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Intl. J. of Mol. Evol. and Biodivers. 2011, Vol. 1, No. 1-5
http://ijmeb.sophiapublisher.com
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mate or forage (Martín and Salvador, 1995). Moreover,
lizards need refuge to run into to avoid predators and
the escape distances are relative to the vegetation
cover because it makes up for the bare ground.
In our study, we tested the effects two diverse habitats
had on
P. algirus
,
P. hispanicus
,
A. erythrurus
. We
hypothesize that lizards will be more active at times
when the sun is directly hitting the surface, and lizards
will prefer open areas within a close distance to low
shrub cover, to maximize their opportunities to bask,
forage and avoid predators.
1 Results
1.1 Escape distance
The correlation between escape distance and
temperature was shown to be non significant (ρ=
0.095, n=46, P=0.529), and escape distance and wind
speed was also not significant (ρ=0.081, n=46, P=
0.594). The Kruskal-Wallis test also showed that
escape distance was not significant (χ
2
=0.433, df=3,
P=0.933; Figure 1). The Mann-Whitney Test showed
the relative escape distance is almost the same
(U=141.5, n=42, P=0.283).
Figure 1 The escape distance of
A. erythrurus
and
Psammodromus sp.
Note: The mean escape distance does not differ between dry
river valley and the gypsum desert., as shown by The
Kruskal-Wallis Test (χ
2
= 0.433, df=3, P=0.933)
1.2 Lizard abundance
Using the Fisher’s Exact Test, aspect was significantly
related the number of lizards that were found on the
side that the sun was shining (P<0.001). Similarly, the
Fisher’s Exact Test gave a significant result for lizard
abundance in each site, separated by time (P<0.001;
Figure 2). Conversely, the Fisher’s Exact Test gave
non-significant results for the number of lizard species
(
A. erythrurus
and Psammodromus sp.) found in each
site (P=1.000). According to the Kruskal-Wallis Test,
lizard abundance was not significantly different at
each of the different sites (χ
2
= 5.115, df = 3, P= 0.164;
Figure 3).
Figure 2 The number of
A. erythrurus
and Psammodromus
sp
.
Note: both are in the dry river valley and the gypsum desert,
separated into the morning (930-1330h) and afternoon
(1400-1730h) surveying sessions. Fisher’s Exact Test shows that
there is a significant difference in frequencies between lizard
abundance and time of day (P<0.001)
Figure 3 Mean numbers of lizards present in each of the study
sites
Note: Fisher’s Exact Test showed that lizard abundance was not
significantly different among sites (P=1.000)
1.3 Habitat variables
The percent vegetation cover was not significantly
different per site (χ
2
=2.412, df=3, P=0.491; Figure 4).
The Generalized Linear Model for the effects the
interactions of habitat, wind speed and temperature
had on escape distance showed all non significant
results. There was no minimum adequate model
because even when the two way interaction terms were
omitted individually (wind speed × air temperature; wind
speed × habitat; air temperature × habitat), to reveal just
the main effects, the model was still insignificant (habitat: