366
German L6pez-Iborra and Jose A. Gil-Delgado
group included two mixed forests and one pine forest, and it also presented
the typical pattern of summer maximum and winter minimum, but with a
marked peak at the end of summer and beginning of autumn corresponding
to the post-breeding migration. The third group included bird communities
with abundance maximum in spring, and a pronounced decrease in summer,
due probably to the high temperatures and summer drought. This group included two holm oak woods and one mixed forest that was also dominated
by holm oak, all of them located in southern Spain (Andalusia). Finally, the
fourth group included bird communities with abundance maximum in winter and minimum in summer, a pattern opposite to that found in our study
area. This group is heterogeneous with respect to habitat types: it included
Mediterranean shrublands, cultivated fields, steppes, and coastal pine woods.
The only two forest habitats included are coastal pine woods located in
southernmost Spain (Dofiana).
All the holm oak forests reviewed here exhibited maximum bird abundance in spring or summer, with minimum values in winter, but two groups
are clearly identifiable: Holm oak forests in the northern half of Spain
reached the maximum abundance in mid-summer, while holm oak forests
located in the southern half of the Peninsula presented the maximum abundance earlier, at the end of spring. In southern forests, most of the birds disappeared from the area at the beginning of summer, producing a summer
minimum. After this season, bird abundance recovered and decreased again
in winter. Thus, it appears that in holm oak forests of southern Spain, the
summer conditions impose more important limitations on the birds than in
more northern areas, where winter would be the critical season. However, altitude seems to play an important role in determining the seasonal pattern of
bird abundance fluctuation, as the holm oak forest studied by Zamora and
Camacho (1984b), placed at about 1000 m a.s.l., suggests. Its bird community
is included within the first group in Fig. 25.5, despite being located in southern Spain.
References
Blondel J, Farre H (1988) The convergent trajectories of bird communities along ecological successions in European forests. Oecologia 75:83-93
Carrascal LM (1986) Estructura de las comunidades de aves de las repoblaciones de Pinus radiata del Pais Vasco. Munibe 38:3-8
Carrascal LM, TelJeria JL (1990) Impacto de las repoblaciones de Pinus radiata sobre la avifauna
forestal del norte de Espana. Ardeola 37:247-266
Carrascal LM, Potti J, Sanchez-Aguado FJ (1987) Spatio-temporal organization of the bird
communities in two Mediterranean montane forests. Holarct Ecol 10: 185-192
Costa L (1984) Composici6n de la comunidad de aves en pinares del Parque Nacional de Donana (suroeste de Espana). Donana Acta Vertebr 11:151-183
Costa L (1993) Evoluci6n estacional de la avifauna en hayedos de la montana cantabrica.
Ardeola 40: 1-11
German L6pez-Iborra and Jose A. Gil-Delgado
group included two mixed forests and one pine forest, and it also presented
the typical pattern of summer maximum and winter minimum, but with a
marked peak at the end of summer and beginning of autumn corresponding
to the post-breeding migration. The third group included bird communities
with abundance maximum in spring, and a pronounced decrease in summer,
due probably to the high temperatures and summer drought. This group included two holm oak woods and one mixed forest that was also dominated
by holm oak, all of them located in southern Spain (Andalusia). Finally, the
fourth group included bird communities with abundance maximum in winter and minimum in summer, a pattern opposite to that found in our study
area. This group is heterogeneous with respect to habitat types: it included
Mediterranean shrublands, cultivated fields, steppes, and coastal pine woods.
The only two forest habitats included are coastal pine woods located in
southernmost Spain (Dofiana).
All the holm oak forests reviewed here exhibited maximum bird abundance in spring or summer, with minimum values in winter, but two groups
are clearly identifiable: Holm oak forests in the northern half of Spain
reached the maximum abundance in mid-summer, while holm oak forests
located in the southern half of the Peninsula presented the maximum abundance earlier, at the end of spring. In southern forests, most of the birds disappeared from the area at the beginning of summer, producing a summer
minimum. After this season, bird abundance recovered and decreased again
in winter. Thus, it appears that in holm oak forests of southern Spain, the
summer conditions impose more important limitations on the birds than in
more northern areas, where winter would be the critical season. However, altitude seems to play an important role in determining the seasonal pattern of
bird abundance fluctuation, as the holm oak forest studied by Zamora and
Camacho (1984b), placed at about 1000 m a.s.l., suggests. Its bird community
is included within the first group in Fig. 25.5, despite being located in southern Spain.
References
Blondel J, Farre H (1988) The convergent trajectories of bird communities along ecological successions in European forests. Oecologia 75:83-93
Carrascal LM (1986) Estructura de las comunidades de aves de las repoblaciones de Pinus radiata del Pais Vasco. Munibe 38:3-8
Carrascal LM, TelJeria JL (1990) Impacto de las repoblaciones de Pinus radiata sobre la avifauna
forestal del norte de Espana. Ardeola 37:247-266
Carrascal LM, Potti J, Sanchez-Aguado FJ (1987) Spatio-temporal organization of the bird
communities in two Mediterranean montane forests. Holarct Ecol 10: 185-192
Costa L (1984) Composici6n de la comunidad de aves en pinares del Parque Nacional de Donana (suroeste de Espana). Donana Acta Vertebr 11:151-183
Costa L (1993) Evoluci6n estacional de la avifauna en hayedos de la montana cantabrica.
Ardeola 40: 1-11