| |
Estimate |
Data quality |
Derivation |
Year of estimate |
| No. of mature individuals |
6000-15000 |
medium |
Estimated |
2003 |
| Population trend |
Decreasing |
poor |
|
- |
| Number of subpopulations |
1 |
- |
- |
- |
| Largest subpopulation |
|
- |
- |
- |
| Generation length (yrs) |
12.1 |
- |
- |
- |
|
Population justification: Based on at sea survey data from 1975 to 2003, Karnovsky et al. (2005) were able to estimate a current North American at-sea population of 39,700, of which 17,000 are likely to be mature breeding individuals. Although this estimate is based on extrapolation from survey data, the population estimate is perhaps best placed conservatively at 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals. |
|
Trend justification: A number of colonies have been extirpated by introduced predators and alien invasive species continue to threaten some colonies. A number of other threatening processes are on-going, the combined effects of which are suspected to be causing a moderate decline in this species's global population. |
| Threat (level 1) |
Threat (level 2) |
Impact and Stresses |
| Biological resource use |
Fishing & harvesting aquatic resources / Unintentional effects: (large scale) |
Timing |
Scope |
Severity |
Impact |
| Ongoing |
Majority (50-90%) |
Slow, Significant Decline |
Medium Impact: |
| Stresses |
| Indirect ecosystem effects, Species disturbance, Species mortality |
|
| Human intrusions & disturbance |
Recreational activities |
Timing |
Scope |
Severity |
Impact |
| Ongoing |
Majority (50-90%) |
Slow, Significant Decline |
Medium Impact: |
| Stresses |
| Species disturbance, Ecosystem degradation, Ecosystem conversion, Species mortality |
|
| Natural system modifications |
Other ecosystem modifications |
Timing |
Scope |
Severity |
Impact |
| Ongoing |
Majority (50-90%) |
Unknown |
Unknown |
| Stresses |
| Ecosystem degradation, Ecosystem conversion, Reduced reproductive success |
|
| Invasive non-native/alien species/diseases |
Problematic native species/diseases |
Timing |
Scope |
Severity |
Impact |
| Ongoing |
Minority (<50%) |
Slow, Significant Decline |
Low Impact: 5 |
| Stresses |
| Reduced reproductive success |
|
| Invasive non-native/alien species/diseases |
Invasive non-native/alien species/diseases / Black Rat (Rattus rattus) |
Timing |
Scope |
Severity |
Impact |
| Ongoing |
Majority (50-90%) |
Slow, Significant Decline |
Medium Impact: |
| Stresses |
| Reduced reproductive success, Species mortality |
|
| Invasive non-native/alien species/diseases |
Invasive non-native/alien species/diseases / Domestic Cat (Felis catus) |
Timing |
Scope |
Severity |
Impact |
| Ongoing |
Majority (50-90%) |
Slow, Significant Decline |
Medium Impact: |
| Stresses |
| Reduced reproductive success, Species mortality |
|
| Pollution |
Industrial & military effluents / Oil spills |
Timing |
Scope |
Severity |
Impact |
| Ongoing |
Minority (<50%) |
Rapid Declines |
Medium Impact: |
| Stresses |
| Species mortality |
|
| Pollution |
Industrial & military effluents / Type Unknown/Unrecorded |
Timing |
Scope |
Severity |
Impact |
| Ongoing |
Unknown |
Unknown |
Unknown |
| Stresses |
| Ecosystem degradation, Ecosystem conversion |
|
| Climate change & severe weather |
Habitat shifting & alteration |
Timing |
Scope |
Severity |
Impact |
| Future |
Whole (>90%) |
Slow, Significant Decline |
Low Impact: 5 |
| Stresses |
| Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion, Reduced reproductive success, Species mortality |
|
This information is based upon, and updates, the information published in BirdLife International (2000)
Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004)
Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.
To provide new information to update this factsheet or to correct any errors, please email BirdLife
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