International Journal of Mol. Ecol. and Conserv. 2015, Vol.5, No. 2, 1-6
2
of African continent (Egwali et al.
,
2005). It has been
rated among the most threatened of African species and
considered as one of the highest priority species for
conservation action amongst the African primate taxa
(Oates, 1994, Tooze, 1994a, b, 1995; cites.org). It is
also the most threatened of the African guenons (Oates
and Anadu, 1989).
Materials and Methods
Study area
Ikot Uso Akpan is located in the southern part of
Nigeria in Akwa Ibom State between 5º7’49’’N and
7º56’47’’E and lies between Ikot Uso Akpan and
Obong Itam villages in Itu Local Government Area
(Egwali et al., 2005). Itu Local Government Area
occupies a landmass of approximately 606.1 0 square
kilometers (onlinenigeria.com, 2011). It is bounded in
the North and North-East by Odukpani in Cross River
State and Arochukwu in Abia State, in the West by
Ibiono Ibom and Ikono Local Government Areas, in
the South and South-East by Uyo and Uruan Local
Government Areas, respectively. The vegetation of the
area along the West line is a swamp forest and moist
lowland forest in the interline (onlinenigeria.com,
2011). The topography of the area is highly undulating.
The area has eight to nine months of raining season
and a short period of three to four months of dry
season. The area has a mean annual rainfall ranges of
2500mm to 3000mm with a mean annual temperature
of about 26.1ºC and a relative humidity of 85 percent
(Metz, 1992; Fasona and Omojola, 2005).
Figure 1: Map of study area and neighboring villages
Source: Egwali
et al.
(2005)
Sampling design
The survey of
C. sclateri
in the study area was carried
out using the
Line-transect method.
The line-transect
is a plotless method in which the observers walk along
straight lines of known length, and are either placed
randomly or systematically across the survey area.
This method has been successfully applied in previous
studies in the tropics (Janson and Goldsmith, 1995;
Buckland et al., 2001; Aguiar and Lacher, 2003;
Egwali, et al., 2005; Quinten, 2008). To ensure
accurate density estimates of
C. sclateris
, the five
fundamental assumptions of Line-Transect method
which are; 1) Objects directly on the line will never be
missed, i.e., g(0) = 1, 2) Points are fixed at the initial
sighting position (i.e., no movement before or after), 3)
Distance and angles are measured exactly, 4)
Sightings are independent events, and 5) For clustered
populations, the probability of sighting a cluster is
independent of cluster size were observed (Buckland
et al., 1993, 2001; Quinten, 2008) for every survey.
The transect lines spanned up to 2km and traversing
the community forest to ensure every portion of the
forest was systematically covered in the study. The
transect line had a diameter of 1m and sighting was
extended to 10m on both sides of the transect line.
C.
sclateri
survey was carried out once every week for a
period of 6 months (3 months each for both dry and
rainy seasons) between 7.00 to 9.00; 9.30 to 11.30;
and 15.30 to 17.30 every census day with the help of
two experienced locals who were familiar with the
study area and monkey. Both locals were made
familiar with the survey equipment (GPS, range finder
and sighting compass, binoculars, etc) and the census
protocol. Survey was carried out once a week for a
period of six months and both visual and audio
observations encountered were documented. Survey
was avoided during rainy days, mainly for two reasons;
first, the raindrops falling in the forest will create an
unfavorable acoustic background for survey reducing
the ability to hear typical animal movements, thus
potentially precluding the detection of
C. sclateri
which would have otherwise been recorded (Peres,
1999). Secondly, some primate species have been
observed to move little or even remain motionless in a
tree during rain (Whitten, 1982; Feuntes, 1996), a
behavior which reduces their likelihood of being
detected.
Results
Distance of encounter
The result of estimate for distance between observer
and animal when first sighted during the dry and rainy
season (Figure 1) indicates that in the dry season, no
encounter was made within 5m sighting distance of
