Lead Vulnerability Index

A. EXPOSURE POTENTIAL
1. Primary foraging technique
10—Dives under water, feeds off bottom
8—Dabbles under water, feeds off bottom
7—Ground gleaner
5—Probes below surface, long bill length (>5 cm)
4—Probes below surface, short bill length (<5 cm)
1—Does not feed in any of these manners

2. Dietary preference
5—Predator or scavenger of (waterfowl)
3—Predator or scavenger of other game species
1—Does not feed in this manner

3. Use of hunted areas
5—Readily inhabits or forages in hunted areas
3—Occasionally inhabits or forages in hunted areas
1—Does not generally utilize hunted areas

4. 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)

5. Social structure
5—Highly colonial or gregarious
3—Semi-colonial or semi-gregarious
1—Solitary

6. Range
5—Present in small part of study area only
4—Present throughout less than half of study area
3—Present throughout about half of study area
2—Present throughout more than half of study area
1—Present throughout entire study area

B. SENSITIVITY
1. Proportion of protein or calcium in diet
5—Low (mostly vegetation)
3—Moderate
1—High (animal matter, mollusks)

2. Dietary preference
5—Granivorous
4—Insectivores
3—Omnivorous
2—Frugivorous
1—Carnivorous

3. Relative Body Size
5—Small (e.g., passerines)
3—Medium (e.g., most waterfowl, gulls)
1—Large (e.g., geese, larger raptors)

C. RESILIENCE OF POPULATION
1. Peak abundance in study area during season of concern
5—Rare (Not normally present)
4—Occasional (Presence possible, but not expected)
3—Uncommon (Presence expected, but not a certainty)
2—Common (Certain to be in suitable habitat)
1—Abundant (Numerous in suitable habitat)

2. Distribution outside of study area
5—endemic to study area
3—present outside of study area, but not abundant
1—abundant outside of study area

3. Reproductive potential
5—Low (1-2 offspring per year)
3—Moderate (3-4 offspring per year)
1—High (>4 offspring per year)

4. Age at first breeding
5—6+ years
4—5 years
3—4 years
2—3 years
1—1-2 years