May 27th, 2008 , 17 Comments »
The table below aims to describe the main threats to serpent and booted eagle species worldwide and to describe current conservation efforts. It is best understood within the context of the table we posted previously (below this table), which detailed numbers and conservation status of these eagles. It is very likely that for some species these data are out of date, incorrect or incomplete. We are seeking help in completing this table. For some species, like golden eagle, the conservation activities that are ongoing are many and we are constrained by space. In the particular case of the golden eagle it is also one of the more common species and has a very large global population. Still, we recognize that national and regional level conservation activities are being pursued and that these efforts are important in maintaining the golden eagle’s current distribution, overall good conservation status and improving its conservation status in some countries. Please take time to look at the table below and use the blog to provide us with information. It is our aim to publish our results in a peer-reviewed journal or e-journal and we will acknowledge those who have contributed to this effort. To contribute to the blog click on the title above. You will find a comment box at the bottom of the page. Use that to submit your comments.
Endangered
| Species |
Common Name |
Main Threats |
Conservation Activities
|
| Eutriorchis astur |
Madagascar Serpent Eagle |
Deforestation and habitat fragmentation |
CITES II. The Peregrine Fund, World Wide Fund for Nature (WWF). Project Masoala and Association pour la Gestion des Aires Protégées. Establishment of a rainforest reserve, research, monitoring and education.
|
| Spilornis [c.] perplexus |
Ryukyu Serpent Eagle |
Destruction of foraging habitat, collisions with cars |
Formal legal protection. Planned research, activities to reduce collisions and restoration of wetlands where they hunt. Public education. Genetic research.
|
| Spilornis [c.] baweanus |
Bawean Serpent Eagle |
Recreational hunting. Habitat loss to logging and burning. |
Genetic research.
|
| Pithecophaga jefferyi |
Philippine Eagle |
Habitat fragmentation and destruction, persecution. Overhunting of prey |
CITES I. Legal protection in Philippines. Various Philippine legislation to support education, protection and protection of habitat. Philippine Eagle Foundation. Philippine Eagle Conservation Programme. The Peregrine Fund. Captive breeding, nest site protection, field research, community-based sustainable resource use initiatives, conservation education
|
| Nisaetus (Spizaetus) floris |
Flores Hawk Eagle |
Deforestation, persecution, live pet trade |
ARRCN Spizaetus Collaboration Project. Survey. Genetic research
|
| Nisaetus (Spizaetus) bartelsi |
Javan Hawk Eagle |
Deforestation for tea and coffee plantations, illegal hunting, live pet trade, ineffective law enforcement |
CITES II. ARRCN Javan Hawk Eagle Project. ARRCN Spizaetus Collaboration Project. Protected as National Bird of Indonesia. Action plan compiled. Public conservation education. Research. Survey. Nest-guarding ?
|
| Nisaetus (Spizaetus) philippensis |
Philippine Hawk Eagle |
Massive and continuing deforestation. Illegal hunting and trapping (even in nominal protected areas), ineffective law enforcement |
Legal protection, including CITES Appendix II and national laws. ARRCN Spizaetus Collaboration Project. Genetic research.
|
| Nisaetus (Spizaetus) pinskeri |
Pinsker´s Hawk Eagle |
Massive and continuing deforestation. Illegal hunting and trapping (even in nominal protected areas), ineffective law enforcement |
ARRCN Spizaetus Collaboration Project. Genetic research.
|
| Aquila (Lophaetus) hastata |
Indian Spotted Eagle |
Habitat loss due to drainage of forests and meadows. Confusion with A. clanga undermines survey and monitoring |
ARRCN Indian Spotted Eagle Project. Genetic research.
|
Near Threatened or Vulnerable
| Species |
Common Name |
Main Threats |
Conservation Activities
|
| Spilornis elgini |
Andaman Serpent Eagle |
Deforestation, potential pressures due to increased human population on island. |
CITES II.
|
| Spilornis [c] minimus |
Central Nicobar Serpent Eagle |
Data deficient. Restricted range. |
Genetic research.
|
| Spilornis [c] abbotti |
Simeulue Serpent Eagle |
Data deficient. Restricted range. |
Genetic research.
|
| Spilornis [c] asturinus |
Nias Serpent Eagle |
Data deficient. Restricted range. |
Genetic research.
|
| Spilornis [c] sipora |
Mentawai Serpent Eagle |
Data deficient. Restricted range. |
Genetic research.
|
| Spilornis [c] natunensis |
Natuna Serpent Eagle |
Data deficient. Restricted range. |
Genetic research.
|
| Spilornis klossi |
Great Nicobar Serpent Eagle |
Data deficient, potential pressures due to increased human population within restricted range |
CITES II.
|
| Spilornis kinabaluensis |
Kinabalu Serpent Eagle |
Deforestation, but poorly known. |
CITES II.
|
| Terathopius ecaudatus |
Bateleur |
Habitat destruction, lack of carrion, nest disturbance, pesticides, inadvertent poisoning |
CITES II.
|
| Circaetus beaudouini |
Beaudouin’s Snake Eagle |
None known. |
CITES II.
|
| Circaetus fasciolatus |
Banded Snake Eagle |
Deforestation and habitat degradation, especially along rivers, human persecution. |
CITES II.
|
| Nisaetus (Spizaetus) nanus |
Wallace’s Hawk Eagle |
Low land forest loss, fragmentation and degradation. Some illegal hunting. Ineffective law enforcement, including in protected areas. |
Legal protection, including CITES II. ARRCN Spizaetus Collaboration Project. Some protected areas
|
| Nisaetus (Spizaetus) kelaarti |
Legge’s Hawk Eagle |
Deforestation, especially of evergreen forests. Forest fragmentation |
ARRCN Spizaetus Collaboration Project
|
| Spizaetus (Oroaetus) isidori |
Black-and-chestnut Eagle |
Probably deforestation. Appears to occupy narrow altitudinal range. Little known. |
CITES II.
|
| Polemaetus bellicosus |
Martial Eagle |
Persecution. |
CITES II.
|
| Aquila (Lophaetus) clanga |
Greater Spotted Eagle |
Habitat destruction including drainage of wetlands, forestry, and intensification of farming. Abandonment of traditional flood plain management, nest disturbance, nest robbing, shooting, poisoning. Hybridisation with lesser spotted eagle (Aquila pomarina), but as yet it is not clear whether this is a natural phenomenon or a result of an increasing difficulty in finding a mate. Thought to be competing for food with the introduced American mink (Mustela vison) in Belarus. |
CITES II. Legally protected on national scale. Regionally protected in Europe by the EU Birds Directive and indirectly by Habitats Directive. International Lesser and Greater Spotted Eagle Working Group formed. Research on hybridisation with lesser spotted eagle habitat requirements and site protection measures in Belarus. RSPB/BirdLife research in Belarus. European Action Plan published in 2000.
|
| Aquila heliaca |
Eastern Imperial Eagle |
Habitat change (conversion of native forests to commercial forests with introduced species with consequent loss of prey), loss of nest sites (large trees), human disturbance, nest robbing, illegal trade, shooting, poisoning, shortage of prey species, and electrocution, live bird trade. |
CITES I. Legally protected in most countries in its range. The Eastern Imperial Eagle Working Group established in 1990. European Action Plan (1996). LIFE Project in Hungary.
|
| Aquila gurneyi |
Gurney’s Eagle |
Possibly threatened by deforestation. Little known. |
CITES II. Survey
|
| Aquila adalberti |
Spanish Imperial Eagle |
Electrocution and accidental trapping and poisoning. |
CITES I. Modifying transmission poles, education. Mostly protected on the local or national scale. Regionally protected in Europe by the EU Birds Directive and indirectly by Habitats Directive. Captive breeding.
|
Least Concern
| Species |
Common Name |
Main Threats |
Conservation Activities
|
| Spilornis cheela ssp. |
Crested Serpent Eagle |
No immediate threats to population and seen as adaptable, but deforestation and keeping as pets in their range are problems. Taxonomic questions exist and resolution of these may give rise to new species that are imperilled. |
CITES II. Survey. Genetic work.
|
| Spilornis holospilus |
Philippine Serpent Eagle |
Deforestation, but seems adaptable. |
CITES II. Genetic work.
|
| Spilornis rufipectus |
Sulawesi Serpent Eagle |
Deforestation and disturbance, but may be adaptable. Little known. Deforestation seems less of an immediate threat than on other islands in the region. |
CITES II. Survey. Genetic work
|
| Dryotriorchis spectabilis |
Congo Serpent Eagle |
Deforestation |
CITES II.
|
| Circaetus gallicus |
Short-toed Snake Eagle |
Habitat loss due to intensified agriculture, shooting on migration, locally windfarms (mostly in Spain) |
CITES II. Regionally protected in Europe by the EU Birds Directive and indirectly by Habitats Directive. Mostly conservation efforts on the local or national scale.
|
| Circaetus pectoralis |
Black-breasted Snake Eagle |
Data deficient, but occurs in a wide range of habitats. |
CITES II.
|
| Circaetus cinereus |
Brown Snake Eagle |
Data deficient. Perhaps vulnerable to habitat degradation. |
CITES II.
|
| Circaetus cinerascens |
Western Banded Snake Eagle |
Deforestation of riverine forests and habitat degradation. |
CITES II.
|
| Nisaetus (Spizaetus) lanceolatus |
Sulawesi Hawk Eagle |
Deforestation and disturbance. Little known. Deforestation seems less of an immediate threat than on other islands in the region. |
CITES II. ARRCN Spizaetus Collaboration Project
|
| Nisaetus (Spizaetus) cirrhatus |
Changeable Hawk Eagle |
Deforestation, human disturbance, subspecies may be threatened due to small ranges (islands) |
CITES II. ARRCN Spizaetus Collaboration Project
|
| Nisaetus (Spizaetus) nipalensis |
Mountain Hawk Eagle |
Deforestation. |
CITES II. ARRCN Spizaetus Collaboration Project
|
| Nisaetus (Spizaetus) alboniger |
Blyth’s Hawk Eagle |
Deforestation. Loss of big trees in which it nests |
CITES II. ARRCN Spizaetus Collaboration Project
|
| Spizaetus tyrannus |
Black Hawk Eagle |
Deforestation. |
CITES II.
|
| Spizaetus (Spizastur) melanoleucus |
Black-and-white Hawk Eagle |
Deforestation, but appears relatively tolerant of habitat change. Range contracting. |
CITES II.
|
| Spizaetus ornatus |
Ornate Hawk Eagle |
Deforestation. Declining at various localities across range |
|
| Stephanoaetus coronatus |
Crowned Eagle |
Deforestation, shooting, trapping, nest disturbance. Overhunting of prey. Declining at various localities across range |
CITES II.
|
| Lophotriorchis (Hieraaetus) kienerii |
Rufous-bellied Eagle |
Habitat destruction (deforestation) |
CITES II. Survey
|
| Aquila (Lophaetus) occipitalis |
Long-crested Eagle |
Adaptable, but potentially vulnerable to degradation of woodland and drainage of wetalnd |
CITES II.
|
| Aquila (Ictinaetus) malayensis |
Indian Black Eagle |
Habitat destruction (deforestation) |
Survey
|
| Aquila (Lophaetus) pomarina |
Lesser Spotted Eagle |
Shooting, habitat loss due to drainage of forests and meadows. |
CITES II. Conservation mostly on the local or national scale. Regionally protected in Europe by the EU Birds Directive and indirectly by Habitats Directive. European Action Plan.
|
| Aquila (Hieraaetus) wahlbergi |
Wahlberg’s Eagle |
Some threat from loss of habitat and locally by accidental poisoning. |
CITES II.
|
| Aquila (Hieraaetus) ayresii |
Ayres’s Hawk Eagle |
Locally shooting and habitat destruction. |
CITES II.
|
| Aquila (Hieraaetus) pennata |
Booted Eagle |
Deforestation and loss of low intensity agricultural systems, human disturbance, persecution, locally windfarms |
CITES II. Regionally protected in Europe by the EU Birds Directive and indirectly by Habitats Directive.
|
| Aquila (Hieraaetus) morphnoides |
Little Eagle |
Locally habitat destruction, but seems to be adaptable. |
CITES II.
|
| Aquila (Hieraaetus) weiskei |
Pygmy/Weiske’s Eagle |
|
|
| Aquila nipalensis |
Steppe Eagle |
Electrocution. Conversion of steepe into agricultural fields, some persecution. |
CITES II
|
| Aquila rapax |
Tawny Eagle |
Accidental and non-accidental poisoning, persecution, shooting. Declines in prey availability. |
CITES II
|
| Aquila chrysaetos |
Golden Eagle |
Habitat loss, declines in prey, locally direct persecution, inadvertent poisoning, human disturbance, electrocution, windfarms. |
CITES II. Regionally protected in Europe by the EU Birds Directive and indirectly by Habitats Directive. Protected in North America by Migratory Bird Treaties. Many conservation efforts, mostly on the local or national scale.
|
| Aquila verreauxi |
Verreaux’s Eagle |
Effects of growing human population including declines in main prey due to overgrazing and hunting. Persecution. Drought. |
CITES II.
|
| Aquila audax |
Wedge-tailed Eagle |
Habitat and nest tree destruction, locally persecution, inadvertent human disturbance, accidental and intentional poisoning, windfarms. Lead poisoning. Threatened with extirpation in Tasmania. |
CITES II. Nesting habitat and nest sites of Tasmanian race afforded some protection in state forests through Forest Code.
|
| Aquila (Spizaetus) africana |
Cassin’s Hawk Eagle |
Apparently relatively adaptable. Deforestation, human disturbance. Poorly known. |
CITES II.
|
| Aquila (Hieraaetus) fasciata |
Bonelli’s Eagle |
Persecution, Habitat loss due to intensified agriculture, Declines in prey, Collision with power lines. Persecution. Locally windfarms. Endangered in its western European distribution. |
CITES II. Mostly conservation efforts on the local or national scale. Regionally protected in Europe by the EU Birds Directive and indirectly by Habitats Directive.
|
| Aquila (Hieraaetus) spilogaster |
African Hawk Eagle |
Habitat change, some shooting and poisoning. |
CITES II.
|
March 29th, 2008 , 4 Comments »
Large raptors are often species of high conservation concern, and this is particularly true for the serpent and booted eagle groups. We are reviewing the status and conservation of these eagles. Because so little is known or published for many of the species in these groups we are seeking comment from other researchers and conservationists with knowledge of these species, particularly those that are not well known.
Eagle taxonomy is changing. We considered 61 eagle species in the (current and historical) genera: Eutriorchis, Spilornis, Pithecophaga, Terathopius, Circaetus, Dryotriorchis, Nisaetus, Stephanoatus, Spizaetus, Hieraaetus, Polemaetus, Lophaetus, Ictinaetus, and Aquila. We recorded, in parentheses, the old names for genera/species to avoid confusion. Our main aim was to assemble information that would be useful for conservation. Phylogeny and taxonomy for us are tools of conservation, and their main function are to identify genetic assemblages (species) upon which most conservation is based, and to promote communication between researchers and conservationists. Some of the species we list are not recognized as valid by others.
The primary sources of information for our review were the Global Raptor Information Network (GRIN)(The Peregrine Fund, Inc http://www.globalraptors.org/grin/indexAlt.asp), the IUCN Red List Database (http://www.iucnredlist.org/search/search-expert.php), Raptors of the World (ROW)(Ferguson-Lees et al 2001), and Birds of the World (BOW) (del Hoyo et al 1999). Other published and unpublished information were used.
Table 1 summarizes our results on species status and population estimates and trends. We are seeking comment on these data from other researchers and conservationists. If you have a comment, correction or addition to our table, please fill in the appropriate boxes below. Eventually, we hope to publish these data in the peer-reviewed literature. We will acknowledge all who have contributed to the final manuscript. We may contact you for clarification of the information you provide. Thank you.
Notes for the table:
Distribution: “Continental (C), Large Island (LI) or Small Island (SI)
Estimated Population Size: Number of individuals) [GRIN unless otherwise noted]
Critically Endangered or Endangered
| Species |
English Name |
Status IUCN |
Status GRIN |
Trend |
Distribution |
Estimated Population Size |
| Eutriorchis astur* |
Madagascar Serpent Eagle |
EN |
EN |
Down |
LI |
101 -1000
|
| Spilornis [c.] perplexus* |
Ryukyu Serpent Eagle |
|
EN |
Stable |
SI |
163 - 387
|
| Spilornis [c.] baweanus* |
Bawean Serpent Eagle |
|
CE |
Down |
SI |
11 - 100
|
| Pithecophaga jefferyi* |
Philippine Eagle |
CE |
CE |
Down |
LI |
101 - 1000
|
| Nisaetus (Spizaetus) floris* |
Flores Hawk Eagle |
EN |
CE |
Down |
LI |
1626 -3875
|
| Nisaetus (Spizaetus) bartelsi* |
Javan Hawk Eagle |
EN |
EN |
Down |
LI |
11 - 100; < 100 pairs4
|
| Nisaetus (Spizaetus) philippensis* |
Philippine Hawk Eagle |
VU |
EN |
Down |
LI/SI |
101 - 1000; 200 - 220 pairs1
|
| Nisaetus (Spizaetus) pinskeri* |
Pinsker???s Hawk Eagle |
|
EN |
Down |
LI/SI |
1001 - 10000; 320 - 340 pairs2
|
| Aquila (Lophaetus) hastata * |
Indian Spotted Eagle |
VU |
EN |
Down |
C |
1626 -3875
|
Near-threatened or Vulnerable
| Species |
English Name |
Status IUCN |
Status GRIN |
Trend |
Distribution |
Estimated Population Size |
| Spilornis elgini* |
Andaman Serpent Eagle |
NT |
CD |
? |
SI |
1626 -3875
|
| Spilornis [c.] minimus* |
Central Nicobar Serpent Eagle |
|
DD |
? |
SI |
11 -100
|
| Spilornis [c.] abbotti* |
Simeulue Serpent Eagle |
|
DD |
? |
SI |
101 - 1000
|
| Spilornis [c.] asturinus* |
Nias Serpent Eagle |
|
DD |
? |
SI |
101 - 1000
|
| Spilornis [c.] sipora* |
Mentawai Serpent Eagle |
|
DD |
? |
SI |
1626 -3875
|
| Spilornis [c.] natunensis* |
Natuna Serpent Eagle |
|
DD |
? |
SI |
101 - 1000
|
| Spilornis klossi* |
Great Nicobar Serpent Eagle |
NT |
NT |
Down |
SI |
163 - 387
|
| Spilornis kinabaluensis* |
Kinabalu Serpent Eagle |
VU |
VU |
Down |
SI |
1626 -3875
|
| Terathopius ecaudatus* |
Bateleur Eagle |
LC |
NT |
? |
C |
15251 - 38750
|
| Circaetus beaudouini* |
Beaudouin’s Snake Eagle |
VU |
DD |
Down |
C |
1001 - 10000
|
| Circaetus fasciolatus* |
Southern Banded Snake Eagle |
NT |
NT |
Up |
C |
1001 - 10000
|
| Nisaetus (Spizaetus) nanus (2) |
Wallace’s Hawk Eagle |
VU |
VU |
Down |
C/LI |
1626 -3875
|
| Nisaetus (Spizaetus) kelaarti* |
Legge’s Hawk Eagle |
VU/NT |
|
Down |
C/SI |
< 1000 adult individuals3
|
| Spizaetus (Oroaetus) isidori* |
Isidor’s Eagle (Black and Chestnut Eagle) |
NT |
NT |
? |
C |
1626 -3875
|
| Polemaetus bellicosus* |
Martial Eagle |
LC |
NT |
Down |
C |
10001 -100000
|
| Aquila (Lophoaetus) clanga* |
Greater Spotted Eagle |
VU |
VU |
Down |
C |
15251 - 38750
|
| Aquila heliaca* |
Eastern Imperial Eagle |
VU |
VU |
Down |
C |
1001 - 10000
|
| Aquila gurneyi* |
Gurney’s Eagle |
NT |
NT |
Up? |
LI/C |
1001 - 10000
|
| Aquila adalbert*i |
Spanish Imperial Eagle |
VU |
VU |
Stable |
C |
101 -1000
|
Lower Risk or Least Concern
| Species |
English Name |
Status IUCN |
Status GRIN |
Trend |
Distribution |
Estimated Population Size |
| Spilornis cheela (14) |
Crested Serpent Eagle |
LC |
LR |
? |
C/LI/SI |
100001 - 1000000
|
| Spilornis holospilus* |
Philippine Serpent Eagle |
LC |
DD |
? |
LI/SI |
15251 - 38750
|
| Spilornis rufipectus (2) |
Sulawesi Serpent Eagle |
LC |
LR |
? |
LI/SI |
10001 -100000
|
| Dryotriorchis spectabilis (2) |
Congo Serpent Eagle |
LC |
DD |
? |
C |
15251 - 38750
|
| Circaetus gallicus * |
Short-toed Eagle |
LC |
LR |
Stable? |
C |
10001 -100000
|
| Circaetus pectoralis* |
Black breasted Snake Eagle |
LC |
DD |
? |
C |
112501 - 387500
|
| Circaetus cinereus* |
Brown Snake Eagle |
LC |
DD |
? |
C |
10001 -100000
|
| Circaetus cinerascens* |
Western Banded Snake Eagle |
LC |
DD |
? |
C |
1001 - 10000
|
| Nisaetus (Spizaetus) lanceolatus* |
Sulawesi Hawk Eagle |
LC |
DD |
? |
LI/SI |
15251 - 38750
|
| Nisaetus (Spizaetus) cirrhatus (5) |
Changeable Hawk Eagle |
LC |
LR |
? |
C/SI |
10001 -100000
|
| Nisaetus (Spizaetus) nipalensis (2) |
Mountain Hawk Eagle |
LC |
DD |
? |
C/LI |
15251 - 38750
|
| Nisaetus (Spizaetus) alboniger* |
Blyth’s Hawk Eagle |
LC |
DD |
Down? |
C/LI |
1001 - 10000
|
| Spizaetus tyrannus (2) |
Black Hawk Eagle |
LC |
LR |
? |
C |
100000 - 1000000
|
| Spizaetus (Spizastur) melanoleucus* |
Black and white Hawk Eagle |
LC |
LR |
? |
C |
10001 -100000
|
| Spizaetus ornatus (2) |
Ornate Hawk Eagle |
LC |
LR |
Down |
C |
15251 - 38750
|
| Stephanoatus coronatus* |
Crowned Hawk Eagle |
LC |
LR |
Down |
C |
15251 - 38750
|
| Lophotriorchis (Hieraaetus) kienerii (2) |
Rufous-bellied Eagle |
LC |
LR |
? |
C |
15251 - 38750
|
| Aquila (Lophoaetus) occipitalis* |
Long-crested Eagle |
LC |
LR |
? |
C |
112501 - 387500
|
| Aquila (Ictinaetus) malayensis* |
Black Eagle |
LC |
LR |
Stable |
C |
10001 -100000
|
| Aquila (Lophoaetus) pomarina* |
Lesser Spotted Eagle |
LC |
LR |
Down |
C |
112501 - 387500; 15000 pairs in Europe5
|
| Aquila (Hieraaetus) wahlbergi* |
Wahlberg’s Eagle |
LC |
LR |
Stable |
C |
100001 - 1000000
|
| Aquila (Hieraaetus) ayresii* |
Ayres’s Hawk Eagle |
LC |
DD |
? |
C |
1001 - 10000
|
| Aquila (Hieraaetus) pennata* |
Booted Eagle |
LC |
LR |
? |
C |
10001 - 100000
|
| Aquila (Hieraaetus) morphnoides* |
Little Eagle |
LC |
LR |
Stable? |
C |
10001 - 100000
|
| Aquila (Hieraaetus) weiskei * |
Pygmy / Weiske’s Eagle |
|
DD |
? |
LI/SI |
NOT ESTIMATED
|
| Aquila nipalensis (2) |
Steppe Eagle |
LC |
LR |
? |
C |
100001 - 1000000
|
| Aquila rapax (3) |
Tawny Eagle |
LC |
LR |
Stable |
C |
100001 - 1000000
|
| Aquila chrysaetos (6) |
Golden Eagle |
LC |
LR |
Stable |
C |
100001 - 1000000
|
| Aquila verreauxii* |
Verreaux’s Eagle |
LC |
LR |
Stable |
C |
10001 -100000
|
| Aquila audax (2) |
Wedge-tailed Eagle |
LC |
LR |
Stable |
C |
100000 - 1000000
|
| Aquila (Spizaetus) africana* |
Cassin’s Hawk Eagle |
LC |
LR |
? |
C |
15251 - 38750
|
| Aquila (Hieraaetus) fasciata (2) |
Bonelli’s Eagle |
LC |
LR |
? |
C |
10001 -100000
|
| Aquila (Hieraaetus) spilogaster* |
African Hawk Eagle |
LC |
LR |
? |
C |
112501 - 387500
|
* = monotypic, () = number of subspecies 1 Gamauf et al. 2005, 2 Preleuthner & Gamauf 1998, 3 Gjershaug in prep 4 Gjershaug 2006.