Alfa females: hyena hormones at work
Erin Kane’s post Convergent Evolution: how cool is that? (http://goo.gl/47I1C) reminded me that hyena females are dominant, e.g., alfa females. Erin’s post also reminded me of our collaboration on work similar to the video.
Evolutionary forces – Working Together
BTW, if you’re thinking about trolling with anti-evolution rhetoric, check this out first, from QualiSoup
OK, back to hyenas and hormones. Spotted hyena females release androgen to their offspring, which makes them more aggressive (think about what you’ve read about athletes using anabolic steroids). This added aggression is important to improve their chance of getting a meal, and therefore survive. It also makes the males more sexually active, early on. This is important as they need practice, to deal with the complicated copulation of hyenas. Female hyenas, especially the spotted hyena, have a pseudo-phallus due to the androgen that they received from their mother, i.e., the clitoris is enlarged. You can read more here: http://goo.gl/g6DA6
Source: The Painful Realities of Hyena Sex
http://goo.gl/SIAXZ via LiveScience
Also check out:
How Aggressive Hyena Moms Give Their Kids a Boost
http://goo.gl/xytFY via Bora Zivkovic
Brains: Another interesting fact about the spotted hyena is that they have a larger brain volume when compared to the striped hyena, brown hyena, and aardwolves. The spotted hyena also possesses a larger anterior cerebrum volume relative to total brain volume than is found in the other hyena species; this region is composed primarily of frontal cortex. These data are consistent with the idea that expansion of the frontal cortex is driven by the demands of processing cognitive information associated with complex social lives, but other factors may drive the evolution of large brains in hyaenids.
Brain size and social complexity: a computed tomography study in Hyaenidae.
Sakai ST, Arsznov BM, Lundrigan BL, Holekamp KE.
Brain Behav Evol. 2011;77(2):91-104. doi: 10.1159/000323849. Epub 2011 Feb 17.
http://www.ncbi.nlm.nih.gov/pubmed/21335942
Symbiotic relations: One more science tidbit, bacteria have a symbiotic relationship with hyenas. The diversity in the bacteria can aid hyenas in identifying members of the same social group based on how the structure of the bacteria affects the odor of the hyena’s scent gland.
Evidence for a bacterial mechanism for group-specific social odors among hyenas.
Theis KR, Schmidt TM, Holekamp KE.
Sci Rep. 2012;2:615. doi: 10.1038/srep00615. Epub 2012 Aug 30.
Hyena art:
The Hyena & Other Men
http://goo.gl/wYUqS via Luis Roca
Elephant love is fierce → This elephant fights off a hyena to save her baby!
http://goo.gl/qv7z0 via Liza Sperling
Image source: http://goo.gl/2xhfe
#ScienceSunday
April 14, 2013
Fantastic post: a high five to the hyena. Those photos of hyenas with African men were unreal! O.o
I’m not sure how my sensibilities will deal with hyena sex so I’ll save that for later
April 14, 2013
David Flick well they’ll have to make sure they kill it first…and hope that a lion won’t come along to try and steal it…
April 15, 2013
David Flick you might want to do some reading about hyenas before deciding that they are “pretty much scavengers”, for example:
http://link.springer.com/article/10.1007/s11284-009-0669-3
http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1997.tb02925.x/abstract
http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2006.00183.x/abstract
Say it with me: The Lion King was not a documentary…
April 15, 2013
David Flick wait, did you just decided to cite “nature shows” over the peer-reviewed studies I linked to above?
April 15, 2013
David Flick oh, but of course not…because “nature shows” trumps scientifically-conducted peer-reviewed studies. Thank you for your time.
April 15, 2013
David Flick so from your research, what is the hunting-scavenging ratio of hyena as compared with other predators on the Serengeti? Are they any more of a scavenger than, say, lions? Also, can you please name any extant predators than will hunt prey larger than themselves alone?
Also, please provide citations for your research.
April 15, 2013
In the link above, The Truth About Hyaenas: debunking hyaena myths (http://goo.gl/g6DA6), there are two myths worth a look: (1) Myth: Hyaenas only eat carrion and (2) Myth: Hyaenas often drive other large predators from their prey.
April 15, 2013
David Flick what are those “countless predators” that can kill prey larger than themselves alone, and secondly see: http://animalcreativity.webs.com/Funston%20et%20al%201998%20Hunting%20by%20male%20lions%20Ecological%20influences%20and%20socioecological%20implications.pdf
From the above: “Adult males tend to refrain from hunting, and pursue prey less often than females do (Schaller 1972; Bertram 1978; Scheel & Packer 1991; Stander 1992a), obtaining most of their food by scavenging from lionesses’ kills, or from the kills of other predators (Schaller 1972; Scheel & Packer 1991).”
[emphasis mine]
April 15, 2013
David Flick That’s really … an interesting thing to say. Wrong, but interesting.
April 15, 2013
Interesting position, David Flick – so, you never listen to your doctor? That’s a scientist. I find it interesting that you are using a computer and internet, considering computer scientists designed the infrastructure, and scientists figured out that whole “electromagnetism thing” in the 1930s. Do you agree that gravity works? I think you more dislike being contradicted by evidence than someone who “disagrees with what scientists say a majority of the time.”
April 15, 2013
So you put yourself in even greater danger by self-medicating and self-diagnosing, without proper training? That’s pretty silly. You could have really damaged yourself that way. I also think you don’t quite understand what science is, given the fact that science has never claimed, and never will claim, to “rationally explain things 100% of the time”.
April 15, 2013
David Flick ; your experiences are your own, but you are certainly not infallible, and no amount of confidence in one’s self is a substitute for a comprehensive education (collegiate or not) and a process designed to explain what can be observed (aka science).
An open-minded person should have no problems accepting evidence. Yet you appear to.
April 15, 2013
David Flick You are starting to derail my post.
Just because the Doctor has A degree doesn’t mean I cant learn the same knowledge he posses without attending college
Although in theory, that is true, it is only true for very gifted individuals. The rest of us need to learn from the experience and knowledge of other, e.g., professors.
The point of this post was to show how interesting hyenas are, specifically how hormones play a role in their behavior and development.
April 15, 2013
Actually, taking vitamins is considered self-medication, which is why some vitamins should not be mixed with prescriptions because of dangerous side-effects. A person with college training and experience would know this. Which is why it is deadly important to entrust your life and health with someone who has actually gone to college and gotten a degree in medicine before you decide to take it in your own hands.
What I am preaching is you cannot, with any sort of honesty say you would actually put the word of an uneducated individual above someone who has spent thousands of hours studying, training, and gaining experience just because you don’t agree with them.
April 19, 2013
I like