Behavioral responses of a predator, the round-tailed horned lizard, <i>Phrynosoma modestum</i> and its prey, honey pot ants, <i>Myrmecocystus</i> ssp.

TitleBehavioral responses of a predator, the round-tailed horned lizard, Phrynosoma modestum and its prey, honey pot ants, Myrmecocystus ssp.
Publication TypeJournal Article
Year of Publication1981
AuthorsShaffer DT, Whitford WG
JournalThe American Midland Naturalist
Date Published1981
Call Number00298
Keywordsant, Myrmecocystus, article, articles, honey-pot ant,SEE <Myrmecocystus, journal, journals, lizard, ant predation, lizard, behavior, lizard,Phrynosoma,behavior, lizard,round-tailed horned lizard, Myrmecocystus, Phrynosoma,ant predation, predation,of ants, reptile, also SEE <LIZARD>

The round-tailed horned lizard Phrynosoma modestum was active and feeding throughout the day from 2 hr after sunrise until sunset. Phrynosoma modestum remained in the shade of large mesquite during midday where they preyed on honey pot ants (Myrmecocystus depilis/mimicus) which were foraging in the canopy and moving across the shaded substrate. Phrynosoma modestum fed at an average of 3.9 +- 2.2 ants bout-1 and average of 7.0 +- 1.7 bouts hr-1. The species diversity of the diet of P. modestum doubled (H' = 0.78 to H' = 1.41) following rainfall when many species of small ants extended their activity to overlap with the activity of P. modestum. Honey pot ants Myrmecocystus mimicus/depilis were, however, the only dependable prey. Simulated predation of 20 ants day-1 and 40 ants day-1 affected activity of M. mimicus/depilis , while simulated predation of 10 ants day-1 had no effect. We estimate that P. modestum removes approximately one-half of the early summer standing crop of M. mimicus/depilis during the summer.

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