The Zoochat Photographic Guide to Monotremes and Marsupials

You can do it!

 

A new species has been added by @Giant Eland with photos of Andean White-eared Opossum Didelphis pernigra.

I used the photo below, but there are several others of the animal in the gallery for the Quito Zoo: Quito Zoo - ZooChat

 

Thanks, yes I have changed the photo to your new one.

When I'm choosing photos for the threads I try to find all the photos I can in the galleries, then select one (or sometimes more) based on how well it shows the features of the species, and especially I look for photos which show the entire animal if possible. This isn't necessarily the "best" photo on offer because often there will be excellent portrait shots which only show the head or don't show a particular anatomical structure. Quite often I will use a photo of lesser quality because it actually shows the animal's form better than a high quality photo does.

I'm also always ready to replace photos I have used with new photos if they show more details or are better in some other useful way.

 

I have added in a photo of Common Planigale (Planigale maculata) by @Najade and one of Brown Antechinus (Antechinus stuartii) by @Chlidonias - both are photos of live animals replacing photos of taxidermy specimens (by @WhistlingKite24 and @Giant Eland respectively).

I also swapped a photo of a taxidermy Common Dunnart (Sminthopsis murina) by @WhistlingKite24 for one by @Chlidonias as it was a better-looking specimen. There are not yet any photos of live Common Dunnarts in the galleries.

Then I swapped a photo by @Giant Eland of a Brush-tailed Possum of the eastern subspecies Trichosurus vulpecula vulpecula for a better one by @Chlidonias; and swapped a photo by @LaughingDove of a dark-morph Short-eared Possum (Trichosurus caninus) for a better one just uploaded by @WhistlingKite24.

And finally I added in a second photo for Lumholtz's Tree Kangaroo by @WhistlingKite24, and swapped the photo of Matschie's Tree Kangaroo by @Tomek for two others, by @cypher and @ThylacineAlive.

So the number of depicted species in the thread remains unchanged, but two species which were represented only by taxidermy specimens are now shown as live animals. The photos of the dasyurids are all on the first page of the thread, the possums are the second page, and the tree kangaroos are on the fourth page.

Najade, cypher and ThylacineAlive all go up one photo in the totals while Chlidonias goes up three photos, WhistlingKite24 ends up on the same total as before, LaughingDove and Tomek both drop down by one photo, and Giant Eland drops two photos. Overall totals (as they were) are in posts #183 and 199 on the previous page, although Goura and Giant Eland both would need one extra added to those totals anyway (see posts earlier on this page).

 

The captive population is probably of mixed origins - they are commonly kept in zoos, labs, and by private keepers. The subspecies are probably invalid. Two or three subspecies have been named but the genetic distinctions do not match (at all!) with distributions of those subspecies, and they are mostly no longer used in Australian taxonomy.

I had missed Dannelboyz's photo I think. It is of the (genetic) southeastern population. I have added it into the thread.

 

In this thread there are 225 photos from 41 photographers, representing 162 species. I will keep the numbers on this post updated whenever I change or add photographs. [Last update 30 March 2024]


One photo:
@Arek
@AWP
@Baldur
@Blackduiker
@cypher
@DaLilFishie
@Deer Forest2
@devilfish
@Eagle
@Fishapod
@Hettie
@Jakub
@Jo Kuyken
@Ornithorhynchus
@robreintjes
@Sun Wukong
@TeaLovingDave
@ThylacineAlive
@Tim May
@toto98
@Veno
@Zia
@ZYBen

Two photos:
@Dannelboyz
@gentle lemur
@Goura
@Maguari
@Michal Sloviak
@Terry Thomas
@Vision

Three photos:
@Javan Rhino
@ro6ca66
@Tomek
@vogelcommando

Four photos:
@alexkant

Ten or more photos:
@LaughingDove (12 photos)
@WhistlingKite24 (14 photos)
@Hix (19 photos)
@Chlidonias (22 photos)
@Giant Eland (41 photos)
@Najade (64 photos)

 

I think I probably had seen it but was unsure whether it was "better" or not. The one I had used is "sharper" but is at night, the newer one is not well-focused but shows the colouration. What I've just done is swapped them, so the photo used in the thread is the one above (the one taken by day) but I have linked to the night photo.

 

That's unexpected. I posted on the Smithsonian Zoo thread (Smithsonian National Zoo News 2020 [Smithsonian National Zoo]) but I'll repeat it here as well.

Basically, like everyone else on here, the only Virginia Opossums for which I am familiar with the appearance are the northern ones from the USA which, it turns out, are pretty different to the subspecies from the south of the range. There is a north-to-south range of colouration, so the northern animals tend to be white or grey with little or no pigment in the soft parts (tail and digits), while southern animals are much darker. In Mexico, where the distributions of the Virginia and Common Opossums overlaps considerably, they can be difficult to distinguish from one another because they are morphologically so similar and yet also both so variable in colouration.

I found a key to Mexican opossum species, and also checked out Fiona Reed's field guide, and the best distinguishing features of living animals are the cheek colour (always pure white in Virginia Opossum - easily seen in all the photos of the National Zoo's animal - but always yellowish or cream in Common Opossum) and the colour of the whiskers (a mix of black and white in Virginia Opossum - which can be seen in the better photos, including some on Zoochat - but all black in Common Opossum). I'd imagine it was these features that made somebody initially question the Common Opossum identity.

These features in addition to the genetic test make me perfectly happy to accept that the animal is a Virginia Opossum. I can still use the photo in the thread though, because it is of a different subspecies to the USA one already pictured.

 

I ended up making quite a few edits to the Didelphis post. The number of species remains the same, and the only species still unrepresented is the Guianan White-eared Opossum D. imperfecta, but I switched some photos around.

I moved the photo of the Smithsonian animal to the Virginia Opossum slot (so now that species has two photos of two subspecies), and for the Common Opossum I used a photo of a museum specimen by @carlos55 (black eared opossum didelphis marsupalis museo de historia natural - ZooChat).

While looking for photos of live Common Opossums I found (apart for all the ones of the Smithsonian's animal) three photos by @Giant Eland. One of an adult animal is actually an Andean White-eared Opossum D. pernigra (common opossum (Didelphis marsupialis) - ZooChat) which was good because the only other photos of that species showed a baby animal, so I swapped the adult one for the baby one.

The other two photos (common opossum (Didelphis marsupialis) - ZooChat and common opossum (Didelphis marsupialis) - ZooChat) are of baby animals in a Colombian zoo, and I'm not convinced of their identity. Common Opossums have entirely black ears - and the taxidermy photo by carlos55 shows that even the babies have black ears - so I suspect these two photos might show baby D. pernigra.

And related to that, the photo I have used for Big-eared Opossum D. aurita, also by @Giant Eland, is also of a baby animal (at a Brazilian zoo) which likewise has white ears whereas this species has black ears, and I suspect this is either D. albiventris or D. imperfecta. However I'm not sure if very young animals have black ears and this is the only photo on Zoochat labelled as a Big-eared Opossum, so I have left it in the thread with a note on possible misidentification.