We’ve experienced some highs and lows and crazy weather in Texas the past few months. But, unfortunately for our rangelands, what we’ve been missing is rain! On Texas rangelands, drought is not an “if” but a “when” and “how long will it last.” So, while we always hope for rain in the forecast, it’s good to prepare for the driest scenario.
This year, water will be a regular feature of TexNat posts. We’ll discuss how wildlife use water, how rain affects plant health and diversity, and how all these things tie together on working landscapes.
To kick things off, let’s start with the basics. Did you know that water comes in three different forms? Animals that are adapted to dry climates are efficient at using these different types of water to survive in harsh conditions.
1. Free water
:liquid H2O, such as that found in rivers, streams, and rain
2. Preformed water
:water contained within substances that an animal eats; succulents are an example of a plant with high water content
3. Metabolic water
:water created as a byproduct of metabolism, along with CO2 and energy
If you’ve ever heard that an animal ‘can go its whole life without drinking water,’ that means the animal doesn’t have to take in any free water. But all animals need water to live, so these critters meet their water needs through the other two forms.
Northern bobwhite quail (Colinus virginianus) are a good example for understanding the importance of different sources of water. Bobwhites can go their whole lives without drinking water, although they are commonly seen at water sources. To survive without free water, the food of bobwhites needs to have a high water content. Different species of seeds and forbs contain varying amounts of preformed water. Many insects are a particularly good resource for quail, because they are high in preformed water and also high in fat. The amount of metabolic water produced is different depending on whether the molecule being metabolized is fat, protein, or carbohydrate, with fat molecules yielding the highest amount of water.