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Avian Conservation in Pacific Northwest Forests: Monitoring, Modeling, and Management. A Landscape-level Approach to Managing Landbird Populations in National Forests using MAPS Demographic Monitoring Data. Phil Nott, Nicole Michel, & Dave DeSante October 2007 Contribution XXX of
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Avian Conservation in Pacific Northwest Forests:Monitoring, Modeling, and Management A Landscape-level Approach to Managing Landbird Populations in National Forests using MAPS Demographic Monitoring Data Phil Nott, Nicole Michel, & Dave DeSante October 2007 Contribution XXX of The Institute for Bird Populations PO Box 1346, Point Reyes Station, CA 94956
Introduction In 1992, The Institute for Bird Populations (IBP) established a network of 36 MAPS demographic monitoring stations (red triangles) across six USDA Forest Service national forests in Oregon (4) and Washington (2). IBP has since operated the monitoring network annually during the breeding season. In 2001, however, the ten-year baseline monitoring dataset was analyzed to determine a) the background values of demographic parameters (e.g. birth and death rates) and b) species-habitat relationships at landscape scales (1000’s of hectares). From these relationships we developed decision-support tools for management decisions regarding breeding landbird populations. Since 2004, six stations in the USFS Region Six MAPS monitoring network have been relocated to conduct effectiveness monitoring of management actions and provide validation data.
Adaptive Management Cycle • Demographic monitoring of birds breeding in national forests of the Pacific Northwest is part of an adaptive management approach: • Monitor annual numbers of adults and young by banding • Quantify demographic parameters (survival and productivity) • Quantify population changes and identify target species • Model species-landscape relationships for target species • Plan management actions designed to improve breeding habitats • Manage the landscape according to the avian conservation goals • Monitor the effectiveness of management plan in achieving goals • Adjust or alter the management plan in an adaptive framework.
Baseline Demographic Monitoring The Region Six MAPS program has trained ~200 intern banders and has involved ~25 field biologists in 16 years IBP conducted baseline demographic monitoring (1992-2001) to quantify demographic parameters and identify proximate causes of population change and source-sink dynamics (see Van Horne 1983). Demographic monitoring is consistent with Level 3 monitoring as described in “USDA Forest Service (USFS) goals and programs for monitoring Neotropical migratory birds (NTMB), RMRS Gen. Tech. Rep. RM-229: 272:274” such that vital rates can be obtained. Analyses provided survival rates and reproductive indices which can subsequently be used as forest “performance measures.” Using this approach we effectively monitored 21 species including 13 species of regional concern. Van Home, B. 1983. Density as a misleading indicator of habitat quality. J. Wildl. Manage. 47:893-90
Species of Management Concern:Survival Performance Measures • A total of 21 species were effectively monitored such that reliable (CV<30%) estimates of annual survival rate were obtained. • Of these, 13 species (listed above) were recognized as species of management concern (including eight Neotropical migrants). • Overall, eight of 12 survival rate estimates exceeded the Northwest regional estimate by up to 8% (and a mean of 4%).
Species of Management Concern:Reproductive Performance Measure • A total of 21 species were effectively monitored such that reliable (CV<30%) estimates of annual survival rate were obtained. • Of these 21 species 13 were recognized as species of management concern (including eight Neotropical migrants). • Eight of the 13 estimates exceeded the Northwest regional estimate (<+8%; mean 4%).
Species – Landscape Models • Using the principles of landscape ecology, we analyzed landscape characteristics in the vicinity of MAPS stations. Such analyses included the following five GIS datasets: • USGS National Land Cover Dataset (NLCD 1992), • USFS Region Six forest canopy cover (raster), • USGS National Elevation Dataset (NED), • StreamNet - 1:100,000 Pacific Northwest hydrography , and • USFS Forest Health Protection Aerial Survey (vector). • These station-specific spatial data were combined with species- and station-specific demographic data derived from our MAPS data.
Management Planning Scenario 1 : Clearcut Douglas Fir stands >60 years old. Scenario 2 : 20% thinned to reduce fuel load. GIS simulations of proposed management provide data to species-landscape models. • The species-landscape models can be used to predict the effects of • alternate management scenarios on a suite of target species. • simulate the proposed management scenarios in GIS • analyze the patterns to obtain a new sets of spatial statistics • populate the models with variable values from each scenario • obtain predictions of the expected numbers of birds. • However, although a management action may improve the breeding potential of the habitat for some species it may reduce the breeding potential for others. In the example above, Scenario 1 benefits Winter Wren populations, while Scenario 2 has a strong negative effect upon Wilson’s Warbler demographics (esp. numbers of young).
Management Implementation A number of different forest management techniques may impact bird populations by altering their breeding and foraging habitats: Clear-cutting – removes canopy and understory habitats and interior forest birds are replaced by successional habitat specialists. Thinning – of old-growth forest appears to benefit some bird populations but the effects vary regionally and by factors such as forest type and health. Fire – prescribed burns also tend to thin the forest and although they immediately benefit cavity-nesting species, little is known about the response of ground- or shrub-nesting species to burns. Pest Control – pesticide application may prevent or reverse forest canopy damage but may be toxic to birds and reduce their prey availability in the year of application.
Swainson’s Thrush : Predicted Response to Management 1.4 Thin 1.2 Control 1 0.8 Adult numbers 0.6 0.4 0.2 0 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 Year Effectiveness Monitoring Management Implementation Following implementation of management plans effectiveness monitoring should be continued to assess the efficacy of these plans in meeting avian conservation objectives. By comparing effectiveness monitoring data with control station data it is possible to quantify the size and direction of effects upon population size and reproductive success. Average body condition (body mass/wing chord) is another indicator of population health. Healthy birds and high productivity are considered typical of source populations in which, on average, the numbers of young produced in a year exceed the numbers of adult deaths and so the excess of young individuals can disperse to other areas. This is the ultimate goal of avian population management. Since 2004 six of the 36 MAPS stations were relocated to thinned areas of different ages but of similar aspect and elevation.
Research Success Stories USFS Region Six MAPS data have been used in multiple research projects: • Contributed to Avian Conservation Node of the USGS National Biological Information Interface by documenting Northwest US regional survival estimates(1992-2003)for 81 landbird species, of which 68 estimates were reliable. • Michel, N., DeSante, D.F., Kaschube, D.R., and Nott, M.P. 2006. The Monitoring Avian Productivity and Survivorship (MAPS) Program Annual Reports, 1989-2003. NBII/MAPS Avian Demographics Query Interface www.birdpop.org/nbii/NBIIHome.asp • Estimated survival rates for 21 species breeding in six national forests of USFS Pacific Northwest Region Six and demonstrated their use as habitat performance measures. • Quantified species-landscape models from which land management guidelines were formulated for 13 species of conservation and management concern. Nott, M. P., D. F. DeSante, P. Pyle, and N. Michel. 2005. Managing Landbird Populations in Forests of the Pacific Northwest Region. Publication No. 254 of The Institute for Bird Populations http://www.birdpop.org/publications/NWFExecReport.pdf Nott, M. P., D. F. DeSante, P. Pyle, and N. Michel. 2007. Demographic Monitoring, Modeling, and Management of Landbird Populations in Forests of the Pacific Northwest : an Application of the MAPS Dataset. USFWS Biological Technical Series (in press). Contribution No. 327 of The Institute for Bird Populations. Quantified species-climate models based on indices of El Niño and North Atlantic activity that explain between 50% and 90% of annual variation in reproductive success. Nott, M.P., DeSante, D.F., Siegel, R.B., and P. Pyle. 2002. Influences of the El Niño/Southern Oscillation and the North Atlantic Oscillation on avian productivity in forests of the Pacific Northwest of North America. Global Ecology and Biogeography 11:333-342. PDF (411KB) Read more about this study of climate and birds All USFSR6–MAPS Publications: www.birdpop.net/publications/USFSR6
Hermit Warbler Dendroica occidentalis North Atlantic Influence ENSO Influence Oceanic Influences on Neotropical Migrants Neotropical migrants and resident birds of the Pacific Northwest experience the influences of two major oceanic phenomena (Nott et al. 2002). Variation in the activity of the Atlantic Ocean affects all northern latitudes including the Pacific Northwest. Neotropical migrants also experience the influence of the El Niño Southern Oscillation (ENSO) of the Pacific Ocean, which more strongly influences southern latitudes than northern latitudes. Migrants face the influence of ENSO on both stopover habitats and winter habitats. Nott, M.P., DeSante, D.F., Siegel, R.B., and P. Pyle. 2002. Influences of the El Niño/Southern Oscillation and the North Atlantic Oscillation on avian productivity in forests of the Pacific Northwest of North America. Global Ecology and Biogeography 11:333-342.
Birds and Climate : El Nino Nott et al. 2002 revealed strong relationships between the El Niño Southern Oscillation (ENSO) phenomena and Neotropical migrant birds of the Pacific Northwest. Neotropical Reproductive Success In El-Niño winters more rainfall is experienced in western Mexico prior to the springtime migration of many Neotropical migrants that breed in the Pacific Northwest. ENSO Precipitation Index 92 94 96 98 00 Higher rainfall may mean more food resources, a higher leaf area index, consequently more shade, and milder conditions. Milder, wetter conditions are likely less physiologically stressful and therefore beneficial to the state of birds about to migrate back to the Pacific Northwest. Consequently, upon their return to the breeding grounds, a pair of birds can produce larger clutches of healthier chicks. Thus, productivity is higher in El Niño years
Birds and Climate : North Atlantic Nott et al. 2002 also revealed strong relationships between the North Atlantic Oscillation (NAO) and “year round” bird populations of the Pacific Northwest. When the North Atlantic oceanic oscillation (NAO) is in its positive phase (warm-phase NAO) the Pacific Northwest experiences a warmer and drier springtime. More overwintering invertebrates, especially Western Spruce Budworm and Douglas-Fir Oak Tussock Moth, survive to initiate earlier, more intense, forest insect outbreaks. Milder winters and an abundance of food benefit bird populations by allowing adults to gain a high physiological state and be in better condition for breeding. Consequently, a pair of birds can produce larger clutches of healthier chicks. Thus, productivity is higher in warm-phase NAO winters.
MAPS Period Forest Pests or Bird Food? Although forest pests such as Western Spruce Budworm (above left) and Douglas-Fir Oak Tussock Moth (inset) can damage timber values they are also a major source of food for breeding birds and their fledglings. 8 DEFOI 6 Reproductive success of resident birds ------------- 4 INDEX 2 0 NAOI -2 1980 1985 1990 1995 2000 The Forest Health Protection unit of USFS Pacific Northwest annually map the extent and severity of outbreaks and thus provides geospatial data with which to compare climate indices and demographic variables derived from MAPS data. The data strongly suggested that the North Atlantic Oscillation drives insect populations and, in turn, the reproductive success of many bird species.
Benefits to the Forest Service The collection and analysis of avian demographic data from MAPS monitoring stations that operate in Pacific Northwest Region Six benefits avian conservation efforts in the USDA Forest Service. Specifically it: • Complies with federal conservation acts to promote and maintain healthy migratory bird populations • Addresses regional monitoring and research requirements for 21 species of conservation concern • Demographic monitoring complies with USFS level 3 monitoring objectives (i.e., quantifying vital rates and source-sink dynamics) • Allows identification of proximate demographic causes of population decline (e.g. poor survival rate or low reproductive success) • Provides decision-support tools for management of multiple bird species to maintain or create “source” habitat • Monitors the effects of land management (“effectiveness monitoring”) in an adaptive management cycle • Increases understanding of bird ecology in forested and successional habitats of Pacific Northwest forests • Tracks responses of avian populations to annual climate and weather variation.