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Matschies Tree Kangaroo Reproductive Research Requests

Tree Kangaroo Reproductive Tissue Request



Request from: Dawn Fleuchaus, Milwaukee County Zoo-Area Supervisor N. America and Australia

Pathologist: Dr. Margaret Highland, DVM


Dawn Fleuchaus and Dr. Margaret Highland are working together to assess reproductive tissue samples collected from Tree Kangaroos (any species), usually assumed to be semen plugs.  Histological testing of semen plugs at the MCZ has shown that sometimes they are and sometimes they're not.  They have found semen plugs, sloughed uterine lining, and even placental tissue- all appear similar visually. 


The goal is to obtain any collectable reproductive tissue samples from Tree Kangaroos.  All that is needed is the tissue sample, a physical description at the time of collection (and digital photos if possible), and brief behavioral/reproductive info.  Please collect "semen plugs" or any tissue believed to be reproductive, and consult the following pages for preservation and shipping info. 


Please feel free to contact Dawn with any questions or comments.  Thank you!  Dawn Fleuchaus, Milwaukee County Zoo-Area Supervisor N. America and Australia  (414) 771-3040 


They are requesting Tree Kangaroo reproductive tissue and semen plugs.  Dates of all reproductive behaviors and gross descriptions of tissue samples collected should be recorded.  If the institution has a pathologist who must process the samples, they should identify cells present in the samples.   The pathologist working on this study, Maggie Highland, can be contacted with any questions.  If it is not necessary for the institutions’ pathologist to process the samples; the samples should be collected, grossly described and stored in formalin for shipment to Dr. Highland.  They have received a grant from the AAZK-Milwaukee Chapter to process the samples and complete the preliminary research of reproductive tissues passed by Tree Kangaroos. 


Any tissue suspected to be reproductive including those found prior to copulatory behavior, immediately following copulation and at expected time of birth should be collected, described, photographed and "fixed” in formalin.  Label each sample with the name of the Institution, date collected, and animal(s) studbook # (s).  If more than one sample is collected in a single day, they can be designated as "institution date collected (a) or (b).  Write a physical description of the tissue, including dimensions and digital photographs if possible.  A record of reproductive behavior should also be recorded, including date of breeding pair introduction, dates and signs of estrus, suspected or confirmed copulation, date sample found, dates and results of pouch checks, date of births, and date of next expected estrus.  Please send the  following form with all available information and digital pictures to Dawn Fleuchaus, MCZ Area Supervisor-N. America and Australia, at the included email or mailing address. 


Preserve the sample in formalin as follows: 

1.                      "Fix” the tissue as soon as possible after being found.  Samples that can not be immediately fixed in formalin, should be refrigerated until they can be.  Submerge the tissue in 10% formalin, using 10x the volume of the tissue.  Tissue samples should remain in the formalin for 5-10 days.

2.                     After 5-10 days, wrap the tissue in formalin soaked paper towel and seal in a Ziplock bag. 

3.                     Label the sample with "Institution, date collected and animal(s) studbook #

4.                     Ship samples along with a written description of the fresh sample to: Dr. Maggie Highland, USDA-ARS ADRU, 3003 ADBF, Pullman, WA  99164-6630.

5.                     Notify Dawn Fleuchaus via email at  when a sample has been shipped.

6.                     Complete the enclosed Tree Kangaroo Reproductive Tissue Data Sheet.  Send Data Sheet and any digital Photographs that were taken, to  or mail to Milwaukee County Zoo, Attn: Dawn Fleuchaus, 10001 W. Bluemound Rd.,  Milwuakee,  WI  53226. 

7.                     If your institution has a pathologist available who needs to do the Histology, please send results with the following form including associated repro behaviors to the address or email below.  We would also be very interested to receive Histology results from testing done previously on any Tree Kangaroo semen plugs, tissue samples or placentas. 


Please feel free to contact Dawn Fleuchaus- MCZ Area Supervisor, N. America and Australia, with any questions, comments, or suggestions.  Thank you!


Dawn Fleuchaus                                             Maggie Highland, DVM

Milwaukee County Zoo                                 USDA-ARS ADRU

10001 W. Bluemound Rd.                             3003 ADBF

Milwaukee  WI  53226                                  Pullman, WA   99164-6630

(414) 771-3040                                    


Tree Kangaroo Reproductive Tissue Data Sheet


Please complete as thoroughly as possible.  Electronic versions of this form, past histology reports of Tree Kangaroo tissue samples and digital photos can also be emailed to    Send form  to:


Milwaukee County Zoo                                           Please call with questions:

Attn:  Dawn Fleuchaus                                            Dawn Fleuchaus (414) 771-3040

10001 W. Bluemound Rd.                                       Pathologists can contact           

Milwaukee, WI  53226                                            Dr. Maggie Highland, DVM                     

                                                                                 directly: :
                                                                                                 608-213-3025 (cell)



Submitting Institution______________________________________________________


Submitting Keeper or contact person_and phone #_______________________________




Studbook # &/or accession #:___________________________________________

Sex___         Age_________   House Name _____________ _________________


Studbook # &/or accession #:___________________________________________

Sex _            Age_________   House Name______________ __________________       


Date sample collected__________________________


Physical description of tissue at time of discovery (include measurements and digital photos if possible)__________________________________________________________________________________________________________________________________________________________________________________________________________________________________


Breeding history & behaviors (introduction dates, observed breeding, dates of estreus, pouch checks + or -, joey DOB…) ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________





In June 2007, a small gelatinous piece of material/tissue was found in the enclosure of MCZ’s 1.1 Matschie’s Tree Kangaroos and submitted to the pathologists.  Initial histologic evaluation suspected the tissue to be "vitelline membrane” indicating a birth; however the degree of autolysis hindered thorough histologic evaluation of this tissue/sample.  This raised a lot of questions as to whether the Tree Roos had been breeding at the time or if a stillbirth or abortion had occurred.  A pouch check was done ~55 days later, which revealed a ~1 ½ " joey, suggesting that conception had taken place approximately the time the tissue had been found.  DOB was estimated at July 28, 2007. 


On December 6th, 2008 the 16 month old male joey was separated from the dam and keepers began to watch for signs of estrus, to reintroduce the breeding pair.  The pair was reintroduced on January 12, 2009.  At this time, keepers were asked to collect and submit all tissue samples and/or possible semen plugs that were found and record all reproductive behaviors.  The samples and observations were as follows.


February 3, 2009- A small (<1 cm in diameter), soft piece of material/tissue was found.  Histology showed ciliated epithelial cells, consistent with uterine lining cells, and abundant mucous.  The original biopsy submitted in June 2007 was re-evaluated and compared to this biopsy.  This biopsy had significantly less autolytic/degenerative change making histologic interpretation easier.  The biopsy submitted in June 2007 was re-evaluated and compared to this biopsy, indicating that the 2007 biopsy was not consistent with vitelline/placental tissue, but rather was of similar character to this biopsy (both being consistent with uterine epithelium).


February 9, 2009- Suspected copulation


February 9, 2009- A long, cylindrical, 4 cm long x 1.5 cm wide, firm/hard piece of tan to light brown to pink material/tissue was found.  Histology confirmed the presence of sperm indicating that the sample was a copulatory/semen plug


February 11, 2009- A similar, cylindrical, 8 cm long x 1 cm wide, piece of firm/hard material/tissue was found and confirmed to be a semen/copulatory plug on histologic examination.


March 23, 2009-  0.1 sitting on exhibit floor AM in ”birthing” position


March 24, 2009- 0.1 sitting on exhibit floor AM in "birthing” position and later passing blood from vulva


March 25, 2009- A small, 2 x 1 x 0.8 cm, gelatinous, opaque gray-white piece of material/tissue was found.  Histologic evaluation suggested placental tissue, as there were a few cells that had multiple nuclei (up to 3) which are most consistent with placental cells (trophoblasts).


April 8, 2009- pouch check done and no joey was present

April 18, 2009- A firm/hard, irregularly cylindrical, 8 cm long x up to 2 cm wide, piece of material/tissue was found which was confirmed to be a semen/copulatory plug on histologic examination.


Summary Table of submitted biopsy samples collected from enclosure

Biopsy/Reference Number





Uterine epithelium/Mucous



Uterine epithelium/Mucous



Copulatory plug



Copulatory plug



Suspect placental tissue



Copulatory plug



            All of these samples and observations are from one breeding pair.  More information is needed, but this information suggests that just before estrus and mating, the female’s uterine lining is possibly sloughed and passed as a small mass of gelatinous, soft tissue.  It is possible that our female conceived during the breedings that took place Feb. 9, 2009 and Feb. 11, 2009 and that the joey was either stillborn/aborted or did not make it into the pouch and died.  Our pathologist was unable to locate histology examples of, or information specifically regarding, Tree Kangaroo placentas/placentation. 

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