Nighttime vs Daytime Toad Movement

This field season has been very busy with tracking toads! I have been following two species of toads, American and Fowler’s toads, at three sites and have had great success. The main setbacks I have faced has been predation and being unable to locate the tagged toads. We had one toad definitely eaten by a snake, confirmed with a strong signal coming from the inside of the snake, as well as a few others that we suspect met the same fate. Even when they are not eaten, sometimes I am unable to relocate the toads. Despite this, I have been able to track many toads this summer and I am getting great data!

Due to predation and occasionally being unable to relocate toads I decided to focus more on the differences between daytime and nighttime movement rather than the toads’ home ranges. This will allow me to study a toad’s movements even if I was not able to track it for as long as I would have liked. While this was not originally the plan, it has led to very interesting findings!  At night, the toads are often very active. I have noticed that both species frequently use the man-made paths, present at all three study sites, which may allow them to forage easier.  In addition, many of the Fowler’s toads go into grassy areas frequently. Because of the toads’ nighttime use of the path and grass patches they are in much more exposed areas than they are in during the day. This is likely due to foraging and, in the case of the Fowler’s toads, may be due to the breeding season. Although many move a lot at night, there are individuals who will not move from a certain location for days. I suspected that if they are always at the same location during the day, they would venture out at night to look for food, but this is not always the case. Some individuals do move at night then return to their usual location during the day, but others do not seem to move during the day or night. While these differences are based on individuals there are some generalizations between the species. Fowler’s Toads, whose breeding season roughly ends in June, have generally been more active than the American Toads, who are not breeding. However, there are individuals in both species who move frequently and those who prefer stay in the same locations.

In the coming weeks I will begin analyzing the microhabitat data I have collected to see which factors are correlated with movement. I have already seen that humidity and rain are correlated with movement and I am excited to see what other factors are important. I will also continue to track the toads we currently have tagged and hopefully tag a few more at each site!

Comments

  1. jnelkayam says:

    This post was really interesting! The more I read of everyone’s research, the more I see people having to adapt to unforeseen circumstances. I really admire your adaptability, and was intrigued by your new observations. Once you start analyzing data to find correlations, what sort of other factors do you foresee yourself taking into account? Are there potential factors that could be difficult to track? I’m interested to see where this takes you!

  2. mjhudson says:

    That’s so interesting to hear about the differences in movement between daytime and nighttime. Do you have any ideas on why that difference would exist? I admittedly don’t know much about toads, but maybe it has something to do with air temperature, with the cold blooded animals preferring to move around when the air is cooler?