Cruz, Felipe

Cruz, Justine

Lawesson, Jonas E.

English

Aquatic Commons

LANT ANA CAMARA L., A THREA T TO NA TI VE PLANTS AND ANIMAL S
by
Felipe and lustine Cruz. Principal Investigators. Petrel Project
and
lonas E. Lawesson. Resident Botanist
Charles Darwin Research Station
For a long time, the Hawaiian or Dark-rumped Petrel, Pterodroma phaeopygia. in the Galapagos Islands,
has been threatened by introduced mammals, documented by several authors (Tomkins, 1980; Duffy,
1984). Many efforts háve been made to control these threats from predators but until now very little
attention has been directed to threats originating from the vegetational changes represented by introduced
plant species. While the control of the animals threatening the petrel on Floreana Island are meeting with
some success, the introduced aggressiveplant, Lantana camara L. (Verbenaceae), is spreading into the
breeding area of the petrel, thus becoming a threat to this bird and also to some other plant species.
L. camara L. is a native plant oftropical America but is now used extensively as an ornament in all warmer
areas of the world. It grows easily into a 1-2 metre high shrub, and is therefore often used as a hedge.
Lantana reproduces itself easily by means offruits, usually eaten by birds, but also vegetatively. Because of
its easy reproduction, dispersal, and vigorous growth, L. camara represents asevere problem around the
world when it escapes into natural areas, as seen in S. Africa, Australia, Hawaii, and the USA. When
conditions are optimal, the area invaded by Lantana turns into an impenetrable 1-2m high stand. The
magnitude of the problem of erradication, once Lantana has become established, is illustrated by the
following citation: "There is little doubt that, where the country lends itselfto it, clearing standing Lantana
with a bulldozer, followed by discing, is the best starting point". (Bartholomew, 1980).
:~J
-.
Felipe Cruz measuring and banding an adult petrel at mouth of nesting cave
Photo: Justine Cruz
The introduced L. camara (vernacular name: Supirosa) which is a close relative to the native L.
peduncularis. is known in Santa Cruz, San Cristóbal, and Floreana. Except for Floreana, the problem of
Lantana is not grave as yet,.but measures to eradicate it from gardens, ete., should be started now, while
the elimination of this dangerous species is still possible.
10
Noticias de Galapagos v.43 1986
On Floreana, Lantana was introduced in 1938 by Ainsley and Francis Conway on their small farm in the
central S.E. of the island. Francis wrote that they established a garden with many varieties of fruits and
flowers, wnich included the first recorded Lantana plants in Galapagos. Whiie clearing for their garden
they would throw cuttings of Lantana over their improvised fence and the extra growth helped to keep out
the marauding wild cattle and pigs. She adds that the "... balsams and lantanas spread into the jungle trails
and the pampas."
Not surprisingly, dense thickets of Lantana resulted, and in these areas the population ofrats is higher,
perhaps because the plants' seeds are a good food source. The native Galapagos finches readily eat and
disperse the seeds and during dry spells cattle and donkeys also take the fruit. By 1983 several extensive
areas in the highlands close to Cerro Pajas and Cerro Ventana had been covered by stand s of Lantana. The
former vegetation types found in these areas, were Scatesia peduculata forest and a dry vegetation
represented.by Croton, Macraea, and Darwiniothamnus. In the areas now being invaded by Lantana some
small populations of rare plant species are found and are therefore in danger ofbeing eliminated. This is
true of 2 of the 3 populations of Lecocarpus pinnatifidus Decaisne (Compositae) and of a population of
Scalesia vil/osa (Compositae). Both species are endemic to Floreana.
The impending spread of this agressive weed to the era ter area of Cerro Pajas, where the Dark-rumped
Petrel nests, is of grave concern. If the plant is allowed to follow its normal growth pattern the resultant
dense thicket will keep the petrels, which nest in burrows, from occupying their historie breeding site. As
Lantana advances there is little doubt but that the Petrels will be forced out ofthe largest remaining nesting
colony in the Galapagos. Likewise littIe doubt remains that important vegetation types, including rare
endemic species, will also become extinct.
Every effort should be made to raise funds to finance an immediate erradication campaign on Floreana. A
positive result would help to save the endangered Dark-rumped Petrel as well as the beautiful Lecocarpus.
LITERA TURE CITED
Bartholomew, B.L. (1980) Lantana Control. The Weed Science Society of Queensland Newsletter 21.
Conway, A. and Francis (1948) The Enchanted Islands, Geoffrey Bles, London: p. 245.
Duffy, D., (1984) The endangered petrel of the Galapagos voIcanoes. Noticias de Galapagos 39: 24-27.
Tomkins, R., (1979) The study and conservation of the Dark-rumped Petrel Pterodroma phaeopygia,
considered to be an endangered species in the Galapagos. Annual Report, Charles Darwin Research
Station: 33-36.
.
11
Noticias de Galapagos v.43 1986


Lantana camara L., a threat to native plants and animals

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Lantana camara L., a threat to native plants and animals

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