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IBA
Criteria
Important
Bird Areas, or IBAs, are sites that provide essential
habitat for one or more species of bird. To qualify as
an IBA, sites must satisfy at least one of the following
general criteria.The
site must support:
- Species
of conservation concern (e.g. threatened and endangered
species)
- Restricted-ranges
species (species vulnerable because they are not widely
distributed)
- Species
that are vulnerable because their populations are concentrated
in one general habitat type or biome
- Species,
or groups of similar species (such as waterfowl or shorebirds),
that are vulnerable because they occur at high densities
due to their congregatory behavior
IBAs in Michigan are identfied
through a process of scientific review by the Michigan
IBA Technical Committee,
consisting of ornithologists, birders, and experts throughout
the state. IBAs are further prioritized as Global and
Continental IBAs by the U.S. IBA Committee, in coordination
with the national IBA office.
In Michigan, we have been
identifying the highest priority Important Bird Areas
in the state, using the Global
and Continental IBA Criteria.
State-level IBA Criteria
for Michigan are described below.
The Michigan Important
Bird Areas Program, through the guidance and input of
state and national staff and the Michigan Important Bird
Areas Technical Committee, developed state level criteria
and thresholds applicable to the avifauna and habitats
found within Michigan. These state level criteria are
formulated to best suit the population levels and habitat
conditions in Michigan and are defined as follows;
|
D1
|
State
Species of Conservation Concern |
|
D4i
|
Top 3-5
sites or 1% of state population |
|
D4ii
|
2,000
Waterfowl (excluding Mallard and Canada Goose) |
|
D4iii
|
100 Wading
birds |
|
D4iv
|
2,500
Gulls (nesting pairs only) |
| D4iv |
25 Terns
(nesting pairs only) |
| D4v |
500 migratory
shorebirds daily |
| D4vi |
1,000
migratory raptors per season |
| D4vii |
exceptional
landbird migration |
1. Michigan Species of
Conservation Concern (D1) - includes species recognized
by the Michigan Department of Natural Resources (MDNR
2011) as endangered or threatened, those recognized by
the Michigan Natural Features Inventory (MNFI) as special
concern, and species on the Audubon WatchList (National
Audubon Society 2011). Specific thresholds are defined
for each species (See
IBA Methodology document).
2. Michigan Congregations
(D4) - sites supporting outstanding congregations (see
Table 1 for details).
Additional Criteria The
Michigan technical committee considered three additional
criteria:
1) Assemblages of regionally-restricted
species. This criterion, which has been implemented in
New York, recognizes sites which support a large number
of species which don't qualify as conservation concern
species under D1, but for which Michigan bears responsibility
for their global conservation, because a significant proportion
of the species global population occurs within the state.
This analysis was halted due to the decision that it was
unlikely to result in a significant number of new IBA
sites, and because the quality of datasets necessary to
justify the requisite spatial analysis was lacking for
Michigan
.2) Landbird Stopover
Concentrations. This criterion, a subcriterion of the
state congregation criterion, has proven difficult to
apply objectively. As a result, no other state IBA program
has been able to implement it. However, the preponderance
of Great Lakes coast magnifies the importance of this
criterion to our state, as shorelines are known to greatly
concentrate landbird migrants. Unfortunately, the lack
of quantitative data consistently documenting not only
presence, but also absence, of landbird concentrations,
makes the application of this criterion highly arbitrary
and subjective. That said, significant advances have been
made by D. Ewert et al., and the committee anticipates
attempting a "first run" of stopover sites once more data
are forthcoming from several ongoing studies.
3) Long-term research
sites. Historically several states have recognized as
IBAs sites where long-term bird monitoring studies are
ongoing. Data from such sites may be valuable toward estimating
population and demographic trends of many species. The
committee argued that such sites would detract from the
robustness of the IBA network since they didn't meet one
of the main IBA criteria, and that such research sites
should be protected by other means. Across the Important
Bird Areas Program this criteria has been discontinued.
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