. Historically, this has meant that many governmental agencies make conservation decisions affecting this group of organisms with limited knowledge about their existing populations. To remedy this situation in Florida, a statewide database containing locations of at-risk butterfly species on conservation lands was developed primarily through the efforts of citizen scientists. This paper describes the data collection methodology that was used and presents several cases studies showing how this database has already made a difference in shaping the decision-making process to help in the conservation of at-risk butterfly species. A discussion of the methodologies used to generate the at-risk butterfly database, relative to more traditional butterfly monitoring surveys, is presented and recommendations are made on ways to optimize the contributions of volunteers to insect conservation and research programs.

Quantifying range‐wide variation in population trends from local abundance surveys and widespread opportunistic occurrence records

Summary Species’ abundances vary in space and time. Describing these patterns is a cornerstone of macroecology. Moreover, trends in population size are an important criterion for the assessment of a species’ conservation status. Because abundance trends are not homogeneous in space, we need to quantify variation in abundance trends across the geographical range of a species. A basic difficulty exists in that data sets that cover large geographic areas rarely include population abundance data at high temporal resolution. Whilst both broad‐scale geographic distribution data and site‐specific population trend data are becoming more widely available, approaches are required which integrate these different types of data. We present a hierarchical model that integrates observations from multiple sources to estimate spatio‐temporal abundance trends. The model links annual population densities on a spatial grid to both long‐term count data and to opportunistic occurrence records from a citizen science programme. Specific observation models for both data types explicitly account for differences in data structure and quality. We test this novel method in a virtual study with simulated data and apply it to the estimation of abundance dynamics across the range of a butterfly species (Pyronia tithonus) in Great Britain between 1985 and 2004. The application to simulated and real data demonstrates how the hierarchical model structure accommodates various sources of uncertainty which occur at different stages of the link between observational data and the modelled abundance, thereby it accounts for these uncertainties in the inference of abundance variations. We show that by using hierarchical observation models that integrate different types of commonly available data sources, we can improve the estimates of variation in species abundances across space and time. This will improve our ability to detect regional trends and can also enhance the empirical basis for understanding range dynamics.

Flexibility in phenology and habitat use act as buffers to long‐term population declines in UK passerines

Ecological responses to environmental change are wide‐ranging, from alterations in the timing of life‐history events to range and population changes. Explaining the variation across species in these responses is essential for identifying vulnerable species and for developing adequate conservation or mitigation strategies. Using population trend data from the UK Breeding Bird Survey, this study examined the association between long‐term population trends (1994–2007) and phenological, life‐history and resource‐use traits of UK passerine species. Phenology, as well as productivity and resource use were significantly associated with long‐term population trends. Average laying date and first clutch laying period were key predictors, with higher population growth rates associated with earlier laying dates and longer laying periods. This suggests that flexibility in the duration of reproductive periods buffers species against environmental changes. Average laying period was particularly important for migrant species. Flexibility in laying dates for these species is constrained by their arrival dates; mean change in arrival date over a twenty‐five year period strongly predicted population trends amongst migrant species. Besides the key role phenological flexibility plays in buffering population declines, we also showed that more productive, generalist species were less likely to have declining populations than species with specialized habitat requirements, particularly those associated with farmland and urban areas and those reliant on highly seasonal food items (i.e. invertebrate eaters). These results underscore the need for a multi‐faceted approach to understanding the mechanisms governing population trends. Additionally, species’ sensitivity to environmental change is likely to depend on interactions between species‐specific phenology, habitat and resource‐use traits.

Predicting how populations decline to extinction

Global species extinction typically represents the endpoint in a long sequence of population declines and local extinctions. In comparative studies of extinction risk of contemporary mammalian species, there appear to be some universal traits that may predispose taxa to an elevated risk of extinction. In local population-level studies, there are limited insights into the process of population decline and extinction. Moreover, there is still little appreciation of how local processes scale up to global patterns. Advancing the understanding of factors which predispose populations to rapid declines will benefit proactive conservation and may allow us to target at-risk populations as well as at-risk species. Here, we take mammalian population trend data from the largest repository of population abundance trends, and combine it with the PanTHERIA database on mammal traits to answer the question: what factors can be used to predict decline in mammalian abundance? We find in general that environmental variables are better determinants of cross-species population-level decline than intrinsic biological traits. For effective conservation, we must not only describe which species are at risk and why, but also prescribe ways to counteract this.

Identifying the ecological causes of long-term declines of wetland-dependent birds in an urbanizing landscape

Many wetland-dependent birds are thought to be experiencing significant population declines, although population trend data for this suite of birds are rare and the causes of declines poorly understood. We used a 26-year dataset (1980-2005) of wetland bird abundance and distribution among 196 wetlands in northeastern Illinois (i.e., Chicago and its suburbs) to evaluate population trends and identify underlying ecological causes. We used aerial photography and GIS to quantify wetland habitat structure (i.e., the extent of emergent vegetation) and changes in surrounding land use. We then evaluated how changes in land use affected the structure of wetlands and ultimately wetland bird populations. Of the 12 species analyzed, seven experienced significant declines, three showed non-significant declines, and two experienced significant increases. Population declines could not be attributed to wetland loss because none of our wetlands were destroyed. Concurrent research at these wetlands also suggests that neither low adult survival nor poor reproductive success were responsible for the declines. Increased development within 2 km of wetlands, however, was associated with extreme changes in the structure of wetlands. Wetlands tended either to lose much of their vegetation and become open ponds, or become rank stands of dense vegetation. Both changes made wetlands less suitable for many wetland birds. While “no net loss” legislation may protect wetlands from being filled or drained, development near wetlands appears to be altering hydrology, resulting in habitat degradation and population declines of several wetland-dependent bird species.

Field-Based Estimates of Avian Mortality from West Nile Virus Infection

One of the unique characteristics of West Nile virus (WNV) in North America is the large number of bird species for which the virus can be fatal. WNV mortality has been documented through experimental infections of captive birds and necropsies of free-ranging birds. Investigations of WNV-related mortality in wild birds often focus on species with dramatic population declines (e.g., American Crow, Corvus brachyrhynchos); however, few studies have addressed WNV-related mortality in species not exhibiting marked population declines since the arrival of WNV. We conducted a mark-recapture study of 204 Northern Cardinals (Cardinalis cardinalis) in an area with endemic WNV activity to estimate WNV-related mortality. Previous research has shown that once a bird is infected and recovers from WNV it develops antibodies making it resistant to future infection. Assuming that mortality risks from non-WNV causes were the same for individuals with (had been exposed to WNV) and without antibodies (had not been exposed to WNV), we compared the survival rates of birds with and without WNV antibodies to estimate the impact of WNV on wild birds. An information theoretic approach was used, and the apparent survival was found to be 34.6% lower for individuals without antibodies during the period when WNV was most active (July-September). However, the apparent survival rate was 9.0% higher for individuals without antibodies over the rest of the year. These differences in apparent survival suggest that WNV increases mortality during the WNV season and that chronic effects of WNV infection may also be contributing to mortality. Although WNV appears to have increased mortality rates within the population, population trend data do not indicate declines, suggesting that some cardinal populations can compensate for WNV-related mortality.

Monitoring Change in Vertebrate Abundance: the Living Planet Index

The task of measuring the decline of global biodiversity and instituting changes to halt and reverse this downturn has been taken up in response to the Convention on Biological Diversity's 2010 target. It is an undertaking made more difficult by the complex nature of biodiversity and the consequent difficulty in accurately gauging its depletion. In the Living Planet Index, aggregated population trends among vertebrate species indicate the rate of change in the status of biodiversity, and this index can be used to address the question of whether or not the 2010 target has been achieved. We investigated the use of generalized additive models in aggregating large quantities of population trend data, evaluated potential bias that results from collation of existing trends, and explored the feasibility of disaggregating the data (e.g., geographically, taxonomically, regionally, and by thematic area). Our results show strengths in length and completeness of data, little evidence of bias toward threatened species, and the possibility of disaggregation into meaningful subsets. Limitations of the data set are still apparent, in particular the dominance of bird data and gaps in tropical-species population coverage. Population-trend data complement the longer-term, but more coarse-grained, perspectives gained by evaluating species-level extinction rates. To measure progress toward the 2010 target, indicators must be adapted and strategically supplemented with existing data to generate meaningful indicators in time. Beyond 2010, it is critical a strategy be set out for the future development of indicators that will deal with existing data gaps and that is intricately tied to the goals of future biodiversity targets.

Using repeated winter surveys to estimate changes in abundance of seed‐eating passerines

Capsule Winter Atlas surveys of 16 species on lowland farmland revealed significant changes in count for four species. Aims To estimate changes in abundance between the early 1980s and late 1990s, of wintering seed‐eating passerines, in ‘core’ areas of lowland Scotland. Methods Ninety‐five Scottish 10‐km squares were selected that held high numbers of seed‐eating passerines in the 1981–84 Atlas of Wintering Birds in Britain and Ireland. The same survey methods were used to resurvey these in winters 1997/98 and 1998/99, and visits were matched as closely as possible for duration and date. Analyses compared counts between the two survey periods for 16 species of seed‐eating passerines and, for 12 of these, differences were also compared with national breeding population trend information for the same period. Results Mean Corn Bunting Emberiza calandra count per visit declined by 62% between the early 1980s and late 1990s, a difference which was statistically significant (P = 0.026). Significant increases were recorded for Yellowhammer Emberiza citrinella (up 62%), Common Linnet Carduelis cannabina (up 3.4‐fold) and European Goldfinch Carduelis carduelis (up 13‐fold). For 12 species for which national breeding population trend data were available, trends were weakly positively correlated (r s = 0.43, P = 0.08) with those from our results, but several species trends were more positive in our study. This difference was particularly marked for Eurasian Tree Sparrow Passer montanus, Goldfinch and Linnet. Conclusion Repeating Winter Atlas surveys offers a useful additional method for assessing population trends. They are particularly useful in a region with low observer coverage and for species that are poorly covered by long‐term bird monitoring data sets. It would be valuable to validate this approach at a regional level, especially in a region for which detailed long‐term bird monitoring data are available.

Assessing Landbird Monitoring Programs and Demographic Causes of Population Trends

Abstract: Population trend data from the North American Breeding Bird Survey (BBS) have been used to identify conservation priorities and justify major conservation initiatives. Yet the BBS has been criticized for potential habitat bias and reliance on abundance indices to estimate trends. We compared 1992–2003 BBS trend estimates to trend estimates derived from bird‐banding data collected as part of the Monitoring Avian Productivity and Survivorship (MAPS) program for 36 wood warbler species. Similarity in trends between the 2 monitoring programs at the survey‐wide and program‐wide scales suggested that each program can provide accurate trend information. The MAPS program, however, was designed primarily to complement (rather than duplicate) count‐based efforts, such as the BBS, by providing estimates or indices of demographic rates. Demographic data from MAPS can be used to lend insight into proximate (demographic) causes of population trends and inform management. We illustrate this with analyses of 1992–2003 MAPS data for yellow warbler (Dendroica petechia). We used reverse‐time capture‐recapture models to evaluate importance of new recruits (including immigrating adults and young from the previous year) relative to surviving adults in explaining variation in trend among BBS physiographic strata. We included the number of young per adult captured (an index of productivity) as a covariate in models to assess effects of productivity on trends. Survival was the key demographic driver of recent population trends. Comparison of MAPS productivity indices and adult apparent survival rate estimates to BBS trend estimates largely confirmed this inference. We suggest that increased MAPS coverage, better coordination between MAPS and the BBS, and continued development of analytical methods that link the 2 programs will enhance the value of these monitoring efforts to land managers and conservation planners working at a variety of spatial scales.

Key conservation issues for migratory land- and waterbird species on the world's major flyways

AbstractAn estimated 19% of the world's 9,856 extant bird species are migratory, including some 1,600 species of land- and waterbirds. In 2008, 11% of migratory land- and waterbirds were classed by BirdLife International as threatened or near-threatened on the IUCN Red List. Red List indices show that these migrants have become more threatened since 1988, with 33 species deteriorating and just six improving in status. There is also increasing evidence of regional declines. Population trend data show that more Nearctic–Neotropical migrants have declined than increased in North America since the 1980s, and more Palearctic–Afrotropical migrants breeding in Europe declined than increased during 1970–2000. Reviews of the status of migratory raptors show unfavourable conservation status for 51% of species in the African–Eurasian region (in 2005), and 33% of species in Central, South and East Asia (in 2007). Land-use change owing to agriculture is the most frequently cited threat affecting nearly 80% of all threatened and near-threatened species. However, while agricultural intensification on the breeding grounds is often proposed as the major driver of declines in Palearctic–Afrotropical migrants, some species appear to be limited by the quantity and quality of available habitat in non-breeding areas, notably the drylands of tropical Africa. Forest fragmentation in breeding areas has contributed to the declines of Nearctic–Neotropical migrants with deforestation in non-breeding areas another possible factor. Infrastructure development including wind turbines, cables, towers and masts can also be a threat. Over-harvesting and persecution remain serious threats, particularly at key migration locations. Climate change is affecting birds already, is expected to exacerbate all these pressures, and may also increase competition between migratory and non-migratory species. The conservation of migratory birds thus requires a multitude of approaches. Many migratory birds require effective management of their critical sites, and Important Bird Areas (IBAs) provide an important foundation for such action; however to function effectively in conserving migratory species, IBAs need to be protected and the coherence of the network requires regular review. Since many migratory species (c. 55%) are widely dispersed across their breeding or non-breeding ranges, it is essential to address the human-induced changes at the wider landscape scale, a very considerable challenge. Efforts to conserve migratory birds in one part of the range are less effective if unaddressed threats are reducing these species' populations and habitats elsewhere. International collaboration and coordinated action along migration flyways as a whole are thus key elements in any strategy for the conservation of migratory birds.

A population model for the black tern Chlidonias niger in West-Europe

Based on empiric data of breeding success and accurate number trends in The Netherlands, a population model for the black tern was constructed. This model is based on Leslie matrices. Reproductive parameters from the four most important landscape types (river landscape, agricultural grasslands, peat marsh and heath land/moors) are used as model input. Highly accurate national population trend data were used to obtain the best (least square) estimate of overall adult and subadult survival (resp. 0.849 and 0.595). Estimating survival parameters in this way might be useful for threatened (bird) species, especially if catching and ringing is difficult or less desired from a conservation perspective. The model shows the actual importance of the river landscape as the main source for reproductive output of the Dutch black tern population. The prediction model was subsequently used to test different conservation strategies for the Dutch black tern population. Conservation strategies ranged from a null scenario (no change in conservation effort) to in- or decreasing the number of rafts in the most productive landscape (river landscape) to a scenario where breeding success is improved recently in agricultural grasslands via minimizing disturbance. For all scenarios, the model predicts a slow to rapid population increase in the Dutch black tern population after 10–20 years. Improving breeding success in agricultural grasslands habitat has the highest added value.

Is the global conservation status assessment of a threatened taxon a utopia?

The signatory countries of the Convention on Biological Diversity agreed to significantly reduce the rate of biodiversity loss by 2010. How will we know, however, if we have achieved this goal? Eight groups of hindrances in evaluating the global conservation status of threatened taxon are identified: (1) the extreme heterogeneity and (2) restricted availability of relevant data; (3) the uncertainty in species number and taxonomic division of the given taxon (Linnean shortfall); (4) the fragmentary distribution knowledge (Wallacean shortfall); (5) the incomplete or incorrect red-listing across the whole distribution area; (6) the lack of homogeneous and exhaustive population trend data; (7) the threat knowledge shortfall; (8) the incomplete general biological knowledge on a given taxon. The Linnean and Wallacean shortfalls lay the foundation of all other hindrances. So long as this dramatic shortfall situation does not change, the adequate assessment of the global status for overwhelming majority of extant taxa will remain a utopia.

Bayesian decision analysis for status of Snake River spring?summer Chinook salmon Oncorhynchus tshawytscha populations at extinction risk

The viability of populations was assessed using population trend data and the Diffusion Approximation (DA) model. Various extinction risk metrics for a population are functions of the DA model parameters, and thus, estimates of the DA model parameters are key quantities. Using Bayesian methods, we showed uncertainty in those estimates, and further proceeded to a decision analysis to assess viability of populations. These methods were demonstrated using population trend data from return years since 1980 on naturally produced Snake River spring-summer Chinook salmon Oncorhynchus tshawytscha populations. Of 19 populations examined, the Catherine Creek population was assessed at serious risk, Tucannon River Spring and Grande Ronde Upper Main stem populations were assessed at minor risk, and the other populations were not at risk. This assessment helps managers to prioritize populations at risk for recovery management.

Are population dynamics of shorebirds affected by El Niño/Southern Oscillation (ENSO) while on their non-breeding grounds in Ecuador?

Declines in avian populations are a global concern, particularly for species that migrate between Arctic-temperate and tropical locations. Long-term population studies offer opportunities to detect and document ecological effects attributable to long-term climatic cycles such as the El Niño/Southern Oscillation (ENSO). In this study, we report possible population-level effects of such climatic cycles on shorebird species that use two non-breeding season sites in Ecuador (Santa Elena peninsula area, near La Libertad). During our 9-year study period (1991/1992–1999/2000), there was a particularly strong ENSO warm phase event during 1997/1998. Population trend data for three species of shorebird, Western Sandpipers ( Calidris mauri), Semipalmated Sandpipers ( C. pusilla), and Least Sandpipers ( C. minutilla), indicated abundances generally declined during the 1990s, but there was an increase in the proportion of first-year birds and their abundance in the years following the 1997/1998 ENSO warm phase. There was some support for variation in apparent survivorship associated with the onset of the ENSO warm phase event in our population models, based on capture–mark–recapture data. Following the 1997/1998 ENSO event onset, individuals for all three species were significantly lighter during the non-breeding season ( F 1,3789 = 6.6, p = 0.01). Least-squares mean mass (controlling for size, sex and day of capture) for first-year birds dropped significantly more than for adults following ENSO (first-year mass loss = 0.69 ± 0.12 g; adult mass loss = 0.34 ± 0.11 g, F 1,3789 = 5.31, p = 0.021), and least-squares mean mass dropped most during the period when sandpipers prepare for northward migration by gaining mass and moulting into breeding plumage. Least Sandpipers may have declined the most in mean mass following ENSO (0.76 ± 0.19 g), whereas Semipalmated Sandpipers were 0.52 ± 0.12 g lighter, and Western Sandpipers 0.40 ± 0.13 g lighter, but overall variation among species before (1992/1993–1996/1997) and after (1997/1998–1999/2000) ENSO was not significant ( F 2,3787 = 1.52, p = 0.22). Anomalously warm and wet conditions associated with strong ENSO warm phases during the non-breeding season may either act directly on shorebirds (increasing metabolic demands) and/or indirectly through reductions in prey availability. Reduced mass and mass gain may explain lower survivorship, particularly in adults, which are more likely to migrate northward in the spring than are first-year birds, at least in Western Sandpipers. Our results suggest a potential mechanism selecting for life history strategies suitable for withstanding long-term fluctuating climatic cycles such as ENSO.

TREND ANALYSIS SHOWS DECLINE OF AN ENDANGERED THERMOPHILIC SPRINGSNAIL (PYRGULOPSIS BRUNEAUENSIS) IN SOUTHWESTERN IDAHO

Abstract We analyzed population trend data during 1991–2004 for the Bruneau hot springsnail (Pyrgulopsis bruneauensis) from rangewide hot spring surveys completed along 4 km of Bruneau River. The objectives of this study were to analyze population trends and assess other measured parameters, such as water temperature, specific conductance, and groundwater decline, for changes that may influence population trends. We used simple linear regression to determine significant relationships between measured parameters. Total numbers of hot springs surveyed in the 4-km reach are declining at a rate of ~5 hot springs per year, and numbers of hot springs containing P. bruneauensis in the same reach are declining at a rate of 3.75 per year. We found that the decline of hot springs with and without P. bruneauensis was significantly related to the decline of the thermal aquifer which underlies this area.

Using Time Series to Estimate Rates of Population Change from Abundance Data

Abstract: Assessing the dynamics of wild populations often involves an estimate of the finite rate of population increase (λ) or the instantaneous rate of increase (r). However, a pervasive problem in trend estimation is that many analytical techniques assume independent errors among the observations. To be valid, variance estimates around λ (or r) must account for serial correlation that exists in abundance data. Time series analysis provides a method for estimating population trends and associated variances when serial correlation of errors occurs. We offer an approach and present an example for estimating λ and its associated variance when observations are correlated over time. We present a simplified time series method and variance estimator to account for autocorrelation based on a moving average process. We illustrate the procedure using a spectacled eider (Somateria fischeri) data set of estimated annual abundances from aerial transect surveys conducted from 1957 to 1995. The analytic variance estimator provides a way to plan future studies to reduce uncertainty and bias in estimates of population growth rates. Demographic studies with policy implications or those involving species of conservation concern should especially consider the correlated nature of population trend data.

Declines in abundance and distribution of the ivory gull (Pagophila eburnea) in Arctic Canada

The ivory gull (Pagophila eburnea) is a seabird that inhabits Arctic oceans throughout the year, often in association with polar pack ice. It is rare (<14,000 breeding pairs globally) and remains one of the most poorly known seabird species in the world. Canada supports breeding populations of international significance, and residents of communities in the Canadian High Arctic currently observe fewer ivory gulls than they did in the 1980s. However, no population trend data existed for this species in Canada prior to this study. We initiated aerial surveys in July 2002 and 2003 of most known ivory gull colonies in Canada to assess current population levels. Forty two colonies were visited, 14 of which were new discoveries. We recorded an 80% decline in numbers of nesting ivory gulls. Several of the largest known colonies were completely extirpated and those that remained supported significantly fewer nesting birds than previously observed. Results were similar in both years despite some differences in local sea ice conditions, suggesting a numerical decline in the population and not simply annual fluctuations in colony occupation. Declines have occurred in all habitat types and across the known Canadian breeding range, suggesting that causes of the decline may be related to factors occurring during migration or on wintering grounds. We recommend that international efforts now be directed at assessing population status and trends of this species in other circumpolar countries.

Monitoring terrestrial mammals in the UK: past, present and future, using lessons from the bird world

ABSTRACT 1. A monitoring network for UK terrestrial mammals, the Tracking Mammals Partnership, is currently being set up to provide a coordinated programme to collect surveillance and monitoring data. 2. Monitoring UK mammals is important for a number of reasons including: setting conservation priorities; measuring the effects of conservation management; managing populations of problem species and the sustainable use of game species; assessing the effects of agriculture and other human activities; providing evidence for the need for policy change; and because of obligations under intergovernmental treaties and national legislation. 3. The bird world, largely but not solely through the work carried out by the British Trust for Ornithology, has provided a useful model for mammal surveillance and some important lessons in setting up and running a UK wide multispecies monitoring programme. 4. Lessons include the importance: of annual monitoring; of long‐term data sets of population indices rather than absolute population sizes; and of the use of volunteers in data collection. 5. Two scoping studies have been carried out to assess the feasibility and costs of setting up a mammal surveillance and monitoring network and the survey methods that could be used for different species. 6. The Tracking Mammals Partnership, comprising 23 organizations, has the remit of implementing the recommendations of the scoping studies. There are a number of programmes operating within the Partnership including the National Dormouse Monitoring Programme, the National Bat Monitoring Programme and the Breeding Bird Survey Mammal Monitoring. There are also a number of pilot schemes being tested. 7. Reports on the population trend data collected should enable more informed policy and management decisions concerning UK mammal species.

Success of the Army's 1996 red‐cockaded woodpecker management guidelines

AbstractIn 1996, the U.S. Army's guidelines for management of red‐cockaded woodpeckers were revised to reduce training restrictions and promote recovery. These seemingly opposed objectives in fact turned out to be mutually supportive. The type of open pine forest that constitutes good red‐cockaded woodpecker habitat also provides visibility and maneuver freedom that is suitable for many types of military training. Training restrictions have not been shown to be particularly important in promoting expansion of red‐cockaded woodpecker populations, but they are certainly a disincentive to installation commanders who must balance the requirement to comply with the Endangered Species Act (ESA) with the requirement to train soldiers to fight and win wars. This paper describes the circumstances that led to the revision of the Army's guidelines, the approach that was used, and a summary of the important changes between the former and the new management guidelines. Population trend data are also presented, and show that red‐cockaded woodpecker populations on Army lands are increasing, suggesting that the new guidelines are beneficial. Furthermore, all Army installations with adequate forested acreage are vigorously pursuing continued population growth to achieve recovery. Lessons learned from the process of revising the Army's approach to red‐cockaded woodpecker management are likely to have applications for other species, particularly on military lands. © 2003 Wiley Periodicals, Inc.