Magpies are medium-sized passerine birds that belong to the crow family. They are found across North America, Europe, and Asia. Known for their intelligence and complex social behaviors, magpies have fascinated people for centuries. But what happens when one of these remarkable birds dies?
Cause of Death
There are several common causes of death for magpies:
Predation
Magpies face predation from a variety of sources. Larger predatory birds like hawks, eagles, and owls frequently prey on magpies. Mammalian predators such as foxes, coyotes, cats, and raccoons also hunt magpies. Magpie eggs and chicks are especially vulnerable to predators.
Disease
Like other birds, magpies can succumb to avian diseases. Salmonellosis, avian pox, aspergillosis, and avian influenza are some diseases known to affect magpies. Parasites like roundworms, tapeworms, and blood parasites can also sicken magpies.
Collision
Another common cause of death for magpies is collision with cars, windows, or other structures. Magpies scavenging roadkill are particularly susceptible to being hit by vehicles.
Starvation
Lack of food resources can lead to starvation. Harsh winters, habitat loss, lack of nesting sites, competition with other magpies for resources, or an inability to forage due to injury or illness are scenarios that can result in starvation.
Old Age
In the wild, magpies generally live 6-10 years. Old age and associated organ deterioration are natural causes of death for elder magpies.
What Happens Immediately After Death
Immediately after death, the magpie’s body will begin showing signs of rigor mortis as the muscles stiffen due to lack of ATP. The muscles will remain stiff for approximately 24 hours before relaxing again.
The magpie’s eyes will typically remain open after death. The body will start to cool to the ambient temperature. Within minutes to hours, the magpie’s corpse will become stiff as rigor mortis sets in.
If the magpie died from trauma or a predator attack, there may be external wounds, bruising, or obvious signs of injury. Birds that died slowly from disease may appear emaciated or show discharge from the eyes, nares, or beak.
Internal bacteria and enzymes start to break down the tissues and organs. This leads to initial decomposition though outward signs may not be noticeable right away.
Decomposition Process
Once the magpie has died, the decomposition process begins immediately and progresses through several stages:
Fresh Stage
This initial stage lasts from the time of death up to around 4 days. Autolysis occurs as the magpie’s enzymes start digesting cells from within. Putrefaction also begins as anaerobic bacteria within the gastrointestinal tract spread, digesting tissues and releasing byproducts associated with decomposition.
The magpie’s body starts bloating due to these decomposition gases. Insects are not yet attracted to the carcass.
Bloat Stage
From approximately days 4-10, the magpie enters the bloat stage. Putrefaction increases and gases build up inside, causing the abdomen to swell. Skin and feathers detach easily. The release of decomposition fluids attract blowflies and flesh flies who lay eggs on the magpie. Maggots hatch and begin consuming tissues. Other insects like beetles and ants also start feeding on the corpse.
Active Decay
Around 10-20 days into the process, active decay sets in. Maggots are at their peak feeding activity. The magpie’s body deflates as gases and fluids escape. Strong odors emanate as decomposition peaks. Beetles and other insects are also actively consuming and dismantling the remains.
Advanced Decay
From around 20 days to 1 year, the magpie enters advanced decay. Most of the flesh has been consumed. Beetles continue to pick apart any remaining tissues. The carcass is greatly desiccated and unrecognizable. Bones begin to show and become bleached by the sun.
Dry Remains
After a year or more, all that may remain of the magpie is dried skin, cartilage, and bones. The speed of the entire decomposition process depends on factors like temperature, moisture, pH, oxygen levels, and accessibility of the carcass to insects and scavengers. In warm, humid environments with many scavengers, decomposition will proceed more quickly.
Scavenging by Other Animals
Scavenging by other animals greatly accelerates the decomposition process. Carrion feeding insects and arthropods arrive first, followed by vertebrate scavengers. Here is a timeline of common magpie scavengers:
0-2 days after death
Blowflies – Often first insect to arrive; lays eggs which hatch into maggots
Flesh flies – Feed on decomposing flesh as adults and larvae
Carrion beetles – Adults and larvae feed on decaying remains
Ants – Feed on maggot secretions, decomposing tissues
2-7 days after death
Turkey vultures – Rip into carcass and feed on flesh
Crows & ravens – Consume eyes and internal organs first
Coyotes & foxes – Scavenge on remains if not dominated by larger scavengers
Rodents – Gnaw on cartilage, soft tissues
1-4 weeks after death
Rat snakes – Consume maggots and carrion beetles
Bobcats – May scavenge the decomposed carcass
Bald eagles – Rip into remains and consume decomposed flesh
Bones
After several weeks, the magpie’s flesh and organs will have been completely consumed or decomposed. All that remains are bones, some connective tissues, and feathers.
Larger bones like the sternum, hips, and leg bones will persist the longest. Small, fragile bones like vertebrae and rib bones decompose more quickly.
With time, the bones become weathered and bleached by the sun. Alternating wet and dry, hot and cold conditions cause the bones to eventually crack and flake apart. Fungal growth may appear on old bones during damp conditions.
Rodents like squirrels, mice, and chipmunks may gnaw on and polish small bones. Larger mammal scavengers sometimes scatter bones by dragging away portions of the skeleton. The magpie’s skull typically persists the longest before eventual decomposition.
Feathers
Feathers from the magpie’s body will detach and blow away during decomposition. However, thick clusters of feathers may remain stuck together on areas like the wings or tail for an extended period.
Sun exposure causes the feathers to fade in color and become brittle over time. Alternating wet and dry conditions take a toll. Bleaching and physical abrasion slowly break feathers down.
Microorganisms colonize the feathers and aid in degradation. Fungal hyphae penetrate the feathers and begin digesting the protein keratin. Bacteria also release enzymes that degrade feathers.
Eventually all feathers either detach or are reduced to fragments by weathering and biodegradation over a period of months to years. The speed of breakdown depends on environmental factors.
Environmental Effects
The environment plays a major role in the decomposition process and breakdown of remains. Here are some key factors:
Temperature
Warmer temperatures accelerate decomposition and scavenging. Bacteria, maggots, and insects are more active in heat. Cooler temperatures slow the process. Remains may freeze instead of decomposing during winter.
Moisture
Bacteria thrive in moist conditions. Damp remains decompose faster than desiccated ones in arid climates. Alternating wet and dry accelerates weathering and breakdown of bones and feathers.
Sun Exposure
Sun bleaches bones and feathers. Powerful UV radiation gradually breaks down tissues. Direct sun dries out carcasses. Shade provides moisture and slows decomposition.
Oxygen Availability
Aerobic decomposition is fastest. Submerged carcasses decompose slowly due to lower oxygen. Buried remains experience slowed decay.
Scavengers & Insects
Scavengers can strip a carcass down to bones in days. Insects speed decay and breakdown. Remains left untouched take much longer to decompose.
Soil/Vegetation
Soil moisture, pH, and nutrients affect decay. Plant roots and burrowing insects infiltrate remains. Tightly woven fallen leaves or buried remains decompose slowly.
Ecosystem Benefits
While the decomposition of a magpie carcass may seem unpleasant, it provides vital nutrients and energy that sustain many different organisms and natural processes. Here are some ecosystem benefits:
Nutrient Cycling
Decomposition returns nutrients like nitrogen, phosphorus, and calcium from the magpie’s body to the soil. This nourishes plants that form the base of the food web.
Soil Fertility
Maggots burrow into the soil beneath remains. Their secretions add organically rich humus, enhancing soil quality.
Food Source
Hundreds of insect species and more than a hundred scavenger species benefit from a single carcass for food.
Ecological Roles
Scavenging fills vital roles in eliminating dead animals, preventing disease spread, redistributing nutrients, and stabilizing ecosystems.
Indicator Species
Scavengers and insects that are attracted to remains can serve as indicators of habitat health and biodiversity.
Importance for Magpies
The decomposition process feeds back to benefit the rest of the living magpie population through several pathways:
Disease Prevention
Prompt decomposition removes infectious carcasses that could spread pathogens like avian influenza to living magpies.
Colonization
Maggots hatching from eggs laid on carrion provide a major food source for nestling and juvenile magpies.
Food Source
Adult magpies scavenge nutritious insects and grubs that are engaged in breaking down remains.
NESTING Material
Magpies incorporate bones, feathers, and other fragments into their nests – recycling the resources.
Nutrient Availability
Nutrients released back into the environment spur insect and vegetation growth that magpies rely on.
Conclusion
To summarize, when a magpie dies, its body undergoes a rapid decomposition process facilitated by insects, scavengers, weather, and microbes. This recycles the nutrients to sustain other lifeforms. Bones and feathers gradually break down over time.
The carcass provides an essential, nutrient-rich food source that sustains a diversity of species and enriches the ecosystem. Scavenging and decomposition fill crucial roles in maintaining natural balances and magpie health. While an individual magpie’s life ends, its nutrients persist in the environment to nourish its species and ecosystem into the future.