Skeletonizing a bird is the process of removing all soft tissue from the bird’s body, leaving only the bones. This is done by biologists and taxidermists to study bird anatomy and create museum displays. The skeletonization process allows detailed examination of the bird’s skeletal structure and can reveal information about the bird’s age, health, species, and more. Here is an overview of the main steps involved in skeletonizing a bird:
Obtaining the Bird Specimen
The first step is acquiring an appropriate bird specimen. This is usually a bird that has died from natural causes or been euthanized for scientific purposes. It’s best to start the skeletonization process as soon as possible after death, before decomposition begins. Once you have the dead bird, keep it refrigerated or frozen if you will not be skeletonizing it right away.
Removing Feathers and Skin
Before removing the flesh, feathers and skin must be removed. Plucking out all the feathers is a tedious process. Using a knife, carefully cut away the skin from the underlying muscle. Be careful not to sever any tendons or ligaments attaching the skin to the body. Peel the skin away slowly, cutting connective tissue as needed. The feet and head usually require extra care when skinning.
Removing Internal Organs
Once the skin and feathers are removed, the next step is removing all internal organs. First, cut off the head and feet. Then, make an incision up the belly from breast to tail. Reach inside the body cavity and scoop out all organs and tissues. Lungs, heart, liver, kidneys and other organs must be fully removed. Rinse the remaining carcass under running water to wash away blood and debris.
Removing Muscles and Connective Tissues
At this point, the skeleton is still concealed under muscles and connective tissue. Gently remove the large flight muscles from the breast area using a scalpel. Then dissect away muscles from the legs. Carefully cut away tendons, cartilage and ligaments from the joints. Removing all remaining flesh and connective tissues is a delicate process requiring precision. Work slowly to avoid damaging small bones.
Degreasing the Skeleton
Once fully dissected, the skeleton must be degreased to remove all remaining fats and grease. This is done through prolonged soaking in a degreasing solution. A diluted detergent solution works well. Allow the skeleton to soak for several days up to a week, changing the solution periodically. Gently scrub to help remove grease. Rinse well and let it dry once degreased.
Whitening the Bones
At this point the bones will likely be stained or yellowed with tissue residue. To whiten them, soak the skeleton for 12-48 hours in a solution of hydrogen peroxide diluted with water. If needed, scrub stubborn stains gently with a soft brush. Rinse the peroxide solution off fully when whitening is complete.
Articulating the Skeleton
To complete the skeletonization process, the bones must be properly articulated. This means reassembling all the bones in their life arrangement. Use string or wire to attach each bone at its joint. Refer to bird anatomy diagrams or actual bird specimens to mimic a natural skeleton pose. The articulated skeleton can then be assembled onto a display stand.
Causes of Bird Deaths
When studying a skeletonized bird, clues about the cause of death may be revealed. Here are some common causes of bird deaths that could show up on examination of the bones:
Blunt Force Trauma
Collision with windows, vehicles, buildings, or other structures often kill birds. Blunt force trauma can fracture bones throughout the body.
Gunshots
Lead bullet fragments lodged in bone are signs of death by shooting.
Electrocution
Burns on the tips of feather shafts happen when birds are electrocuted by power lines. Bone damage at contact points may occur.
Poisoning
While poisoning usually leaves no marks on the skeleton, toxicology tests can detect poisonous substances.
Disease
Bacterial, viral and fungal infections can cause bone abnormalities and damage. Arthritis and bone deformities may also be seen.
Starvation
Extreme weight loss is evident by prominent breastbone keel and thin fragile bones in starved birds.
Skeletal Anatomy
A bird’s skeleton contains many bones specially adapted for flight. Key elements include:
- Skull – Beak bones, brain case, eye sockets
- Cervical vertebrae – Bones of the neck
- Clavicles – Collar bones connecting breastbone to shoulders
- Scapula – Shoulder blades
- Coracoid – Part of shoulder joint
- Humerus – Upper bone of wing
- Radius, ulna – Lower wing bones
- Carpometacarpus – Wrist/hand bones
- Digits – Finger-like wing bones
- Ribs – Protect chest organs
- Sternum – Breastbone with large keel
- Pelvis – Hip/waist bones
- Femur – Upper leg bone
- Tibiotarsus – Lower leg bone
- Tarsometatarsus – Ankle/foot bones
- Phalanges – Toe bones
Skeletal Adaptations for Flight
Bird skeletons exhibit many special adaptations that enable flight. These include:
- Lightweight, hollow bones to minimize weight
- Fused clavicles fused to form rigid wishbone shape
- Keeled breastbone for large flight muscle attachments
- Reduced number of digits to support wing feathers
- Loss of teeth and reduced skull bones
- Broad shoulder girdle for powering wings
- Strengthened humerus to withstand flight forces
- Rigid trunk for transferring energy between wings
- Shortening of tail
Cleaning the Bones
After skeletonization is complete, proper cleaning and preservation of the bones is important. Here are some tips for cleaning a bird skeleton:
- Use a toothbrush to gently scrub any dirt or grease
- Soak in hydrogen peroxide if whitening is needed
- Rinse bones and allow to dry fully
- Consolidate with glues or preservatives if needed
- Store skeleton in an airtight container to prevent damage
Skeleton Display Methods
Articulated bird skeletons can be displayed in various ways for educational or decorative purposes, including:
- Mounted upright on a post or stand
- Suspended by invisible thread
- Encased in glass or acrylic case
- Mounted in a flying or perching pose
- Embedded in clear resin
- Affixed to a decorative base or plaque
Preserving Specimens in Museums
In museums, bird skeletons are carefully preserved using archival methods. This may involve:
- Pest management to prevent insect damage
- Humidity/temperature control to prevent warping
- Handling with gloves to prevent skin oil damage
- Supportive mounts for fragile bones
- Coatings to prevent bone deterioration
- Periodic inspection for any issues
Proper preservation keeps specimens intact for decades or even centuries.
Skeletal Differences by Bird Species
While all bird skeletons share basic similarities, differences can be seen between species adapted to different lifestyles and flight styles. Some examples include:
- Owls – Large eye sockets, flexible neck, strong talons
- Hawks – Broad shoulders, long legs, curved beak
- Hummingbirds – Tiny delicate bones, short wingspan
- Ostriches – Thick leg bones, vestigial wings, large sternum
- Woodpeckers – Reinforced skull, short tail, strong claws
- Penguins – Solid bones, rotating wrists, flattened sternum
Identifying Species from Skeletons
Ornithologists can often identify the species of a bird from examination of the skeleton alone. Clues include:
- Skull and beak shape
- Number and form of vertebrae
- Keel shape and size
- Leg bone proportions
- Foot arrangement
- Wing structure
- Presence of specialized structures
Measuring bones and comparing anatomy to reference specimens helps pinpoint the species. DNA analysis can also be used.
Famous Skeleton Specimens
Some particularly famous and significant bird skeleton specimens include:
- Archaeopteryx – Ancient evolutionary link between dinosaurs and birds
- Dodo – Extinct flightless bird from Mauritius
- Terror bird – Giant prehistoric carnivorous bird
- Passenger pigeon – Extinct due to overhunting
- Saber-toothed parrot – With unique beak adapted for eating seeds/nuts
- New Zealand moa – Giant extinct flightless birds
These provide insights into paleontology, extinction, and avian evolution.
Recreating Damaged Specimens
Although missing or damaged bones present challenges, researchers have techniques to reconstruct incomplete specimens including:
- 3D scanning and printing missing elements
- Mirroring bones from one side to recreate the other
- Referencing related complete specimens
- Computer modelling to estimate missing pieces
Careful reconstruction returns cultural, scientific, and educational value to damaged skeletons.
Conclusion
Preparing a bird skeleton involves meticulously removing all soft tissue to articulate the bones. The resulting specimen can provide insights into anatomy, species characteristics, ancient birds, and more. With proper preservation and display, bird skeletons can be studied and appreciated for generations to come.