TRADE IN THE GRAY PARROT Psittacus erithacus ON THE
ISLAND OF PRINCIPE (SÃO TOME AND PRINCIPE, CENTRAL
AFRICA): INITIAL ASSESSMENT OF THE ACTIVITY AND
ITS IMPACT
J. Juste B.*
Estación Biológica de Doñana, Consejo Superior de Investigaciones CientUlcas, Pabellón del Peru, Avda Maria Luisa s/n
Sevilla 41013, Spain
Keywords: gray parrot, Psittacus erithacus, conservation status, PrIncipe Island, Central Africa.
Grant, 1970; de Naurois, 1983; Jones et al., 1991). The
African gray parrot is well known for its wide vocalization potential and speech-mimic ability (Pepperberg,
1981). This, together with its relatively long lifespan,
has resulted in its being considered the most valuable
and popular cage bird (Rutgers, 1979). Its trade to
Western countries has flourished despite being an internationally protected species. When Principe’s gray parrot population was specifically included in Appendix I
of CITES, the commercial exploitation of this insular
population was condemned, and there is still international concern about the consequences of this trade.
The lack of data on the issue has also been complained
of by various sources (Jones et at., 1991; IUCN, 1993).
This article presents the first data on the exploitation
of and commerce in the gray parrot on the island of
PrIncipe, as well as on its impact and socioeconomic
significance.
INTRODUCTION
METHODS
PrIncipe (l032_1c43 N and 7°20’—7°28’ E) is a small
oceanic island (128 km2) forming part of a volcanic
chain which divides the Gulf of Guinea in a SW direction, and which also includes the islands of Bioko (a
land-bridge island), São Tome and Annobón (oceanic
islands). Due to their oceanic character, the flora and
fauna of these islands, specifically of PrIncipe, present a
high level of endemism. The conservation of these
unique ecosystems has become a subject of increasing
international interest (Atkinson et a!., 1991; Jones et
a!., 1991; Jones, 1994; Juste B. & Fa, 1994).
Alexander (1909) described Principe’s gray parrot
populations as a new species because of its bigger size
and dull darker colour. It was then considered as an
endemic race Psittacus erithacus princeps by Bannerman (1914), and it was still considered as such by Snow
(1950), but since Amadon (1953) even the subspecific
status has not been recognized (Mackworth-Praed &
Data were gathered in January and September 1994. A
total of six hunters were interviewed separately, and the
information given was compared. Interviews with local
people and authorities were carried out in order to ascertain the social acceptance of the parrot-catching activity.
During five days, hunters were accompanied on their trips
to various ecosystems within the forest. This allowed an
in-situ introduction to the hunters’ campsites as well as
to the techniques used. During these trips, the number
of nests counted during walks of 1 h (c. 4 km) with the
hunters in different ecological zones was used as an
estimation of the relative density of nests in these zones.
Two of these walks were made through the relatively
undisturbed Southern lowland rain forest (from Praia
Seca to Ribeira Porco), one in the high primary forest
(upper part of Papagaio river) and one in a typical
cacao plantation (around Bella Vista cocoa plantation).
Abstract
The trade in PrIncipe‘s gray parrot Psittacus erithacus
population was assessed during a two-month slay on the
island. It was established that the gray parrot nests
throughout the island. including on cocoa plantations.
Despite increasing commerce, it can still be considered a
common species on the island. Techniques of capture,
which yield a total of approximately 1500 chicks per
year, in addition to an unspecjJIed number of adults, are
described. Since trade in the gray parrot is probably resulting in the depletion of the species, the assessment of the
insular population and the evaluation of the impact of the
activity are urgently needed. These studies should involve
local hunters.
*Correspondence to: J. Juste B., Department of Biology,
Texas Tech University, Lubbock, TX 79409-3131, USA.
Tel.: 806 742 2715; Fax: 806 742 2963; e-mail:
BCJJB@TTACS.TrU.EDU
RESULTS
Parrot breeding
It was established that the gray parrot uses all types of
Fig. 1. Map of the island of Principe showing the various
nesting areas of the gray parrot: a, zone of maximum nest
density in the primary lowland rain forest; b, zone of intermediate density in the primary mountain forest; c, zone of low
density in the main zones of cocoa plantation. Location of
temporary campsites used by the collectors: 1, Praia Cará
(Praia São Tome); 2, Ribeira Porco; 3, Praia Seca. The dark
line represents the border of the proposed protected area.
forest on the island of Principe for breeding, including
the cocoa plantations (Fig. 1). A total number of 25
nests were found, all situated in hollows at heights of
I 5—30 m. At least four tree species were used for nesting (Table 1), but the most frequently selected (15 out
of 25 nests) was the viro Cleistanthus sp. Relative nest
density (nest/h search) was three times higher in the
southern forests, although the scarcity of data did not
allow statistical analysis of these differences (Table 1).
At the time of the survey, parrots were still hatching
and hunters reported a clutch size of two or three.
depending on the natural conditions for the year.
EXPLOITATION
At least 10 people were counted as devoting themselves
exclusively to this activity on the island of Principe.
According to the island’s civil authorities, the number
rises to 30 when part-time hunters are included. Collecand intensifies during
tion begins in mid-October,
November to January, working in groups of two or
three. Although covering the entire island, collectors
are more systematic in the southern forests, setting up
temporary camps on the Praia Cará, very close to Praia
São Tome, the Ribeira Porco, and the Praia Seca on
the southern coast (Fig. 1). They undertake an average
of three to five tours per year to these camps, each lasting four to seven days. From their campsite they
undertake established tours, during which they check
trees known to contain nests. Using ropes, they climb
the trunks until they reach the hollow containing the
nest. All of the chicks in the nest are captured but the
nest sites are apparently not damaged since they are
re-used in later years. The number of parrot chicks
obtained by each hunter per tour varies between five
and 30 (averaging about 20) and the total yield varies
greatly from year to year (it was very low in 1993, but
was expected to be high in 1994). From our data, and
considering only full-time hunters (10), a total annual
extraction of 600—1000 chicks can be estimated; in
good years, it could exceed 1500 chicks. In addition to
the chicks, adult specimens are also captured throughout the year on the entire island, using traps or lassos
placed in palm trees Elaeis guineensis in front of the
ripe fruit which the parrots voraciously seek out. A
reliable estimate of the number of trapped adult
parrots was not possible. The parrots are sold to intermediaries, the price varying locally depending on the
supply, usually between 4000 and 5000 dobras (US$ 1
900 dobras) per adult parrot and between 5000 and
8000 dobras per chick.
DISCUSSION
Parrot breeding
The usage by parrots of cocoa plantations as suitable
areas for nesting points to greater plasticity in
behaviour than previously thought (Harrison & Steele,
1989). Various collectors have documented
the
existence of nests even in hollows in the low-lying
shrubs which cover the peaks of the Mesa, Foucinho
de Cão, and As Mamas summits, and even in rocky
crevices. Our data agree with the consensus among
hunters that the only remaining patch of lowland rain
forest is the area of highest nest density. This area
stretches between the rivers Ribeira São Tome and
Ribeira Porco (Fig. 1). The reported number of chicks
per nest is also consistent with existing data on the
reproduction of the species (Mackworth-Praed & Grant,
1970; Smith, 1975).
The usual moment for capture of the chicks is at the
end of the nesting period, which, for the gray parrot,
lasts approximately 60 days (Smith, 1975). In Principe,
breeding begins in September and lasts until January.
Despite the synchronization of hatching described for
PrIncipe (de Naurois, 1983), the collectors unanimously
reported earlier hatching in the northern part of the
island, where the climate is much drier (Jones & Tye,
1988). According to the hunters the production of
chicks can vary dramatically and the fluctuation is a
result of the cycles of flowering and fruit-bearing for
some trees, especially in ‘lutrineira’ Erythrina spp. and
‘marapiâo’ Fagora macrophylla trees which provide
nutrition for the parrots during their nesting period.
Table 1. Distribution of parrot nests density (nest/h) according to habitat and nesting trees
Nesting tree
Viro Cleistanthus sp.
Aceitona Manilkara multinervis
Amoreira Clorophora excelsa
Lutrineira Erythrina sp.
Total nests
Census 1
Lowland rain forest
Census 2
Lowland rain forest
Census 3
High rain forest
6
3
8
1
1
1
1
2
10
4
—
9
Exploitation and trade
Parrot chicks are sold to resident foreigners and tourists,
and/or are transported abroad for sale, mainly to
Libreville, Luanda or Lisbon. From the collected data,
the activity brings the hunters an approximate annual
revenue between 4.8 and 8 million dobras (US$
5300—8900). This represents a substantial sum of
money given the country’s fragile economic situation,
with a per capita annual income of US$ 430 (WB,
1991) and negative economic growth (EIU, 1991).
Taking these conditions into account, an increase in the
capture of parrots can be expected, since a hunter can
generate nearly his mean per capita annual income in
just two months.
Legal status
Legal consideration of this activity is extremely inconsistent, depending basically on the will of the island’s
highest administrative authority (the Minister of the
region). No general environmental legislation exists in
the country, nor any specific legislation on this issue.
The capture of parrots, which was officially prohibited
in the past, is currently undertaken in a semi-clandestine way, although at the same time official fees are collected by the administration. In fact, the transport of
one parrot per person is permitted, while a licence costing 500 dobras (US$ 0.55) per individual must be
obtained from the Assembly for larger quantities,
although this is easily avoided. At the international
level, the fact that the country is not a party to CITES
impedes the possibility of taking any dissuasive action
or applying pressure. However, concern and a consciousness about the problem does exist, both among
PrIncipe’s local population and within the country’s
administration.
Impact
A reference to the capture of parrots was made by
Bannerman (1914), who even then estimated a decline
in the population. More recently de Naurois (1983)
referred to the capture of chicks for sale (in small
quantities) in the 1960s. Nonetheless, capture for commercial purposes on the present scale is a relatively
recent phenomenon (for about the last 15 years).
Knowledge of the location of trees with nests, as well
as the technical expertise to climb some of them (at
times it is necessary to climb up with long poles with a
lasso to remove the chicks), is transmitted from person
to person. The nests are visited a number of times until
Census 4
Cocoa plantation
Total
nests
2
2
5
3
2
25
it is ascertained that the chicks are covered with their
definitive coat of feathers, at which point they are
taken. Since there are no property rights and the chicks
belong to the first person who manages to capture
them, they are sometimes removed at a very young age,
which must lead to a high degree of mortality. The
capture of reproducing adults is especially serious and
has a direct effect on the population dynamics. The
population growth rate in long-lived species is much
more affected by loss in adult classes than by decrease
in productivity (Lande, 1988). In this case the adult
parrot capture results not only in the loss of a nest for
a particular year, but also in the loss of their reproductive potential.
Our data indicate that the figure of 3000 chicks
taken per year quoted by Jones et al. (1991) may be an
overestimate, even for good reproductive years. Nevertheless, the current rate of extraction is probably not
sustainable on a long-term basis. In fact, the majority
of local people interviewed declared that there was
already a noticeable reduction in the number of parrots
on the island. Moreover, the financial incentive for this
activity is likely to increase as a result of the collapse of
the typical economic practices such as cacao or coffee
farming, which now reflect production levels less than
one-third of the average crops for the past 10 years
(MADR, 1993). It is therefore important to evaluate
the current status of the population and the impact of
the current capture of parrots. Basic studies on the
ecology and ethology of the island’s species should be
undertaken and should involve the local collectors,
taking advantage of their knowledge and skills. In this
way, the support of at least part of the population and
of the administration can be counted on, given the
increasing awareness about the danger that the current
uncontrolled capture of chicks and adults poses for
Principe’s parrot population.
The ‘ecological zone’ designated by Jones et al.
(1991) was recently delimited within the framework of
the European Union’s ECOFAC project (Juste B.,
1994). The effective protection of this area would significantly contribute to halting this trade, since the highest density of nests occurs in the remaining southern
forest included within it.
ACKNOWLEDGEMENTS
This work was funded from the European Union’s
ECOFAC Project. I am very grateful to Claudia Keller
for assistance during the field work; to A. Gascoigne,
Vidi, Lulü and all the friends who helped me in
PrIncipe, and M. Ferrer, F. Hiraldo, J. Bustamante, C.
Ibáñez and S. Kasper for their comments on first
drafts.
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