Ever wonder do birds pee? Well, the short answer is no, birds do not pee because all of their waste leaves their body as poop. Basically, birds don’t separate their pee (uric acid) from their poop so it comes out all in one.
Animals are consumers that need to feed in order to provide their bodies with adequate nutrients for survival. Part of being a consumer is evolving ways of removing excess waste from our bodies. These can be things that we cannot digest, such as cellulose that humans cannot digest, things that we no longer need, like excess vitamins and dangerous compounds.
For instance, when humans and other animals consume protein we are consuming a nitrogen-rich compound. When these nitrogen compounds are broken down, one of the waste product they produce is ammonia, which is toxic.
In order for ammonia to not be toxic, it must be heavily diluted. Because their environment is water, fish are capable of simply excreting ammonia and using the water to dilute it. For mammals and avians, we have to turn ammonia into a less toxic compound that we are capable of diluting.
Mammals turn ammonia into urea, which is removed via our urine. Unlike fish, which are basically always releasing ammonia, mammals care capable of storing urea for longer periods of time as we can maintain the dilution levels with little harm to ourselves.
Birds and reptiles turn these nitrogen compounds into uric acid. While this process is energy intensive, it is a successful evolution for birds.
Birds are vertebrate animals that have evolved with a singular purpose: to fly. Since their beginnings about 170 million years ago, flight has proven so successful for them, on an evolutionary scale, that everything about them has been about ensuring that they can retain features for flight.
Planes and trains have taken inspiration from birds to develop faster, safer, and better means of transportation for humans. The wings of planes were developed from the wings of birds. We learned to fly by understanding how birds flew.
There are exceptions to this as there are exceptions to anything else. The largest bird is the ostrich, which can reach heights of 9 ft. The smallest bird is the bee hummingbird, which can reach heights less than 3 inches. There are the penguins that have retained winged-like features but have become adapted to flying in the ocean.
Besides the wings, bones, and feathers, birds have developed other anatomical features to ensure they can still fly. Their digest tract allows them more freedom to fly because they can collect food and store it for later digestion. This means that they can fly longer without having to search for food.
Their means of reproduction has also been optimized for flight because they get to lay eggs outside of their bodies. By having the eggs in a nest, the birds do not have to carry extra weight around, which would hinder their flying.
With the energy demands of their body, the digestive/urinary tract of birds have been optimized to ensure that mostly waste is removed and not water or nutrients.
Birds And Peeing
Birds do not pee in a similar fashion as mammals. Humans, like mammals, have two means of removing waste that include the colon for fecal removal and urethra for urine removal. In birds, urine and fecal matter are removed together.
Birds, like mammals, have kidneys that are used for filtration, excretion/secretion, and absorption. As with mammals, the kidneys of birds are used to conserve water and important resources, like sugar, by filtering them out of the waste products that end up in the urine.
The urinary tract moves urine (containing uric acid) from the kidneys to the ureters and finally the cloaca. The cloaca fulfills many roles in the bird. Along with expelling waste products, it is also where eggs are expelled from. Some birds mate via their cloaca as well. This multi-purpose nature means that birds do not have to develop other organs, which might make them heavier.
The urine is excreted from the cloaca along with fecal matter. This is the white paste that we see when birds hang around us. The paste is almost devoid of any water as it is thick and very concentrated.
While an energy-intensive process, the kidneys are able to extract as much water and nutrients from the urine so that the bird does not need a constant refill of water and can keep flying.
Exceptions To the Rules
While most birds expel uric acid in their urine, hummingbirds are an exception to this because they mostly excrete ammonia as a waste product rather than turn into something else to then excrete. They are still capable of producing uric acid, but can also just get rid of ammonia.
While most birds cannot store their urine and it must be removed along with fecal matter, the common ostrich is an exception to this. The ostrich has evolved to have a dilated pouch, called the coprodeal epithelium, in the ureter.
This pouch is similar to the mammalian bladder in that it stores the urine until it is secreted. The urine is still secreted in the cloaca. This difference is owed to the fact that the ostrich is a land bird and does not need to be worried about being slowed down due to this extra weight.
Additional Waste Removal
Because birds can be found across the globe and they also migrate across it as well, they are not always near sources of freshwater. This means that they have to find other water sources to remain hydrated. This source tends to be saltwater.
Many seabirds have evolved a specialized salt gland that is responsible for removing the excess salt from the bird’s body. The glands are modified tear gland that removes salt through the nostrils of the birds.
The penguin, which is constantly swimming through ocean waters, has these glands to ensure they remain hydrated because there is rarely any freshwater around them. This is especially true for those that live in the Antarctic regions.