Segregation, that animals of different sex and/or age do not spend time together all year round, is a common phenomenon. One example is that males and older individuals in migratory birds wintering further north. Migration time also affects the distribution of birds in the wintering area. European Robins that migrate in late autumn tend to winter farther east. Another factor that affects wintering areas is global warming. Today wintering birds do not migrate as far as they used to. The aim was therefore to investigate if Robins segregate during winter and if they segregate by sex, age and/or migration time and to see if the wintering area has changed since 1950. Analysis of Robins ringed at Ottenby Bird Observatory that has been recovered during winter was conducted. To obtain an indication on what influences Robins in their choice of wintering area, an analysis was done with migration year, age, and migration time (sex was excluded in this analysis) to analyse what effects migration distance. The geographical centroid was used for representing the wintering area. The difference between the group’s centroid was tested with a permutation test. The result indicated that migration time best explains the distribution of Robins in the wintering area. Robins that migrate late migrate shorter and winter further northeast, this is probably due to sequential migration of different populations. No effect of age or migration year was observed. The wintering area appears to have moved north, which indicates that Robins are affected by global warming.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-05-06T00:00:17Z No. of bitstreams: 1 AnyellePRE_DISSERT.pdf: 3332574 bytes, checksum: 6eba66f5232c1024161e4faadd9f882f (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-05-16T12:04:56Z (GMT) No. of bitstreams: 1 AnyellePRE_DISSERT.pdf: 3332574 bytes, checksum: 6eba66f5232c1024161e4faadd9f882f (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-05-16T12:05:16Z (GMT) No. of bitstreams: 1 AnyellePRE_DISSERT.pdf: 3332574 bytes, checksum: 6eba66f5232c1024161e4faadd9f882f (MD5) / Made available in DSpace on 2017-05-16T12:05:44Z (GMT). No. of bitstreams: 1 AnyellePRE_DISSERT.pdf: 3332574 bytes, checksum: 6eba66f5232c1024161e4faadd9f882f (MD5) Previous issue date: 2017-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The increasing degradation of natural wetlands has led many shorebirds populations to use alternative or complementary habitats. The artificial salines are one of the most common alternative habitats used by shorebird to feed and rest in coastal areas. The aim of this study was to investigate the richness, composition, habitat use and seasonal variation of shorebirds species associated with the artificial salines of the Apodi-Mossoró Estuary, Brazilian semiarid. Between August 2012 and July 2016, fortnightly shorebirds Charadriiformes censuses were conducted (2 h duration) in an area of 145 ha of saline from this Estuary (04°57’S; 37°08’O), in periods of high and low tide. A cumulative total of 28,868 records of individuals of 19 species Charadriiformes were obtained during 192 censuses. The number of records of shorebirds per census in the summer (2nd fortnight of August to the first fortnight of March: 167.9 ± 16.9 records, mean ± SE, N = 112 censuses) was similar to that sighted in the winter (2nd fortnight of March to the 1st fortnight of August: 125.7 ± 11.4, N = 80) (U = 4221; p = 0.495). In the summer period, the number of shorebirds records per census did not vary between periods of high tide and low tide (U = 1280; p = 0.094). On the other hand, in the winter, the number of shorebird records at high tide was higher than at low tide (U = 501.5; p = 0.004). Comparing the use of microhabitats over the studied saline area, shorebirds were more frequent in the evaporation ponds (85% of total records), and less frequent in pumping (9%) and crystallization (6%) ponds. There was a significant difference in the number of records of individuals/ha (density), with the highest density of individuals per census in the evaporation ponds (H = 246; p < 0.0001). The evaporation and pumping ponds were used mainly for foraging (respectively 79% and 76% of the records by microhabitat) and the crystallization pond for resting (75%). Our results shows that the Apodi-Mossoró Estuary may be recognized as an important area for the conservation of migratory and resident Charadriiformes populations in the South America. The use of artificial salines of this Estuary by shorebirds as alternative habitats for feeding and resting makes important to implement a continuous environmental monitoring program in the salines in order to ensure the maintenance of species-specific ecological requirements and to avoid chemical contamination of these animals / A crescente degradação de áreas úmidas naturais tem levado muitas populações de aves limícolas a buscarem habitats alternativos ou complementares, sendo as salinas artificiais um dos locais mais utilizados por estes animais para alimentação e descanso. O objetivo deste estudo foi investigar a riqueza, a composição, o uso do habitat e a variação sazonal de espécies de aves limícolas associadas às salinas artificiais do Estuário Apodi-Mossoró, semiárido brasileiro. Entre agosto de 2012 e julho de 2016, foram realizados quinzenalmente censos (2 h duração) de aves limícolas Charadriiformes em uma área de 145 ha de salina deste Estuário (04°57’S; 37°08’O), em períodos de maré alta e baixa. Um total acumulado de 28.868 registros de indivíduos de 19 espécies Charadriiformes foram obtidos em 192 censos. O número de registros de aves limícolas por censo no verão (2ª quinzena de agosto a 1ª quinzena de março: 167,9 ± 16,9 registros, média ± EP, N = 112 censos) foi semelhante ao registrado no inverno (2ª quinzena de março a 1ª quinzena de agosto: 125,7 ± 11,4, N = 80) (U = 4221; p = 0,495). No período do verão, o número de registros de aves limícolas por censo não variou entre períodos de maré alta e de maré baixa (U = 1280; p = 0,094). Por outro lado, no inverno, o número de registros em maré alta foi maior que em maré baixa (U = 501,5; p = 0,004). Em comparação ao uso de microhabitats na salina, as aves limícolas foram mais frequentes nos tanques de evaporação (85% do total de registros), e menos frequentes nos tanques de bombeamento (9%) e de cristalização (6%). Houve diferença significativa no número de registros de indivíduos/ha (densidade), com a maior densidade de indivíduos por censo nos microhabitats de evaporação (H = 246; p < 0,0001). Os tanques de evaporação e bombeamento foram utilizados principalmente para o forrageamento (respectivamente, 79% e 76% dos registros em cada um dos tipos de microhabitat) e os de cristalização para o descanso (75%). A partir destes resultados, o Estuário Apodi-Mossoró pode ser reconhecido como uma relevante área para a conservação de populações de Charadriiformes migratórias e residentes na América do Sul. O uso das salinas deste Estuário como habitats alternativos para alimentação e descanso por aves limícolas implica na necessidade de implementação de um programa de monitoramento ambiental continuado nas salinas, a fim de garantir a manutenção dos requerimentos ecológicos espécie-específicos e a não contaminação química destes animais / 2017-05-05