Seabirds of the Lower Texas Coast

SEABIRDS of the LOWER TEXAS COAST.pdf

© Copyright  Brad McKinney  31 October 31, 2004 (updated Sep 2009)

*species in bold print are Texas Review Species, requiring written or photographic documentation.

Note: the majority of the above species are found (or have been recorded) in offshore and pelagic waters, although some are more likely found along the immediate coast. These “coastal” species include Northern Gannet, Magnificent Frigatebird, Brown Booby, and Black-legged Kittiwake.

 

Yellow-nosed Albatross Thalassarche chlororynchos

Status: Accidental in the Gulf of Mexico. Of the four records for the Texas, three are from South Texas: Port Isabel, 14 May 1972; South Padre Island, 28 October 1976; deepwater off South Padre Island, 26 September 2003. The most recent sighting off South Padre Island appears to be the Indian Ocean race, which has a whiter head than the nominate South Atlantic race.

Habitat: This species is found in both the South Atlantic and Indian Oceans. Vagrant birds along the Texas coast have been encountered both on the immediate coast as well as in deep pelagic waters.

Similar Species: Any “yellow-nosed” albatross sighting in Texas waters would require the elimination of at least Black-browed and Gray-headed Albatrosses, both of which have a circumpolar distribution in the southern oceans. Although the likelihood of either species showing up along Texas coast is remote, they would at least seem to be potential vagrants to the Gulf of Mexico. Of the three species, Yellow-nosed Albatross has the whitest color in the underwing (or narrowest black underwing margins).

 

Cory’s Shearwater Calonectris diomedia

Status: Rare to uncommon in offshore Gulf of Mexico waters in summer and fall. Both subspecies, C.d. borealis (Atlantic Cory’s) and C.d. diomedia (Scolopi’s Shearwater) have been documented off the Lower Coast. Best months are August through October. Sometimes seen from land at South Padre Island or Boca Chica.

Habitat: offshore and pelagic waters of the Gulf of Mexico.

Similar Species: Cory’s Shearwater most closely resembles Greater Shearwater. Cory’s differs from Greater by having a yellow bill, lack of contrast in crown, solid grayish brown nape, and a clean white underwing pattern. By contrast, Greater Shearwater has a black bill, dark cap, distinct white collar, and dark markings on underwing.

 

Greater Shearwater Puffinus gravis

Status: Accidental in fall; one record for the Lower Coast, 1 October 2004.

Habitat: offshore and pelagic waters of the Gulf of Mexico.

Similar Species: See Cory’s Shearwater.

 

Sooty Shearwater Puffinus griseus

Status: Accidental along the Texas coast. One record for the Lower Coast, Boca Chica on 6 January 1992.

Habitat: This wide-ranging species is found in deep waters of both Atlantic and Pacific Oceans.

Similar Species: Although Sooty Shearwater is often indistinguishable from Short-tailed Shearwater (Pacific Ocean), this all dark shearwater with silvery underwing is unlike any other Atlantic Ocean shearwater.

 

Manx Shearwater Puffinus puffinus

Status: Accidental in fall; one record from the Lower Coast, 13 September 2002.

Habitat: pelagic waters of the Atlantic Ocean. Manx Shearwater prefers colder water than Audubon’s.

Similar Species: See Audubon’s Shearwater

 

Audubon’s Shearwater Puffinus Iherminieri

Status: Rare to uncommon in offshore Gulf of Mexico waters in summer and fall (August – September). Less common than Cory’s Shearwater.

Habitat: pelagic waters of the Gulf of Mexico, usually where the water depth is greater than 100 fathoms. Unlike Cory’s, this species is very rarely seen in the relatively shallow waters over the continental shelf. Audubon’s Shearwater prefers warmer waters than Manx Shearwater.

Similar Species: Audubon’s Shearwater most closely resembles Manx Shearwater. Audubon’s differs from Manx, by having relatively shorter wings, longer tail, and most importantly black undertail coverts.

 

Leach’s Storm-Petrel Oceanodroma leucorhoa

Status: Rare summer and fall visitor in offshore Gulf of Mexico waters.

Habitat: widespread species occurs in Pacific, Atlantic, and Indian Oceans.

Similar Species: Leach’s Storm-Petrel is very similar to the more common Band-rumped Storm-Petrel. Best clues are flight style and rump pattern. Leach’s flight style is nighthawk-like, with deep, erratic wingbeats whereas Band-rumps fly with steady wingbeats and arcing glides. Leach’s also generally shows a broken white rump and a more pronounced forked tail (although both of these features can be tough to see at sea).

 

Band-rumped Storm-Petrel Oceanodroma castro

Status: Uncommon and regular in offshore Texas waters from spring through fall. Usually more numerous in June and July. One inland record at Edinburg, 25 June 1954.

Habitat: Pacific and Atlantic warm-water species. Atlantic Ocean population moves into the deepwaters of the Gulf of Mexico in summer. This species is occasionally seen in the relatively shallow waters over the continental shelf. Band-rumps have also been driven inland by tropical storms.

Similar Species: Very similar to the much rarer Leach’s Storm-Petrel, but has notable differences in flight style (see Leach’s Storm-Petrel account). Band-rumped Storm-Petrels have steady wingbeats, and resemble small, dark, white-rumped shearwaters. Compared to Leach’s, Band-rumps have a whiter rump and more squared tails.

 

Red-billed Tropicbird Phaethon aethereus

Status: Accidental in the Gulf of Mexico. Red-billed Tropicbirds have been recorded in Texas from April through November. Two records for the Lower Texas Coast: off South Padre Island, 18 July 2001 and 26 September 2004.

Habitat: This species is found in Caribbean and Atlantic Ocean, as well as the eastern Pacific and northern Indian Ocean. Birds that show up in Texas waters are likely from the Atlantic race (P.a.mesonata). At least several of the Texas records (including the South Texas bird) have been juveniles. Unlike other pelagic species, Red-billed Tropicbirds are occasionally found in the relatively shallow waters over the continental shelf. Sometimes follow boats.

Similar Species: Although Red-billed is the only tropicbird to be recorded in Texas waters, White-tailed Tropicbird is a potential vagrant (some say overdue) in Texas waters. Red-billed Tropicbird can be distinguished from White-tailed Tropicbird in both adults and juvenile plumage by having black primary coverts. Compared to juvenile White-tailed, juvenile Red-billed also has an eyeline that meets behind the nape and a more finely barred back.

 

Masked Booby Sula dactylatra

Status: Uncommon but regular nonbreeding summer resident (May-October) in offshore and pelagic Gulf of Mexico waters. Seen fairly regularly on South Padre Island pelagic birding trips during summer and fall. Birds are often seen in the relatively shallow continental shelf waters, sometimes in the vicinity of shrimp boats. On rare occasions, this species is found along the immediate coast.

Habitat: offshore and pelagic waters off the Lower Texas Coast.

Similar Species: Brown Booby has been recorded a half dozen times along the coast in all seasons. Brown Booby has a browner plumage (dark brown breast) and yellow feet. Masked Booby, especially juveniles, may be confused with larger Northern Gannet, which is a fairly common migrant and winter resident along the Lower Coast. Although both species may be present off the South Texas coast in migration (Oct and May), there is very limited seasonal overlap. Virtually any sulid seen from the coast between Nov-May would be a Northern Gannet unless proven otherwise.

 

Brown Booby Sula leucogaster

Status: Very rare (six records) in coastal South Texas. Most likely in summer and fall, but has occurred in all seasons.

Habitat: along the immediate coast, including Port Isabel, South Padre Island, and Boca Chica and Laguna Madre. This species has been found perched on rock jetties, channel markers, and on spoil islands; may occur on occasion in offshore and pelagic waters off the Lower Texas Coast.

Similar Species: Brown Booby can be distinguished from both Northern Gannet and Masked Booby by its browner plumage (dark brown breast and all dark back and rump) and yellow feet. Both Northern Gannet and Masked Booby show variable amounts of white in rump or uppertail coverts. Masked Booby always shows white breast.

 

Northern Gannet Morus bassanus

Status: Uncommon yet regular winter resident along the coast. Often seen in small groups of two to four birds (sometimes in short lines); most overwintering Northern Gannets range from juvenile to 3rd-year birds, very few in adult plumage. Almost any sulid seen from Lower Texas Coast beaches from November through May would be this species.

Habitat: Often seen from land along the open gulf coast, rarely seen from the Laguna Madre.

Similar Species: Northern Gannet is quite similar to Masked Booby, both being large, long-winged seabirds with varying amounts of dark and white plumage. Juvenile Northern Gannet show white uppertail coverts while Masked Booby has a white rump. Although difficult to see (except at close range), Northern Gannet has feathering that extends well in front of the eye. Fortunately both species occur in different seasons (gannets in winter and boobies in summer). In addition, Northern Gannet is usually found in close proximity to the immediate coast as well as offshore waters, while Masked Booby is usually seen far from shore in offshore and pelagic waters.

 

Magnificent Frigatebird Fregata magnificens

Status: Uncommon summer visitor to the immediate coast, rare in pelagic waters and at inland locales. Very rare in western Valley, accidental in winter.

Habitat: Seen along the immediate coast, where it can pirate food from coastal gulls and terns. Most often seen soaring high in the sky.

Similar Species: With long sharp-angled black wings and long forked tail, Magnificent Frigatebird is unmistakable.

 

South Polar Skua Catharacta maccormicki

Status: One record off the Lower Coast on 1 October 2004. This bird, was accepted by the TBRC and is the first record for Texas and the Gulf of Mexico.

Habitat: This Antarctic nester visits the western Atlantic Ocean during the summer months.

Similar Species: This species can be distinguished from Pomarine Jaeger by larger size, broader wings, and lack of barring in uppertail coverts.

 

Pomarine Jaeger Stercorarius pomarinus

Status: Uncommon to rare migrant and winter visitor and a rare summer visitor along the coast and in pelagic waters.

Habitat: coastal and offshore waters. May be seen chasing gulls and terns along jetties or near shrimp boats.

Similar Species: Very similar to Parasitic Jaeger. Identification difficult. Pomarine is heavier bodied and a relatively longer and thicker bill. David Sibley, from The Sibley Guide to Birds, points out that, “the combination of dark head and light uppertail coverts is typical of Pomarine and is never shown by Parasitic. The large bill is sharply bicolored and contrasts with the dark face, often conspicuous at a distance.” Pomarine Jaegers, like the smaller Long-tailed Jaeger, have strongly barred uppertail coverts. The central tail feathers on adult birds are long, rounded and twisted. The tail feathers of adult Parasitic Jaegers are pointed.

 

Parasitic Jaeger Stercorarius parasiticus

Status: Rare migrant and winter visitor along the coast and offshore waters; very rare in summer.

Habitat: coastal and offshore waters. May be seen chasing gulls and terns along jetties or near shrimp boats.

Similar Species: Very similar to Pomarine Jaeger. Identification difficult. Parasitic is more slender bodied than Pomarine Jaeger, having a relatively shorter and thinner bill. The tail and underwing coverts on Parasitic Jaeger are duller than the (boldly patterned) Pomarine and Long-tailed Jaegers. This feature creates little contrast between the underwing coverts and the flanks. The central tail feathers on adult birds are pointed, unlike the round and twisted tail feathers of Pomarine Jaeger.

 

Long-tailed Jaeger Stercorarius longicaudus

Status: Accidental along the coast in summer and fall. There are three records from the Valley: two from Port Isabel on 8 June 1989 and 17 June 1992, and one off South Padre Island on 26 September 2004.

Habitat: coastal or offshore waters.

Similar Species: Long-tailed Jaeger is the smallest (and rarest) of the three jaeger species. Adults are fairly distinctive, lacking white wing patches on underwing and long central tail feathers. However, juveniles can be similar to larger Parasitic Jaeger. Juvenile Long-tailed Jaeger is usually gray-toned (Parasitic is browner), with strongly barred tail coverts and a pale head. Sometimes visible are contrasting white shafts of the two outermost primary feathers of the upperwing.

 

Black-legged Kittiwake Rissa tridactyla

Status: Rare winter visitor to the Valley.

Habitat: pelagic and coastal waters, and inland watercourses.

Similar Species: Adult non-breeding Black-legged Kittiwake has a similar facial pattern (auricular spot) as adult Bonaparte’s Gull, but differs in size (larger), upperwing pattern (pale primaries and small black wingtips), and bill color (all yellow). First-winter Black-legged Kittiwake has a black collar, black legs, and a bold “M” upperwing pattern. By comparison first-winter Bonaparte’s Gull has no collar, pink legs, and a weak “M” upperwing pattern. Compare also with Black-headed Gull.

 

Bridled Tern Sterna anaethetus

Status: Uncommon summer visitor (May-September) to offshore and pelagic waters. Pelagic birding trips during the 1990’s turned up numerous birds during the summer seasons, and the species was removed from Texas Review Species in 1997. May be found singly, in small flocks, or in large feeding congregations, sometimes with Sooty Terns. Very rare along the coast following tropical storms.

Habitat: pelagic waters. Often found perched on driftwood, along Sargassum weed lines, and other floating material.

Similar Species: Similar to Sooty Tern. Although the color of the wings and upperparts is an important first clue, it is helpful to use a combination of field marks before making an identification. Bridled Tern differs from the slightly larger Sooty Tern by the combination of dark gray (not black) wings and upperparts, more extensive white outer tail feathers, and whiter forehead. Juveniles are very white-headed (juvenile Sooties are completely black). Unlike Sooty Tern, Bridled is often found perched on floating debris, especially along weed lines.

Voice: soft whistled, “wheeep.”

 

Sooty Tern Sterna fuscata

Status: Uncommon to rare summer visitor to pelagic waters off the Texas coast. Often found near deepwater tuna schools. Very local breeding species along the Lower Laguna Madre near Arroyo City (April-June). Occasionally seen along the coast at South Padre Island and Boca from April-September. There are many records along the coast and at scattered inland locations following tropical storms.

Habitat: pelagic waters, spoil islands (for nesting) and coastal beaches

Similar Species: Most closely resembles the slightly smaller Bridled Tern. Sooty Tern can often be distinguished from Bridled Tern because of its jet-black plumage and stockier build, however, distant birds on the open ocean can prove to be challenging. Juveniles are completely black, and are easiest to identify. In addition to plumage differences, adult Sooties show only narrow white outer tail feathers (Bridled are much more extensively white) and a more limited amount of white in forehead.

Voice: a distinctive high nasal, “wackee-wak”

 

Brown Noddy Anous stolidus

Status: Accidental in fall. Two records: along South Padre Island in the wake of Hurricane Gilbert, 1 8 September 1988; offshore of Port Isabel, 12 September 1992. Has been recorded from both pelagic waters and along the coast after the passage of tropical storm activity.

Habitat: pelagic waters

Similar Species: Very similar to Black Noddy (no South Texas records) and juvenile Sooty Tern (uncommon). Brown Noddy differs from Black Noddy by the combination of larger size, dark brown (not black) plumage, relatively shorter and thicker bill, and less contrasting white crown. Differs from juvenile Sooty Tern by having complete dark brown (not black) plumage, double-rounded tail (not forked), shorter, more rounded wings, and behavior (swooping flight or hovering along the surface).

Voice: low-pitched grating calls