The bird’s digestive system is different than many other animals. They have organs not seen in most other animals because they are specifically designed for certain tasks that only the bird carries out. Organs you may never heard of that are part of the bird’s digestive system are the crop, the proventriculus, and the gizzard. All of these have specific functions that carry out the complicated task of breaking down food and allowing a bird to absorb life-sustaining nutrients.
Birds have beaks that are shaped according to the kind of food they eat. Parrots and other birds that eat large, thick, hard shelled nuts need a really strong curved beak to put enough pressure on the nut to crack it. The curve of the beak also serves as an aide in climbing up branches in trees. Birds with straighter pointed beaks eat more smaller, softer seeds so they don’t need as powerful of a beak. They also often use their beak as a pecking tool to quickly peck insects or other “peck-able” objects.
Birds have no teeth, so there is no chewing before food is coated with a bit of saliva and travels down to it’s first destination; the crop. This little organ is usually visible on the outside of the bird’s body. It appears as a little lump. A pouch where food accumulates and stored. It kind of hangs out here while small amounts drop down in to the next organ of digestion; the Proventriculus.
The Proventriculus is the first of two parts of the stomach. This first stomach is the one that secretes the juices that help break down the birds food for digestion. Special glands release digestive juices to soften food so that the birds body can take it apart on a molecular level and use it to keep the bird alive. Then the food passes to the Ventriculus. This is the more muscular second half of the stomach, more commonly known as the gizzard. Here, food is squashed and smashed and generally just beaten up. The gizzard often contains grit or gravel to help grind up food. The gizzard is very very powerful. Some birds ingest whole seeds that have not been shelled. In cases like this, the gizzards power, along with some hard pieces of grit, break down the shell so the nutrient-filled insides can be processed. When the gizzard is finished with it’s job, the food slips into the intestines of the bird.
In the intestines, more juices are excreted. Bile and enzymes designed to break food down even more get to work on the food. In the intestines, tiny particles of food nutrition pass through teeny tiny holes to travel through the blood stream and are used to “fuel” the bird. At the end of the line, some parts of the food cannot be used by the bird. This unusable food, along with waste products brought back from the bloodstream, come out of the bird as feces and urine. All waste leaves the bird from the Vent or Cloaca. Since birds eat often and have such a high metabolism, they excrete waste often. A bird can have as many as fifty bowel movements a day.
– Written by: Arianna Pleitez