The results propose that the balance between natural selection for inconspicuousness and sexual selection for conspicuousness may vary among the lizard populations. At SL, the habitat consists primarily of gray rocks, so the SL collared lizard population has a small chance to hide. Because of this, the male SL lizards are a dull greenish-brown color that is similar to the females and rocks. At GM, the background is more complicated, so the male lizards are more conspicuous compared to the rocks and females (Macedonia et al. 2004). More than double the number of models was preyed upon at SL than at GM, which shows that natural selection restricts sexual selection for colorful males more ...view middle of the document...
However, the results of the study being analyzed expose a direct relationship between conspicuousness and predator detection.
The research was done very well; however, some changes need to be made. Adequate descriptions of the three populations of the collared lizards were not given in the study. It was difficult to judge their conspicuousness compared to one another without descriptions and photographs of the lizards. The researchers simply stated that the lizards had significant differences in color conspicuousness. They briefly mention that models were painted green or blue-green depending on which lizard they are trying to recreate, but they give no explanation of which colors goes with which lizard population.
The investigators stated in their methods that they used photographs of the three lizard populations to try to match, by eye, the color of the lizards and paint them accordingly. The investigators also stated that they were unable to get spectrophotometric readings of the models until right before the experiment. Because of this, the results of the models’ contrast with the background at each site were inaccessible until after the experiment. This was very disadvantageous because the models’ spectrophotometric readings could have been very different than the live lizards readings. In other words, the models’ contrast with the different backgrounds could have been completely different from the live lizards’ contrast with the backgrounds, causing the study to be to be insignificant. If these readings between the models and the live lizards were different, predators would perceive them differently, causing irrelevant results. The readings were similar between model and live lizards, but not exact. If the researchers knew this beforehand, they may have been able to improve the models, making the results more sound.
Although all other variables were held constant in order to see how color affects predation, this, is not what happens in nature. It is important to note that behavior was not discussed much in the study. According to Forsman and Appelqvist (1998), being preyed upon by a predator depends on conspicuousness and behavior. The predation rates of different colored organisms could be similar if they took part in predator avoidance behaviors.
The methods that the investigators used were well thought out. It was important that the investigators made each lizard model exposed to each natural habitat. Some habitats are more complex than others, so conducting the experiment in each environment was needed to see how each habitat influenced the outcome. Overall, the study was well done.
This study adds further evidence that increased conspicuousness leads to an increase in predation. More research on this subject needs to be done with the same populations of lizards as this study as well as other species to see how conspicuousness influences predation. Other research on how different predators and habitat...