satellite view from PMNM
E komo mai; welcome! Midway Atoll National Wildlife Refuge is surrounded by a lei of foam in the middle of the North Pacific; it's a beautiful, special place.

Not only are there albatross on Midway, but many other interesting kinds of wildlife, both on the land and in the sea. Please enjoy exploring FOAM, an educational blog actively done while on Midway from May through August 2010. Posts are added from off-Midway, as information becomes available. If you're interested in a particular topic, please use the search box or the alphabetical list of "labels" along the left side of the blog page.

Sunday, June 27, 2010

What's a Bolus Burrito?

UPDATE, May 10, 2011:  
In response to a comment that accompanied this post last June, I gave a source for boluses for classroom dissections.  That source is no longer active.  The Fish and Wildlife Service currently has the bolus dissemination project on hold until further notice.  We all hope that one day FWS can start up the collection and dissemination of boluses again, after the Refuge has a chance to complete tsunami recovery projects and a Visitor Services position is filled for Midway Atoll.  Iʻll certainly add to this post as information becomes available.

In the meantime, as part of a collaborative education partnership, a non-profit organization Oikonos is distributing a limited number of boluses to school groups.  The Oikonos website has a wealth of educational activities!  Contact Michelle Hester who will connect you with the albatross bolus coordinator for more details.
_______________________________________________________________________________________________________ wouldn't want to eat a bolus burrito!

As albatross grow up, they begin to be able to toss up out of their stomach any objects they can't digest.  (See FOAM's "Albatross Barf" video.)  These indigestible objects are tightly packed into what's called a bolus. You've probably heard of fur balls that cats make, and maybe you've known that owls get rid of mouse fur and bones in pellets; so a bolus is like a cat fur ball or owl pellet.

photo by Mike Neal
Albatross feed on flying fish eggs and squid. Squid are mostly digestible, except for their hard mouths, called beaks, that feel like your finger nail. Flying fish eggs are completely digestible, but they're often attached to natural objects -- like floating sticks or volcanic rocks called pumice -- which are definitely not digestible. So albatross come equipped to toss up boluses to get rid of these unwanted items.

Nowadays, many boluses have plastic in addition to squid beaks, sticks and pumice. The picture on the top left shows pieces of plastic, fishing line, a bottle cap, and even a toothbrush in a loosely packed bolus! The bolus on the right is much more tightly packed.

It is educational to see what a real bolus looks like; it helps people understand why they need to be more careful how they get rid of their trash. Many teachers ask Midway Atoll National Wildlife Refuge for boluses for their students to dissect, or take apart. Take a look at bolus dissection activities on the Oikonos website, or a recent dissection on FOAM's post "Marine Debris: Aunty Moana's Little, Green, Square Things.

photo by Mike Neal
That's why Marty and I are making "bolus burritos."  We put a bolus on a piece of scrap paper that's being reused as a paper tortilla. Then we roll up the bolus in the paper and fold in the paper ends --> a bolus burrito!  Now we label the burrito with the date when the bolus was collected and from which island of the Atoll it came.  How many bolus burritos are in the picture, not even counting the boluses in the plastic bag by my right foot?! Lots! -- all for teachers and their students!


Mrs P said...

I love this! How would one go about requesting a bolus burrito?

Anonymous said...

What does a bolus smell like?

What happens to the birds that eat garbage?

Barb said...

Mrs. P (& Jennifer, who wrote by email) -- I have asked my supervisor about how teachers can get boluses. I should have an answer soon, and will post the info here. Stay tuned!

Anonymous --
--Since the albatross eat seafood (for example: squid and flying fish eggs), the boluses do smell like raw seafood...and sometimes, if the boluses have been sitting out for awhile, they smell like *rotten* seafood; yuck! That's why we usually do the "bolus burrito" wrapping in the USFWS's garage, and not in the office!
--Very unhappily, sometimes the evidence is that birds can die from too much garbage, like plastic marine debris, in their stomachs. But the good news is that, since there are a lot of boluses with the plastic in them, many birds are able to get the plastic out of their stomachs by way of throwing up a bolus.

Barb said...

Another educator just asked these questions, via email:
"While doing a bolus dissection lab this spring, I had a student ask me how long it takes for each albatross to accumulate the material to make one bolus? So basically, how many boluses does a bird produce per year? They did a beak count, and they were curious to know how many squid they ate over a period of time. Any ideas?"

Anybody have answers? I'll try and ask USFWS biologists, and research the questions as well.

Ty said...

Do other birds produce boli (Is that the plural?)?

Barb said...

OK! Here's how a teacher can get boluses for students to dissect: phone or email Barbara Maxfield in the US Fish and Wildlife Service office in Honolulu--

She will try and distribute the limited number of boluses fairly.

In the meantime, I'll try to collect, wrap and dry out as many of them as I can; promise!

laney said...

Hi Marty and Barb,
I facilitated a Teachers Workshop presented by Cousteau's Ocean Futures in June. We completed a bolus dissection and teachers are wanting to do this activity in their classrooms. Can teachers request a bolus from FOAM? The activity is very impactful!
Laney Heath

Barb said...

Hi Laney,
Teachers *can* request a bolus!...but not from FOAM. Check out the Comment from June 29 which gives the contact information for getting boluses; it's right above your Comment. You're absolutely right: bolus dissection really makes an impact on students. Let me know if I can help further. aloha, Barb

Barb said...

Back in June there were two questions I never got back to with answers. I've now had a chance to follow up on them, and here are repeats of the questions, and then their answers--

(1) "how many boluses does a bird produce per year?" The answer is: we really don't know!

In regard to albatross chicks, first of all, they have to grow up enough to be able to perform the proper muscle actions to get the bolus up. But the albatross experts I've talked to don't know for sure if albatross chicks toss up several smaller or only one big bolus. Maybe we could post a camera over a fenced-in group of young albatross and collect some data about this?! --but we wouldn't want the fence to interfere with adults getting in and out to feed their young.

In regard to albatross adults, nobody seems to have actually seen them toss up a bolus while they're on land; the hypothesis is that the birds must do it while at sea. Since we haven't observed adults pass up a bolus, we don't know how often they do it.

Therefore, the boluses that are gathered on Midway, Kure Atoll and elsewhere -- all terrestrial places -- must be from albatross chicks. Presumably, if you're dissecting a really big bolus, you could hypothesize it was just the one bolus that an individual albatross chick tossed up??

(2) Ty asked, "Do other birds produce boli (Is that the plural?)?" The answer is yes! For example, Wedge-tailed Shearwaters will pass up...boli, I guess they're called!

Unknown said...

I have received boluses from Oikonos in the past. Since they no longer are offering them I was wondering if there were any other organizations that were. I live in Oklahoma and do a unit on oceanography where I talk about the EGP. I love to bring this hands-on activity to my Bio II classes. We are willing to purchase the boluses if needed. Thank you, Tereasa Vachon

Barb said...

Tereasa -- The email you gave is not working for me; I'm getting a mailer-daemon when I try to use it. I'm anxious to respond to your request, so please post a correct email address.