Moment in the Sun: Species’ Summer Adaptations Provide Ways to Protect Them
The sun has moved to its highest position in the sky this year. We’ve experienced the day with the longest period of daylight and the shortest night of the year. All of this can only mean one thing: it’s summertime in the US.
Of course, summer ushers in warmer temperatures. It also often brings changes in rainfall, from drier conditions in Oregon and Washington to monsoon rains in Arizona and New Mexico to the continuation of the rainy season in Florida – and everything in between.
Amphibians and reptiles are highly attuned to the changing conditions of the seasons, and they respond to the summer with a wide range of fascinating behaviors and other adaptations. In response, our work to protect them and their habitats shifts to take advantage of the ways they cope with the warmest months of the year.
They Can Stand the Heat – With Summer Adaptations
Through specialized behaviors, physiological adjustments, and more, amphibians and reptiles not only survive but thrive in some of the harshest summer weather in the US.
Case in point, in the eastern states, western lesser sirens have a unique way of coping when the wetlands they inhabit dry up during the summer. They first burrow into the mud at the bottom of their pond. Their skin then secretes a thick layer of mucus as the mud dries. The mucus becomes a cocoon, which helps to keep them from drying out.
Some of the most conspicuous adaptations, however, are found in the amphibians and reptiles of desert climates. These species have evolved incredible traits to thrive in the extreme summer conditions of the deserts in the western and southwestern states.
Species like lowland leopard frogs and barred tiger salamanders inhabit rare oases in these arid lands – permanent water sources such as ponds, streams, or springs.
Some barred tiger salamanders even exhibit something called neoteny, which means that throughout adulthood they retain the characteristics that allowed them to live in water as larvae (like tadpoles), such as gills. This way, they can simply remain in the water and avoid living on the surrounding hot, dry lands where they’d risk drying out.
Other desert amphibians don’t rely on bodies of water year-round but instead are adapted to live mostly on land – or more accurately, under the land. Sonoran Desert toads, Couch’s spadefoots, and lowland burrowing treefrogs have mastered the art of living underground.
For the majority of the year, these amphibians live in burrows, providing shelter from scorching temperatures and minimizing water loss.
Reptiles in desert ecosystems face similar challenges, mostly centered around maintaining their body temperatures. Although these ectotherms need sources of heat, getting too hot can be dangerous for them.
For example, diurnal lizards, meaning ones that are active during the day, like desert iguanas, Gila monsters, and common chuckwallas manage their body temperatures by basking in sunlight to absorb heat. But then they seek shade and burrows or alter their body orientations before they warm up too much.
Northern black-tailed rattlesnakes are also typically diurnal, but they shift their activity seasonally based on temperature. In the spring and fall, they become somewhat more crepuscular, or active at dawn and dusk, and in the hot summer months, they’re often nocturnal.
Our Work Heats Up: Safeguarding Species During the Summer
For many of these species, summertime is the best time to carry out targeted conservation and restoration efforts on the ground in PARCAs, or Priority Amphibian and Reptile Conservation Areas, across the US.
For example, in the Cochise, Bootheel, and Gila PARCAs of Arizona and New Mexico, the summer months bring monsoon rains that can darken the big desert skies and drop large amounts of water all at once.
Survival for many desert amphibians, like Couch’s spadefoots, Sonoran Desert toads, and western narrow-mouthed toads, hinges on their ability to exploit temporary pools during the monsoon. They gather at these sites to “explosively” breed, meaning they congregate in large numbers for a short period.
Our team capitalizes on these brief windows of opportunity to gather critical information about the populations of amphibians that rely on the short-lived pools formed by these dramatic thunderstorms by monitoring them during their equally dramatic breeding events. The data we collect then informs the habitat restoration and conservation efforts we conduct during the rest of the year.
Just east in a narrow area nestled between Houston, Austin, and Dallas, Texas, we’re doing some detective work with partners to protect the Endangered Houston toad.
These toads are active aboveground in early spring and summer, and we’ve installed automated wildlife sound recorders across the region to listen for their calls. When we detect the peaceful trills of the Houston toad, we know that’s an area they’re using.
We then work with landowners at these sites to conduct habitat restoration, especially during the summer. It’s the most effective time of the year for much of this work, particularly efforts to remove invasive plants given that it’s their growing season.
Farther east, we’re also continuing our work protecting the nests of imperiled bog turtles in the Southern Appalachians PARCAs, or Priority Amphibian and Reptile Conservation Areas. In the spring and early summer, rare female bog turtles lay 3-5 eggs in a nest within the sedges.
We then surround the nests with wire cages to protect the vulnerable eggs from predators like skunks and raccoons, whose populations have increased alongside increasing human development. When the eggs hatch in the late summer, the young turtles will have been given their best chance.
Because of their amazing adaptations and unique life histories, these remarkable species persist through the summer months in even the most oppressive of climates. With your help, we can continue to give them their best odds for the future, through the balmy days of summer and beyond.
