Why Would A Bird Die Suddenly? | Cause Of Sudden Death In Birds

Unexpected and sudden deaths of companion birds are one of the most heartbreaking incidents for any bird lover or fancier. Avian creatures are notoriously good at hiding injuries or diseases because their weakness causes trouble to their territory by attracting predators. 

Both wild and pet birds can succumb to mild or severe illness, and most of the bird feeders do not understand the signs and symptoms of the disease with which birds have been fighting for quite some time.

Bird feeders have to constantly observe their health, appearance, poops, behavior, food habits, and environment regularly to understand the cause of diseases and take steps to prevent spreading illness among birds.

How do bird feeders know precisely how sick a bird? How to recognize the signs of illness? This article aims to discuss some common symptoms of infections, possible dangers a bird would face, and what owners have to do when there is sudden death. Keep reading to know the answers to such commonly asked questions. 

What causes birds to die suddenly?

Environment, climate, pollution, diet, and diseases are the leading causes of the sudden death of avian creatures. Migrated birds face lots of obstacles like heat, building structures, improper food or habitant and electrical wires while taking a long flight, and many lose their life on the way.

Some unavoidable causes that can kill birds in a short period are:

Night fright

One of the common causes of the bird’s sudden death without proper reason or evidence is night fright. Night fright is the sudden unwanted loud sound or disturbance in the bird room or cage that can make birds frenzy and frighten them. 

To keep themselves out of danger, they try to get out of the cage. As a result, the birds get thrashed within the cell and are caused injuries or instant death.

Freezing or snow

An unexpected cold snap or heavy snow can kill small winter bird species depending on the degree of the cold temperature and shelter they choose to live in.

Heat or exhaustion

Migrating avian species have to cover long distances with improper habitat, and the environment can succumb to exhaustion. Even though birds don’t die immediately, they will get disoriented and crash into the ground due to fatigue.

Related Read: Why Don’t Birds Get Electrocuted? | How do birds sit on power lines?


Thousands of birds die every day due to the pollution that happens in many ways. Oil spills in large amounts in the sea or minor poisonous gases in the air, or other toxic hazards getting released into the environment are some of the ways through which pollution happens. Pollution leads to a high bird mortality rate and causes a significant impact on bird nesting, food habits, and migration routes.

Rain or Storm 

Large storms and hurricanes can kill dozens of shore avian species and waterfowls. They are capable of destroying their nesting habitats. A violent storm, brutal hail, lightning strikes, or whipping winds can decimate a bird roost and affect their lives.


Infections such as avian influenza, West Nile Virus, and avian botulism can cause devastating destruction on flocks of birds. If the situation becomes deadly, diseases spread to other avian species and lead to pandemics among humans.


Invasive predators such as feral cats, rats, raccoons, dogs, and snakes can kill thousands of birds and quickly wipe out birds’ nesting colonies and significantly impact local bird populations.


Mites, ticks, and other bites can spread fatal diseases to birds and harm their flocks, and even cause feather damage that results in catastrophic.

Why do dead birds have blood in their mouth?

Conure bleeding syndrome (CBS) is a traceable disease and severe internal or external bleeding. CBS often chalked up to vitamin and mineral imbalances and nutritional deficiencies such as lack of calcium, vitamin K, and vitamin D.

CBS’s symptoms and signs may resemble other illnesses, including trauma, heavy metal poisoning, viral infection, liver diseases, fungal infections, or lead toxicosis. 

The specific symptoms of a bleeding deficiency syndrome include:

  • Feather picking
  • Behavior changes
  • Weakness
  • Loss of balance
  • Shallow breathing
  • Increased thirst and urination
  • sleepiness

A lack of vitamins and calcium may prevent or slow normal clotting, which may increase excessive bleeding. The retrovirus is also a potential cause or contributing factor for CBS syndrome.

How to recognize sick birds or bird illnesses?

A sick bird never shows signs and symptoms of an infection openly, but watching closely – bird feeders can recognize it and can treat them. There are two ways to acknowledge the sick birds when it lands in your backyard :

  • By appearance
  • By behavior

Recognizing sick birds by physical appearance

A good physical and healthy bird looks active with clear eyes, intelligence, a straight posture body, and has vibrant, colorful, and bright feather plumage. Sick birds show several symptoms in their physical appearance, such as:

  • Fluffed, matted, rumpled, or dirty feathers when it’s not cold
  • Unfocused eyes
  • Swollen or dull eyes or membranes like cere
  • Nose or mouth discharge
  •  wet eye
  • Missing or dropping feathers – consistency or color
  • Visible wounds, lesions, or injuries
  • Discolored or overgrown beak

Recognizing sick birds by behavior

Healthy birds are always alert, perky, active in feeding and preening, and doing everyday bird activities. Sometimes even healthy birds might not be mobile and generally be clued to its surroundings, and it reacts like they have been threatened. A sick bird shows unusual behavior such as:

  • Panting or trouble or puffing in breathing
  • Inability or reluctance to fly
  • Drinking a large amount of water
  • Sitting in one place, even predators approached
  • Unsteady posture
  • Slouched or drooping wings
  • Increase or lack of appetite
  • Wheezing or sneezing
  • Regurgitating or vomiting
  •  Limping
  • Change in screaming or biting behavior
  • Change in activity level and fighting capability
  • Diarrhea
  • Weight gain or loss
  • Change in poop color
  • Roosting in open porches or areas
  • Turning their head in one side
  • Unhealthy birds get snapped by a healthy one
  • Squinting to fall asleep

Not all birds exhibit the above symptoms but unusual behavior enough to warrant caution the birds are sick and need a medical examination. 

The Bird fanciers primarily have to keep observing their habits and changes in them. Earlier detection of sickness in birds can at least pave the way for treatment and their survival. Do not let your carelessness come in the way when you’re around birds. Careful and constant observation can prevent the unexpected deaths of many birds.

Leave a Comment