Hi everyone, my name is Lauren
and I'm a Kupu Americorp member
with the U.S. Fish and Wildlife Service and I'm super excited
to have you all with me to go through our online bolus
dissection activity.
I work in our Pacific Islands office which is located in
Honolulu and from there we manage refuges all throughout
the Pacific.
One of the remote places we take care of is Midway Atoll
National Wildlife Refuge.
And so midway is located about 1200 northwest of the main
Hawaiian Islands.
Midway only has a land mass of 2.5 square miles but it's home
to over 3 million seabirds. Which is pretty incredible.
And the most abundant species or at least most abundant
seabird species is the Laysan albatross and that’s whose
bolus we are going to dissect today.
And so what is a bolus,
to put it frankly for you it is bird vomit.
And more specifically chick vomit.
Before a young albatross chick is ready to fly for the first time,
or fledge, it wants to be as light as it possibly can be.
So anything it has in its stomach that it can’t break down it
wants to get out. So it will throw up or cast a bolus.
And you may be thinking, what the bird would be eating
anyway that’s indigestible?
Why would the bird’s parents feed it something that it can't
break down that just sits in its stomach?
In terms of natural items, what we see most commonly are
squid or squid beaks. So squid, fish, and fish eggs are the main
components of an albatross diet. Those are the things that
to bring back to their chick because they are super nutrient
rich and help the chick to grow really fast.
So these beaks as they bring the squid back to the chick - all the
soft and squishy bits of the squid is digested but that beak
is left. So that's just one more adding to the pile
in their stomach.
What's more alarming that we see more and more frequently
are pieces of plastic or other man-made debris
in the boluses.
So we'll see lighters. We'll see fishing line. We'll see, in this
case we have an example of one that's encased in
modge podge, an entire tooth brush.
So it can be pretty crazy what you find, what these seabirds
are finding, and what they are bringing back to their chicks.
And so we use boluses as a way to study albatross diet and also
as a way to bring awareness to this issue of human debris and
how humans impact our marine environment.
So I'm super excited to go through this with you today.
We are going to pick apart a bolus that was collected on
Midway Atoll about a year ago.
So I’m super excited to see what we can find and I’m going
to sort the contents and talk you through it.
If you have any questions feel free to leave them in the
comments and I'll try to answer them for you in the chat.
Ok so this is the table set up that you might have noticed
behind me in the introduction.
This is where we are going to do the dissections.
I've got a couple of tools here I usually just use my hands so
I’ve got my gloves on, but just in case I also have some
tweezers, a magnifying glass, and a ruler so I can give you a
sense of scale as we go along.
But yeah we are going to get started.
So every year boluses are collected out on midway atoll.
We have a process for this where they are numbered and
accounted for. And collected in certain areas so we know what
species we are collecting from.
As you can see we are collecting from 2019 and the ‘L’ means
that it was collected from a Laysan albatross.
We are just going to open it up and see what we find. So these
are collected on Midway and dried and we just process them