Nombre
El significado de los modelos de coloración en serpientes como estrategia antipredatoria frente a las aves (The significance of snake colour patterns as an antipredatory strategy against avian predators)
Fecha de fin
Fecha de inicio
Mappes, Riitta Johanna
Institución
University of Jyväskylä (Finlandia)
Código
NA
Código de acceso
2007/42
Entidad financiera
Secretaría General de Política Científica y Tecnológica, MEC (Mejora y acceso de las Infraestructuras Científicas y Tecnológicas Singulares, ICTS. Plan Nacional I+D+I)
Resumen
The objectives of the suggested work are to study:
1) Does zigzag pattern of Natrix maura provide protection against avian predators
through mimicry?
2) Is there variation in the aposematic, cryptic and disruptive coloration of snake species
present in Doñana, and which species and strategies show highest variability?
3) Which bird species are the main avian predators of snakes in Doñana? And how does the predators’ community structure affect predation on snakes?
The objectives are to continue the experiment started in 2003 and 2004 (Proyecto nº 15/2003) by conducting more plasticine model experiments to determine whether previously observed benefit of zig-zag patterned snakes against avian predators is caused by aposematism or disruptive coloration. The hypothesis is that the benefit of zig-zag pattern is based both on disruptive coloration and aposematism. We expect that disruptively colored and aposematic models survive equally well on natural background but aposematic model survive better on white background. In other words, on natural background both disruptive and aposematic signaling work, but on white background when both models are equally visible, aposematic models gain due to their warning signals. We expect the bilineata-type models to have the lowest survival on both background. Other objectives are to gain more information about avian predator attacks on snakes, and to determine the variability in the zigzag pattern in the two species since the pattern of the mimic species is expected to be more variable. The further work also aims to provide more information about the avian predator species that prey on snakes and their reactions to differently patterned snakes.
1) Does zigzag pattern of Natrix maura provide protection against avian predators
through mimicry?
2) Is there variation in the aposematic, cryptic and disruptive coloration of snake species
present in Doñana, and which species and strategies show highest variability?
3) Which bird species are the main avian predators of snakes in Doñana? And how does the predators’ community structure affect predation on snakes?
The objectives are to continue the experiment started in 2003 and 2004 (Proyecto nº 15/2003) by conducting more plasticine model experiments to determine whether previously observed benefit of zig-zag patterned snakes against avian predators is caused by aposematism or disruptive coloration. The hypothesis is that the benefit of zig-zag pattern is based both on disruptive coloration and aposematism. We expect that disruptively colored and aposematic models survive equally well on natural background but aposematic model survive better on white background. In other words, on natural background both disruptive and aposematic signaling work, but on white background when both models are equally visible, aposematic models gain due to their warning signals. We expect the bilineata-type models to have the lowest survival on both background. Other objectives are to gain more information about avian predator attacks on snakes, and to determine the variability in the zigzag pattern in the two species since the pattern of the mimic species is expected to be more variable. The further work also aims to provide more information about the avian predator species that prey on snakes and their reactions to differently patterned snakes.