Territoriality is seen across different species of animals anywhere, from birds, fish, and mammals to reptiles. Although many animals use several types of signals to defend their territories, signals in different sensory modalities have varying properties that may influence their effectiveness in different contexts. This study investigates whether male plateau fence lizards (Sceloporus tristichus) use chemical or visual behavior during territory defense. Both visual and chemical communication modalities inform the audience about the producer’s physiological condition. The results show no obvious tradeoff between visual and chemical modalities in the behavior recorded in the presence of another male lizard compared to when undisturbed, suggesting that these signals are not used in territory defense. An increased visual head bob display is the most common spiny lizard territory defense response to conspecific intruders. However, this is not always the case, as environmental and evolutionary constraints influence communication. This species does not perform typical territorial behavior. However, there was a significant increase in aggressive visual displays, called full shows, in the presence of the intruding live stimulus. An increase in full shows could be a less conspicuous way to defend their territory instead of performing an entire broadcasting head bob display while perched in an open/exposed habitat notably filled with predatory birds. This shows modification within one communication modality to result in more effective communication.

Human land use and land cover change alter key features of the landscape that may favor habitat selection by some species. Lizards are especially sensitive to these alterations because they rely on their external environment for regulating their body temperature. However, because of their diverse life-history traits and strategies, some are able to respond well to disturbance by using their habitat in various ways. To understand how they use their habitat and how human modifications may impact their ability to do this, biologists must identify where they occur and the habitat characteristics on which they depend. Therefore, I used species occupancy modeling to determine (1) whether disturbance predicts the presence of two sympatric congeneric (species of the same genus) lizard species Sceloporus grammicus and S. torquatus, and (2) which habitat characteristics are essential for predicting their occupancy and detection. I focused my study in central Mexico, a region of prevalent land use and land cover change. Here, I conducted visual encounter and habitat surveys at 100 1-hectare sites during the spring of 2019. I measured vegetation and ground cover, average tree diameter, and abundance of refuges. I recorded air temperature, relative humidity, and elevation. I summarized sites as either undisturbed or disturbed, based on the presence of human development. I also summarized sites by ecosystem type, desert or forest, based on vegetation composition (i.e., desert-adapted vs. non-desert-adapted plants), evidence of remnant forest, air temperature, and relative humidity. I found that S. torquatus was more likely to be present in disturbed habitat, whereas S. grammicus was more likely to be present in areas with leaf litter, tree cover, and woody debris. S. torquatus was twice as likely to be detected in forests than deserts, and S. grammicus was more likely to be detected at sites with high elevation and high relative humidity, low temperature, and herbaceous and grass cover. These results emphasize the utility of species occupancy modeling for estimating detection and occupancy in dynamic landscapes.