Friday, October 21, 2011

South African Gulls


Kelp Gull was very common along the coast from Port Elizabeth to Namibia

During my recent jaunt to Southern Africa I was able to reacquaint myself with two gull species I'd seen several times before plus add a new one to my life list. The most prominent among these was Kelp Gull (Larus dominicanus). Its range extends from the west coast of South America through the subantarctic islands to southern Africa to Australia. There are several extralimital records from the United States. A quick check of my records revealed observations from Ecuador, Peru, Chile, Argentina, Brazil (Sao Paulo State), Tasmania and South Africa within its usual range. The first one I ever saw was on the coast of Texas in 1985 and several years ago one spent a considerable amount of time on the lower Chesapeake Bay in Maryland. Last winter there was one in Pasco County, Florida. To be sure this bird gets around.

Given its large size this gull could easily be mistaken for either Lesser Black-backed Gull or Great Black-backed Gull. However except for the extralimital birds the ranges of these three species do not overlap. In Southern Africa this species is also referred to as the "Cape Gull" which is the subspecies vetula. Maybe some day some enterprising taxonomist will decide that Cape Gull and Kelp Gull are two different species. They certainly look and sound and behave the same in my eyes.

The only Gray-hooded Gulls I found were near the St. Lucia wetlands northeast of Durban
Another gull with which I was able to reacquaint myself was Gray-hooded Gull
(Chroicocephalus cirrocephalus) which is patchily distributed in South America and in Africa south of the Sahara. The first one I ever saw was on the coast of Peru in October 1996 and then later I found several along the edge of the Rio de la Plata in Buenos Aires, Argentina. Those were my only observations until the one group of Gray-hooded Gulls I saw in South Africa. As recently as the summer of 2011 one was observed on Coney Island in New York City and before it the only North American record was of a bird here in Florida.

Hartlaub's Gull seemed fairly common along the coast from Cape Agulhas to the Namibia border
The only new species of gull I added to my life list was Hartlaub's Gull (Chroicocephalus hartlaubii). This diminutive species, in the same genus as Gray-hooded Gull, is largely restricted to the coast of South Africa and Namibia. In many ways this bird reminded me of both Mediterranean Gull and Slender-billed Gull from Europe and the Middle East.

My first Hartlaub's Gulls were in a small flock hunkered down in a howling gale at Cape Recife Nature Reserve near Port Elizabeth. They were in a mixed species flock that included Antarctic Terns and Roseate Terns. On arrival in Cape Town I found them almost equal in abundance to Kelp Gull and that level of abundance seemed constant along the coast north to Alexander Bay on the Namibia border. The birds in this picture were photographed (do you take photographs with a digital camera when there is no film?) at the Paarl Waterbird Sanctuary (a euphemism for the city of Paarl sewage treatment lagoons) about 100 km northeast of Cape Town. I was actually surprised to see them that far inland because everything I had read before the trip suggested they were tightly associated with coastal habitats.

Despite the abundance of habitat that seemed perfect for gulls only these three species were found along all of the coast of South Africa that I searched. There are extralimital records of other gull species (including several from North America) in South Africa. However for some reason the diversity of gulls in southern Africa is quite small. I guess that is another ornithological "why" question I'll have to obsess on until I figure out the reason.

2 comments: