Human-Altered Tree-Based Habitats and Their Value in Conserving Bird and Bat Diversity in Northeast Luzon, The Philippines - Smallholder Tree Growing for Rural Development and Environmental Services - page 353

Probably as a result of the small sample size due to averaging scores per locality
to avoid pseudo-replication, none of the reported differences in average bird and bat
species richness and abundance between habitat types proved significantly different
in pair wise comparisons per locality (non-parametric Wilcoxon signed rank test for
related samples).

16.3.5 Relations Between Species Richness and Abundance

and Habitat and Landscape Variables

We tested for correlations between average bird and bat species richness and abun-
dance (all bird and bat species, forest birds, forest bats, cave roosting bats) and
average habitat characteristic and landscape variables per locality. Within Gmelina
forest, a negative relationship (Spearman r = −0.899, n = 6, p < 0.05) was found
between the average number of houses within 100 m of a point count and the aver-
age number of forest bird species observed per point count. For the other two habi-
tat types this relationship was less obvious (Fig. 16.4A), and not significant. For

3.0 3.0

A

B

2.5

2.5

2.0

2.0

1.5

1.5

1.0

1.0

HABITAT
Shrub-land
Homegarden
Gmelina

HABITAT
Shrub-land
Homegarden
Gmelina

.5

.5

0.0

0.0

0 10000 20000

0 2 4 6 8 10 12 14 16

Number of houses Distance to contiguous forest (m)

18
16
14
12
10
8
6
4
2
0

C

HABITAT
Shrub-land
Homegarden
Gmelina

0 10000 20000

Distance to contiguous forest (m)

Fig. 16.4 Relationships between the number of houses within 100 m of the centre of a point count and
the average number of forest bird species observed per point count (A), the distance to contiguous forest
and the average number of forest bird species observed per point count (B) and the distance to contigu-
ous forest and the average number of all resident bird individuals observed per point count (C)