Productive year for Cayennes
Cayennes (Sterna sandvicensis eurygnatha)
Cayennes (Sterna sandvicensis eurygnatha)
are terns, small gull-like seabirds, which breed on Aruba from March
till August. They are entirely sea-going and feed mostly on small fish
but also squid and some insects. Aruba is an important area for this
tern specie, about 15% of the world population breeds here. On Aruba the
Aruba Tern Project monitors the terns for nine years now. The project is
designed and conducted by Dr. Adrian del Nevo of Applied Ecological
Solutions Inc. in collaboration with the Aruba Government, CaribeAlaska
and funded by Valero Aruba Refinery. Within the project the terns in San
Nicolas Bay, are banded. This year a total of 1200 Cayenne chicks were
banded, which are a lot more in comparison with other years. In all the
years prior about 7000 chicks were banded. The birds are banded so that
the location of its death can be determined upon retrieval of the band.
In Oranjestad about 100 chicks were reared.
Banding chicks
To band the chicks the project had to use several volunteer groups.
This because of the greater amount of chicks, to reduce the amount of
time the chick is separated from its parents and because growth data are
collected at the banding. This data would be the length of the wing and
the weight of the chick. To assess the growth of the chick, several of
them would need to be recaptured within a week and have their wing
length remeasured. The difference in wing length would provide an
estimate of their growth. Also the amount of chicks recaptured against
the chick newly banded would provide an idea of their total number.
Department of Agriculture, Husbandry & Fisheries assisted with the
monitoring of the Cayennes in Oranjestad and the banding of the chicks.
Lots of small fish
Indications are that this year there is a lot more of small fish.
According to the Fishery Section of the department lots of fishermen
mentioned this unusual amount of fry fish. On the reefs at banding one
could see the amount of fish being brought in by the birds. In general
terns would feed at 60 km. north of Aruba. The great amount of chicks
could also be to the fact that no rats were signalled upon the reef the
Cayennes breed upon, contrary to another reef Islet. Next to the good
news about the successful reproduction of the Cayennes it has to be said
that the endangerment of the seabirds on Aruba has not diminished.
Coastal development is still in full bloom. This directly eliminates
suitable habitat for the birds, but also increases the pressure of human
activity on adjacent ones. This year in March, human activity has been
noticed on the reefs of San Nicolas Bay. The government of Aruba would
like to conserve them for nature. To this end the Veterinary Service
approached a professional pest control to eradicate the rats on the
reefs.
For more information call 5856473 or email dirlvvm@setarnet.aw
[Information courtesy of Mr. Facundo Franken of the Department of
Agriculture, Husbandry and Fisheries (DLVVM) - Nature Management]
