Mollymawks

Genus Thalassarche

Ten species listed here.

  • Atlantic Yellow-nosed Albatross Thalassarche chlororhynchos, Tristan da Cunha archipelago.
  • Indian Yellow-nosed Albatross Thalassarche carteri, Pr. Edward, Crozet, Kerguelen, Amsterdam, St Paul Is.
  • Grey-headed Albatross Thalassarche chrysostoma, South America, South Georgia, Pr. Edward, Crozet, Kerguelen, Maquarie, Campbell Is.
  • Black-browed Albatross Thalassarche melanophris, Falklands, South Georgia, Crozet, Kerguelen, Heard, Maquarie, Snares, Antipodes and Campbell Is.
  • Campbell Albatross Thalassarche impavida, only Campbell Island.
  • Buller's Albatross Thalassarche bulleri, two subspecies:
    • Buller's Albatross Thalassarche b. bulleri, Chatham and Three Kings Is.
    • Pacific Albatross Thalassarche b. platei, Snares and Solander Is.
  • Shy Albatross Thalassarche cauta, two subspecies: 
    • Tasmanian Shy Albatross Thalassarche c. cauta, Tasmania.
    • New Zealand White-capped or Auckland Shy Albatross Thalassarche c. staedi, Auckland, Chatham and Antipodes Is.
  • Chatham Albatross Thalassarche eremita, Chatham Is.
  • Salvin's Albatross Thalassarche salvini, Bounty, Snares and Crozet Is.

Evolution and taxonomy

Distribution


All Mollymawks are Southern Hemisphere breeders and some species wander around the globe, such as Black-browed, Grey-headed and possibly Shy and Salvin's. Other, such as the Atlantic and Indian Yellow-nosed have a more resticted, but still vast area, in the respective oceans. Both Buller's are confined to the southern Pacific and the Campbell remains in the New Zealand and Australian waters.

Behaviour

The Thalassarche species are 'small' abatrosses (3-5 kg). Like the Great Albatrosses the smaller Mollymawks are  perfectly adapted to a gliding flight and dynamic soaring. Nevertheless they are better equipped for a flapping flight, which is expressed by the proportional weight of the flight musculature (ca 9%), smaller wing loading and lower aspect ratio (ca 13.8). Feeding is mainly done by surface picking but Black-browed and Grey-headed have been observed diving to about 6.5 m (Prince et al. 1994; Huin & Prince 1997). Walking and standing is relatively well developed as in the other albatrosses.

Osteology

Mollymawk skulls are rather similar in shape and proportions. Dénes & Silveira (2007) made an extensive study of the cranial osteology of several Thalassarche and Diomedea species (see References). Murphy (1936) published detailed drawings of Thalassarche bills and plate lay out.

skull Atlantic yellow-nosed albatross Thalassarche chlororhynchos

Atlantic Yellow-nosed Albatross Thalassarche chlororhynchos. South Africa
Culmen: 109.2 mm, total: 177,5 mm, unsexed adult
skull grey-headed albatyross Thlassarche chrysostoma

Grey-headed Albatross Thalassarche chrysostoma. Location unknown
Culmen 115.8 mm, Total:193.1 mm, unsexed adult. Courtesey of G. v.d. Brink 
skull black-browed albatross Thalassarche melanophris

Black-browed Albatross Thalassarche melanophris. Falkland Islands. 
Culmen: 121.3 mm, Total: 192.5 mm, unsexed adult. Courtesey of Joost Pompert, Falkland Is Fisheries Dept. 


New Zealand White-capped Albatross Thalassarche c. staedi. Cable Bay, NZ
Culmen ca 125 mm, Total: 202 mm, unsexed adult

References

Photo upper right:
New Zealand White-capped Albatross © Eric Preston