Question

vulnerable species - are species whose population: - has been reduced by <> - with further significant reduction projected within 10 years - occupies an extent of occurrence of less than 20,000 km2 (7,722 mi2) or area of occupancy of less than 2,000 km2 (772 mi2) - with <> of occupancy and continued decline or fragmentation of habitat - has less than 10,000 mature individuals

Explanation:

To fill in the blanks for the definition of vulnerable species, we refer to the IUCN Red List criteria for vulnerable species:

First Blank (Population Reduction):

Vulnerable species are those whose population has been reduced by ≥ 30% (this is a key criterion from IUCN: a population reduction of at least 30% over the last 10 years or three generations, whichever is longer, or with a projected reduction of ≥ 30% in the next 10 years/three generations). So the first blank should be filled with a value like "30% or more" (or "≥ 30%").

Second Blank (Extent/Area of Occupancy):

For the area of occupancy/extent of occurrence, vulnerable species often have an extent of occurrence < 20,000 km² with a continuing decline (or similar phrasing about ongoing reduction) in occupancy/habitat. The second blank relates to the trend of the habitat/occupancy, so terms like "continuing decline", "ongoing reduction", or "further decrease" fit here (aligning with the IUCN criteria of continuing decline in area, extent, or quality of habitat).

Final Filled Definitions (Example):

• “has been reduced by $\boldsymbol{30\%}$ or more” (with further significant reduction projected within 10 years)
• “occupies an extent of occurrence of less than 20,000 km² (7,722 mi²) or area of occupancy of less than 2,000 km² (772 mi²) with $\boldsymbol{continuing\ decline}$ of occupancy and continued decline or fragmentation of habitat”

These values align with the International Union for Conservation of Nature (IUCN) Red List criteria for classifying a species as “Vulnerable.”

Answer:

To fill in the blanks for the definition of vulnerable species, we refer to the IUCN Red List criteria for vulnerable species:

First Blank (Population Reduction):

Vulnerable species are those whose population has been reduced by ≥ 30% (this is a key criterion from IUCN: a population reduction of at least 30% over the last 10 years or three generations, whichever is longer, or with a projected reduction of ≥ 30% in the next 10 years/three generations). So the first blank should be filled with a value like "30% or more" (or "≥ 30%").

Second Blank (Extent/Area of Occupancy):

For the area of occupancy/extent of occurrence, vulnerable species often have an extent of occurrence < 20,000 km² with a continuing decline (or similar phrasing about ongoing reduction) in occupancy/habitat. The second blank relates to the trend of the habitat/occupancy, so terms like "continuing decline", "ongoing reduction", or "further decrease" fit here (aligning with the IUCN criteria of continuing decline in area, extent, or quality of habitat).

Final Filled Definitions (Example):

• “has been reduced by $\boldsymbol{30\%}$ or more” (with further significant reduction projected within 10 years)
• “occupies an extent of occurrence of less than 20,000 km² (7,722 mi²) or area of occupancy of less than 2,000 km² (772 mi²) with $\boldsymbol{continuing\ decline}$ of occupancy and continued decline or fragmentation of habitat”

These values align with the International Union for Conservation of Nature (IUCN) Red List criteria for classifying a species as “Vulnerable.”