WALLACE RESOURCE LIBRARY Lecture 07 – Mexican Herpetofauna and Adaptation This is an ‘example’ of a lecture that is given to A level students as part of their academic lecture series whilst on their expedition. It has been produced for the exclusive use of the lecturer conducting the series and is solely intended for educational purposes. Most of the material comes from Operation Wallacea sources and any other material that has been used has been credited (as far as is possible) to the appropriate author wherever possible. This lecture is only to be used for EDUCATIONAL purposes.
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WALLACE RESOURCE LIBRARY Lecture 07 – Mexican Herpetofauna and Adaptation
WALLACE RESOURCE LIBRARY Lecture 07 – Mexican Herpetofauna and Adaptation. This is an ‘example’ of a lecture that is given to A level students as part of their academic lecture series whilst on their expedition. - PowerPoint PPT Presentation
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WALLACE RESOURCE LIBRARYLecture 07 – Mexican Herpetofauna and
Adaptation
This is an ‘example’ of a lecture that is given to A level students as part of their academic lecture series whilst on their expedition.It has been produced for the exclusive use of the lecturer conducting the series and is solely intended for educational purposes.Most of the material comes from Operation Wallacea sources and any other material that has been used has been credited (as far as is possible) to the appropriate author wherever possible.
This lecture is only to be used for EDUCATIONAL purposes.
WALLACE RESOURCE LIBRARYLecture 07 – Mexican Herpetofauna and
Trapping surveys• Active trapping (larger species)• Pitfall traps (smaller species)
Fixed-width Searches
Pros• Good for both reptiles and amphibians• Can be used along transects or in specific areas (e.g. along
streams or around lakes) • Effort and time regulated searches of the undergrowth,
capturing any specimens found• Captures more cryptic species
Cons• Scares many away so capture rate
not necessarily high
Pitfall traps
• Pros– Can be placed along transects or in
specific locations– Does not scare away animals like
active searching• Cons
– Labour intensive and not always successful
– Size of bucket influences species captured
Concept of Adaptation
‘The adjustment or changes in behavior, physiology, and structure of an organism to become more suited to an
environment.’
• The word adaptation is normally reserved for inheritable genetic changes developed in a population over a long period of time.
• This is Evolution through Natural Selection
Adaptations in Herps
Aposematism
• In latin apo = away and sematic = sign or meaning
• Some organisms are brightly coloured advertising that they are ‘nasty’ tasting or dangerous to be near as they can sting or bite.
.
Types of MimicryBatesian mimicry• Mimic resembles a model that is
poisonous or unpleasant to eat• Mimic thus benefits because predators
have learned to avoid the model• Usually based on appearance, but also
calls, scents etc
Mullerian mimicry• Two or more equally poisonous or
distasteful species have a similar colour pattern
• Reinforces the warning each gives to predators
Examples mimicry
Mimicry in coral snakes is complicated. There are a number of species of New World coral snakes belonging to two separate families, some poisonous (Elapidae) and some non-poisonous (Colubridae). Which is the poisonous one?