55 51 91288761 biokruger@gmail.com
POSTO DE TRABALHO A QUE
SE CANDIDATA
Aluno de Doutoramento
EXPERIÊNCIA PROFISSIONAL
01 de Julho 2006 – 28 de
Fevereiro 2008
Bolsista de Iniciação Científica CNPq
Universidade do Vale do Rio dos Sinos, São Leopoldo (Brasil)Participante em atividades de pesquisa, incluindo atividades em laboratório e campo. Participante em produção científica.
01 de Março 2008 – 31 de
Janeiro 2009
Bolsista de Iniciação Científica CNPq
Universidade do Vale do Rio dos Sinos, São Leopoldo (Brasil)Participante em atividades de Pesquisa: trabalho de campo, laboratório e produção científica. Auxilio à outros alunos de Iniciação Científica, e auxilio à bolsistas de Pós-Graduação.
01 de Março 2009 – 28 de
Fevereiro 2011
Bolsista de Mestrado CNPq
Universidade do Vale do Rio dos Sinos, São Leopoldo (Brasil)Desenvolvimento de dissertação de mestrado, participação nas atividades currículares do curso de mestrado, participação em atividades de pesquisa: campo, laboratório e produção, Auxílio a alunos de Iniciação Científica.
01 de Março 2009 – 18 de Abril
2012
Pesquisador no Programa Antártico Brasileiro pelo INCT-APA
Participação nas atividades de campo por períodos de dois a quatro meses nas Operações XXVIII, XXIX e XXX, produção científica relacionada ao tema.01 de Março 2011 – 31 de
Dezembro 2012
Bolsista DTI-3 CNPq
Instituto Nacional de Ciência e Tecnologia Antártico de Pesquisas Ambientais, Rio de Janeiro (Brasil) Desenvolvimento de pesquisa sobre ecologia de aves marinhas antárticas com uso de telemetria, sensorimento remoto e mapeamento de áreas reprodutivas.01 de Outubro 2012 – 20 de
Dezembro 2012
Professor
Curso Técnico em Meio Ambiente Colégio PVSinos, São Leopoldo (Brasil)Orientação de alunos no trabalho de conclusão de curso. Carga horária de 8 horas semanais. EDUCAÇÃO E FORMAÇÃO
01 de Março 2003 – 28 de
Fevereiro 2008
Bacharel em Ciências Biológicas
Universidade do Vale do Rio dos Sinos, São Leopoldo (Brasil) Biologia Geral, Zoologia, Ecologia.01 de Março 2011 – 31 de
Dezembro 2012
Bolsista DTI-3 CNPq
Instituto Nacional de Ciência e Tecnologia Antártico de Pesquisas Ambientais, Rio de Janeiro (Brasil) Desenvolvimento de pesquisa sobre ecologia de aves marinhas antárticas com uso de telemetria, sensorimento remoto e mapeamento de áreas reprodutivas.01 de Março 2009 – 18 de Abril
2012
Pesquisador do Programa Antártico Brasileiro
Instituto Nacional de Ciência e Tecnologia Antártico de Pesquisa Ambiental, (Brasil) Participação nas atividades de campo em períodos de dois a quatro meses nas Operações Antárticas XXVIII, XXXIX e XXX. Participação em atividades de pesquisa, divulgação e produção científica.COMPETÊNCIAS PESSOAIS
Língua materna português
Outras línguas COMPREENDER FALAR ESCREVER
Compreensão oral Leitura Interacção oral Produção oral
inglês C1 C2 C1 C1 C2
espanhol C1 C2 B2 B1 B1
Níveis: A1/A2: Utilizador básico - B1/B2: utilizador independente - C1/C2: utilizador avançado
Quadro Europeu Comum de Referência para as Línguas Competências de comunicação
Competências de organização
Competências técnicas
Competências informáticas
INFORMAÇÃO ADICIONAL
Filiações Instituto Nacional de Ciência e Tecnologia Antártico de Pesquisas Ambientais - INCT-APA
Laboratório de Ornitologia e Animais Marinhos - UNISINOS Centro do Mar e Ambiente, Universidade de Coimbra
Participação em Projectos 2007-2015 – Monitoramento de aves e mamíferos marinhos na costa do Rio Grande do Sul, Brasil..
2013-2015 – Distribuição e ecologia trófica de aves marinhas de Trindade e São Pedro São paulo: subsídios para avaliação de poluentes orgânicos e contaminação em ambientes oceânicos. 2013-2017 – Macroecologia de Procellariiformes do Oceano Atlântico: Medindo impactos do clima e da pesca sobre ecologia trófica e espacial de quatro aves marinhas pelágicas.
conservation and recovery.
2004-2008: Efeito do fogo sobre flora e fauna no Planalto do Rio Grande do Sul.
Publicações Artigos:
Petry MV, Basler AB, Valls FCL, Krüger L (2013) New southerly breeding location of king penguins (Aptenodytes patagonicus) on Elephant Island (Maritime Antarctic). Polar Biology. DOI
10.1007/s00300-012-1277-1
Krüger L & Petry MV (2011) On the relation of antarctic and subantarctic seabirds with abiotic variables off south and southeast Brazil. Oecologia Australis, 15(1): 51-58.
Petry MV, Moura R, Krüger L (2010) Penguin colonies and weather in Admiralty bay in a colder year. Annual Activity Report INCT-APA: 78-81.
Petry MV, Petersen ES, Krüger L (2010) Distance association among Antarctic and subantarctic seabirds. Annual Activity Report INCT-APA: 82-86.
Petry MV, Krüger L, Moura R (2010) Topographical characteristics used by Southern Giant Petrel Macronectes giganteus at Stinker Point, Elephant Island. Annual Activity Report INCT-APA: 87-90. Schulz UH, Krüger L, Petry MV (2010) Nest attendance of Southern Giant Petrel (Macronectes giganteus) on Elephant Island. Annual Activity Report INCT-APA: 95-99.
Krüger L & Petry MV (2010) Black-and-white Monjita (Xolmis dominicanus) followed by the Saffron-cowled Blackbird (Xanthopsar flavus): statistical evidences. Ornitología Neotropical, 21: 299-303. Petry MV & Krüger L (2010) Frequent use of burned grasslands by the vulnerable Saffron-Cowled Blackbird Xanthopsar flavus: Implications for the conservation of the species. Journal of Ornithology. 151: 599-605.
Petry MV, Petersen ES, Scherer JFM, Krüger L, Scherer AL (2010) Notas sobre a ocorrência e dieta de Macronectes giganteus no Rio Grande do Sul. Revista Brasileira de Ornitologia, 18(3): 237-239. Petry MV, Krüger L, Fonseca VSS, Piuco R; Brummelhaus J (2009) Diet and ingestion of synthetics by Cory's Shearwater Calonectris diomedea off southern Brazil. Journal of Ornithology. Journal of Ornithology, 150: 601-606.
Petry MV, Fonseca VSS, Krüger L, Piuco R, Brummelhaus J (2008) Shearwater diet during migration along the coast of Rio Grande do Sul, Brazil. Marine Biology, 154: 613-621.
Artigos no Prelo Krüger L, Sander M, Petry MV. Responses of an Antarctic Southern Giant Petrel population to climate change. Annual Activity Report INCT-APA 2012.
Petersen ES, Krüger L, Petry MV. Rsponses of an Antarctic Kelp Gull Larus dominicanus reproductive population to Climate. Annual Activity Report INCT-APA 2012.
Petry MV, Krüger L. Foraging distribution of an Antarctic Southern Giant Petrel population. Annual Activity Report INCT-APA 2012.
Valls FCL, Krüger L, Petry MV. Finding Krill: individual foraging variation of Pygoscelis antarctica on Elephant Island. Annual Activity Report INCT-APA 2012.
Krüger L, Valls FCL, Moura EJT, Petry MV (2012) Passeriformes de campo e suas associações com a paisagem. In: I Simpósio Internacional sobre Conservação de Aves, Foz do Iguaçu, Paraná, Brasil. Petersen ES, Krüger L, Valls FCL, Basler AB, Seibert S, Piuco RC, Sander M, Petry MV (2012). Distribuição das areas de reprodução de aves em Stinker Point (IBA 071), Ilha Elefante. In: II Simpósio Brasileiro sobre Pesquisa Antártica, São Paulo.
Petersen ES, Piuco RC, Valls FCL, Krüger L, Seibert S, Basler AB, Sander M, Petry MV (2012) Mapeamento das areas de reprodução de aves na Baía do Almirantado, área especialmente manejada (ASMA nº1). In: II Simpósio Brasileiro sobre Pesquisa Antártica, São Paulo.
Valls FCL, Krüger L, Petry MV (2012) À procura de Krill: variação individual de forrageio do Pinguim Antártico Pygoscelis antarctica na Ilha Elefante. In II Workshop APECS-Brasil.
Kisckporski PS, Maciel FO, Krüger L, Valls FCL, Scherer AL, Petersen ES, Petry MV (2012) Influência do Índice de Oscilação Sul na flutuação de Sterna hirundinacea no litoral médio do Rio Grande do Sul, Brasil. In: II CICPG Congresso de Iniciação Científica e Pós-Graduação, São Leopoldo. Vier GV, Krüger L, Petersen ES, Petry MV (2012) Influência das mudanças climáticas sobre a distribuição de Thalassarche chlororhynchos na costa Sul-Sudeste do Brasil. In: II CICPG Congresso de Iniciação Científica e Pós-Graduação, São Leopoldo.
Krüger L, Sander M, Petry MV (2012) Responses of an Antarctic Southern Giant Petrel population to climate change. In II Workshop APECS-Brasil.
Petry MV & Krüger L (2012) Preliminary results on foraging distribution by an Antarctic Southern Giant Petrel population. In II Workshop APECS-Brasil.
Petry MV & Krüger (2010) A preliminary evaluation of temperature influences on decreases of Southern Giant Petrel from Elephant Island, South Shetland Islands, Antarctica. In SCAR Meeting – XXXI SCAR and Open Science Conference.
Petry MV, Krüger L, Piuco R, Brummelhaus J (2010) A preliminary evaluation of temperature influences on Penguins from Elephant Island, South Shetland Islands, Antarctica. In SCAR Meeting – XXXI SCAR and Open Science Conference.
Petry MV, Brummelhaus J, Piuco RC, Krüger L, Santos CR (2010) Population Trends of breeding seabirds in Admiralty Bay, King George Island, South Shetlands. In SCAR Meeting – XXXI SCAR and Open Science Conference.
Petry MV, Petersen ES, Krüger L (2010) Spatial Auto and Cross Correlations Indicate Association Distances among Antarctic and Subantarctic seabirds. In SCAR Meeting – XXXI SCAR and Open Science Conference.
Heinz CH, Krüger L, Seibert S, Petry MV (2010) Influências de monoculturas sobre populações de passeriformes ameaçados no Planalto das Araucárias, Rio Grande do Sul. In II seminário Internacional de Educação e Pesquisa em Ecologia.
Seibert S, Krüger L, Duarte A, Petry MV (2010) The Skua nest distance from Penguins can enhance the potential intra-specific competition and predation. In II seminário Internacional de Educação e Pesquisa em Ecologia.
Krüger, Lucas ; Petry, Maria Virginia . Variação sazonal da abundância de Arthropoda epifítico de campo sobre influência do fogo.. In: VII Congresso de Ecologia do Brasil, 2007, Caxambú. Petry, Maria Virginia ; Krüger, Lucas . Evidências de seleção de hábitat pelo veste amarela
Xanthopsar flavus. In: XV Congresso Brasileiro de Ornitologia, 2007, Porto Alegre. In: XV Congresso Brasileiro de Ornitologia, 2007.
Krüger L (2012) Como as populações de aves marinhas antárticas respondem às mudanças climáticas globais? In: 20 anos do curso de Biologia Unochapecó e Dia do Biólogo, Chapecó, Santa Catarina, Brasil.
Krüger L, Seibert. As mudanças Climáticas e os predadores de topo na Antártica. In: I Oficina de Trabalhos do Módulo 2 INCT-APA. São Leopoldo, Rio Grande do Sul, Brasil.
Cursos Ministrados Curso:
Petry MV, Petersen ES, Krüger L (2010) Capacitação em identificação de Aves Marinhas em alto mar a bordo dos navios de pesquisa do PROANTAR entre Rio Grande e Rio de Janeiro.
Petry MV, Petersen ES, Krüger L (2009) Capacitação em identificação de Aves Marinhas em alto mar a bordo dos navios de pesquisa do PROANTAR entre Rio Grande e Rio de Janeiro.
ANEXOS ▪ PETRY_ETAL_INPRESS.pdf ▪ Krüger&Petry_2011.pdf ▪ Kruger_&_petry_2010.pdf ▪ petry&kruger_2010.pdf ▪ petry_etal_2008.pdf ▪ Petry_etal_2009.pdf ▪ petry_etal_2010_macronectes.pdf
S H O R T N O T E
New southerly breeding location of king penguins (Aptenodytes
patagonicus) on Elephant Island (Maritime Antarctic)
Maria Virginia Petry•Aparecida Brusamarello Basler• Fernanda Caminha Leal Valls•Lucas Kru¨ger
Received: 2 August 2012 / Revised: 29 November 2012 / Accepted: 3 December 2012 Ó Springer-Verlag Berlin Heidelberg 2012
Abstract In the 2009–2010 austral summer, two breeding pairs of king penguins were recorded at Stinker Point, Elephant Island, Maritime Antarctic. This is the first record of king penguins breeding south of 60°S. The finding suggests a possible range extension of this species and increases the number of breeding bird species at Stinker Point, which was recently appointed as an Important Bird Area in Antarctica.
Keywords Biogeographic range shift Breeding site Elephant Island New record Sphenisciformes
Introduction
King penguins Aptenodytes patagonicus breed in the sub-Antarctic region (45°–55°S). The largest colonies occur at South Georgia in the southern Pacific Ocean and Kerguelen Islands, Prince Edward Island and the Crozet Islands in the southern Indian Ocean. Non-breeders are occasionally found at higher latitudes, for example, at the Antarctic Peninsula (Williams1995). Breeding colonies are located in flat, vegetation-free coastal areas, as well as on gentle, vegetated slopes. Some colonies are several hundred meters away from the high water mark. Colonies vary in size and can comprise hundreds of thousands of birds (Weimerskirch et al. 1992; Aubin and Jouventin 1998). The laying and chick-rearing period extends between 14
and 16 months (Mu¨ller-Schwarze 1984; Weimerskirch et al.1992; van Heezik et al. 1994). The most southern known breeding colonies occur on South Georgia (Murphy
1936; Watson et al.1975; Mu¨ller-Schwarze1984). The first observation of non-breeding king penguins on Elephant Island was made by Furse and Bruce (1972), and molting individuals were occasionally recorded at Stinker Point between 1983 and 1993 (Petry 1994). In 1838, large numbers of king penguins were reported from the South Shetlands (Murphy1936). Since this report did not mention any evidence of breeding or established pairs, however, king penguins were not considered as a breeding species in regions south of 55°S (Murphy1936; Watson et al.1975; Harrison 1983; Mu¨ller-Schwarze 1984; Williams 1995). This paper reports the southern-most confirmed record of breeding king penguins in Antarctica.
Materials and methods
Seabird population inventories were conducted at Stinker Point, Elephant Island (61°0703100S, 55°1902600W) (Fig.1)
during austral summers (early November to late March) between 2009 and 2011. In the course of these censuses, king penguins were constantly observed. Presence and behavior of the specimens were recorded, and they were photographed.
Results and discussion
In the 2009–2010 austral summer, we recorded the first breeding attempt of king penguins at Stinker Point, Ele-phant Island. A total of four individuals were involved in this observation. The first was seen close to a breeding
M. V. Petry (&) A. B. Basler F. C. L. Valls L. Kru¨ger Laboratory of Ornithology and Sea Animals,
Universidade do Vale do Rio dos Sinos, Av. Unisinos, no. 950, Cristo Rei, 93.022-000, Sa˜o Leopoldo, Rio Grande do Sul, Brazil e-mail: vpetry@unisinos.br
123
Polar Biol
group of chinstrap penguins (Pygoscelis antarctica) on December 5, 2009, when the beaches were still covered with ice. On December 20, 2009, when the ice on the beach had melted considerably, two king penguins were sighted near the same place. Both individuals remained at this location, and on 25 December two additional individuals were seen at the site. The four individuals performed courtship displays as described by Mu¨ller-Schwarze (1984) (Fig.2a, b). On January 3, 2010, one individual had a visible brood patch (Fig.2c), and another one was incu-bating. We inspected the animal and verified the presence of an egg (Fig.2d). On January 6, 2010, we left the island. When we returned on February 9, 2010, the king penguin pairs had abandoned the site. The following summer we arrived later at the island. On December 24, 2010, we recorded three individuals at the same location as in the previous year. Two of them appeared to be incubating (however, we did not inspect the individuals to confirm the presence of eggs this time, in order to avoid disturbing the animals). The third individual had a distinct brood patch. The documentation of at least two individuals continued over the months, and in the first week of March 2011 both individuals had chicks (Fig.2e, f). It was not possible to monitor the survival of the chicks, since we left the island in early March. This record of breeding king penguins increases the number of bird species reproducing at Stinker Point, which was recently appointed an Important Bird Area (IBA Ant071) (Harris et al.2011).
This observation reflects a possible southward range extension of king penguins. Although we recorded only
two breeding pairs, two consecutive breeding attempts seem to be evidence for new colonization. However, the factors that led the king penguins breed at a place as far south as Elephant Island can only be speculated. Possible explanations include the overcrowding in colonies at the southern boundary of the king penguin distribution range as well as an increased utilization of food resources in southern waters as a consequence of climate change. The recent recovery of king penguin populations (Woehler and Croxall1997) led significantly increased population den-sities at some sites, and as a result the colonies margins got too close to the coast, causing displacement of pairs at the periphery of the colonies and ultimately range extensions (Chamaille´-Jammes et al.2000). In the wake of climatic changes, the beaches of Elephant Island could gradually turn into a suitable breeding habitats for emigrant king penguins due to rising temperatures in the Maritime Ant-arctic (Turner et al.2005; Steig et al. 2009). In general, there is evidence that ocean warming is affecting king penguin populations. Le Bohec et al. (2008) found a decreased average adult survival of king penguins in rela-tion to warmer sea surface temperatures. Pe´ron et al. (2012) proposed that ocean warming is causing individuals of Crozet Island population to forage southerly than expected. Such range extensions are thought to be related to a southward dislodgement of the 4°C isotherm and, as a consequence, of the penguins’ optimal foraging zone (Pe´ron et al.2012). There is also evidence of southward shifts of pelagic fish communities, which represent an important food resource for king penguins (Hobday2010; Fig. 1 Location of Elephant
Island (left map), of Stinker Point (upper right map), and of king penguins at Stinker Point (star in the lower right map)
Pe´ron et al. 2012). Moreover, there is a proven range extension of macaroni penguins Eudyptes chrysolophus that was triggered by the warming of the Antarctic Pen-insula (Gorman et al. 2010). Williams (1995) also sug-gested that climate change is one of the greatest reasons for the recent changes in the distribution of penguin popula-tions. The Antarctic Polar Frontal Zone (APFZ), a complex transition region between circumpolar Antarctic and sub-Antarctic waters, is highly dynamic, and the productivity can be spatially extensive and temporarily stable over several weeks (Weimerskirch 2007). In general, king penguins are known to forage in areas with a wide variety of physical characteristics, such as the oceanographic fronts (Bost et al.1997).
Nonetheless, king penguins chicks need large cre`ches to be able to survive the first winter, when they are left alone by the parents and only fed intermittently (Stonehouse1960; Le Bohec et al.2005). Small breeding groups with less than 20 pairs are able to raise chicks in Falklands, but it is unknown whether this is also possible on South Georgia where winters are longer and colder (Stonehouse1960). Le Bohec et al. (2005) found chicks grouped at cre`ches with a maximum average abundance of about 500 individuals at a minimum temperature of about -5°C at Crozet Island (46°250S, 51°450E). Based on this observation, it seems unlikely that the few breeding king penguins have already established a viable breeding colony on Elephant Island, where the climate is clearly harsher. Over the past two decades, average temperatures on the South Shetlands
during winter (May–August) were -16.6°C ± 4.2 SD, and absolute minimum temperatures could be as low as -28°C (INPE—inpe.br). Although we showed that king penguins produce eggs and chicks in summer conditions on Elephant Island, attempts of small numbers to breed will have very probably failed during the winter. However, we believe that the number of breeding king penguin pairs will rise signif-icantly in the future, and in the long run the winter cre`ches may reach the critical size that is needed for the chicks to survive. Continued monitoring of these pairs in coming years will provide more evidence needed to confirm this hypothesis.
Acknowledgments This research was supported by National Institute of Science and Technology—Antarctic Environmental Research—INCT-APA; National Counsel of Technological and Scientific Development—CNPq; Foundation of Research Support, Rio de Janeiro—FAPERJ; Brazilian Antarctic Program; Secretariat of the Interministerial Commission for Sea Resources—SECIRM—and University of Vale do Rio dos Sinos. We thank Elisa de Souza Petersen and Gisele Dantas for providing photographs. Finally, we are grateful to Emily Toriani Moura and Dieter Piepenburg for revising the language of our manuscript.
References
Aubin T, Jouventin P (1998) Cocktail-party effect in king penguin colonies. Proc R Soc B 265:1665–1673
Bost CA, Georges JY, Guinet C et al (1997) Foraging habitat and food intake of satellite tracked king penguins during the austral summer at Crozet Archipelago. Mar Ecol Prog Ser 150:21–33 Fig. 2 King penguins at Stinker Point. Courtship displays in late December (a, b; the latter photograph was taken by Elisa de Souza Petersen); individual with brood patch (c); confirmation of an egg in January 2010 (d) and chicks in March 2011 (e, f; photographs taken by Gisele Dantas)
Chamaille´-Jammes S, Guinet C, Nicoleau F, Argentier M (2000) A method to assess population changes in king penguins: the use of a geographical information system to estimate area-population relationships. Polar Biol 23:545–549
Furse JR, Bruce G (1972) Ornithology Report. In: Burley MK (ed) Joint service expedition: elephant Island, 1970–1971, Annex F. Ministry of Defense, London, pp F1–F11
Gorman KB, Erdmann ES, Pickering ABC et al (2010) A new high-latitude record for the macaroni penguin (Eudyptes chrysolo-phus) at Avian Island, Antarctica. Polar Biol 33:1155–1158 Harris CM, Carr R, Lorenz K, Jones S (2011) Important bird areas in
Antarctica: Antarctic Peninsula, South Shetland Islands, South Orkney Islands—Final Report. Environmental Research & Assessment Ltd, Cambridge
Harrison P (1983) Seabirds. Beckenham, Kent
Hobday AJ (2010) Ensemble analysis of the future distribution of large pelagic fishes off Australia. Progr Oceanogr 86:291–301 Le Bohec C, Gauthier-Clerc M, Le Maho Y (2005) The adaptive
significance of cre`ches in the king penguin. Anim Behav 70: 527–538
Le Bohec C, Durant JM, Gauthier-Clerc M et al (2008) King penguin population threatened by Southern Ocean warming. Proc Natl Acad Sci USA 105:2493–2497
Mu¨ller-Schwarze D (1984) The Behavior of Penguins: adapted to ice and tropics. State University of New York Press, Albany Murphy RC (1936) Oceanic birds of South America. Macmillan, The
American Museum of Natural History, New York
Pe´ron C, Weimerskirch H, Bost C-A (2012) Projected poleward shift of King Penguins’ (Aptenodytes patagonicus) foraging range at
the Crozet Islands, southern Indian Ocean. Proc R Soc B. doi:
10.1098/rspb.2011.2705
Petry MV (1994) Spatial distribution and population aspects of the avifauna of Stinker Point—elephant Island—South Shetland— Antarctica. Dissertation, Universidade do Vale do Rio dos Sinos Steig EJ, Schneider DP, Rutherford SD et al (2009) Warming of the Antarctic ice-sheet surface since the 1957 international geo-physical year. Nature 457:459–463
Stonehouse B (1960) The King Penguin Aptenodytes patagonica of South Georgia. I. Breeding behaviour and development. Scien-tific reports. FIDS 23:1–81
Turner J, Colwell SR, Marshall GJ et al (2005) Antarctic climate change during the last 50 years. Int J Climatol 25:279–294 Van Heezik YL, Seedon PJ, Cooper J, Plo¨s AL (1994)
Interrelation-ships between breeding frequency, timing and outcome in king penguins Aptenodytes patagonicus: are king penguins biennial breeders? Ibis 136:279–284
Watson GE, Angle JP, Harper PC (1975) Birds of the Antarctic and Sub-antarctic. American Geophysical Union, Washington Weimerskirch H (2007) Are seabirds foraging for unpredictable
resources? Deep-Sea Res Part II 54:211–223
Weimerskirch H, Stahl JC, Jouventin P (1992) The breeding biology and population dynamics of king penguins Aptenodytes patago-nica on the Crozet Islands. Ibis 134:107–117
Williams TD (1995) The Penguins: Spheniscidae. Oxford University Press, Oxford
Woehler EJ, Croxall JP (1997) The status and trends of Antarctic and sub-Antarctic seabirds. Mar Ornithol 25:43–66
Oecologia Australis 15(1): 20-27, Março 2011 doi:10.4257/oeco.2011.1501.05
ON THE RELATION OF ANTARCTIC AND SUBANTARCTIC SEABIRDS WITH ABIOTIC VARIABLES OF SOUTH AND SOUTHEAST BRAZIL
Lucas Krüger 1& Maria Virginia Petry2
1 Universidade do Vale do Rio dos Sinos, Centro de Ciências da Saúde, Área de Conhecimento e Aplicação de Biologia. Av. Unisinos 950, Cristo Rei,
São Leopoldo, RS, Brasil. CEP: 93022-000.
2 Universidade do Vale do Rio dos Sinos, Laboratório de Ornitologia e Animais Marinho. Av. Unisinos, 950, Cristo Rei, São Leopoldo, RS, Brasil.
CEP: 93022-000. E-mail: vpetry@unisinos.br
ABSTRACT
The distribution of wintering seabirds is influenced by biotic and abiotic oceanic processes. Ocean productivity is a main parameter at small and large scales, but the role of abiotic parameters at large scales may be explored further. Thus, we conducted bird surveys between Rio Grande and Rio de Janeiro (Brazil) onboard NApOc Ary Rongel from April 11st to 13th of 2009. The samples comprised 10 minutes each hour, from sunrise until sunset. Abiotic data were collected by NApOc Ary Rongel equipment. Data were analysed through CDA, PCA of species and CDA functions, and Multiple Regressions of CDA functions with sum of the abundances of all Antarctic and Subantarctic species observed, and the sum of all tropical and subtropical species’ abundances. We verified through PCA that Thalassarche chlororhynchos and T. chrysostoma are associated with greater wind speeds and air temperatures, Calonectris diomedea and Puffinus gravis are associated with greater depths, sea surface temperatures and atmospheric pressures. As a group, Antarctic / Subantarctic species are associated with higher wind speeds, higher air temperatures, lower atmospheric pressures and shallower depths. Tropical / subtropical birds did not respond to any CDA functions. At small scales (<10km), seabirds tend to respond to local gradients in productivity, chlorophyll concentrations, depth and salinity. Nonetheless at larger scales (>100km), seabirds’ distributions and abundances may be mainly driven by wind, associated with low pressures zones. At larger scales, the ability of disperse over greater distances may play a fundamental role.
Keywords: Seabirds at sea; association; bathymetry; dispersal; hydrography; migration; open ocean; winter. RESUMO
RELAÇÃO DAS AVES MARINHAS ANTÁRTICAS E SUBANTÁRTICAS COM VARIÁVEIS ABIÓTICAS NO SUL E SUDESTE DO BRASILA distribuição de aves marinhas migratórias é influenciada por processos oceânicos bióticos e abióticos. A produtividade oceânica é o principal parâmetro em pequena e larga escalas. No entanto, o papel dos parâmetros abióticos em grande escala pode ser investigado. Dessa forma, foram realizadas contagens de aves entre o Rio Grande e o Rio de Janeiro (Brasil) a bordo do NApOc Ary Rongel de 11 a 13 de abril de 2009. Cada amostragem se deu durante 10 minutos de cada hora, do amanhecer ao entardecer. Os dados abióticos foram coletados por meio dos equipamentos instalados no NApOc Ary Rongel. Os dados foram analisados por meio de CDA, PCA das espécies e funções de CDA e regressão múltipla das funções de CDA com a soma de todas as abundâncias das espécies originárias da Antártica e Subantártica, bem como a soma das abundâncias das espécies oriundas da região tropical e subtropical. Verificou-se por meio da PCA que Thalassarche chlororhynchos e T. chrysostoma encontram-se associados com maior velocidade do vento e temperatura do ar, enquanto que Calonectris diomedea e Puffinus gravis ocorrem associados a maiores profundidades, temperatura marinha e pressão atmosférica. Como grupo, as espécies Antárticas / Subantárticas ocorrem associadas a maior velocidade do vento, maior temperatura aérea, pressão atmosférica mais baixa e menor profundidade. As aves Tropicais / Subtropicais não apresentaram respostas a quaisquer das funções
de CDA. Em escala pequena (<10km), as aves marinhas tendem a responder a gradientes de produtividade, concentração de clorofila, profundidade e salinidade. Em grande escala (>100km), contudo, a distribuição e abundância das aves marinhas podem estar relacionadas principalmente ao vento associado a zonas de baixa pressão. Ainda em grande escala, a habilidade de dispersão por grandes distâncias pode desempenhar papel fundamental.
Palavras-Chave: Aves marinhas no mar; associação; batimetria; dispersão; hidrografia; migração; oceano aberto; inverno.
RESUMEN
RELACIONES DE AVES MARINAS ANTÁRTICAS Y SUBANTARTICAS CON VARIABLES ABIOTICAS DEL SUR Y SURESTE DE BRASIL. La distribución de las aves marinas migratorias está influenciada por procesos oceánicos bióticos y abióticos. La productividad oceánica es un parámetro principal a pequeña y gran escala, no obstante el rol de los parámetros abióticos a grandes escalas debe continuar siendo investigado. De esta manera, realizamos censos de aves entre Río grande y Río de Janeiro (Brasil) a bordo de NApOc Ary Rongel, desde el 11 al 13 de Abril de 2009. Cada registro comprendió 10 minutos cada hora, desde el amanecer hasta el atardecer. Los datos abióticos fueron colectados por los equipamientos electrónicos instalados en NApOc Ary Rongel. Los datos fueron analizados por medio de CDA, PCA de especies y funciones de CDA y regresión múltiple de funciones de CDA con la suma de todas las abundancias de especies de Antártida y Subantártida observadas y la suma de las abundancias de especies tropicales y subtropicales. Verificamos a través de PCA que Thalassarche chlororhynchos y T. chrysostoma están asociados con mayor velocidad del viento y temperatura del aire, mientras que Calonectris diomedea y Puffinus gravis están asociados a mayores profundidades, temperatura superficial del mar y presión atmosférica. Las especies antárticas/subantárticas, tomadas como un grupo, están asociadas con mayor velocidad del viento, mayor temperatura del aire, menor presión atmosférica y menor profundidad. Las aves del grupo Tropical/subtropical no respondieron a ninguna función de CDA. A menor escala (< 10 km), las aves marinas tienden a responder a gradientes locales de productividad, concentración de clorofila, profundidad y salinidad. Sin embargo, a mayor escala (> 100 km), la distribución y abundancia de las aves marinas pueden estar principalmente influenciadas por el viento, asociado con zonas de baja presión. A mayores escalas, la habilidad de dispersión a mayores distancias puede desempeñar un rol fundamental.
Palabras clave: Aves marinas en el mar; asociación; batimetría, dispersión; hidrografía; migración; océano abierto; invierno.
INTRODUCTION
The distribution of seabirds at sea is influenced by a number of biotic and abiotic factors, such as hydrography, productivity, fisheries and colony placing (Garthe 1997, Weichler et al. 2004, Ribic
et al. 2005). The local productivity and fisheries
are the main factors ruling the seabird’s movements during the breeding season, as seabirds are central-place foragers during this period (Ollason et al. 1997, Ainley 1980, Ainley et al. 1982, Woehler & Croxall, 1997, Woehler et al. 2001, Woehler 2006). In the non-breeding period the seabirds are also influenced by productivity, but they typically search for their food over greater areas of open ocean, no longer under constraints imposed by chick attendance. During the
breeding the required energetic inputs are greater, and birds may associate with different environmental cues for dealing with prey searching (Barret et al. 2007).
The South and Southeastern coast of Brazil is a key wintering area for seabirds as a result of the Falklands and Brazilian Oceanic Currents confluence that results in high local productivity (Borzone et
al. 1999, Fernandes & Brandini 1999). The area is
used by many seabird species from many continents (Vooren & Brusque 1999). Thus, one may question the role of abiotic (hydrographic and atmospheric) conditions in determining seabird movements during their non-breeding period. Particularly interesting is to compare such responses between breeding and non-breeding grounds. The present study examines the influence of abiotic factors on the distribution
of seabirds of the South and Southeast Brazil coast, paying special attention to Antarctic and Subantarctic species in their non-breeding, winter period.
METHODS
The study was conducted onboard NApOc Ary Rongel, a ship that supports the Brazilian Antarctic Program. Data were collected during the return of the ship to Brazil, in the route from Rio Grande and Rio de Janeiro (Figure 1), between 11st and 13th of April in 2009. The samples comprised 10 minutes periods each hour, by the continuous method, taking in account all birds within 300-m from the ship board, from sunrise until sunset between 6 am and 6 pm. (Tasker et al. 1984). Thus, our time effort was 360 minutes. We sampled the birds in the 180º around the ship, but birds flying behind or around the ship
(ship-attending birds) were excluded from analysis. No fishing vessels where registered during the samples. Abiotic data were collected by NApOc Ary Rongel onboard equipment.
The abiotic factors were analysed by latitude through Canonical Discriminant Analysis (CDA) by enter method and measured by Square Euclidian Distance. The regression scores from discriminating functions were saved and used in a Principal Component Analysis (PCA) to examine the relationships among species and abiotic gradients. For such analyses, we used the species registered at least in two samples. Species were grouped by their breeding in two categories: Antarctic/Subantarctic and Tropical/Subtropical. Abundances of both groups were used in multiple regressions to look for effect of discriminating scores. All analysis were conducted on SPSS 18.0.
Figure 1. Sampled area in the continental shelf of South America (left) and the detail (right) of the route of the ship between Rio Grande and
RESULTS
103 birds were counted, belonging to eight species and one genus of seabirds. We grouped three species and Procellaria genus as Antarctic/ Subantarctic taxa, four species as Tropical/ Subtropical seabirds and one species (Puffinus
puffinus) as a Northern Hemisphere Migrant (Table
1). P. puffinus was excluded from analyses, as only one individual was recorded. CDA resulted in four functions that explained 100% of the data variation (Table 2). Abiotic conditions varied as a function of latitude during the survey. Depth, sea surface temperatures, atmospheric pressures and air temperatures tending to be lower between 31°S and 28°S, and higher between 27°S and 23°S (Function 1, Figure 2 and Table 3). Wind direction and velocity increased between 23°S and 28°S, but tended to decrease north of 31°S (Function 2, Figure 2 and Table 3). These patterns can be explained by the passage of a cold front during the survey. Depth is associated with the ship position on the cruise track; the greatest distances from the coast coincided with
the intermediary latitudes. PCA resulted in four components (axes) explaining 63.71% of variation. Combined, axes one and two explained 40% of the variation. The two Thalassarche species associated with CDA Function 4, C. diomedea and P. gravis associated with CDA Function 1, S. leucogaster associated with CDA Function 3, and P. incerta tended to associate with Function 2 (Figure 3).
The multiple regressions resulted in three models, from which the model 3 (R²=0.28) explained most of variation (Table 4). The model shows that the Antarctic species are related to deeper water, higher atmospheric pressures, greater wind velocities, and lower atmospheric and sea surface temperatures (Y=0.57 - 0.38*SCORE3 + 0.23*SCORE4). Tropical species, despite two other models were shown to be significant, were not significantly related to abiotic factors in this study as neither R² was above 0.10, so the Functions could not explain the abundances of tropical species observed in this study as a group (Table 5). Possibly the absence of response by the tropical seabirds is explained by the short survey period, but this can not be assured.
Species Group
Procellaria aequinoctialis Antarctic / Subantarctic
Procellaria sp. Antarctic / Subantarctic
Thalassarche chlororhynchos Tropical / Subtropical
Puffinus puffinus North Migrant
Thalassarche chrysostoma Antarctic / Subantarctic
Puffinus gravis Antarctic / Subantarctic
Pterodroma incerta Tropical / Subtropical
Calonectris diomedea Tropical / Subtropical
Sula leucogaster Tropical / Subtropical
Table 1. Species registered in the NApOc Ary Rongel cruise between Rio Grande and Rio de Janeiro, and species
grouping
Table 2. Functions of Canonical Discriminant Analysis (CDA), variance explained by function and Canonical
Correlation Coefficients (CCC) between Functions and variables.
Functions Eigenvalues % of variance % cumulative of variance CCC
1 4.708 56.6 56.6 0.908
2 2.177 26.2 82.8 0.828
3 1.276 15.3 98.1 0.749
4 0.157 1.9 100 0.369
Table 3. Correlations between abiotic variables and the standardized functions of the Canonical Discriminant Analysis
(CDA). Variables ordered by greater correlation with any function.
Variables Function 1 Function 2 Function 3 Function 4
Depth (m) 0.793* 0.059 -0.518 0.048
Sea Temp. (°C) 0.434* 0.049 0.221 0.428
Pressure (mmHg) 0.244* -0.02 -0.226 0.002
Wind Direction (º) -0.255 0.818* 0.039 -0.211
Wind Speed (knots) -0.218 0.25 -0.324 0.874*
Air Temp. (°C) 0.531 -0.212 0.463 0.661*
* Greater absolute correlation between variable and function.
Table 4. Multiple regression models between CDA Scores and Abundance of Antarctic/Subantarctic species.
Model R Adjusted R² F P
1 0.560a 0.256 5.47 0.001
2 0.560b 0.271 7.447 <0.001
3 0.552c 0.277 10.954 <0.001
a. Predictors: (Constant), Score4, Score3, Score2, core1 b. Predictors: (Constant), Score4, Score3, Score1 c. Predictors: (Constant), Score4, Score3
Table 5. Multiple Regression models between CDA Scores and abundance of Tropical / Subtropical species.
Model R Adjusted R² F P
1 0.389a 0.08 2.13 0.91
2 0.389b 0.099 2.91 0.04
3 0.375c 0.106 4.09 0.02
a. Predictors: (Constant), Score4, Score3, Score2, Score1 b. Predictors: (Constant), Score4, Score3, Score2 c. Predictors: (Constant), Score4, Score3
Figure 02. Principal Component Analysis (PCA) between species and the CDA Function Scores.
DISCUSSION
Species that breed at higher latitudes have the tendency to associate during the winter, non-breeding season with areas in accordance to sea bottom, water column and surface current (Skov & Durinck 2000, Chapman et al. 2004, Ribic et al. 2008). However, different species’ strategies will result in different species’ associations and relationships with abiotic conditions (Woehler et al. 2010). At the species level, we verified that most pelagic seabirds tend to occur were the water is deeper, and with greater atmospheric pressures (C. diomedea and P. gravis) and strong winds (Thalassarche). Strong winds and higher air pressures can indicate associations with atmospheric fronts (eg Amorim et al. 2008, Bost et
al. 2009). The movement of air masses from high
to low pressure zones and higher speed wind fronts provide a less expensive way of traveling for seabirds (Adams & Flora 2010), and they may rapidly cross larger differently-characterized water masses in the process. Ribic et al. (2008) showed that the depth
is the most important factor affecting three seabird species distribution at Antarctica in the winter. Those birds are related with deeper waters such as migrating Antarctic / Subantarctic birds (present study). Amorim et al. (2008) found a negative relation between shearwaters and depth, in contrast to our results. Amorim et al. (2008) sampled during the breeding period and near colonies, while we sampled in the winter and relatively distant from the colonies. Our analysis showed that shearwaters may respond differently to that specific variable, assuming different strategies throughout the year. Zones of shallower depth near the colonies may provide more productive waters as consequence of nutrients upwelling inshore, but the confluence in Brazilian offshore waters also provides relatively high productivity. Productivity may be a secondary (but also important) factor for some species, what varies year to year (Ribic et al. 2008).
The responses to sea surface temperatures vary among species and between seasons, being positive during fall and negative during summer (O’Hara
et al. 2006). Our results also showed this positive
association with sea surface and air temperatures (Table 3 and 4) during the winter survey. During summer, seabirds search for the cooler conditions (cold water fronts and confluences are more productive) while they may seek higher sea surface temperatures in the winter. At the group level, Antarctic and Subantarctic seabirds are also associated with higher sea surface and air temperatures, but tended to be present at the front of air masses dislodgements, in the low pressures zones, using far more efficient the air currents for their traveling. Low pressure zone (= rising air in the Southern Hemisphere), provides lift. However our evaluation could not examine the role of confluences, and their characteristics of productivity and temperatures that also favours seabirds typical of higher latitudes during breeding (Merket et al. 2002, Weichler et al. 2004, Ohara et
al. 2006, Woehler 2006, Hyrenbach et al. 2006), but
may be a secondary factor during the winter (Ribic et
al. 2008). Instead, a model that includes biotic factors
such as productivity, chlorophyll and tracking of seabirds may furnish explanation to the data variation not explained by our analyses.
REFERENCES
ADAMS, J. & FLORA, S. 2010. Correlating seabird movements with ocean winds: linking satellite telemetry with ocean scatterometry. Marine Biology, 157: 915-929.
AMORIM, P.; FIGUEIREDO, M.; MACHETE, M.; MORATO, T.; MARTINS, A. & SANTOS, R.S. 2008. Spatial variability of seabird distribution associated with environmental factors: a case study of Marine Important Bird Areas in the Azores. ICES Journal of Marine Science, 66: 29-40.
AINLEY, D. G. 1980. Seabirds as marine organisms: A review. Rep.Calif. Coop. Oceanic Fish Invest., 21:48-53.
AINLEY, D.G.; RIBIC, C.A. & FRASER, W.R. 1982. Does prey preference affect habitat choice in Antarctic seabirds? Marine Ecology Progress Series, 90: 207-221.
BARRET, R.T.; CAMPHUYSEN, C.J.; ANKER-NILSSEN, T.; CHARDINE, J.W.; FURNESS, R.W.; GARTHE, S.; HüPPOP, O.; LEOPOLD, M.F.; MONTEVECCHI, W.A. & VEIT, R.R. 2007. Diet studies of seabirds: a review and recommendations. ICES Journal of Marine Science, 64:1675-1691.
BORZONE, C.A.; PEZZUTO, P.R. & MARONE, E. 1999. Oceanographic 1 characteristics of a multi-specific fishing ground of the central south Brazil bight. Marine Ecology, 20:132-146. BOST, C.A.; COTTÉ, C.; BAILLEUL, F.; CHEREL, Y.; CHARRASSIN, J.B.; GUINET, C.; AINLEY, D.G. & WEIMERSKIRCH, H. 2009. The importance of oceanographic fronts to marine birds and mammals of the southern ocean. Journal of Marine Systems, 78: 363-376.
CHAPMAN, E.W.; RIBIC, C.A. & FRASER, W.R. 2004. The distribution of seabirds and pinnipeds in Marguerite Bay and their relationship to physical features during austral winter 2001. Deep-Sea Research II, 51: 2261-2278.
FERNANDES, L.F. & BRANDINI, F.P. 1999. Microplankton communities in the Southwestern Atlantic Ocean: biomass and distribution in November/1992. Brazilian Journal of Oceanography, 47: 189-205.
GARTHE, S. 1997. Influence of hydrography, fishing activity, and colony location on summer seabird distribution in the south-eastern North Sea. ICES Journal of Marine Science, 54: 566-577. HYRENBACH, K.D.; VEIT, R.R.; WEIMERSKIRCH, H. & HUNT JR. G.L.2006. Seabird associations with mesoscale eddies: the subtropical Indian Ocean . Marine Ecology Progress Series 324:271-279.
MERKEL, F.R.; MOSBECH, A.; BOERTMANN, D. & GRONDHAL, L. 2002. Winter seabird distribution and abundance off south-western Greenland, 1999. Polar Research, 21:17-36.
O’HARA, P.D.; MORGAN, K.H. & SYDEMAN, W.J. 2006. Primary producer and seabird association with AVHRR-derived sea surface temperatures and gradients in the southeastern Gulf of Alaska. Deep-Sea Research II, 53: 359-369.
OLLASON, J.G.; BRYANT, A.D.; DAVIS, P.M.; SCOTT, B.E. & TASKER, M.L. 1997. Predicted seabird distributions in the North Sea: the consequences of being hungry. ICES Journal of Marine Science, 54: 507-517
RIBIC, C.A.; CHAPMAN, E.; FRASER, R.W., LAWSON, G.L. & WIEBE P.H. 2008. Top predators in relation to bathymetry, ice and krill during austral winter in Marguerite Bay, Antarctica. Deep-Sea Research II, 55: 485-499.
SKOV, H. & DURINCK, J. 2000. Seabird distribution in relation to Hydrography in the Skagerrak Continental Shelf Research, 20: 169-187
TASKER, M.L.; JONES, P.H.; DIXON, T.J. & BLAKE, B.F. 1984. Counting seabirds at sea from ships: a review of methods employed and a suggestion for a standardized approach. Auk 101: 567-577.
VOOREN, C.M. & BRUSQUE, L.F. 1999. As aves do ambiente costeiro do Brasil: biodiversidade e conservação. Fundação Universidade Federal de Rio Grande, Rio Grande, RS. 40p. WEICHLER, T.; GARTHE, S.; LUNA-JORQUERA, G. & MORAGA, J. 2004. Seabird distribution on the Humboldt Current in northern Chile in relation to hydrography, productivity, and fisheries. ICES Journal of Marine Science, 61: 148-154. WOEHLER, E.J. & CROXALL, J.P. 1997. The status and trends of Antarctic and sub-Antarctic seabirds. Marine Ornithology 25: 43-66.
WOEHLER, E.J., COOPER, J., CROXALL, J.P., FRASER, W.R., KOOYMAN, G.L., MILLER, G.D., NEL, D.C., PATTERSON, D.L., PETER, H.-U., RIBIC, C.A., SALWICK, K., TRIVELPIECE, W.R. & WEIRMIRSKIRCH, H. 2001. A statistical assessment of the status and trends of Antarctic and Subantarctic seabirds. SCAR, Cambridge. 45 pp.
WOEHLER, E.J. 2006. Status and conservation of the sea birds of Heard Island. p. 186-187. In: K Green & E Woehler (eds) Heard Island: Southern Ocean sentinel.Chipping Norton, New South Wales: Surrey Beatty & Sons. 270 p.
WOEHLER, E.J.; RAYMOND, B.; BOYLE, A.; STAFFORD, A. 2010. Seabird assemblage observed during the BROKE-West survey of the Antarctic coastline (30ºE – 80E), January – March 2006. Deep-Sea Research II, 57: 982-991.
Submetido em 27/08/2010 Aceito em 10/03/2011
299
SHORT COMMUNICATIONS
ORNITOLOGIA NEOTROPICAL 21: 299–303, 2010
© The Neotropical Ornithological Society
BLACK-AND-WHITE MONJITA (XOLMIS DOMINICANUS) FOLLOWED BY THE SAFFRON-COWLED BLACKBIRD
(XANTHOPSAR FLAVUS): STATISTICAL EVIDENCE
Lucas Krüger & Maria Virginia Petry
Laboratory of Ornithology, Universidade do Vale do Rio dos Sinos – UNISINOS, Av. Unisinos, 950, CEP: 93022-000, São Leopoldo, Rio Grande do Sul, Brazil.
E-mail: vpetry@unisinos.br
Noivinha (Xolmis dominicanus) seguida pelo Veste-amarela (Xanthopsar flavus): evidências estatísticas.
Key words: Black-and-white Monjita, Xanthopar flavus, Saffron-cowled Cowbird, Xolmis dominicanus,
association, habitat, logistic regression, null model.
INTRODUCTION
The Saffron-cowled Blackbird (SCB)
(Xantho-psar flavus) inhabits grasslands in Uruguay,
Argentina, and southern Brazil. The species inhabits both grasslands, which are used as preferential habitat for foraging, as well as wetlands and marshes, where it breeds (Fon-seca et al. 2004, Fraga 2005).
The SCB forms foraging flocks with other species (mainly other Icteridae and Tyran-nidae) supposedly taking advantage of the fact that other species serve as sentinels for the flock. One of the species to which the SCB is associated is the Black-and-white Monjita (BWM) Xolmis dominicanus (Fontana & Voss 1996).
There is descriptive evidence of an associ-ation preference of the SCB for BWM, rather than with other species (Días & Maurício
2002). The BWM exhibits the typical behav-ior of Tyrannidae, waiting on a perch usually less than 2 m above the ground and catching insects that pass by, preferably in areas where the soil is visible (Orians 1978) and, perhaps for this reason, it is a species that acts as an effective sentinel. The SCB forages by search-ing on the ground for invertebrates by walk-ing around and pickwalk-ing them up (Ridgely and Tudor 1989). This behaviour makes the flock more vulnerable to attacks from predators and explains the need for constant vigilance (Dias & Maurício 2002).
The interaction between the SCB and BWM has long been recognized, but the exact nature of the interaction is unknown. The lit-erature only provides descriptive evidence of this association and there is a lack of statistical evidence. Thus, the present study offers the first inferential assessment, using logistic
300
KRÜGER & PETRY
regression and null model to test whether such an association exists or is merely the product of chance.
STUDY SITE AND METHODS
The study was undertaken in the Araucaria Highlands, also known as Araucaria Plateau region (state of Rio Grande do Sul, southern Brazil) in the municipalities of São Fran-cisco de Paula, Cambará do Sul, Jaqui-rana, Bom Jesus, and Vacaria between 29°26’46.9”S, 50°36’32.4”W and 28°31’10.2”S, 50°49’26.0”W. Thirty wet-lands (marshes) were investigated on a monthly basis between November 2008 and March 2009. These marshes are small for-mations stemming from the accumulation of rainwater in depressions within the undu-lating terrain, which are dominated by aquatic macrophytes rooted in the soil
(grasses and sedges) as well as bushes (Ludwi-gia, Baccharis), with no visible surface water. The mean area of marshes is 2.13 ± 2.32 ha, the greatest area has 10.5 ha while the small-est is 0.16 ha.
Each marsh was observed once per month, using two methodologies for the sam-pling of the birds: 15-min census from an ele-vated point using binoculars 10X50 and, subsequently, a visual census by walking in a constant speed around the marsh edge. The association was tested through Logistic Regression, by which we tested with SPSS 17.0 whether the presence of BWM influ-ences the presence of SCB,. To test whether the association probability is different than that expected by chance, we compared a real linear regression model to a random linear regression model (10,000 iterations) between BWM and SCB abundance, using the EcoSim software program (Gotelli & Entsminger
FIG. 1. Receiver Operating Characteristic (ROC) curve (solid line) and diagonal reference line (dotted line). The accuracy of predicting the presence of Saffron-cowled Blackbird by the presence of Black-and-white Monjita is fair (AUC = 0.746). Diagonal segments are produced by ties.
301
SHORT COMMUNICATIONS
2009). We applied the analysis over the cumu-lative number of individuals in the marsh-lands.
RESULTS AND DISCUSSION
The logistic model showed that the presence of BWM in a marsh influences positively the presence of SCB (Nagelkerke R² = 0.28; Wald = 5.94; P = 0.014; Y = -0.916+2.015X). The area under the ROC curve (AUC) is 0.75 (Null Hypothesis area = 0.5; SE = 0.092 Asymptotic P = 0.02). The ROC (Receiver Operating Characteristic) curve allows mea-suring the predictive power of independent variable over a binary dependent one. The AUC is a probabilistic measure of the test accuracy. AUC values vary between 0.5 and 1.0, where one is the perfect adjust of the model, and 0.5 is the fail of the model. The more AUC reaches 0.5, the more random is the association between variables. So the accuracy to predict the presence of SCB by the presence of BWM is fair (Fig. 1).
The regression analysis resulted in an observed model, in which BWM abundance had a positive influence over SCB abundance (Y = 2.294+2.291X; R = 0.51). The simulated model did not reveal a relationship between the species (Y = 6.807-0.003X; R = -0.001). The comparison of the observed model with
the model generated from the average of sim-ulations indicated that the association between SCB and BWM is different from what would be expected by chance, with the Observed Intercept lower than expected and Observed Slope and R greater than expected. Thus, the influence of BWM abundance over SCB abundance is greater than that expected by chance; if the association was random, the observed model would be equal to the simu-lated model. As we find models are different, we assume that this association exists indeed (Table 1, Fig. 2).
The results indicate that there is an associ-ation between the SCB and BWM, but it is not an obligatory association. This is indi-cated by the R values and cases in which the SCB occupied marshes without the presence of the BWM. On the other hand, the number of BWMs in a marsh had a certain influence over the size of the SCB flock.
Our field observations evidence that SCBs follow BWMs movements, as we often observed that when one or more BWMs left the marshland towards the neighboring grass-lands, they were usually followed by the SCB flock. The same behaviour was observed by Dias & Maurício (2002). Our field observa-tions neither argue for or against the hypothe-sis that there are benefits for neither. We believe that SCB follows BWM for the likely
TABLE 1. Linear Regression Models between abundances of Black-and-white Monjita and Saffron-cowled Blackbird, and comparison of observed and simulated models (iteration = 10,000).
Intercept Slope R
Observed Mean of simulated Variance of simulated
Number of times observed < simulated Number of times observed = simulated Number of times observed > simulated Standardized Effect Size
P (observed <= expected) P (observed >= expected) 2.294 6.807 2.697 9916.0 0.0 84.0 1.399 0.008 0.992 2.291 -0.003 0.697 84.0 0.0 9916.0 2.748 0.992 0.008 0.513 -0.001 0.035 84.0 0.0 9916.0 2.748 0.992 0.008
302
KRÜGER & PETRY
advantages provided by the sentinel behavior of the latter species, as is discussed in litera-ture (Días & Maurício 2002, Fraga 2005). It is still necessary to quantify these benefits, such as measuring and comparing the forag-ing performance and response time of anti-predatory behaviour of SCB in the presence and absence of BWM.
As both species are classified as Vulnera-ble (Birdlife International 2008a, b), all new information is relevant. It is also important to quantify the co-occurrence of these two spe-cies to understand to what extent this associa-tion influences habitat selecassocia-tion and usage, as well as the role of environmental characteris-tics in these processes so that conservation and favorable management practices can be implemented.
ACKNOWLEDGMENTS
We are grateful to the “União Protetora do Ambiente Natural” (UPAN) for the
partner-ship in the project Threatened Birds of the Araucaria Highlands, in which course the data for this paper were collected; to the “Fundação o Boticário de Proteção à Natureza” for their financial support of the project. We also acknowledge the support from our colleagues at the Laboratory of Ornithology, Fernanda Valls and Suzana Sei-bert, whose participation in the fieldwork was fundamental to the data collection.
REFERENCES
BirdLife International. 2008a. Species factsheet:
Xolmis dominicanus. Downloaded on 4 April
2009 from http://www.birdlife.org . BirdLife International. 2008b. Species factsheet:
Xanthopsar flavus. Downloaded on 4 April 2009
from http://www.birdlife.org.
Días, R. A., & G. Maurício. 2002. Natural history notes and conservation of a Saffron-cowled Blackbird Xanthopsar flavus population in the southern coastal plain of Rio Grande do Sul, Brazil. Bird Conserv. Int. 12: 255–268. FIG. 2. Linear Regression between Black-and-White Monjita (BWM) and Saffron-Cowled Blackbird (SCB) abundances. Circles indicate the observed data and solid line represents the linear model of observed data. The squares indicate simulated data and the dashed line is the linear model for simulated data.
303
SHORT COMMUNICATIONS
Fraga, R. M. 2005. Ecology, behavior and social organization of Saffron-cowled Blackbird
(Xan-thopsar flavus). Ornitol. Neotrop. 16: 15–29.
Fonseca, V. S. S., M. V. Petry, & F. L. S. Fonseca. 2004. A new breeding colony of the Saffron-cowled Blackbird (Xantopsar flavus) in Rio Grande do Sul, Brazil. Ornitol. Neotrop. 14: 1– 5.
Fontana, C. S., & W. A. Voss. 1996. Área de uso e atividade diária de Heteroxolmis dominicana (Ty-rannidae) em dois banhados de São Francisco de Paula, Rio Grande do Sul. Acta Biol. Leopoldensia 18: 105–122.
Gotelli, N. J., & G. L. Entsminger. 2009. EcoSim: Null models software for ecology. Version 7. Acquired Intelligence Inc. & Kesey-Bear, Jeri-cho, Vermont. Downloaded on 9 October 2009 from http://www.garyentsminger.com/eco-sim/index.htm.
Orians, G. H. 1978. On the status of Xolmis
domini-cana. Auk 95: 411.
Ridgely, R. S., & G. Tudor. 1989. The birds of South America: the oscine passerines. Univ. of Texas Press, Austin, Texas.
O R I G I N A L A R T I C L E
Frequent use of burned grasslands by the vulnerable
Saffron-Cowled Blackbird Xanthopsar flavus: implications
for the conservation of the species
Maria Virginia Petry•Lucas Kru¨ger
Received: 5 May 2009 / Revised: 17 November 2009 / Accepted: 21 December 2009 / Published online: 28 January 2010 Ó Dt. Ornithologen-Gesellschaft e.V. 2010
Abstract In the world scenario of declining grassland bird populations, South American species are a particular concern. The Saffron-Cowled Blackbird Xanthopsar flavus is endemic to grasslands in Central and southern South America and its status is vulnerable. Natural history studies stress a number of factors responsible for the decline in its populations. In this paper, we present results from a grassland fire experiment aimed at evaluating the effect of grassland fires on foraging (grasses) and breeding (mar-shes) habitat use by the Saffron-Cowled Blackbird in a region where fire has been used for centuries as a tool for cattle management. We compare burned grasslands with a control treatment and grasslands within a conservation unit, evaluating uses before and after burning as well as relating bird abundance with environmental characteristics. We found that the Saffron-Cowled Blackbird used the burned treatments more frequently and avoided habitats with tall grasses and developed vegetation. Thus, this species is absent from the conservation unit, which has not experi-enced fires in nearly three decades. The Saffron-Cowled Blackbird depends on the existence of marshes (breeding habitat) surrounded by short grasses (foraging habitat). In the study region, short grasses are a result of burning practices. As the burning period coincides with the breeding season, the lack of criteria on the part of land-owners regarding how to apply and control fire poses a permanent threat to these populations.
Keywords Farmland Fire Grassland Habitat structure Marsh
Introduction
The main factors involved in species extinction are related to the human activities of environmental exploitation (Vitousek et al. 1997; Owens and Bennett 2000; Davis et al.2006), the consequences of which are habitat degra-dation, fragmentation and disconnection (Ehrlich 1988; Brooks et al. 2002). Habitat loss and fragmentation in grasslands are historical consequences of livestock farming and burning practices (Bilenca and Min˜arro2004). This human-driven impact severely alters plant structure and composition (Whelan 1998; Harrison et al. 2003; Fynn et al. 2004), which are habitat characteristics to which grassland birds are sensitive (Davis2005; Renfrew et al.
2005; Warren and Anderson2005).
A worldwide decline in populations of grassland bird species as a response to the expansion and intensification of human exploitation of grassland environments is recogni-sed by science. Such trends have mainly been determined in Europe (Donald et al.2006; Sanderson et al.2006) and North America (Vickery and Heckert1999). There is also evidence of the human influence on the decline of grass-land bird populations in South America, despite the lack of a long-term databanks that permit such an inference (Filloy and Bellocq2007; Azpiroz and Blake2009).
The Saffron-Cowled Blackbird (SCB), Xanthopsar flavus, is an endemic species of grasslands in southern South America (Collar et al.1992). Its distribution is restricted to southern Brazil (Dias and Maurı´cio2002; Fonseca et al.
2004), northern Argentina (Collar et al.1992), Uruguay and Paraguay (Azpiroz2000). The largest populations are found
Communicated by J. Fjieldsaˆ.
M. V. Petry (&) L. Kru¨ger
Laboratory of Ornithology, Universidade do Vale do Rio dos Sinos, UNISINOS, Av. Unisinos, 950, Sa˜o Leopoldo, Rio Grande do Sul 93022-000, Brazil
e-mail: vpetry@unisinos.br
123
J Ornithol (2010) 151:599–605 DOI 10.1007/s10336-009-0489-9
in Uruguay, Paraguay and southern Brazil, but are thought to be declining in the three countries. In Argentina, it is likely that population numbers have never been very high (Birdlife International2007). The SCB inhabits open lands and uses grass habitats for foraging and marshlands for breeding (Fonseca et al.2004; Fraga2005). The SCB is considered vulnerable on both the regional and global level. It appears that its population is declining quickly (Fontana et al.2003; Birdlife International 2007). Belton (2000) stresses the urgent need for actions to avoid the extinction of this species in the state of Rio Grande do Sul in southern Brazil.
Natural environments throughout the area of distribution of the SCB are under pressure from human activities. The conversion of grasslands and wetlands into crop lands as well as habitat degradation, overgrazing, the presence of cattle in marshes, burning practices and nest parasites are likely the key factors involved in the decline in popula-tions. However, the exact effect of these factors remains unclear (Collar et al. 1992; Fraga et al. 1998; Birdlife International 2007). Furthermore, the extent to which environmental factors and habitat characteristics determine habitat use on the part of the SCB is unknown. Thus, the aim of the present study was to evaluate habitat use by the SCB in foraging (grass) and breeding (marsh) habitats as a response to fire and to determine the effect of multiple fire-related factors on the preferences of this bird.
Methods Study area
The study areas were located in the municipality of Cam-bara´ do Sul in the highlands of the state of Rio Grande do Sul in southern Brazil (mainly called the Araucaria High-lands or Araucaria Plateau). These areas fall within the Aparados da Serra National Park (ASNP) (29°070S, 50°01W and 29°150S, 50°100W) and surrounding farm-lands. The Araucaria Highlands region is approximately 1,000 m above sea level. Average annual temperature is around 18°C, with temperatures dropping below 0°C dur-ing the peak of winter in July and reachdur-ing 30°C in summer (January and February). Relative humidity remains around 80% throughout the year. Average monthly rainfall ranges from 80 mm in January to 300 mm in October.
The region falls within the domain of the Atlantic rainforest, where there is a natural landscape of Araucaria Mixed Forests in a grassland matrix. The plant species composition of these grasslands is influenced by tropical grasslands in central South America as well as subtropical/ temperate grasslands of the Andes and Argentina. The grasslands of the Araucaria Highlands are mainly domi-nated by a number of grass species and bushes from the
family Asteraceae, such as Baccharis sp., Conyza sp. and Trichocline sp.
As the historically foremost economic activity of rural communities, livestock farming has had such a profound environmental impact over the centuries that there is cur-rently no way of measuring it. Annual or biennial burning practices have been applied in association with cattle farming for at least the last 300 years and are a cultural trait of farmers (Pillar2003; Bilenca and Min˜arro2004). Therefore, grasslands are short, with predominant vegeta-tion under 60 cm. The opposite occurs within conservavegeta-tion units, i.e. Aparados da Sera National Park (ASNP), where grass readily grows above 120 cm and a number of bushes emerge from herb vegetation reaching 2 m in height.
The topography of the region has a series of undulations. In the lower portions, the grasslands are replaced with marshes or bogs formed by the accumulation of rainwater. The vegetation is composed mainly of Sphagnum, sedges, grasses, Ludwigia bushes and Eryngium pandanifolium. Like the grasslands, these wetlands also diverge in aspect and size inside and outside conservation units. Within the ASNP, wetlands can reach a few square kilometres in width, whereas on farmlands, they are restricted to no more than a few hundred square metres.
Study design
The study was carried out in grasslands on farms where the SCB has previously been recorded (Fonseca et al.2004) as well as in grasslands in the ASNP. Grasslands on farms were burned either annually or biennially until 2003, whereas ASNP grasslands have not been burned for nearly 30 years. Three types of treatment were established: Fire and Control treatments (on the farms) and Park treatments (in the ASNP). Each treatment was made up of four rep-licates on 4 ha spaced at least 500 m apart. Burning practices in the Control treatments have not been carried out since 2003. The Fire treatments underwent one event of experimental fire in August 2005. The farms are used for cattle production and, despite being a conservation unit, the ASNP also has low densities of cattle in some areas, par-ticularly where the present study was conducted.
The wetlands studied were those in which the SCB has previously been recorded breeding and were located on the grasslands of farms outside the ASNP and near, although outside, the Fire and Control treatments. The wetlands were denominated: W1, approximately 100 9 30 m, located between two Control treatments; W2, approxi-mately 70 9 33 m in size, located between two Fire treatments; and W3, approximately 56 9 45 m, located between Control and Fire treatments. The three wetlands had predominantly shallow water depths of less than 1 m and were at least 300 m from any replicate of Control and
123
Fire treatments. There are also marshlands in the ASNP, although they are greater in extent than the marshlands on the farms.
Burning
Burning is a cultural tradition among farmers in the region and the annual or biennial application of fire in mid- to late winter and early spring has been carried out for centuries. As the rigorous cold and frequent frosts kill and dry out the photosynthetic tissue of plants, reducing its nutritional characteristics, burning is justified by farmers as a stimulus for the re-growth of vegetal tissue, which in turn becomes a better food source for cattle. The present study applied experimental burnings with the help of local landowners and an IBAMA (Brazilian Institute of Environment and Renewable Natural Resources) team specialised in the control of fire in natural systems. Burning occurred in the first half of August in 2005, when environmental condi-tions were suitable for fires. Farmers and landowners apply the fire after a heavy frost followed by sunny and windy days.
Burning was performed in all the Fire treatments as well as adjacent areas, as cattle graze with more intensity over burnt vegetation, which could over-impact the Fire treat-ments with overgrazing. This means that the grassland burnings came very close to the wetlands located near the Fire treatments, such as W3 and principally W2, which was between two Fire treatments. The Control treatments were not burned and a 50-m margin around the 4-ha area of the treatments provided protection from the fire. The W1 wetland, located between two Control treatments, was also protected from the effects of fire. As the Park treatments were located within a conservation unit, they underwent no burning and there was no proximity effect from burnt areas. Bird censuses
Monthly censuses were carried out between August 2004 and July 2006. Thus, there were 12 samples before and 12 samples after the fire for each of the treatments and wet-lands. Censuses were performed with binoculars (10 9 50) in 100-m transects walked at a constant speed in the treatment areas and parallel to the margin of the wetlands. Grassland characterisation
For the evaluation of grassland structure, five sampling points were randomly selected for each replicate. Each point was qualitatively sampled in a 20-m radius for the following parameters: Vegetation Height, measured as short (vegetation below 60 cm), intermediate (vegetation between 60 and 100 cm) and tall (vegetation above
100 cm); Grass Density, determined as low, intermediate or high, depending on the amount of soil visible in the vegetation strata; Grass Coverage, classified as continuous coverage of grass or grasses structured in tufts; presence of shrubs less than 1 m, between 1 and 2 m and more than 2 m tall; Litter Height, classified as low, intermediate and high; and grazing intensity, as a classification of the extent to which cattle use the area.
Statistical analysis
Differences in frequency of use were tested using the chi-square test. Structural differences between grassland treatments were determined by Canonical Discriminant Analysis and Stepwise Method using Squared Euclidean Distance as a dissimilarity measure. The influence of grassland characteristics on SCB abundance was tested through Principal Component Analysis. All analyses were performed using the SPSS 17.0 software program.
Results
SCBs were more abundant in Fire treatments, less abundant in Control treatments and absent in Park Treatments. Thus, the chi-square test was only performed for Fire and Control treatments. Similarly, SCBs were more abundant at W2, intermediate at W3 and less abundant at W1.
Frequency of use for the three wetlands as well as Fire and Control treatments differed before and after burning (Table1). Frequencies in W1 and W2 were greater after the burning than before; the frequency after burning in W2 was disproportionately greater. The frequency in W3 was lesser after the burning than before. Frequencies of use in Fire treatments were low before the burning and increase considerably after the burning, whereas the opposite occurred in Control treatments (Table1).
Comparing the Fire and Control structures, two vari-ables were selected for the model: Grazing Intensity (F = 39.62; P \ 0.001) and Litter Height (F = 26.45; P\ 0.001). Comparing the three treatments, the following
Table 1 Frequencies of use (%) at wetlands W1, W2 and W3, and at treatments fire (F) and control (C) before and after burning, and X2 test results
Areas Before After X2 P
W1 4.17 10.26 8.02 0.005 W2 4.81 62.5 154.29 0.000 W3 12.82 5.45 9.28 0.002 F 6.56 57.38 49.28 0.000 C 34.43 1.64 36.36 0.000
