Ontogenetic Niche Shifts

Definition: Ontogeny

-the origination and development of an organism, usually from the time of fertilization of the egg to adult OR -the study of the entirety of an organism's lifespan.

Important Images/Graphs: Niche Segregation

*refer to exam 2 doc*

Definition: Ontogenetic Niche Shift (ONS)

-an ecological phenomenon where an organism changes its diet or habitat during its ontogeny

Bodysize and thermal biology in active foragers

-cooling rates influence habitat use by Autarchoglossans. -Three sympatric species of Ameiva use different habitats: • large under canopy • medium in edge • small in short vegetation • Juveniles of large species used habitat of small species.

ONS in Crocodylia

-dramatic shift at 50cm body length (happens in all crocodilians) -> shared ancestral trait ex. nile crocs

Turtles: Life History

-high adult survivorship -high neonate mortality -"lost years" of juveniles

Central Theme

-niche classes undergo ontogenetic niche shifts

Hypotheses

1. Hatchlings and juveniles will useseasonal wetlands. 2. Subadult alligators will disperse between multiple wetlands and between the wetlands and the creek. 3. Adult females will use the creek but will move into the wetlands to nest. 4. Adult males will stay on the creek

Sand Dune Lizards

Sceloporus arenicolus -habitat specialist in shinnery oak sand dune in NM -only use sand dune blowouts (found nowhere else)