[order] PROCELLARIIFORMES | [family] Procellariidae | [latin] Pachyptila salvini | [authority] Mathews, 1912 | [UK] Salvins Prion | [FR] Prion de Salvin | [DE] Kleiner Enten-Sturmvogel | [ES] Pato petrel de Salvin | [NL] Salvins Prion
Monotypic species
Genus
Prions are a race of abundant small petrels from the Antarctic and subantarctic region with very similar plumages: a white body, bluish grey upperparts with a dark M on the back and upper sides of the wings when seen from above. Although there is considerable difference in measurements, the main difference between the species lies in the shape of the bills. These vary from small ‘pointed’ via ‘fulmarish’ to extreme broad. Characteristic are the lamellae along the sides of the palate in all species. These form a sieving structure to filter small food particles from the water. The development of these lamellae and grooves vary depending on the species. Bills of all Prions are bluish, except in the Broad-billed which has a blackish bill. Identification of the Prions at sea is very difficult. Therefore much of the pelagic distribution is unknown.
The taxonomy of the Prions is difficult and possibly not yet fully understood. It is mainly based on size and structure of the bill. But since there is a lot of intraspecific variability and intergradation between the recognized species and subspecies, the discussion on this topic is not closed yet. The list below shows the seven species that are accepted generally, including the recent separation of the MacGillivrayi’s Prion.
Very much like the Antarctic Prion it has grey and white plaumage, but with a somewhat smaller collar and longer blue bill.
| wingspan min.: |
57 |
cm |
wingspan max.: |
58 |
cm |
| size min.: |
25 |
cm |
size max.: |
28 |
cm |
| incubation min.: |
43 |
days |
incubation max.: |
52 |
days |
| fledging min.: |
52 |
days |
fledging max.: |
65 |
days |
| broods: |
1 |
|
eggs min.: |
1 |
|
| |
|
|
eggs max.: |
1 |
|
Indian Ocean : South. The Medium-billed prion is found breeding at the Prince Edward Islands (South Africa), Crozet Islands, Amsterdam Islands and St Paul Island (French Southern Territories). It ranges at sea from South Africa east to New Zealand
This marine species normally occurs offshore, and can be found in areas of upwelling outside the breeding season. It nests in burrows, usually on islands, inland on highland plateaux or on slopes with grass or shrubs. It can also be found in caves or crevices.
This small prion breeds colonially on a number of subantarctic islands in the southern Indian Ocean. The colonies of Medium-billed Prions are attended nocturnally in order to avoid predation by skuas. The nests are concealed in burrows usually dug into soil. Nests are attended regularly for several months prior to breeding. A single egg is laid in November or early December, which is incubated for around 50 days. Both parents share the incubation duties and feed the chick once it is hatched. The chicks fledge around 60 days after hatching.
Its diet is comprised mostly of crustaceans, especially krill, but also fish and squid, all of which it catches either by hydroplaning, surface-seizing or filtering.
httpv://www.youtube.com/watch?v=HxWQ1Fphq5k
copyright: Peter Fraser
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The Medium-billed Prion is not considered threatened. Although numbers have declined on some islands where rats and feral cats have been introduced, the world population is estimated at around 12 million birds. Consequently, they are given a classification of Least Concern
Disperses widely over S Indian Ocean, ranging N to South Africa and Australia; some wander further E to New Zealand, apparently mostly immatures.
