Petroleum Crude Oil Utility Index

A. EXPOSURE POTENTIAL
1. Time spent on or in water
5—Nearly always
4—Most of the time
3—Half of the time
2—Less than half of time
1—Seldom or never

2. Escape behavior
5—Dives
4—Swims, but sometimes dives
3—Swims
2—Flies, but sometimes swims
1—Flies

3. Primary foraging technique
5—Dives or is submersed in water
4—Dabbles in water
3—Probes mud or stalks
2—Skims surface of water
1—Does not forage in water

4. Preening or grooming behavior
5—Preens or grooms feathers or fur
1—Does not preen or groom

5. Exposure of eggs
5—Eggs laid in water
4—Eggs laid near water
3—Eggs laid away from water, transfer from adult likely
(e.g., waterbirds)
2—Eggs laid away from water, transfer from adult not
likely (e.g., turtles, terrestrial birds)
1—Does not lay eggs or does not breed in study area

6. Use of urbanized areas or shipping channels
5—Readily inhabits and/or forages in these areas
3—Occasionally utilizes these areas
1—Avoids these areas

B. GEOGRAPHIC OCCURRENCE
1. Range
5—Present throughout entire study area
4—Present throughout more than half of study area
3—Present throughout about half of study area
2—Present throughout less than half of study area
1—Present in small part of study area only
2. Residency
5—Year-round resident (does not migrate)
4—Migrates within study area
3—Migrates beyond study area (present during breeding)
2—Migrates beyond study area (present during winter)
1—Transient (present during migration only)

C. EASE OF COLLECTION
1. Social structure
5—Highly colonial or gregarious
3—Semi-colonial or semi-gregarious
1—Solitary

2. Accessibility of sampling unit
5—Individuals or nests are easily accessible
3—Individuals or nests are moderately accessible
1—Individuals or nests are difficult to access

3. Ease of capture or trappability
5—Easy to capture or trap
3—Moderate
1—Difficult

4. Abundance in study area
5—Abundant (Numerous in suitable habitat)
4—Common (Certain to be in suitable habitat)
3—Uncommon (Presence expected, but not a certainty)
2—Occasional (Presence possible, but not expected)
1—Rare (Not normally present)

5. Federal or state management status in study area
5—Not protected
4—Protected (managed population)
3—Threatened
1—Endangered

D. QUANTITY OF EXISTING EXPOSURE AND
EFFECTS DATA
5—Substantial data
3—Some data
1—Very little data