As a result of bird censuses, 21 species and 1,825 individuals were recorded. The most species (13 species) were observed in the largest urban park (3.4 ha). No significant correlation between the number of species and the area of urban park was detected (p=0.1; Fig. 2), though a significant correlation between the number of species and the area of vegetation cover could be found (r=0.40, p<0.01; Fig. 3).
The result of the TWINSPAN classification is shown in Table 1 as a species-sample ordered table and in Fig. 4 as schematic diagram. The studied urban parks were classified into four types. The characteristics of each type were as follows: Type D (urban parks Nos. 12, 13, 14 and 15) comprised most large parks in the study area. Eastern turtle dove Streptopelia orientalis, pale thrush Turdus pallidus, Daurian redstart Phoenicurus
auroeus, Japanese bush warbler Cettia diphone and black-faced bunting Emberiza spodocephala were characteristically observed in these parks (Table 1). It is generally known that these species, except E. spodocephala, prefer
Fig. 3. Correlation between the number of species and the area of vegetation cover within urban parks
In type C parks (Nos. 1, 10, 16, 17 and 19) as well as in type D parks, the great tit Parus major was typically observed. Type C parks had smaller areas, but also high levels of tree vegetation cover. Grey starling Sturnus cineraceus was predominantly observed in type A (Nos. 6, 7, 8, 9 and 11) and C parks, and dusky thrush Turdus naumanni was mainly observed in type A. Type A (except one park) comprised the small parks located near large woodlands in the northwestern part of Nishinomiya City. Small and/or isolated urban parks were classified as type B (Nos. 2, 3, 4, 5, 18 and 20). In these parks, we recorded only bird species that tend to inhabit urban areas such as common pigeon Columba livia var. domestica, browneyed bulbul Hypsipetes amaurotis and mountain sparrow Passer monta – nus.
Table 1. Classification of species and parks by TWINSPAN. The output of TWINSPAN is a two-way table. It shows that parks are ordinated along the horizontal axis and species are ordinated along the vertical axis. All parks (and all species) are classified into a hierarchy of smaller and smaller (and more similar) groups by successive divisions. The divisions at each level of the hierarchy are indicated by lines of zeroes and ones below and to the side of the table. Where zeroes change to ones, a division is indicated (marked with lines). The numbers in the table show the pseudospecies cut level of each species.
1 2111 11111
Fig. 4. Schematic diagram of typically observed species, classified by TWINSPAN into four park types