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Bird Conservation in the Hudson River Valley

Hudson Valley Habitat Management Decision Tree (for managing bird habitats)

Who Should Use this Decision Tree?
In general, this decision tree is for properties at least 5 acres in size and in mostly rural, natural settings. In some special cases it could apply to smaller properties, e.g., where a 3-acre patch within a large forest might be managed for early-successional forest habitat. This decision tree does not apply to suburban or urban areas.

Introduction

The suitability of a specific property for breeding birds is determined by both the habitat conditions of the property itself and the habitat conditions of the landscape surrounding the property.  There is a tremendous amount of scientific literature about the habitat requirements of individual species as well as groups of species, e.g., mature forest birds, and growing bodies of literature demonstrating that many species are area-sensitive (i.e. they need large patches of habitat to reproduce successfully) and that the composition of the surrounding landscape also matters.  Recent research also shows that birds use different types of habitat at different times in their life cycles, e.g. many mature forest breeders use early-successional forest habitat after breeding but before migrating.  Not surprisingly, there is not perfect agreement among the research findings in this field, but certain patterns and consistencies have begun to emerge.  For example, several grassland birds generally do not nest successfully in grasslands that are smaller than 50 or 100 acres, and they do better in landscapes dominated by open habitats, even if not all of those habitats are suitable grasslands.  Similarly, many forest birds do best in landscapes dominated by forest, even if they choose to nest in a relatively small patch of forest in that landscape.  Collectively, this is far too much information for most landowners and managers to take into consideration when deciding how to management their property.  Those bodies of research and those emerging patterns have been synthesized to create this decision tree to help landowners who want to help birds.

This decision tree is meant to provide general guidance to landowners and land managers interested in managing a property for birds of conservation concern.  It recognizes that the decisions made by individual landowners may impact the habitat quality of their neighbors’ properties for better or for worse, and vice versa.  This decision tree is meant to improve the value of a landscape to birds by advising the management of individual properties.  It will steer management away from maintaining small, isolated grasslands in largely forested landscapes (which do not benefit grassland birds and contribute to fragmenting forests) and promote creating and maintaining grasslands in largely open landscapes.  It also will help maintain a desired range of early-successional forest habitats within a forested landscape, which is beneficial to forest-breeding birds and also migrating birds in spring and fall.

This decision tree directs land managers to reasonable management options.  For example, a property located within an open landscape could provide high quality grassland bird breeding habitat, but if the property is currently forested, it would be very intensive to convert it to grassland and this decision tree would not direct a land manager to clear a forest to create grassland habitat.  Ultimately, the recommendations of this decision tree should be evaluated with several other considerations before making a final management decision, for example, landowner objectives and comfort level, aesthetics, soils, slopes, hydrology, the presence of invasive species or pests and state or federally listed species.  We recommend that land managers and landowners using this decision tree consult with their state wildlife agency or Natural Heritage Program to inquire as to whether or not there are likely to be unique considerations regarding the management of their property, such as the presence of state-listed species or rare ecosystem types that may call for special management practices.  If, for example, a high-priority mature forest species like Cerulean Warbler is using one’s property, it should be managed for Cerulean Warbler even if the decision tree suggests that early-successional forest habitat should be considered as a management objective.

How to use a decision tree

A decision “tree” consists of a series of questions, the answers to which lead one from a starting point to a solution (in this case, a recommendation).  The questions generally have only two or three possible answers, and so they are like “branches” of a tree leading away from the trunk.  At each question, the user determines which branch to follow until the final recommendation is reached.  To use this decision tree, start with Step 1 below and follow the answers to the questions through to the end, which is a suggestion for how you might consider managing your property to help birds of conservation concern.

Step 1: Determine what type of “landscape” surrounds your property.
Landscape is defined as a 2,500-acre block (approximately 1,000ha, 4mi², 10km²; or a block measuring 2mi x 2mi, 3.2km x 3.2km, or 3200m x 3200m) centered on and surrounding the property to be managed.  Property is defined as the area to be managed as one unit; it may not include all of the land you own in the area, even if those lands are adjacent to each other. If the property you want to manage is composed of two types of habitat, treat them separately when using this decision tree. For example, if you are interested in managing 100 acres and 70 acres are forested while 30 are old field, then you should consider those as two separate units and work through the decision tree for each one separately. If the property is 2,500 acres or more, then your property is also the landscape.  Use Google Earth, Google Maps, MapQuest, or a topo map to determine what proportion of the landscape is in forest.  Urban, industrial, agricultural, and other such areas are considered non-forest. Suburban areas generally are considered non-forest, unless the houses are scattered widely in a forested area, in which case they are considered as forest.

Is the landscape <50% forested, that is, Primarily Open?
Is the landscape between 50% and 70% forested, that is, Mixed?
Is the landscape >70% forested, that is, Primarily Forested?

Use these images below to help you place the landscape into one of those categories:

50%	70%

Click here to see an example of how to answer the above questions regarding your landscape.

Step 2: Based on the landscape you determined in step one above, select your landscape:

Primarily Open
Mixed
Primarily Forested