Pterodroma baraui 

Scope: Global

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Procellariiformes Procellariidae

Scientific Name: Pterodroma baraui
Species Authority: (Jouanin, 1964)
Common Name(s):
English Barau's Petrel
French Pétrel de Barau
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International.
Identification information: 38 cm. Medium-sized, grey-and-white gadfly petrel. White forehead, black cap merging to greyish-brown back and upperwing. Paler wing-tips give scaled appearance. Slightly darker tail. Moderately defined "M" mark across wings. White chin, throat and rest of underparts, except for some grey mottling on sides of breast and flanks. White underwing with dark trailing edge, dark tip, narrow black edge to leading edge distal to carpal joint. Black thickens at joint. Then clear black bar extending from joint towards centre of wing. Similar spp. Capped appearance, white underparts, and distinctive underwing separate this from any other Indian Ocean Pterodroma.

Assessment Information [top]

Red List Category & Criteria: Endangered B2ab(iii,v) ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Attié, C., Bretagnolle, V., Gee, B. & Le Corre, M.
Facilitator/Compiler(s): Anderson, O., Benstead, P., Calvert, R., Ekstrom, J., Shutes, S., Stattersfield, A., Taylor, J., Temple, H.
This species may have undergone a rapid population decline owing to illegal shooting in the 1990s, but has apparently recovered. However, it has a very small range when breeding (probably at fewer than five locations) and a small population, both of which are thought to be declining. It is therefore classified as Endangered.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Pterodroma baraui nests on the Massif of Piton des Neiges, Réunion (to France) and has been discovered breeding on Rodriguez (Van den Berg et al. 1991). It has been observed at sea north of Réunion, from the Oman Sea as far as Sumatra and around the Cocos Keeling Islands, and south-east towards Australia (Barré et al. 1996), as far as about 200 km south and 600 km east of Réunion (Van den Berg et al. 1991). Recent tracking data indicate they can travel much greater distances, migrating eastward up to 5,000 km from their breeding colony to the central and eastern Indian Ocean (Pinet et al. 2011).

Countries occurrence:
Indonesia; Réunion
Australia; Mauritius; Mozambique; South Africa
Present - origin uncertain:
British Indian Ocean Territory; Christmas Island; Cocos (Keeling) Islands; Sri Lanka
Additional data:
Estimated area of occupancy (AOO) - km2:6Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:16000000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:4Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:NoLower elevation limit (metres):320
Upper elevation limit (metres):2800
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:In 1987, the population was estimated at 3,000 breeding pairs based on colony and coastal counts, and 15,000 individuals based on transects at sea. In 1992, it was estimated that up to half the breeding population may have been killed by illegal shooting. Although this may have been an overestimate, the population appears to have recovered to former levels (because of large numbers of non-breeders) following the cessation of shooting (V. Bretagnolle in litt. 1999). More recently, improved knowledge of the colonies indicates that 4,000-5,000 pairs may be a more accurate estimate of breeding numbers, although this could be optimistic (V. Bretagnolle in litt. 2007). In 2001, based on the discovery of new breeding colonies, 4,000 to 6,500 breeding pairs spread over 10 colonies was estimated. The most reliable recent estimate available is that of 3,000-4,000 pairs given by V. Bretagnolle (in litt. 2007). This equates to 6,000-8,000 mature individuals, or roughly 9,000-12,000 individuals in total.

Trend Justification:  The species is suspected to be undergoing a long-term decline in line with increased juvenile mortality caused by disorientation resulting from light pollution; predation by introduced species is also likely be a significant factor.

Current Population Trend:Decreasing
Additional data:
Number of mature individuals:6000-8000Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
No. of subpopulations:1Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:Yes
No. of individuals in largest subpopulation:100

Habitat and Ecology [top]

Habitat and Ecology:It nests on cliff-ledges in volcanic ash soils beneath sparse, heathy vegetation such as Philippia montana associated with upland elfin forest (Probst et al. 2000). It fishes over a wide area, sometimes associated with flocks of feeding seabirds, and occasionally near fishing boats (Barré et al. 1996, Probst et al. 2000). A study of grounded birds in 2005 suggested that most juveniles left their colonies over a period of eight days, beginning four days after the new moon in early April (Fontaine 2005a).  During the non-breeding season, it forages in regions characterised by warm sea surface temperatures and low productivity, consistent with strong and reliable easterly winds, between the western South Equatorial Current and the eastern Equatorial Counter Current (Pinet et al. 2011). Birds leave the colony late March, reaching wintering areas in mid-April, returning to the colony 5-15 September (Pinet et al. 2011). Both sexes, and breeders and non-breeders, show similar migration schedules, with males returning to the colony slightly earlier, and mean return dates coinciding with full moon phase, suggesting that birds use this cue to synchronise their activity (Pinet et al. 2011). Mean distances travelled per day on route to wintering areas was 110-600 km, once there this dropped significantly (Pinet et al. 2011). There is considerable consistency in wintering areas year on year (Pinet et al. 2011). It feeds at the surface, taking mostly squid and fish, foraging alone or in small flocks, often associating with sooty terns Sterna fuscata and Audubon shearwaters Puffinus lherminieri. Stable isotope data suggest that young and adults consume different prey (Pinet et al. 2009).

Systems:Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):15.6
Movement patterns:Full Migrant
Congregatory:Congregatory (and dispersive)

Threats [top]

Major Threat(s): Cats predate adults and fledglings and rats may predate chicks and eggs, although no attempt has been made to quantify this due to the very rough topography (M. Le Corre in litt. 1999, V. Bretagnolle in litt. 2007). Rats and/or cats and/or goats have been noted at all visited colonies (V. Bretagnolle in litt. 1999). In 2005, the remains of birds predated by rats and cats were found at a colony at 2,500 m, and cats were judged to be the main culprits (Fontaine 2005b). Similar findings were reported in 2009, where 58% of the birds killed by cats were adults and 42% were fledglings (Faulquier et al. 2009). The presence of only a few cats may pose a major threat to this species, due to the loss of adult birds rather than chicks and eggs (which is the major threat posed by rats) (Pinet et al. 2009). Thus if cat control led to an increase in rat density it may not lead to a decline in the petrel population (although further work on this is necessary) (Pinet et al. 2009).

Juveniles are attracted by lights in urban areas, where some die of starvation or are taken by cats and dogs (Le Corre et al. 1996, Le Corre et al. 1999). Light-induced mortality of the juveniles of this rare petrel is a considerable problem likely to affect the species long term populations dynamics. Widespread light pollution such as street lamps and sport installations are responsible for the greatest majority of petrel light-induced mortality on Réunion (Le Corre et al. 2002). It has been suggested perhaps as many as 40-60% of young birds are disorientated and ultimately suffer light-induced mortality each year (Le Corre 1999, Le Corre et al. 2002). Mountaineering is becoming a popular sport and could be a potential threat (Probst et al. 2000). The species is potentially threatened by climate change because it has a geographically bounded distribution: its altitudinal distribution falls entirely within 1,000 m of the highest mountain top within its range (3069 m).

Population modelling has indicated that these threats (especially those reducing adult survival such as cat predation) may drive the species to extinction (Pinet et al. 2011).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
The local authorities have taken steps to stop shooting (Bretagnolle and Attié 1993, Thiollay 1996, M. Le Corre in litt. 1999). Since 1996, there has been a campaign to quantify urban light-induced mortality and to rescue as many birds as possible, with increasing success in finding and rescuing birds: over 604 in 1999 (Le Corre et al. 2002), 787 in 2001 (Ghestemme 2001); around 90% are successfully released (Le Corre et al. 1996, Le Corre et al. 1999, M. Le Corre in litt. 1999, Le Corre et al. 2002). In 2005, only 252 grounded birds were found and rescued, perhaps owing to poor food availability, predation at colonies, a global decline in numbers or weather conditions that favoured flights at higher altitudes (Fontaine 2005a). Measures to reduce light pollution, especially during the April fledging, have been proposed (Le Corre et al. 2002). Since 2004, the community of Cilaos, close to the species's colonies, has taken part in efforts to reduce lighting, and there has been a corresponding decrease in the numbers of grounded birds (Fontaine 2005a). The breeding colonies will be classified as a protected area with access authorised for conservation and research purposes only (Probst et al. 2000). The trapping of rats is taking place at P. baraui colonies in an effort to study their population size and diet, and to gather knowledge in preparation for their control (Fontaine 2005b).

Conservation Actions Proposed
Carry out surveys to obtain an up-to-date population estimate. Conduct regular surveys to monitor population trends. Control predators, particularly cats, at breeding colonies (V. Bretagnolle in litt. 1999, V. Bretagnolle in litt. 2007). Cat control at breeding colonies is required year-round, particularly during the non-breeding season when efforts are likely to have the most effect due to the reduction of other available prey (Pinet et al. 2009). Legislative change is first required to allow the control of feral cats, as these are currently protected alongside domestic cats under French legislation (Pinet et al. 2009). Instigate a comprehensive education program to demonstrate the impact of feral cats to the local population (Pinet et al. 2009). Ensure that a protected area is declared as soon as possible to include all colonies (Pinet et al. 2009). Continue rescue programme of young birds attracted by lights (Le Corre et al. 2002). Investigate light-reduction programmes either through light-shielding or light-restriction during April and May (M. Le Corre in litt. 1999, Le Corre et al. 2002), and consider adjusting its direction, intensity and colour, and the use of temporary black-outs (Salamolard et al. 2007).

Citation: BirdLife International. 2012. Pterodroma baraui. The IUCN Red List of Threatened Species 2012: e.T22698035A40201748. . Downloaded on 05 December 2016.
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