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The Danish Red Data Book
Home | Taxon list | IUCN Red List Categories |
| A. Reduction in population size | Critically Endangered (CR) | Endangered (EN) | Vulnerable (VU) |
| A1. An observed, estimated, inferred or suspected population size reduction of ... | < 90% | < 70% | < 50% |
|
...over the last 10 years or 3 generations, whichever is the longer, where the causes of the reduction are: clearly reversible AND understood AND ceased, based on (and specifying) any of the following:: a. direct observation b. an index of abundance appropriate for the taxon c. a decline in area of occupancy, extent of occurrence and/or quality of habitat d. actual or potential levels of exploitation e. the effects of introduced taxa, hybridisation, pathogens, pollutants, competitors or parasites. | |||
| A2. An observed, estimated, inferred or suspected population size reduction of ... | < 80% | < 50% | < 30% |
|
...over the last 10 years or 3 generations, whichever is the longer, where the reduction or its causes may not have ceased OR may not be understood OR may not be reversible, based on (and specifying) any of the following: a. direct observation b. an index of abundance appropriate for the taxon c. a decline in area of occupancy, extent of occurrence and/or quality of habitat d. actual or potential levels of exploitation e. the effects of introduced taxa, hybridisation, pathogens, pollutants, competitors or parasites. | |||
| A3. A population size reduction of at least ... | 80% | 50% | 30% |
|
...projected or suspected to be met within the next 10 years or 3 generations, whichever is the longer (up to a maximum of 100 years), based on (and specifying) any of the following:: b. an index of abundance appropriate for the taxon c. a decline in area of occupancy, extent of occurrence and/or quality of habitat d. actual or potential levels of exploitation e. the effects of introduced taxa, hybridisation, pathogens, pollutants, competitors or parasites. | |||
| A4. An observed, estimated, inferred, projected or suspected population size reduction of ... | < 80% | < 50% | < 30% |
|
...over any period of 10 years or 3 generation period, whichever is the longer (up to a maximum of 100 years), where the time period must include both the past and the future, and where the reduction or its causes may not have ceased OR may not be understood OR may not be reversible, based on (and specifying) any of the following: a. direct observation b. an index of abundance appropriate for the taxon c. a decline in area of occupancy, extent of occurrence and/or quality of habitat d. actual or potential levels of exploitation e. the effects of introduced taxa, hybridisation, pathogens, pollutants, competitors or parasites. | |||
| B. Geographic range ... | Critically Endangered (CR) | Endangered (EN) | Vulnerable (VU) |
| ... in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both: | |||
| B1. Extent of occurrence estimated to be (in km2), and estimates indicating any two of (a-c): | < 100 | < 5.000 | < 20.000 |
| B2. Area of occupancy estimated to be (in km2), and estimates indicating any two of (a-c): | < 10 | < 500 | < 2.000 |
| a. Severely fragmented or known to exist at: | only 1 location | 2-5 locations | 6-10 locations |
| b. Continuing decline, observed, inferred or projected, in any of the following: i. extent of occurrence ii. area of occupancy iii. area, extent and/or quality of habitat iv. number of locations or subpopulations v. number of mature individuals. | |||
| c. Extreme fluctuations in any of the following: i. extent of occurrence ii. area of occupancyl iii. number of locations or subpopulations iv. number of mature individuals. | |||
| C. Population size ... | Critically Endangered (CR) | Endangered (EN) | Vulnerable (VU) |
| ... estimated to number less than (mature individuals) and either: | < 250 | < 2.500 | < 10.000 |
| C1. An estimated continuing decline of at least | 25% | 20% | 10% |
| in (years) | 3 | 5 | 10 |
| or (generations) | 1 | 2 | 3 |
| whichever is longer OR | |||
| C2. C2. a continuing decline, observed, projected, or inferred, in numbers of mature individuals AND at least one of the following (a-b): | |||
| a. Population structure in the form of one of: | |||
| i. no subpopulation estimated to contain more than (mature individuals), OR | 50 | 250 | 1.000 |
| ii. at least (%) of mature individuals are in one subpopulation | 90% | 95% | all (100%) |
| b. Extreme fluctuations in number of mature individuals. | |||
| D. Population size | Critically Endangered (CR) | Endangered (EN) | Vulnerable (VU) |
| ...estimated to number less than (mature individuals) | 50 | 250 | 1.000 |
| VU D2. Population with very restricted area of occupancy or number of locations can be assessed vulnerable | - | - | < 20 km2 or < 5 known locations |
| E. Quantitative analysis | Critically Endangered (CR) | Endangered (EN) | Vulnerable (VU) |
| ...showing the probability of extinction in the wild is at least | 50% | 20% | 10% |
| within (years) | 10 | 20 | 100 |
| or (generations) | 3 | 5 | - |
| whichever is the longer (up to a maximum of 100 years) | |||
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