What this shows:
Each row is a species. Each square represents a year (since 1950).
Tip: Shows trends over the years of appearance in Essex County of each rare species.
Colour meaning:
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Dark red – exceptional year for that rarity with many observation dates
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Orange – species recorded multiple days that year
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Light orange – few records
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No colour – no records for that year
Data is based on historical checklist frequency in Essex County.