Falkland Islands biogeography: converging trajectories in the South Atlantic Ocean

Abstract

Aim This paper describes the biogeographical setting of the Falkland Islands, in the context of the relationships of the islands’ biota to other sub‐Antarctic/cold temperate lands. Location The analysis focuses primarily on the Falklands biota, and explores its relationships to those of Patagonian South America and South Africa, other southern lands and the islands of the sub‐Antarctic Pacific, Indian and Atlantic Oceans. Methods The study derives largely from literature sources on the biota and geological history of the Falkland Islands. Results The animals and plants known from the Falkland Islands exhibit strong affinities with those of Patagonian South America, and especially Tierra del Fuego; additional affinities are with various remote islands of the sub‐Antarctic, as well as New Zealand and to a lesser extent Australia; often these are shared with Patagonia. While the biotic affinities might be interpreted, by some, as indicating a former Gondwanan/South American geological connection of the Falklands, geological evidence points to the Falklands formerly having a land connection to south‐eastern South Africa. Only faint hints of a South African biotic connection remain. The historical biotic and geological connections of the Falklands thus conflict. Moreover, the Falklands biota is so strongly Patagonian that derivation of that biota is best seen as resulting from dispersal, much of it probably recent. This dispersal biota appears to have replaced, and perhaps displaced, the South African biota present on the islands as they detached from South Africa and drifted across the south Atlantic Ocean, as it opened up as South America and Africa drifted apart.

Phylogeography of the southern skua complex—rapid colonization of the southern hemisphere during a glacial period and reticulate evolution

“…Furthermore, the geographic position of the Falklands, and the overlap in nonbreeding distribution of Falkland Skua with Brown Skua (Phillips et al, 2007) suggests a higher likelihood of genetic exchange with other taxa, potentially hampering the exact disclosure of historic processes. However, glaciation of Antarctica was near its maximum at 150,000 yBP whilst the Falklands were probably never heavily glaciated (McDowall, 2005). This may have facilitated colonization of the Falklands from skua populations at the Antarctic Peninsula, South Georgia and the Patagonian fjords.…”

The origins of the enigmatic Falkland Islands wolf

“…The mystery is deepened by the absence of any other terrestrial mammals on the islands. While the flora and fauna of the islands show overwhelming Patagonian biogeographical affinities 10 , the physical isolation of the islands (B460 km from the South American mainland) has resulted in a number of theories to explain the origin of the FIW. These include semi-domestication and transport of a continental ancestor by humans sometime after their arrival in southern South America B13-14.5 ka (refs 11,12) or natural dispersal via rafting on ice or over a land bridge during Pleistocene glacial sea level minima 1,[13][14][15] .…”

Influences on and origins of terrestrial biodiversity of the sub-Antarctic islands

“…2003. The debate essentially rests on whether all the islands share enough of their biotas to form a single biogeographic entity (as proposed by Holdgate 1960, Skottsberg 1960, Udvardy 1987, van de Vijver & Beyens 1999, or whether there are sufficient regional differences simply to require that each is most appropriately linked to the Southern Hemisphere continent to which they arc closest (Gress itt 1970, Smith 1984, Morrone 1998, Cox 2001, McDowall 2005.…”