A behaviour known as fecal sac ingestion is a common and important practice in many bird species. Here’s why they do it
1. Nest Hygiene
Maintaining Cleanliness: Young birds produce fecal sacs, which are mucus-covered packages of feces. These sacs are easy for the parents to pick up and remove from the nest. By consuming or discarding these sacs, the parents keep the nest clean, which reduces the risk of parasite infestation and disease.
![](https://www.singaporegeographic.com/wp-content/uploads/2024/07/VII_2825.jpg)
2. Predator Avoidance
Minimizing Odors: Fecal sacs can emit odors that attract predators. By removing or eating the sacs, the parents minimize these scents, making the nest less detectable to potential threats.
3. Nutritional Reclamation
Recovering Nutrients: In the early stages of development, chicks may not fully digest their food, resulting in fecal sacs that still contain valuable nutrients. By consuming these sacs, the parents can reclaim some of these nutrients, which can be beneficial, especially when food resources are limited.
![](https://www.singaporegeographic.com/wp-content/uploads/2024/07/VII_2822.jpg)
4. Energy Efficiency
Efficient Disposal: Carrying fecal sacs away from the nest requires energy and time. Eating them allows the parents to quickly dispose of the waste and return to feeding or protecting their young without expending extra energy.
Please see this Video that can see clearly how the mother feeds the babies and was waiting for a while, to let the poop come out, and take it and eat it or throw it away. I took some videos ( not good results / sharp ) but could see the mother ate it.
This Video of a yellow-vented bulbul was recorded in Singapore.
Location: Sungei Buloh – July 2024