Bird Skeletonizing Manual

Written & Formatted by: Andrea Rios Dominguez (2018) Edited by: Theresa Barclay (2020)

© 2020 Museum of Vertebrate Zoology

Eugene Beckes

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Table of Contents

Anatomy reference images …………………………………………………. Page 2

Station setup …………………………………………………. Page 3

Initial data collection and setup …………………………………………………. Page 3-5

Taking photos …………………………………………………. Page 6-7

Weighing the specimen …………………………………………………. Page 7

Checking molt …………………………………………………. Page 7-8

Skinning …………………………………………………. Page 9

Skull windows …………………………………………………. Page 10

Opening and sexing …………………………………………………. Page 10

Examples of gonads …………………………………………………. Page 11-12

Internal anatomy reference …………………………………………………. Page 13

Taking tissues …………………………………………………. Page 14-15

Stomach contents, syrinx, parasites …………………………………………………. Page 15

Finishing and cleaning up …………………………………………………. Page 16

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Anatomy Images for reference

Page 3

Setting up your station Materials

● bird ● original data ● skeleton tag ● gloves ● bird worksheet ● micron pen ● forceps ● scissors (large and small) ● tray (optional) ● camera* ● ruler ● tissue vial ● vial pen* ● MVZ barcode (for tissue vial) ● paper towel labeled with H, L, M, K ● wet sample vial (for syrinx,

stomach contents, and/or parasites)

● fluid tag ● EtOH* (70 or 95% depending) ● Prep Lab Catalog* ● extra paper towels (optional) ● scale* ● bird field guides* ● probe (optional) ● biohazard bin*

*only need access to these items, you do not need to keep them at your station at all times

Beforeyoustartcutting● Set up your station completely including all of the above listed materials (or access* to them) ● Identify the bird genus and species; check the field guides if unsure and double check with Terri

or the class coordinator. Record this on your worksheet. ○ Note the family of the bird as well to use when looking at the molt guide later

■ TIP – Look at coloration, patterns, and the number of primaries and secondaries to determine species. Coloration may give you an idea of what the sex is too!

● Fill out the top of your worksheet:

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○ Accn #, received from, and other Reference # (if there is one) should be on your original data, if not, check in with Terri or the class coordinator

■ Write the other reference # as it is on the original data (i.e. patient or admit # 213) unless it is Lindsay Wildlife which should be LWH - year - # (i.e.LWH-13-123)

■ Donations from Lindsay say Lindsay Wildlife Museum since that is the larger organization but we record our specimens as received from Lindsay Wildlife Hospital because that is who we work with directly.

■ If “received from” is unclear, ask Terri or the class coordinator, don’t guess. ○ Locality (specific to general). Include the county and state. NO abbreviations

■ If a state is written, we assume the specimen is from the United States so there is no need to write the country. If it isn’t from the USA, record the country as well.

■ Do not record the postal/zip code ■ Check a locality if you’re unsure of or missing some information. If there is no

locality (check with Terri or class coordinator), write “No Data” in pencil on your worksheet and in the catalog.

■ Make sure your locality is where the bird was found, not the finder’s contact info ○ Date specimen collected

■ Date collected is written Day Month Year with no abbreviations or punctuation (i.e. 23 February 2011).

■ If we received the specimen from a rehabilitation facility (Wildcare, Lindsay Wildlife, etc.), the date it was found or taken out of the wild/it’s natural habitat is the date collected. DO NOT mix this up with the date of death or with the date it was donated to us from another facility or acquired by another institution. If there is no other date than the date of death, then, and only then, can you use that as the collected date.

■ If the "date collected" and the date of death are different, record both on your worksheet (date of death near the bottom right). Write the "date collected" in your catalog entry header under locality and date of death in other original information. Example: Received from Lindsay Wildlife Hospital (LWH-12-453, date of death: 6 Mar 2012).

■ If there is no date information at all (double check with Terri or class coordinator), write “No Data” in pencil on your worksheet and in the catalog.

■ DOA = Dead on arrival Wildcare original data Wildcare: Locality = “No Data”

● Claim your unique PLC number

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○ In the Prep Lab Catalog, write the next available number in the margin. Write as much identifying information as possible, including locality and date collected to avoid two people using the same PLC #. Species is also helpful.

○ Write your claimed PLC# and Accn # on all pieces of the original data (donation sheets)

as well as your worksheet, tags, and vials.

Lindsay Wildlife Hospital Miscellaneous data

● Prepare your specimen tag and tissue vial using the guides below. ○ On your tissue vial, write small (and legible!) and leave space near the bottom of the label

● Take photos

○ DO NOT wear dirty gloves while handling the camera ○ You need the trifecta in every photo: tag, specimen, and ruler!

■ Try to get all three in focus for all photos

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■ Make sure the correct side of the ruler is showing (the side with mm on it) ■ TIP – Take a close up picture of the PLC side of the tag before taking pictures of

the specimen in case the tag is unclear in the photos ○ Checklist of pictures to take:

■ Close up of the skeleton tag (PLC side, should be in all photos) ■ Dorsal (back) ■ Ventral (chest) ■ Lateral (side) ■ Face profile ■ Wing (with feathers spread, both front and back) ■ Tail (with feathers spread, both front and back) ■ Injuries, other observations or abnormalities, any identifying markings, etc.

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● Weigh the bird ○ Choose the correct scale for your bird

■ If your bird is under 200g, use a scale that measures to the nearest 0.1g ■ If your bird is over 200g, use a scale that measures to the nearest 1g

○ Don’t forget to zero the scale if you are using a tray or paper towel ○ Make sure you are using grams not milligrams or another measurement ○ Write the weight on the skeleton tag

● Check for molt.

○ Look up the bird’s family in the Molt Guide to find the expected number of primaries, secondaries, and rectrices

■ Also check if you need to check for skull windows. ○ Check for molt by counting the feathers to identify any that are missing or vascularized at

the base of the feather shaft (it would be a darker, blueish color as opposed to mature white-shafted feathers) or have a sheath around the base of the shaft. Record which feathers show evidence of molt (see examples on page 8)

■ Count from the middle to the tip of the wing for primaries, the middle towards the body of the bird for secondaries, and the middle to the outside for rectrices

■ TIP – Finding the joint between the humerus and the radius/ulna can help distinguish between the primaries and secondaries

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– Body molt is best determined once you begin skinning your bird and you can see on the underside of the skin if the feather shafts are dark colored Counting primaries and secondaries No wing molt

Feather in sheath/wing molt Primaries and secondaries in sheath

Counting rectrices (12 total) No tail molt Rectrices in sheath (tail molt)

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Youarereadytostartskinning!***Check in with Terri or the class coordinator before you cut or remove feathers***

● Remove/pull out the primaries and secondaries on the wings and the rectrices on the tail

○ Be careful not to remove the alula, a special tiny digit (refer to skeleton image, page 2) ● Separate the feathers on the chest along the keel until you can see bare skin

○ NOTE: – Most birds have feather tracts, so there are various parts of their body that actually don’t have feathers, but they are covered by feathers elsewhere (see below). Waterbirds do not have feather tracts but have them all over their skin, you have to simply separate the thick layer of feathers until you reach skin.

● Make small cut through the skin layer on the keel, but do not cut into the tissue underneath ○ TIP – Lightly pinch and lift the skin up to avoid cutting too deep!

● Continue cutting from top of the keel down to cloaca and peel/cut skin away from the body using forceps, scissors, and/or your hands, without piercing the tissue or body cavity beneath

● Remove as much of the skin as possible from the bird before opening up the body cavity ○ DO NOT cut into the body cavity before you’re ready to sex the bird and take tissues ○ If your bird’s body cavity is already open (necropsied or other reason), skin only enough to

be able to sex and take tissue samples then continue skinning after. The longer your tissues are exposed, the more they will degrade.

○ If you accidentally open your specimen, tell an instructor and the instructor will evaluate if it's small enough to continue skinning (try not to make the hole larger) or if they will need to sex and tissue the bird immediately and then you can continue skinning after

● Remember to check for body molt (example seen below)

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● Check for skull windows/skull ossification on passerines with Terri or the class coordinator ○ The molt guide should have told you whether or not you need to check for skull windows ○ Ossification looks like tiny pin prick size bubbles on the skull. If a skull is unossified or has

skull windows it may be soft, but make sure it’s not due to injury (i.e. window hit)

Youarereadytocutandopen! ***Check in with Terri or class coordinator and have them open and sex your specimen. DO NOT

open your own bird until Terri or the class coordinator has cleared you to do so.***

● Once the bird is clean, open up the body cavity with careful cuts through the membrane ■ TIP – When cutting in the body cavity, pull the membrane away from the body to

avoid cutting into organs. For easier viewing, you may carefully cut alongside the the rib closest to the abdominal cavity, but avoid breaking ribs!

● . Look for gonads towards the back of the body cavity, above the kidneys ○ Record the bird’s sex on the worksheet and write the proper symbol (♂ or ♀) on the

skeleton tag and tissue vial ■ NOTE: – Most birds only have one ovary and it’s usually found on the bird’s left

side (your right side as you look into the body cavity). It can often be identified by it’s bumpy texture, which is the presence of minute ova, if not more obvious differentiated ova. Some birds do have two ovaries so always check both sides, but be careful not to mistake the adrenal glands for gonads. There will be 2 testes in males and they will often be a defined round/oval shape.

○ Take a picture of the gonads with your completely labeled skeleton tag and a ruler ■ TIP – Putting the camera on macro mode can help take a better picture

○ Measure the gonads and record the measurements on your worksheet ■ Remember to take measurements in mm not cm or inches

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Undifferentiated ovary

Ovary with minute ova

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Ovary with differentiated ova

Testes

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Reference image of bird internal anatomy

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● Take the tissue samples: ■ TIP – Enlist the help of Terri or the class coordinator to help you identify the

tissues. ○ Place all samples on your paper towel labeled HLMK before placing them in the vial ○ Heart, liver, muscle, kidney (put into the tissue vial in this order)

■ The heart is higher up in the body cavity, often behind another membrane. When sampling the heart, be careful not to rip the syrinx.

■ When sampling the liver, avoid the gallbladder by taking from the bird’s left side (right when looking into the cavity). The green gallbladder contains bile that will degrade your tissues if released. If this does happen, notify the class coordinator or a UGSI and take tissue samples as quickly as possible.

■ The kidneys are long and slender organs along the spine at the back of the body cavity down near the cloaca and are often behind membranous layers. They can be seen clearly in most of the gonad pictures on pages 10-11.

■ When taking muscle, taking breast tissue from the outside of the bird is the easiest way to get your sample. If there is not enough tissue on the chest, try taking muscle from a leg.

■ DO NOT fill the tissue vial to the very top. Tissues expand as they freeze and need space to do so or the vial will break.

○ Make sure to record the MVZ tissue barcode number on the worksheet. ○ The tissue vial should be labeled with PLC#, genus, species, Accn#, and sex. Place the

barcode sticker as shown below, trying not to cover any data. ■ If for some reason data will be covered, cover the Accn NOT the PLC

Step 1: Completely labeled vial including sex

Step 2: Place the barcode above the data

Step 3: Wrap the barcode around the vial

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○ Place the tissue vial in the chest freezer in the appropriate tissue box and write the PLC#, Accn#, and number of vials on the paper inventory inside

● Check the stomach contents and record a description on the worksheet ○ If there is reason to save the stomach contents (such as another animal), place them in a

jar with a fluid tag and 70% ethanol (check in before saving) ● Collect the syrinx (the bird’s voice box)

○ It lies behind and above the heart when the specimen is on it’s back. Make sure to cut above the fork in the syrinx (somewhere along the trachea) and below the fork (across both bronchi) - you want to save as much of its morphology as possible (see page 12).

○ The syrinx itself is the boxy section where the trachea splits so it is easy to accidentally rip it while taking it out (or if pulling out the heart) if you are not careful.

○ Place the syrinx into a jar of 70% ethanol. ■ On the cap of the jar, write the PLC# and Accn# with a vial pen, not a micron pen.

If an Accn has not yet been assigned, leave it blank (do not write “No Accn”). The fluid tag should have the PLC# and genus on the front, vial contents on the back (“syrinx”), and be written with a micron pen.

■ When writing the cap, try to write small and along the rim. Later someone will need enough space to add 3-4 lines of additional data in the center, see below.

■ TIP – Let the label dry for a few moments before putting it in the ethanol or it may come off. Similarly, let the cap dry before touching it because until it dries it can smear or come off as well.

● If you find any parasites, preserve them in a vial ○ Endo/ectoparasites use 95% ethanol, not 70% in their vial jars, which are labeled the

same as the syrinx vial jars.

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Finishingup:CleantheBird!● Double check you have filled out all the information you need to/can on your worksheet ● Remove remaining skin (including the feet scales if possible), feathers, tissues and most of the

muscle. DO NOT remove the eyeballs. ○ Birds have eye rings we keep with the skeleton ○ Body cavity should be empty when you are done

● Attach the skeleton tag by stringing it around the sternum (or the furcula/clavicle if the bird is too big, see page 2 for skeletal reference)

● Place your bird into the soak bucket (if necessary) ○ Make sure the water is running slowly and the bucket is not covering the sink drain ○ If the specimen is clean enough to bypass soak bucket (check in to make sure), blow the

brains using a syringe, tie up the bird as small as possible, and hang it up to dry ■ Make sure the tag is visible and hanging away from the body so it doesn’t stick to

anything as it dries ■ If your skeleton for some reason has small or broken pieces, try to tie them to the

bird if possible. If unable to tie parts to the rest of the bird skeleton, consult Terri or the class coordinator on how to best group the parts together.

● Clean your workstation

○ Wash your tools, bleach your workspace/contaminated surfaces, sweep your area, etc. ● Write your catalog entry

○ Do not write past the punch holes in the margin of the catalog ○ TIP – Use the bird example entries in the front of the catalogue to help you check the

information and proper format – Write out your entry on scratch paper and get it checked before writing in the catalog

in order to catch any mistakes and to avoid having to rewrite the entire page ● Paperclip the original data to your worksheet. Remember to write your PLC and Accn on all

original data if you haven’t already done so, then place your papers in the basket near the shelf with the worksheets and guides.

● Sign out in the daily prep lab log (next to the data basket) ○ Name, Catalog #, Accession (Accn) #, Genus and species of prep, Type of prep

(complete skeleton + syrinx (70% EtOH))