Tuesday, January 31, 2023
SCIENMAG: Latest Science and Health News
No Result
View All Result
  • Login
  • HOME PAGE
  • BIOLOGY
  • CHEMISTRY AND PHYSICS
  • MEDICINE
    • Cancer
    • Infectious Emerging Diseases
  • SPACE
  • TECHNOLOGY
  • CONTACT US
  • HOME PAGE
  • BIOLOGY
  • CHEMISTRY AND PHYSICS
  • MEDICINE
    • Cancer
    • Infectious Emerging Diseases
  • SPACE
  • TECHNOLOGY
  • CONTACT US
No Result
View All Result
Scienmag - Latest science news from science magazine
No Result
View All Result
Home SCIENCE NEWS Biology

Fighting fiddler crabs call each other’s bluff

April 5, 2016
in Biology
0
Share on FacebookShare on Twitter
IMAGE

Credit: Daisuke Muramatsu

Male fiddler crabs bluff their way through fights. They also adapt their combat strategies if they have lost their original enlarged claw and have regrown a more fragile, weaker one. These are some of the findings of wildlife researchers Daisuke Muramatsu of Kyoto University and Tsunenori Koga of Wakayama University in Japan, who spent time on a mudflat watching how fiddler crabs use deception to their favour. Their study is published in Springer's journal Behavioral Ecology and Sociobiology.

Male fiddler crabs (Uca lactea) fight aggressively over territory and burrows. Their prized weapon is their enlarged major claw, which grows on either the left or right side. During Muramatsu and Koga's observations of a dense crab colony in the Waka River estuary in Japan, they videotaped 138 such fights. In general, those with longer claws came up trumps. Animals that participated in these bouts were caught and their body parts thoroughly examined, measured and marked.

The researchers distinguish original from regrown claws by checking whether these had teeth in their gape or not. Although regenerated claws often grow back to the same size as that of the original, these replacements are of weaker standard. Based on Muramatsu and Koga's observations, fiddler crabs seem unable to visually discriminate one from the other, because males with regrown claws (so-called regenerated males) were not picked on more to fight with than others. Of the 138 fights observed, only 42 were between males with original claws and those with regrown ones.

The researchers saw no fight which included a male whose lost claw had not yet grown back to its original size. This suggests that these crabs are unwilling to engage in fights until their claws are completely regrown. Once in place, regenerated males chose smaller and opposite-handed opponents as a way of protecting their inferior regrown claws from possible injury. Claws are generally grappled more tightly in same-handed fights.

Males with regrown claws make a show of being aggressive to deter opponents, but surrender easily when the fight escalates in intensity. These initial bluffing tactics to ward off opponents seem to be partially successful, because they are not engaged in fights more than others. Regenerated males are victorious in two out of every five such encounters.

Males with their original claws intact tend to choose same-handed opponents. As part of their own counter-bluff tactics, they persist in contests even when their opponents are larger. They go into a fight assuming that the opponent has a regenerated claw and, if this is the case, the regenerated male will therefore retreat.

"Fiddler crab males adapt their fighting tactics and choice of opponent depending on whether they have lost their major claw," says Muramatsu, who adds that this shows that animals are able to switch tactics during their lifetime.

"The findings are in line with current theories that predict that animal signals are generally honest, but each signalling system allows for deception," adds Koga.

###

Reference: Muramatsu, D. & Koga, T. (2016). Fighting with an unreliable weapon: opponent choice and risk avoidance in fiddler crab contests, Behavioral Ecology and Sociobiology. DOI 10.1007/s00265-016-2094-2

Media Contact

Joan Robinson
[email protected]
49-622-148-78130
@SpringerNature

http://www.springer.com

Share25Tweet16Share4ShareSendShare
  • blank

    Null results research now published by major behavioral medicine journal

    545 shares
    Share 218 Tweet 136
  • New study shows snacking on mixed tree nuts may impact cardiovascular risk factors and increase serotonin

    127 shares
    Share 51 Tweet 32
  • Cambridge-led consortium receives $35m to boost crop production sustainably in sub-Saharan Africa

    65 shares
    Share 26 Tweet 16
  • This groundbreaking biomaterial heals tissues from the inside out

    65 shares
    Share 26 Tweet 16
  • New analogue quantum computers to solve previously unsolvable problems

    64 shares
    Share 26 Tweet 16
  • Almost all of Africa’s maize crop is at risk from devastating fall armyworm pest, study reveals

    64 shares
    Share 26 Tweet 16
ADVERTISEMENT

About us

We bring you the latest science news from best research centers and universities around the world. Check our website.

Latest NEWS

New study shows snacking on mixed tree nuts may impact cardiovascular risk factors and increase serotonin

Null results research now published by major behavioral medicine journal

Hydrogen peroxide from tea and coffee residue: New pathway to sustainability

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 205 other subscribers

© 2022 Scienmag- Science Magazine: Latest Science News.

No Result
View All Result
  • HOME PAGE
  • BIOLOGY
  • CHEMISTRY AND PHYSICS
  • MEDICINE
    • Cancer
    • Infectious Emerging Diseases
  • SPACE
  • TECHNOLOGY
  • CONTACT US

© 2022 Scienmag- Science Magazine: Latest Science News.

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In