Leopold-Pine Island IBA: Detailed Stewardship Recommendations

LEOPOLD-PINE ISLAND IMPORTANT BIRD AREA

DETAILED STEWARDSHIP RECOMMENDATIONS

MICHAEL J. MOSSMAN

YOYI STEELE

STEVE SWENSON

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TABLE OF CONTENTS

TABLE OF CONTENTS

INTRODUCTION

AXIOMS OF BREEDING BIRD MANAGEMENT

SPECIFIC MANAGEMENT GUIDELINES FOR INDIVIDUAL SPECIES AND SPECIES GUILDS

Henslow's Sparrow

Grasshopper Sparrow

Field Sparrow

Red-headed Woodpecker

Willow Flycatcher

Emergent marsh bird community

Forest bird community

SPECIFIC MANAGEMENT GUIDELINES FOR INDIVIDUAL TRACTS WITHIN THE IBA

Phill and Joan Pines Tract

Leopold Memorial Reserve

Pine Island State Wildlife Area

Baraboo River Waterfowl Production Area

Lower Baraboo River Floodplain Forest

INFORMATION NEEDS

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INTRODUCTION

This document represents the latest step in the ongoing process to effect bird conservation on the 15,000 acre Leopold-Pine Island Important Bird Area (LPI IBA), along the Wisconsin and LowerBarabooRivers in south-central Wisconsin. This process began with the initial identification of the potential IBA based on incomplete available information, proceeded through the design and accomplishment of a thorough inventory and monitoring baseline, the analysis and evaluation of the inventory data, identification of an appropriate IBA boundary, formal IBA approval and dedication, and extensive data interpretation and meetings withthe diversepartners responsible for managing the various tracts (Table 1) within the IBA. This culminated in 2009 with AStrategic Vision for Bird Conservation on the LPI IBA, which describes the IBA and its breeding avifauna, identifies bird and habitat priorities, and suggests management priorities for individual tracts. This current stewardship document follows the Strategic Vision and additional conversations with land managers, and makes more specific goals and recommendations for tract-specific management that we hope integrate goals of both the IBA and the individual tracts, which are managed by various public agencies and private owners. We also hope that it furthers the process of adaptive management by whichpriority-setting, planning, management and evaluation are integrated and evolve for the benefit of the birds and plant-animal communities of this unique and significant IBA, as well as benefiting the people who manage and appreciate it.

Table 1. Tracts within the Leopold-PineIslandIBA.

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The Strategic Vision emphasizes a mosaic of open and semi-open communities, especially native and surrogate grasslands, shrub communities, marshes, savannas and barrens, and limited areas of floodplain forest. Specifically, it states:

…this IBA’s best contribution to bird conservation lies with the more open-country habitats, particularly grassland, shrub, and savanna communities. Management and restoration activities should focus on expanding these habitat types. Marsh communities are well-represented in some portions of the IBA and support a diverse bird assemblage, including several Priority Species; these communities should be maintained and restoration opportunities pursued. The forest communities in the IBA also support several Priority Species; however, opportunity for those species is significantly higher at other sites farther downstream along the Wisconsin River and throughout the Driftless Area. Forest habitats should be maintained but not be targeted for restoration or additional management, except perhaps in the LowerBarabooRiverFloodplainForest, which needs more evaluation.

Overall, our process recognizes the following lowland habitat associations as highly significant for management in the Leopold-Pine Island IBA floodplain: Black Oak Forest, Shrub Carr, Native Grassland, Oldfield, Marsh and Grass Hay. Highly significant upland habitat associations include Cutover or BurnedOverForest, Shrubby and Non-shrubby Oldfield, Native Prairie and Grass Hay. Upland and lowland Savanna and River Barrens have high potential significance if expanded (p. 36).

Of the IBA’s 117 breeding bird species (the Strategic Vision documented 116, but subsequent surveys in the LBRFF have added Prothonotary Warbler), 24 are identified as Priority species(Table 2) on the basis of high regional conservation priorities and the ability to inform management on the IBA. The Strategic Vision stopped short of setting population goals for any species but identified tract-specific opportunities and management needs that would best contribute to the overall value of the IBA for Priority birds and the plant-animal communities they represent.

Table 2. The 24 Priority Species with moderate or high opportunity to inform management decision-making at the Leopold-Pine Island IBA by broad habitat category.

In the remainder of this stewardship document, we first describe some general “axioms” that may serve as useful habitat management guidelines across all tracts, then guidelines for a selection of Priority Species (including population goals) and habitat guilds. This is followed by a fairly detailed treatment of species and habitat priorities for each tract, which we have divided into tentative management units, and suggested management actions. We end with a list of information needs.

We expect that the priorities and recommendations described in this report will be modified as the IBA’s community of partnerscontinues managing the land, evaluating the results, considering new information and opportunities, and working to mesh objectives of the varied programs and principles that guide management on individual tracts. Regardless of these inevitable changes, we hope that this community nurtures and actively pursues its commitment to “a whole that is greater than the sum of its parts”, and by so doing, helps the LPI IBA realize its full conservation potential.

AXIOMS OF BREEDING BIRD MANAGEMENT

• Management for birds should be considered within the context of management for entire plant-animal communities:Bird-related goals for this IBA are not meant to trump broader goals for the complex ecosystems of which they are part, but rather to complement them. The constellation of Priority bird species was chosen partly for its ability to indicate ecosystem health, e.g., to reflect the range of conditions that suit not only these species but other plant and animal species as well, and most of our recommendations are community-oriented. Priority bird populations can be used to help gauge the success of community management goals, but only in addition to other indicators such as population monitoring data for other priority plant and animal species, species lists, etc. We encourage explicit objectives for non-bird species, and consider it a welcome challenge to integrate them with those of the IBA. In some cases, management to benefit an entire community or its other priority components may modify management recommended specifically for a priority bird species, e.g., where prescribed fire regimes must be adapted to accommodate fire-sensitive grassland species, including rare herptiles and insects such as Regal Fritillary.
• Size matters:Bigger blocks of habitat are better than small blocks, because they are managed more efficiently, they provide for bird species that may be sensitive to edge or area effects, and they accommodate natural variation in site characteristics and diverse habitat structure. This IBA is naturally quite varied in site, exposure, topography, hydrology and history, and large habitat patches are not always practical or desirable, nor should we expect or desire an unvaried structure within large management units.
• Connectivity matters: When possible and practical, blocks of similar habitats should be connected rather than separated by dissimilar habitats; for example in areas where forest is high priority, it will be improved by foresting or reforesting interior openings, or fields that separate nearby woods. Important open grasslands should not be separated by tree rows or hedgerows, or interrupted by isolated woodlots. When considered important, corridors between blocks of similar habitat should be widened. This general rule should be balanced by the fact that many habitats in this IBA are naturally fragmented, and always the challenge is to create the balance that best accommodates site characteristics and the needs of Priority species.
• Context matters: A habitat surrounded by physically similar habitat is of more value than a habitat surrounded by a physically dissimilar habitat. For example, a 20-acre block of sparse grassland will be much better for Grasshopper Sparrow if it is surrounded by denser grassland than if surrounded by shrubs or trees, even though in each case the surrounding habitat is inappropriate for Grasshopper Sparrow. The surrounding grassland also has the advantage that it may accommodate species like Eastern Meadowlark that use both sparse and thick grassland structures. Some habitats naturally often occur in small blocks surrounded by rather dissimilar habitats, and certain bird species birds are adapted to this situation; for example small (<1 acre) savannas surrounded by grassland can provide excellenthabitat for Eastern Meadowlark and Red-headed Woodpecker, while small (<0.25 acre) patches of shrubs surrounded by grassland or marsh can be very appropriate for Willow Flycatcher.
• Temporal and spatial dynamism: Specific habitat types, their distribution and abundance are in a constant state of flux. Under appropriate management, populations of some Priority bird species will move around the IBA over time. The important result is long-term population levels across the entire IBA. This is most obviously the case for species that prefer habitats that are typically short-lived at certain successional stages, for example woody growth in grasslands, sparse vegetation at the early stages of prairie restoration, or shrubby forest openings. Slower changes are to be expected in the dynamics of other communities or habitat features such as the development of woodland or savanna structure, old-growth characteristics, supercanopy white pines, oak regeneration, etc. Hydrological variations (e.g., associated with drought cycles and flood events) also contribute to this dynamic across the IBA.
• Match management goals with site, landscape and ownership limitations and opportunities:This common theme is to be assumed in setting management goals for all communities, bird species specific properties and management units within the IBA. Theart of balancingboth science and practicality is essential if management is to succeed without wasted time and effort, or unneeded conflict. For example, an area such as the Baraboo River WPA, already dedicated to providing waterfowl nesting and migration habitat, provides excellent opportunity for Priority birds of hemi-marsh and grassland; the private Pines Tract presents options for cattle grazing not likely to occur on Public or NGO lands, and this presents excellent possibilities for grassland habitat suitable for species that prefer short and sparse grass-forb cover; the Leopold Memorial Reserve is naturally fragmented by its mosaic of hydrological, soil and historical characteristics, and has an existing goal, history and expertise to create and manage native plant-animal communities, so a natural mosaic of marsh, shrub and savanna communities is especially appropriate and probably more likely to succeed here than elsewhere in the IBA.
• Gradual ecotones are of more value than hard or sharp transitions between habitat types, especially when these follow natural transitions in substrate, hydrology etc. This often provides habitat for species that may find their best habitat opportunities in these ecotones (e.g., Willow Flycatcher, Blue-winged Warbler), as well as often being suitable for birds whose breeding territories extend mostly into one or the other adjacent habitat. Moreover, gradual ecotones allow individual plant species and communities to shift or migrate readily in response to changing conditions such as hydrology and climate, both of which can be expected to continue in the near and distant future. For example, we generally recommend “feathered” or gradual, “soft” borders between open grasslands and forest tracts, e.g., a 10-30m-wide band of shrubs or scattered trees.
• Woody cover in open grasslandssuch as sedge meadow, prairie, and oldfieldshould be scattered or clumped, less than 15% cover, and ephemeral. Linear woody cover is undesirable because it fragments open grasslands and serves as a pathway for predators and an inroad for competitors of forest edge. Shrub-loving birds on the IBA Priority list and SGCN do well among scattered shrubs or shrub patches (e.g., Willow Flycatcher), or in shrubby forest openings (e.g., Blue-winged Warbler), and do not rely on hedgerows. Scattered woody cover should be considered ephemeral in the sense that shrub or seedling growth is likely to increase in areas between fire or cutting events, or where fire is incomplete; but these should be controlled before they become so widespread or strongly rooted, that they interfere with grassland management. Thus it is likely that woody growth will come and go at specific spots in a grassland over the course of many years, and that the pattern of this patchiness will constantly change as management, succession and site characteristics interplay. Exotic woody growth should not be tolerated.
• Savanna structure can be variable, with 5-30% canopy cover, most of it from mature, open-grown fire-resistant trees, primarily oaks, and 0-30% total shrub and sapling cover. As with the open grassland, the low woody cover should be considered ephemeral, but some stems should survive to replace canopy trees. Savanna pasture, if not overgrazed, can provide valuable habitat, especially if it helps create or maintain an open ground layer.Savannas are generally more valuable for Priority birds if adjacent to some grassland.
• “Surrogate” (non-native) communities can have high or low values to priority birds, depending on management:In general, the types of active agriculture that provide appropriate habitat for Priority and other breeding birds include low- to moderate-intensity pasture and late-cut hay. Row crops provide nonesting habitat, and very little foraging habitat (mostly for turkeys, cranes and blackbirds), and is best if no-till; alfalfa is a breeding bird sink because nest attempts almost always fail due to frequent cutting;grass or grass-legume hay provides good breeding habitat if cut only after July 15;small grains provide marginal nesting habitat at best (if harvested after July 15)and may provide marginal feeding habitat to birds that nest in secure nesting habitat nearby. On the other hand, many grassland and shrub habitats dominated by non-native ground cover or simplified mixtures of native grasses can be extremely valuable to Priority birds: oldfields at various stages of woody invasion; warm-season CRP or “duck-nesting” cover; and unmowed former hay or pasture.

• Exotics are an ongoing and significant issue on all properties of the IBA, although more so in some Units than others. The effect may be direct and immediate (e.g., by quickly creating simple monotypic stands suitable for only a few bird species), or more gradual and long-term (e.g., thick shrub growth limiting establishment of tree seedlings in forest stands); in either case, extreme or widespread invasions can limit future management options. Often, if exotics can be maintained as a minor component of a community, the effect on Priority and other breeding birds is minimal. Although the list of significant exotic invasives is long for the IBA, the most critical are:
• Reed canary grass invasion dramatically simplifies and deteriorates habitat for grassland birds and waterfowl, more so when it becomes dominant than when it remains mixed with native grasses, sedges and forbs. Monotypes are most likely in situations such as drained muck soils, sites repeatedly silted-over with fertile agricultural run-off, and where invasion is longstanding, and in these areas drastic control or conversion measures may be needed. In areas that still retain significant native herbaceous cover, reed canary grass may be kept in check with burning. This species is especially critical to control in newly established prairie or grass plantings, as well as in floodplain forests where it already occurs and the canopy is further opened by harvest or savanna restoration; in such forest sites, harvest may be ill advised, especially if fire cannot be used to control invasion afterward.
• Buckthorn, honeysuckle and garlic mustard are major threats to upland and floodplain forests and their edges, and active control is essential for the long-term health and regeneration of nearly all forested tracts in the IBA.
• Narrowleaf cattail and phragmites can form monotypic stands, preclude native emergent marsh plants, and produce a depauperate bird fauna dominated by a few species such as Red-winged Blackbird and Marsh Wren. Even though the latter species is High Priority in the IBA, its populations can be maintained by native vegetation such as native cattail and river bulrush, which tend not to from dense, extensive, monotypic stands and thus provide for more bird species.

• Maintaining open (grassland, marsh) and semi-open (savanna, barrens, shrub carr) habitats can be done with a variety of methods, including timber harvest, mechanical removal, chemical treatment, cultivation, mowing, grazing, and spring and fall burning. Bird species vary in their habitat needs, and thus respond differently to extent and density of woody cover, thatch accumulation, forb vs. grass cover, and herbaceous height and density, etc., and thus to different types and intervals of disturbance. Some important examples are described in the following section on Specific Management Guidelines. At a given site, target plant communities and bird species should fit with site characteristics and with management constraints and opportunities.
• River corridor management involves minimizing human disturbance during Sandhill and Whooping Crane migration in October-November, especially at traditional roosting areas.

SPECIFIC MANAGEMENT GUIDELINES FOR INDIVIDUAL SPECIES AND SPECIES GUILDS