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1

Seasonal variation in the body size-body mass relationship in the Southern Grey Shrike Lanius meridionalis

100%
Campos F., Gutierrez-Corchero F., Hernandez M. A., Lopez-Fidalgo J.
Acta Ornithologica
|
2008
|
tom 43
|
nr 2
139-143
The variation of male (n = 105) and female (n = 107) Southern Grey Shrike body mass has been analyzed in northern Spain during 2000-2002. The annual cycle was divided into autumn (October and November), winter (December to February) and breeding season (March to July), the latter subdivided into egg incubation, small nestlings and large nestlings periods. In order to analyze body mass, the residual index (RI) was used because it corrects body mass related to body size. The mean RI value for males was negative during the whole breeding season and positive during autumn and winter and it did not vary greatly between the periods. In females, the mean RI was definitely greater during egg incubation compared to other periods. The RI value of females was higher than that of males during the egg incubation and large nestlings periods, showing no significant differences in other periods. Female Southern Grey Shrikes (but not males) fitted to the programmed anorexia hypothesis during the breeding season whereas in winter they did not increase their body mass, in clear contrast to what has been put forward in some theoretical models.
2

Breeding success of Southern Grey Shrikes Lanius meridionalis in agricultural areas: the influence of nest site characteristics

88%
Campos F., Santamaria T., Gutierrez-Corchero F., Hernandez M. A., Mas P.
Acta Ornithologica
|
2011
|
tom 46
|
nr 1
Three hundred and thirty nests of Southern Grey Shrike Lanius meridionalis were located during 1998-2010 in two highly fragmented Mediterranean agricultural areas of Spain (Olite in Northern and Toro in Western part of the country). Most nests (ca. 85%) were built in thorny shrubs (mainly Dog Rose Rosa sp. and Blackberry Rubus ulmifolius) and thornless shrubs (mainly Holm Oak Quercus rotundifolia and Kermes Oak Quercus coccifera). Based on a logistic regression, three factors had an influence on breeding success: study area, breeding phenology, and plant cover type. Location of the nest inside the shrub, as well as luminosity inside a shrub varied between studied shrub species, but did not significantly affect breeding success. The percentage of successful nests was significantly higher in Olite than in Toro (64.5% and 37.9% respectively). In Olite, but not in Toro, clutches laid early (first egg laid prior to 1st May) were more successful than clutches laid late. The highest breeding success was recorded in nests located in thorny shrubs and, especially, in those found in Blackberry bushes. Conservation of Blackberry shrubs appears to be an appropriate measure to increase breeding success of the Southern Grey Shrike.
3

Biometric differences among the Dipper Cinclus cinclus populations of Spain

88%
Campos F., Gutierrez-Corchero F., Hernandez M. A., Rivas J. M., Lopez-Fidalgo J.
Acta Ornithologica
|
2005
|
tom 40
|
nr 2
87-93
The length of the tarsus and wing, and the weight of the Dipper were measured in four mountain ranges in Spain (Cantabrian Mountains, western Pyrenees, the Central Mountains and Sierra Nevada). Birds from the Sierra Nevada were the largest but there were no significant differences among the other three areas. In the north, the range of the C. c. cinclus and C. c. aquaticus subspecies overlapped. In the south only aquaticus was present and in the central mountains only cinclus. The biometrics of cinclus in the north and centre were similar but aquaticus was larger in the south than the north. Spanish populations of C. cinclus thus appear to go against the predictions of Bergmann's rule. The residual index (RI) was calculated for individual birds from the regression of mass/tarsus length. RI was higher in males than females in the northern populations, but the same in the centre and south. According to this index, males (but not females) were heavier than the theoretical weight in the north and lighter in the centre and southern ranges. Some other variations in the Spanish populations are also discussed.
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