Red Fire Ant Effects on Broad-Snouted Caiman Nest Success

This article surround the relationship between red fire ants (Solenopsis invicta) and the success of broad-snouted caiman (Caiman latirostris). This article was published within the Journal of Herpetology and was composed by the authors Maria Marco, Alejandro Larriera and Carlos Pina. Within their conducted research, they sought to analyse how red fire ants affected the survivability of broad-snouted caiman. They also wanted to see if red fire ants had any direct or indirect effect on the nest success and hatching behaviour of wild broad-snouted caiman (particularly the behaviour of females). In order to test their hypotheses, they constructed artificial nests (each containing about 15-19 eggs of one clutch) and monitored/recorded the survival rate of the caiman hatchlings after exposure to ant attacks. This was done to test their hypothesis in captivity. To replicate the S. invicta / C. latirostris relationship in the wild, the researchers chose ten natural nests from the wild (built by female C. latirostris). From a total of 120 incubated eggs, they placed some of the eggs in wild caiman nests, some in a nest colonised only by S. invicta and some in another nest without the red fire ants.

C. latirostris

S. invicta

They found that within artifical nests that were replicated in "captivity," the red fire ants would decrease the hatchling survival rates by 10% by attacking and killing the hatchlings once they reach their final development stage and begin pipping. However, those nests that are created in the wild had a 43% decline in nest success. Under either habitat, when there was no presence of ants at all, there was 100% hatchling rate and survival rate. Moreover, the red fire ants invasiveness of caiman nests is due to the eggs' provision of warmth and food for the ants. However, their presence negatively affects the survivability of hatchlings directly by their attacks on the eggs, and also indirectly by their interference with parental care between mother and eggs. 

This article greatly shows how parental care is an essential factor in the survivability of new eggs. Amphibians and reptiles are tend to be very protective of their young, and when the young are not cared for properly, predation becomes more prevalent. I found it very interesting that nests in the wild had a 43% decline in success rate. I wonder if this is because there is more exposure to red fire ants. Perhaps wild red fire ants are more aggressive?

Source Link: http://eds.a.ebscohost.com.nuncio.cofc.edu/eds/pdfviewer/pdfviewer?sid=8b80bbb8-6d0b-4221-8dac-7e8ca1ae72f1%40sessionmgr4003&vid=8&hid=4110 

Source Citation: Marc, M. P., Larriera, A., & Piña, C. I. (2015). Red Fire Ant ( Solenopsis invicta) Effects on Broad-Snouted Caiman (Caiman latirostris) Nest Success. Journal Of Herpetology, 49(1), 70-74. doi:10.1670/12-279