Details

Autor(en) / Beteiligte

• Matsumasa, Masatoshi
• Murai, Minoru
• Christy, John H.

Titel

A low-cost sexual ornament reliably signals male condition in the fiddler crab Uca beebei

Ist Teil von

• Animal behaviour, 2013-06, Vol.85 (6), p.1335-1341

Ort / Verlag

London: Elsevier Ltd

Erscheinungsjahr

2013

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Empirical studies of the reliability of sexual signals are needed to test the prediction that females should prefer males in good condition. We examined whether an attractive sexual signal used by male fiddler crabs, Uca beebei, reliably indicates male condition by measuring male blood glucose and lactate levels in the field. The signal is a mud structure, a ‘pillar’, that attracts females for mating. Blood lactate levels (a measure of energy expenditure) of pillar builders (P males) immediately after they built their pillars did not differ from those of nonbuilders (NP males), suggesting that the cost of building a pillar is small. However, P male lactate levels were significantly higher than those of NP males late in the activity cycle after P males had invested more in vigorous courtship using claw ‘waving’. Whereas P males maintained their glucose levels (a measure of energy availability as the major fuel for ATP production) at around 30mg/dl throughout their daily activity period, NP males showed significantly lower levels in the middle of the period. These results confirm that pillars reliably signal a male’s condition, as measured by his ability to maintain a blood glucose level necessary for costly courtship, even though the construction of a pillar has minimal energetic cost. •Does production of a sexual signal by male fiddler crabs depend on male condition?•Blood glucose and lactate levels indicated condition and signal production costs.•Only males in good condition built mud pillars and invested in costly claw waving.•The construction of attractive mud pillars was not energetically costly.•Pillars reliably indicate male condition but not because they are costly to produce.