2y ago

Sexual Dimorphism in Long Eared Owls (how to tell boys from girls by just looking at them)

Today's post is from the Owl Research Institute.

Did you know you can tell the sex of an adult Long- eared Owl by color?
Though it may be subtle to the untrained eye, Long- eared Owls display sexual color dimorphism in their plumage. The Owl Research Institute tested this using a soil color chart to score the facial disk, tarsometatarsus, and underwing coverts of adult Long- eared Owls. Overall, females were found to be darker in color than males.
Photos 3-6 show adult male and female Long-eared Owls side-by-side. Can you guess which are which? Comment your guesses below!
Read more about sexual color dimorphism in Long- eared Owls in ORI's 2016 publication titled 'Sex Differences in Long-eared Owi Plumage Coloration'.

21 comments

Amazingly superb stuff!!
But also a bit of a familiar format (not the topic tho) ... knowyourmeme.com/family-guy-skin-color-chart
I mean ... they even have about the same expression on their faces ...
- This image was the first thing I thought when I saw this post. I figured this one could get us on the front page today.
- I love how the owls just look offended at how they're being grabbed and inspected
- Since I got beaten to the Peter Griffin meme....
The girl owls generally have bigger hooters.
- You're not supposed to stare at those though! 😜
  Just as a reminder though, since owls don't nurse, they lack those hooters.
Yes, I will try to owl-ify the meme you are probably thinking of at some point today!
- (I couldn't wait - that's why I said 'can't wait')
  
  Thanks for saving me the work!
  I was going to have Male and Female as the key and try to leave Peter's outfit, but you did a great job!
  It's not showing up in my app (Summit) so I'm just going to repost it here for anyone else with the save problem. It showed up on the web version just fine.
Quick definition of sexual dimorphism from Wikipedia:
Sexual dimorphism is the condition where sexes of the same species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most dioecious [things with distinct male and female organisms, ie dont reproduce asexually] species, which consist of most animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, or behavioral or cognitive traits. Male-male reproductive competition has evolved a diverse array of sexually dimorphic traits. Aggressive utility traits such as "battle" teeth and blunt heads reinforced as battering rams are used as weapons in aggressive interactions between rivals. Passive displays such as ornamental feathering or song-calling have also evolved mainly through sexual selection. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is monomorphism, when both biological sexes are phenotypically indistinguishable from each other.
I read that as long eared dimorphism and was so confused for a second.
- Some of the pics show one with longer looking ears, so you're still technically correct! 😁

21 comments