Kai Caspar
@nomascus.bsky.social
Zoology lecturer @hhu.de | Armchair biologist | Focus on rodents underground and gibbons in the trees, also one of @themanybirds.bsky.social | Organismic vertebrate biology
November 6, 2025 at 7:20 PM
The mammalogy course had luck with the marsupials at Zoo Duisburg today. Devils, koalas, macropods, wombats ...
October 29, 2025 at 4:47 PM
The mammalogy course had luck with the marsupials at Zoo Duisburg today. Devils, koalas, macropods, wombats ...
Dancing crested gibbons made it into National Geographic!
The individual shown in the article (Polly) actually features in our study - which you can find here:
link.springer.com/article/10.1...
The individual shown in the article (Polly) actually features in our study - which you can find here:
link.springer.com/article/10.1...
October 14, 2025 at 10:44 AM
Dancing crested gibbons made it into National Geographic!
The individual shown in the article (Polly) actually features in our study - which you can find here:
link.springer.com/article/10.1...
The individual shown in the article (Polly) actually features in our study - which you can find here:
link.springer.com/article/10.1...
A couple of snapshots from Plzen Zoo today
September 6, 2025 at 4:39 PM
A couple of snapshots from Plzen Zoo today
Just visited Lucy and the Dikika child in Prague.
Icons.
Icons.
September 1, 2025 at 4:13 PM
Just visited Lucy and the Dikika child in Prague.
Icons.
Icons.
Broad in scope but strikingly concise, highly accessible, and nuanced - go get this book if you have even the slightest interest in birds and/or vertebrate brain evolution. I will use it a lot. Congrats @evoneuro.bsky.social!
#neuroskyence 🧪
#neuroskyence 🧪
August 18, 2025 at 7:08 PM
Broad in scope but strikingly concise, highly accessible, and nuanced - go get this book if you have even the slightest interest in birds and/or vertebrate brain evolution. I will use it a lot. Congrats @evoneuro.bsky.social!
#neuroskyence 🧪
#neuroskyence 🧪
Close-up of a male Bornean orangutan I met at the zoo last week. Different from their Sumatran relatives, Bornean orangs have strongly pigmented eyes. The iris is surrounded by an arcus senilis. In humans, these lipid deposits may form at an old age but manifest a lot earlier in many other primates.
August 4, 2025 at 8:36 PM
Close-up of a male Bornean orangutan I met at the zoo last week. Different from their Sumatran relatives, Bornean orangs have strongly pigmented eyes. The iris is surrounded by an arcus senilis. In humans, these lipid deposits may form at an old age but manifest a lot earlier in many other primates.
We are currently testing highly underrated and understudied colobus monkeys for @manyprimates.bsky.social at Zoo Krefeld.
It's a start - but ManyPrimates needs more colobines (and gibbons) for fair representation!
It's a start - but ManyPrimates needs more colobines (and gibbons) for fair representation!
July 26, 2025 at 1:47 PM
We are currently testing highly underrated and understudied colobus monkeys for @manyprimates.bsky.social at Zoo Krefeld.
It's a start - but ManyPrimates needs more colobines (and gibbons) for fair representation!
It's a start - but ManyPrimates needs more colobines (and gibbons) for fair representation!
New comparative study by Sulser & McPhee on anatomical proxies of sensory ecology in tenrecs and otter shrews, featuring some nice CT visualizations of the trigeminal nerve 🧪
www.nature.com/articles/s42...
www.nature.com/articles/s42...
July 25, 2025 at 6:06 PM
New comparative study by Sulser & McPhee on anatomical proxies of sensory ecology in tenrecs and otter shrews, featuring some nice CT visualizations of the trigeminal nerve 🧪
www.nature.com/articles/s42...
www.nature.com/articles/s42...
Will be worth the wait, I guess ... 🧪
June 20, 2025 at 11:54 AM
Will be worth the wait, I guess ... 🧪
Bizarre bird phylogeny still on display at Augsburg Zoo.
June 17, 2025 at 9:55 PM
Bizarre bird phylogeny still on display at Augsburg Zoo.
Always a treat - Heinrich Harder's (restored) palaeoart pieces at Zoo Berlin's aquarium building.
Only today I noticed that the dorsal spines of the Edaphosaurus are not depicted to support a sail here.
Only today I noticed that the dorsal spines of the Edaphosaurus are not depicted to support a sail here.
May 26, 2025 at 4:18 PM
Always a treat - Heinrich Harder's (restored) palaeoart pieces at Zoo Berlin's aquarium building.
Only today I noticed that the dorsal spines of the Edaphosaurus are not depicted to support a sail here.
Only today I noticed that the dorsal spines of the Edaphosaurus are not depicted to support a sail here.
We point to photoprotection, sexual selection, genetic drift & non-referential signaling as non-mutually exclusive factors that might have driven the evolution of peri-iridal pigmentation. Many of these ideas were sparked by research inspired by the CEH. It has an important legacy either way. 10/11
May 15, 2025 at 7:41 PM
We point to photoprotection, sexual selection, genetic drift & non-referential signaling as non-mutually exclusive factors that might have driven the evolution of peri-iridal pigmentation. Many of these ideas were sparked by research inspired by the CEH. It has an important legacy either way. 10/11
We recommend to leave the CEH behind and focus on other avenues of research to understand how peri-iridal tissue color evolved in primates – there’s huge diversity that requires an explanation and that the CEH stands no chance to make sense of. 9/11
May 15, 2025 at 7:38 PM
We recommend to leave the CEH behind and focus on other avenues of research to understand how peri-iridal tissue color evolved in primates – there’s huge diversity that requires an explanation and that the CEH stands no chance to make sense of. 9/11
3) Evidence that human eye appearance is superior to e.g. chimps’ when it comes to signalling gaze is slight and not available for naturalistic settings. In fact, chimps’ eye gaze is well visible from 10s of meters away and their eyes are the most conspicuous feature of their faces. 7/11
May 15, 2025 at 7:36 PM
3) Evidence that human eye appearance is superior to e.g. chimps’ when it comes to signalling gaze is slight and not available for naturalistic settings. In fact, chimps’ eye gaze is well visible from 10s of meters away and their eyes are the most conspicuous feature of their faces. 7/11
2) Peri-iridal color differs between human populations. Low-latitude populations, which are traditionally underrepresented in this line of research, can have notable pigmentation. 6/11
May 15, 2025 at 7:34 PM
2) Peri-iridal color differs between human populations. Low-latitude populations, which are traditionally underrepresented in this line of research, can have notable pigmentation. 6/11
1) Extensive peri-iridal depigmentation has evolved multiple times in non-human primates. Both at individual and species level, humans are not unique. Here’re just a couple of examples. 5/11
May 15, 2025 at 7:32 PM
1) Extensive peri-iridal depigmentation has evolved multiple times in non-human primates. Both at individual and species level, humans are not unique. Here’re just a couple of examples. 5/11
Due to the whites of the eye, humans have a uniquely communicative gaze. Other primates have dark eyes, hiding their gaze from conspecifics. We cooperate, they compete. Common knowledge – right? Yes, but it’s incorrect, as we argue in our new paper 🧵🧪1/11
onlinelibrary.wiley.com/doi/10.1111/...
onlinelibrary.wiley.com/doi/10.1111/...
May 15, 2025 at 7:26 PM
Due to the whites of the eye, humans have a uniquely communicative gaze. Other primates have dark eyes, hiding their gaze from conspecifics. We cooperate, they compete. Common knowledge – right? Yes, but it’s incorrect, as we argue in our new paper 🧵🧪1/11
onlinelibrary.wiley.com/doi/10.1111/...
onlinelibrary.wiley.com/doi/10.1111/...
Visited the Piesberg (Osnabrück) today - hunting for fossil plants with @kpg13.bsky.social
May 4, 2025 at 3:52 PM
Visited the Piesberg (Osnabrück) today - hunting for fossil plants with @kpg13.bsky.social
Strangely, habitual aerial urination is only known from Amazon river dolphins, documented from various populations. Is it unique to them or just underreported in other lineages (as implied by this palaeoart piece by @joschuaknuppe.bsky.social)? As always, more data is needed … 8/9
April 19, 2025 at 12:46 PM
Strangely, habitual aerial urination is only known from Amazon river dolphins, documented from various populations. Is it unique to them or just underreported in other lineages (as implied by this palaeoart piece by @joschuaknuppe.bsky.social)? As always, more data is needed … 8/9
The original work by Araujo-Wang et al. argues that river dolphins respond to urine-borne chemicals, using the vibrissae on their rostrum. But vibrissae do not sense chemicals and cetaceans without them do just fine identifying conspecifics based on urine cues. 2/9
doi.org/10.1016/j.be...
doi.org/10.1016/j.be...
April 19, 2025 at 12:39 PM
The original work by Araujo-Wang et al. argues that river dolphins respond to urine-borne chemicals, using the vibrissae on their rostrum. But vibrissae do not sense chemicals and cetaceans without them do just fine identifying conspecifics based on urine cues. 2/9
doi.org/10.1016/j.be...
doi.org/10.1016/j.be...
Why do Amazon river dolphins urinate into the air? A recent paper suggests they do it to compete and communicate status. In a new commentary, I argue that this behavior is more parsimoniously explained as play. 1/9
Comment
authors.elsevier.com/a/1kyOl1LenM...
Video
www.youtube.com/watch?v=72yf...
Comment
authors.elsevier.com/a/1kyOl1LenM...
Video
www.youtube.com/watch?v=72yf...
April 19, 2025 at 12:37 PM
Why do Amazon river dolphins urinate into the air? A recent paper suggests they do it to compete and communicate status. In a new commentary, I argue that this behavior is more parsimoniously explained as play. 1/9
Comment
authors.elsevier.com/a/1kyOl1LenM...
Video
www.youtube.com/watch?v=72yf...
Comment
authors.elsevier.com/a/1kyOl1LenM...
Video
www.youtube.com/watch?v=72yf...
The most memorable things that happened in my life in the last 6 years according to my phone
March 22, 2025 at 10:29 PM
The most memorable things that happened in my life in the last 6 years according to my phone
Awesome shot of raccoons on @inaturalist.bsky.social by user sofiaaa1999
www.inaturalist.org/observations...
www.inaturalist.org/observations...
March 15, 2025 at 7:36 PM
Awesome shot of raccoons on @inaturalist.bsky.social by user sofiaaa1999
www.inaturalist.org/observations...
www.inaturalist.org/observations...
Birds were the unexpected highlight of the day, though: flightless Fuegian steamer ducks (Tachyeres pteneres) 🪶
March 13, 2025 at 4:51 PM
Birds were the unexpected highlight of the day, though: flightless Fuegian steamer ducks (Tachyeres pteneres) 🪶