Study Design
Where was the study located?
Tucson, Arizona
In what setting was CTM determined for each species?
In the lab
When did most of the ant species abandon the cacti in the study?
During peak daytime temps, around 10am-4pm (Fig. 3)
What does each species gain from the mutualism?
Ants gain food, plants gain protection
What is the common name of the cactus in the study?
fishhook barrel cactus
Was body size a factor in determining different CTM between species?
No
Which ant species visited plants that reached the lowest maximum temperature?
Southern fire ant (S. xyloni)
What are obligate associates?
Species that cannot survive/thrive without one another in a mutualism.
What is the genus of bugs that feed on the cacti in the study?
Narnia
What was the relationship between plant surface temperature and ambient air temperature in the study (higher, lower, equal)?
Plant surface temperature was higher than the ambient air temperature in the study (Fig. 2).
How do the ant species in the study partition resources?
Spatially by visiting different individual cacti, but also temporally (throughout the day) based on their thermal tolerances and surface temps of the cacti
What is the new name of the genus that used to be called Acacia?
Vachellia
What time of year were the field observations in the study conducted and why?
September, because "this is the time of year when F. wislizeni sets fruit and is potentially most vulnerable to attack by insect herbivores, which feed on the fruits and seeds"
What explains the spatial heterogeneity in surface temperature of plants?
angle relative to ground, direction the plan tis facing, whether it is in direct sun or shade, whether or not it is bearing fruit
What do the authors suggest is the relationship between competitive dominance (in this case aggressive behavior) and effectiveness mutualistic interactions?
A direct positive correlation (better competitors are better at performing their jobs as mutualists)
How do ants sense a large herbivore's presence?
odor cues, unnatural vibrations
What was the main knowledge gap that this study sought to address?
There was little research on the thermal ecology of species interactions, as opposed to the thermal ecology of individual organisms
How might rising temperatures due to climate change affect these types of ant-plant mutualisms?
Rising temperatures could favor ants that are more thermally tolerant but are competitively and mutualistically inferior, reducing the benefit to ant-defended plants
How does the High noon ant (F. pruinosus) compensate for its lack of competitive dominance? In other words, what tradeoff exists here?
Tradeoff between thermal tolerance and behavioral dominance. The high noon ant is more tolerant of high thermal extremes to compensate for its lack of competitive dominance at more mild temperatures.
Why might ants be more effective than other types of defense (e.g. spines, thorns, chemical defenses)?
Ants can protect against a wide range of herbivores, from small insects to large mammals like elephants! On the other hand, defenses like thorns may deter a larger mammal herbivore but not insects.