the Cuban tree frog, American green tree frogs modified their calls to be shorter, louder, and more frequent so that potential mates would have a better chance of detecting the call. Threats As a tadpole, the American green tree frog is easily predated by sunfish, bass, and dragonflies, including both aeshnidae and libellulidae odonate naiads. The species is especially vulnerable to predation when living in temporary ponds compared to permanent waters. To combat predation, green tree frog tadpoles may increase hiding behavior while in water to avoid capture. The American green tree frog is also prone to a few parasites, including nematodes, protozoans, and trematodes. Contrary to most amphibians, the American green tree frog is not easily susceptible to the Batrachochytrium dendrobatidis (Bd) pathogen and the disease chytridiomycosis. Reasons explaining why are relatively unknown, but one study hypothesizes that variances in climate, frog immunity, and frog habitat are potential factors. Physiology Androgens Androgens, such as dihydrotestosterone and testosterone, are the primary energy resource for American green tree frogs when engaging in acoustic signal calling. When a male frog engages in vocalization either for aggression or mate attraction, androgen energy stores are used and become depleted. Interestingly, glucocorticoids, such as corticosterones, also appear to change during calling behavior. According to the Energetics-Hormone Vocalization model, glucocorticoid levels in males will rise as androgen levels decrease following vocalization. When observing hormonal levels in both calling and satellite non-calling males, reduced androgen levels and elevated glucocorticoid levels are found among satellite non-calling males compared to calling males. These observations suggest a possible mechanism dictating vocalization and the alternation between calling and non-calling behavior in the green tree frog. Further study is required however on the relationship between glucocorticoids and male vocalization to consider causality. The causality of vocalization by androgens is also limited by the American green tree frog’s social environment. According to one study, androgens themselves were not sufficient to initiate call signals in male frogs when in the presence of social stimuli such as other frog choruses. This suggests that androgens on their own may provide males with enough motivation to call, but they may also require additional social context to produce various call signals during situations such as mating. As pets American green tree frogs are popular pets because of their small size, appearance, and the undemanding conditions needed to take care of them. Unlike many amphibians, they do not require