During winter, the gray treefrog hibernates within its arboreal habitat, taking refuge in tree hollows and crevices (4). Throughout this period it is extremely cold in certain parts of its range, with some areas experiencing temperatures below freezing. This highly adapted frog produces glycerol during periods of cold weather, which allows an individual to ‘freeze’ itself, while maintaining interior metabolic processes at a very slow rate (2) (3) (4).
After emerging from hibernation in early spring (3) (4), the male gray treefrog begins calling to find a mate (4), as well as to establish a breeding territory
. Most reproduction takes place early in the calling season, which usually begins in late April and ends in early August (3). The male and female gray treefrog mate up to three times per season (5).
The territorial male defends its territory by fighting with other males who enter its area. Fighting between two males usually consists of 30 to 90 seconds of wrestling, shoving, kicking and head butting until the subordinate male retreats
. To instigate mating, the female approaches the calling male and touches him, before rotating 90 degrees (3). Amplexus may last for several hours, although only an hour is spent depositing and [fertilising] the 1,000 to 2,000 eggs laid by the female (4). The male and female float on the surface of the water and the female lays the eggs in small quantities while they are fertilised by the male (3) (4). The eggs are usually divided into masses containing up to 40 eggs, which are surrounded by a transparent mucous layer (3) (4) (5). The mucous layer swells and attaches the mass to a substrate (4) (5).
The eggs of the gray treefrog hatch up to five days after deposition, although this varies depending on the water temperature (3) (4). Between 10 and 60 minutes before hatching, the embryo rotates its head against the edge of the egg and releases a fluid, which helps to break down the wall of the egg (4). The larval period usually lasts between 40 and 60 days, after which the larva metamorphoses into its adult form (3) (4). Within a week, the juvenile will have dispersed from its natal pond (5). The gray treefrog reaches sexual maturity at around two years old (3).
The diet of the gray treefrog mainly consists of spiders, mites, harvestmen, crickets, moths, roaches and other invertebrates (2) (3). This nocturnal species forages throughout the night in both low and high vegetation, which it is able to climb due to specialised adhesive pads on the tips of its digits (4).