Skip to main content
Log in

Taking a risk: how far will male fiddler crabs go?

  • Original Article
  • Published:
Behavioral Ecology and Sociobiology Aims and scope Submit manuscript


Courtship is costly for males when it increases their energy expenditure and predation risk. There are several ways in which males might be able to mitigate these costs, or compensate for them by elevating the benefits of courtship. First, they could selectively court more profitable females. Second, they could adjust the amount of risk they take against their residual reproductive value. Third, they could sometimes use cheaper signals to deceive females. In the fiddler crab Leptuca terpsichores (Crane, 1941), males risk losing their burrow to another crab and falling prey to a bird when they leave their burrow to intercept a mate-searching female and lead her back to the burrow for mating. Some males build sand hoods at their burrow entrances, which are landmarks that attract females and allow males to relocate their burrows quickly with little error. Here, we show that (1) males took greater risks when courting larger females by travelling farther away from their burrows; (2) the distance a male moved from his burrow did not depend on his size (hence, age); and (3) males with sand hoods did not travel farther away from their burrows than males without hoods, and they were not more likely to reach females. Taking greater risks when courting larger (more fecund) females appears to be a key means through which male fiddler crabs can achieve a more favourable balance between the costs and benefits of courtship.

Significance statement

Courtship and mate choice can be costly for males. Males may improve the balance between courtship costs and benefits by modifying their risk-taking during courtship according to the perceived value of the female, or their expectations of future reproduction. Male fiddler crabs move away from their burrows to court females, which is risky because they may lose the burrow or be attacked by predators. We used the distance a male travels from his burrow as an index for the level of risk he is willing to take. We explored the effects of female size, male age, and the presence of a sand hood at the burrow entrance on distance travelled during courtship. Males took greater risks to court larger females, but did not adjust risk-taking according to their age (expected future reproduction) or whether their burrow had a sand hood.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2

Similar content being viewed by others


  • Callander S, Jennions MD, Backwell PRY (2012) The effect of claw size and wave rate on female choice in a fiddler crab. J Ethol 30:151–155

    Article  Google Scholar 

  • Candolin U (1997) Predation risk affects courtship and attractiveness of competing threespine stickleback males. Behav Ecol Sociobiol 41:81–87

    Article  Google Scholar 

  • Christy JH, Backwell PRY, Goshima S, Kreuter T (2002) Sexual selection for structure building by courting male fiddler crabs: an experimental study of behavioral mechanisms. Behav Ecol 13:366–374

    Article  Google Scholar 

  • Christy JH, Baum JK, Backwell PRY (2003) Attractiveness of sand hoods built by courting male fiddler crabs, Uca musica: test of a sensory trap hypothesis. Anim Behav 66:89–94

    Article  Google Scholar 

  • Clark CW (1994) Antipredator behavior and the asset-protection principle. Behav Ecol 5:159–170

    Article  Google Scholar 

  • Cordes N, Engqvist L, Schmoll T, Reinhold K (2014) Sexual signaling under predation: attractive moths take the greater risks. Behav Ecol 25:409–414

    Article  Google Scholar 

  • Engqvist L, Cordes N, Reinhold K (2015) Evolution of risk-taking during conspicuous mating displays. Evolution 69:395–406

    Article  PubMed  Google Scholar 

  • Esfandi K, He XZ, Wang Q (2015) Flirtation reduces males’ fecundity but not longevity. Evolution 69:2118–2128

    Article  PubMed  CAS  Google Scholar 

  • Goshima S, Koga T, Murai M (1996) Mate acceptance and guarding by male fiddler crabs Uca tetragonon (Herbst). J Exp Mar Biol Ecol 196:131–143

    Article  Google Scholar 

  • Greenspan BN (1980) Male size and reproductive success in the communal courtship system of the fiddler crab Uca rapax. Anim Behav 28:387–392

    Article  Google Scholar 

  • Hayes CL, Booksmythe I, Jennions MD, Backwell PRY (2013) Does male reproductive effort increase with age? Courtship in fiddler crabs. Biol Lett 9:20121078

    Article  PubMed  PubMed Central  Google Scholar 

  • Hines AH (1982) Allometric constraints and variables of reproductive effort in brachyuran crabs. Mar Biol 69:309–320.

    Article  Google Scholar 

  • Hirt K, Ruch J, Schneider JM (2017) Strategic male mating behaviour in Argiope lobata. Anim Behav 124:27–34

    Article  Google Scholar 

  • Hoefler CD (2008) The costs of male courtship and potential benefits of male choice for large mates in Phidippus clarus (Araneae, Salticidae). J Arachnol 36:210–212

    Article  Google Scholar 

  • Hyatt GW (1977) Field studies of size-dependent changes in waving display and other behavior in the fiddler crab, Uca pugilator (Brachyura, Ocypodidae). Mar Behav Physiol 4:283–292

    Article  Google Scholar 

  • Kim TW, Christy JH (2015) A mechanism for visual orientation may facilitate courtship in a fiddler crab. Anim Behav 101:61–66

    Article  Google Scholar 

  • Kotiaho JS, Simmons LW (2003) Longevity cost of reproduction for males but no longevity cost of mating or courtship for females in the male-dimorphic dung beetle Onthophagus binodis. J Insect Physiol 49:817–822

    Article  PubMed  CAS  Google Scholar 

  • Møller AP, Jennions MD (2002) How much variance can be explained by ecologists and evolutionary biologists? Oecologia 132:492–500

    Article  PubMed  Google Scholar 

  • Murai M, Goshima S, Henmi Y (1987) Analysis of the mating system of the fiddler crab, Uca lactea. Anim Behav 35:1334–1342

    Article  Google Scholar 

  • Nakano R, Skals N, Takanashi T, Surlykke A, Koike T, Yoshida K, Maruyama H, Tatsuki S, Ishikawa Y (2008) Moths produce extremely quiet ultrasonic courtship songs by rubbing specialized scales. P Natl Acad Sci USA 105:11812–11817

    Article  Google Scholar 

  • Reading KL, Backwell PRY (2007) Can beggars be choosers? Male mate choice in a fiddler crab. Anim Behav 74:867–872

    Article  Google Scholar 

  • Reaney LT, Backwell PRY (2007) Risk-taking behavior predicts aggression and mating success in a fiddler crab. Behav Ecol 18:521–525

    Article  Google Scholar 

  • Ribeiro PD, Christy JH, Rissanen RJ, Kim TW (2006) Males are attracted by their own courtship signals. Behav Ecol Sociobiol 61:81–89

    Article  Google Scholar 

  • Rypstra AL, Walker SE, Persons MH (2016) Cautious versus desperado males: predation risk affects courtship intensity but not female choice in a wolf spider. Behav Ecol 27:876–885

    Article  Google Scholar 

  • Saher NU, Qureshi NA (2017) Construction of earthen structure as a sexual signals in the fiddler crabs. Int J Aquat Biol 5:40–46

    Google Scholar 

  • Scharf I, Peter F, Martin OY (2013) Reproductive trade-offs and direct costs for males in arthropods. Evol Biol 40:169–184

    Article  Google Scholar 

  • Shih H-T, Ng PKL, Davie PJF, Schubart CD, Türkay M, Naderloo R, Jones D, Liu M-Y (2016) Systematics of the family Ocypodidae Rafinesque, 1815 (Crustacea: Brachyura), based on phylogenetic relationships, with a reorganization of subfamily rankings and a review of the taxonomic status of Uca Leach, 1814, sensu lato and its subgenera. Raffles B Zool 64:139–175

    Google Scholar 

  • Wedell N (2010) Variation in male courtship costs in butterflies. Behav Ecol Sociobiol 64:1385–1391

    Article  Google Scholar 

  • Williams GC (1966) Natural selection, the costs of reproduction, and a refinement of Lack’s principle. Am Nat 100:687–690

    Article  Google Scholar 

  • Zeil J, Layne J (2002) Path integration in fiddler crabs and its relation to habitat and social life. In: Wiese K (ed) Crustacean experimental systems in neurobiology. Springer, Berlin, Heidelberg, pp 227–246

    Chapter  Google Scholar 

Download references


We thank the Australian National University and the Smithsonian Tropical Research Institute for their support.


This study was funded by a Research School of Biology (ANU) grant to PRYB.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Siobhan J. Heatwole.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval and permits

This research did not require ethics clearance from the Republic of Panama or the Australian National University. No crab was injured during the research, and they all continued their regular activities after release. The study was approved by the Autoridad de los Recursos Acuáticos de Panamá under permit number 84. Permission to work at our study site on the naval base was given by the Servicio Nacional Aeronaval under permit number SPO-0017.

Additional information

Communicated by T. Breithaupt

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Heatwole, S.J., Christy, J.H. & Backwell, P.R.Y. Taking a risk: how far will male fiddler crabs go?. Behav Ecol Sociobiol 72, 82 (2018).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: