Bird strikes are an unfortunate occurrence in airports and other aerodrome areas. Bird strikes not only leads to the demise of the birds, it also causes damage to aircrafts and disrupts airside operations. Depending on the type of bird and the number of birds struck at one time, bird strikes can lead to potentially fatal accidents. It is important to be able to identify the bird species commonly involved in striking aircrafts to provide a species baseline data to better aid in habitat management programmes at the airside.
Carcass condition
After a bird strike, the condition of the carcass may vary from a whole intact carcass to a partial carcass of missing body parts to a mangled carcass where the bird could be almost unrecognizable. There could be situations where there are very few remains of the bird left and having a collection of bird specimens and their body parts can come in very helpful for comparison.
Methods for Identification
Visual & Physical Characteristics
For a whole intact bird carcass, it is easier to identify the bird species by its visual and physical characteristics compared to a mangled one. Physical characteristics such as the face shape, beak type, size, plumage colour and markings/patterns can help to identify the bird. Juvenile birds usually have different plumage colours compared to their adult counterparts, thus is good to be familiar with all the stages; juvenile, subadult and adult physical appearance of the bird.
Below is an example of a carcass (left) we collected, compared with a photo of a Juvenile Brahminy Kite (right) below.
Images credits: ©️Mastermark Pte Ltd (left); ©️Prashanth Chandra (right)
From the carcass photo above, the chestnut brown feathers (7-10) are a clear indicator that it is a juvenile Brahminy Kite carcass instead of a juvenile White-Bellied Sea Eagle (WBSE). We also considered the size and weight of the carcass which weighs lighter than a WBSE. Additional information on Brahminy Kite can be found on our website article highlighting the species here.
Below is another example of visually identifying a carcass, based on its physical characteristics.
Image credits: ©️Mastermark Pte Ltd (left); ©️Charles J. Sharp (right)
From the carcass, the seed-eating beak indicates it is a species of Munia, with brown plumage which is common in Munia juveniles. The size of the carcass also matches that of a Munia size which led us to conclude that this carcass is most likely a Munia.
Comparison With Known Specimens
The carcasses above are easier to identify visually by their physical characteristics due to them being fully intact. However, some bird carcasses can be more mangled or have missing body parts, it may be a bit more challenging to just identify them visually. Thus, having a collection of different bird specimens can aid in future identification of the carcasses. For example, being able to compare a mangled carcass with feather or talon specimens.
Images (from left): Juvenile White-bellied Sea Eagle's primary feather, Brahminy Kite's primary feather, Dark morph Changeable Hawk-Eagle's primary & secondary feathers and, White-bellied Sea Eagle's talons; courtesy of ©️Mastermark Pte Ltd
Documentation of Carcass Photos for Future References
In addition to having a collection of physical specimens, documenting photos of the different bird carcass can aid in future identification of carcasses. Birds of different species may be very similar looking, it would be helpful to document photos with measurements of certain key body parts for future comparison. For example, the juveniles/sub-adults of a Brahminy Kite and a WBSE are very similar, when the carcasses are not fully intact it would be difficult to properly distinguish the two. Having photo references showing the difference in sizing would be advantageous in identification. Below is a juvenile WBSE carcass and we measured the size of the head and beak.
Image credits: ©️Mastermark Pte Ltd
Time and the Surrounding Habitat
Another important factor that can aid in the identification of a bird carcass is the time and location the carcass was found. Carcasses of birds that are found at night could belong to nocturnal birds that are predominantly active during the night. Knowing the behaviour of a bird and combined with the knowledge of the surrounding habitat in the aerodrome, can help narrow down the kind of birds that could be in that area.
Here is an example of a barely recognizable carcass below found at night.
Image credits: ©️Mastermark Pte Ltd (left and middle images); ©️The Feather Atlas (right)
This mangled carcass was found at night, it was barely recognizable without prominent body parts seen. Taking into consideration that the carcass was found at night, the location where it was found (a place where previous sightings of the species were reported) and compared the feather patterns, we concluded that it belonged to a Barn Owl.
Putting It All Together
Identification of bird carcasses has its challenges, especially those that are mangled and are visually indistinguishable like a smashed-up pile of feathers. When identifying just by visual physical characteristics is insufficient, take note of the time and the surrounding habitat or use any other recorded data of the area that you may have. Having knowledge of what species of birds have been sighted in that area the carcass was found will help in this case. When you have a suspected bird in mind, compare the carcass to known physical samples or previously documented photos. A combination of all these methods will greatly aid in your identification of the bird carcasses and hopefully helps in getting a better understanding of what birds are being struck in the airport.
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