Table 1. Elements of the ecologically-based hazard index for assessing the relative risk of different life-history characteristics to fire ant impacts. Fire ant impacts on wildlife, and characteristics that lead to vulnerability to fire ant impacts, are reviewed in Allen et al. (2004). Life-history characteristic Safe Vulnerable Reproduction live-bearing egg-bearing Eggs hard-shelled soft-shelled Nests in trees on ground Foraging aerial/arboreal on ground Young precocious altricial Reproductive timing fall and winter spring and summer