By Tom Dietz
Walking the beach can be an adventure and a treasure hunt of sorts. There’s always the chance of a unique discovery and even the regular beach debris is never dull. I’d been focused for months on photographing a deteriorating gray whale killed by a ship prop strike.
Along with that project I became obsessed with taking photos of washed-up seabird carcasses. There is a beauty in all aspects of nature. Some of the birds had GPS tracking devices attached which I returned to their scientific owners. But one bird I came upon drew me in for closer inspection and ultimately to wanting to preserve it in some way.
I’m a big fan of pelicans. The B52’s of the sky. There hadn’t been many washed up seabirds for a week or so when I came upon Pelecanus occidentalis (Linnaeus, 1766) californicus (Ridgway, 1884). This majestic bird was just lying in the sand, deteriorating, and with its head pointing back towards the ocean. A dog had clearly wandered around it, but the carcass, entwined in seaweed, was otherwise undisturbed. I took a photo and studied the bird’s structure. The creature’s unique air sacs that line the underside of its skin, helping in flotation, were still wholly intact. I then continued my walk south along the beach to see what other treasures presented themselves.
In 1903 President Teddy Roosevelt created the Nation’s first National Wildlife Refuge,
Florida’s Pelican Island to protect pelicans and other species, e.g., egrets, from hunters in search of plumage. Another threat to the species came from chemical pesticides, such as DDT. The banning of DDT and several other chemicals in the 1970s helped the species make a robust recovery and today sits with a Conservation status of “Least Concern” on the IUCN classification scale.
Wandering the beach, my mind kept coming back to the pelican. I headed back deciding a closer look at the beak, gular pouch and skull would be interesting. With my knife, I found a spot a few vertebrae down from the skull to cut through and separate the head from the body. The neck is tough with plenty of muscle mass that helps protect it from 60 foot plus dives.
The gular pouch is unique. It is a thick layer of skin, veiny, with a thin leather like feel, and attached to the lower jaw. The jaw is very flexible and can bow outwards to allow for the pelican to capture its prey with its pouch analogous to a fishing net. The pouch has amazing lateral stretch characteristics and more limited stretch in the longitudinal direction. The pouch can hold up to 3 gallons of water and up to 24 pounds of weight. Being highly vascularized the pouch offers the pelican exceptional cooling.
Right before the pelican dives, it takes a deep breath forcing air into special structures in its skull and jaw bones, called pneumatic foramina. This stored air can help to cushion the bird from the impact forces associated with hitting the water while hunting. Those structures also add to other mechanisms to assist the bird in creating buoyancy.
Having the bird’s head in the workshop, I went into museum preservation mode. My vision was a mount to display the skull and its beak, one of the largest amongst birds.
After removing the few vertebrae near the skull, I used a garden hose to clean the accumulated mud and sand from the head.
Next up was a dissection of the gular pouch and removal of bulk tissue with a scalpel. With that done, I cut through ligaments that hold the lower jaw to the skull. A short piece of coat hanger was inserted into the base of the skull where the spinal cord passes through to dislodge brain tissue. I then used a syringe filled with water to wash out the brain cavity.
My preferred method for degreasing and cleaning up bones is hot water maceration. It can potentially shrink the bones and damage them but by only heating to 150F, bacteria and viruses can be killed while lessening these negative effects. However, this is not the preferred prep method for taxidermy.
Using my turkey deep frying setup, I heated the skull and beak to 150F in a mild enzyme detergent for an hour at a time.
At each hour, I removed more tissue and then the individual bones were freed. The smaller bones were put into a cheese cloth wrap and placed in the detergent bath to continue the tissue removal process.
It’s a good idea to take photographs of the small bone orientation so that reassembly is easier.
Next was the whitening /bleaching process. I used off the store shelf hydrogen peroxide at 3% strength. The skull and beak were placed in a tub while the small bones were treated in small plastic containers. The bones were allowed to soak in the H2O2 overnight.
Post bleaching, the bones were rinsed in distilled water several times over the course of a day and then allowed to air dry for several days. You can also bleach them in the sun.
For the reassembly process I used a cyanoacrylate glue with a point applicator to precisely put the skull bones back in place. The angles were critical to get everything to fit back together although in their natural state the bones are not touching but held together by a system of ligaments, muscle, tendons, and cartilage. Sculpting clay was useful in aligning the bones for assembly.
After the skull’s base bones were in place, I arranged the lower jaw to angle down, allowing for a full view of the skull and beak’s structure.
With the skull and beak position set, I worked with brass rods and solder to create a mount that would support and provide some protection the skull and beak.
A stained walnut base with a recessed flat brass bar finished the display and hopefully do a little honor to this majestic brown pelican.
Another couple of birds I don’t often see on the beach are Fulmars and Jaegers. I was able to collect the heads of a washed-up Northern Fulmar and an immature Jaeger (whose species was difficult to determine with confidence). I found the Jaeger (genus:Stercorarius) first and prepped and mounted it. The Northern Fulmar (Fulmarus glacialis) came a few months later. I had wanted to preserve its upper bill (naricorn) but I failed to remove it soon enough from the hot water resulting in it softening too much and losing its shape upon cooling. I was able to modify the Jaeger mount to accommodate the Fulmar skull. Spending some time on-line and in the bird identification literature, I note a dearth of quality species specific bird skull information. Might be time to create a bird skull reference data base.