Hostname: page-component-77c89778f8-m8s7h Total loading time: 0 Render date: 2024-07-20T06:29:49.089Z Has data issue: false hasContentIssue false
  • English
  • Français

Comparison of non-invasive methods for quantifying population density of the fiddler crab Uca tangeri

Published online by Cambridge University Press:  19 September 2003

Joana M. Jordão  and
Rui F. Oliveira
Joana M. Jordão
Affiliation:
ISPA, Unidade de Investigação em Eco-Etologia, R. Jardim do Tabaco, 34, 1149-041 Lisboa, Portugal, E-mail: jjordao@ispa.pt and ruiol@ispa.pt
Rui F. Oliveira
Affiliation:
ISPA, Unidade de Investigação em Eco-Etologia, R. Jardim do Tabaco, 34, 1149-041 Lisboa, Portugal, E-mail: jjordao@ispa.pt and ruiol@ispa.pt
Get access Rights & Permissions [Opens in a new window]

Abstract

Excavation counts (absolute density), burrow counts and surface active individuals visual counts in a Uca tangeri population were compared. Population density estimated from burrow counts was not significantly different from population density estimated by excavation, but the population density estimated with visual counts was significantly lower than the absolute density. Ovigerous females should be the main cause of these differences because they frequently remain underground, but other groups of crabs are also contributing to this difference. Burrow counting is an accurate and quick non-invasive method for the census of U. tangeri. Other population measures (e.g. sex ratio) are not obtainable by burrow counting and only further understanding of the activity patterns of this species along the tide cycle, moon phase and reproductive season will allow visual counting of surface active individuals to be used as quick, efficient and non-invasive method for crab density and population structure estimation.

Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 83 , Issue 5 , October 2003 , pp. 981 - 982
Copyright
Copyright © Marine Biological Association of the United Kingdom 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ens, B.J., Klaassen, M. & Zwarts, L., 1993. Flocking and feeding in the fiddler crab (Uca tangeri): prey availability as risk-taking behaviour. Netherlands Journal ofSea Research, 31, 477–494.Google Scholar
Hagen, H.-O. von, 1962. Freilandstudien zur Sexual und Fort pflanszungs biologie von Uca tangeri in Andalusien. Zeitschrift fu«r Morphologie und O«kologie der Tiere, 51, 611–725.Google Scholar
Lourenco, R., Paula, J. & Henriques, M., 2000. Estimating the size of Uca tangeri (Crustacea: Ocypodidae) without massive crab capture. Scientia Marina, 64, 437–439.Google Scholar
Macia, A., Quincardete, I. & Paula, J., 2001. A comparison of alternative methods for estimating population density of the fiddler crab Uca annulipes at Saco Mangrove, Inhaca island (Mozambique). Hydrobiologia, 449, 213–219.CrossRefGoogle Scholar
Mouton, E.C. & Felder, D.L., 1996. Burrow distributions and populations estimates for the fiddler crabs Uca spinicarpa and Uca longisignalis in a Gulf of Mexico salt marsh. Estuaries, 19, 51–61.Google Scholar
Oliveira, R.F., Machado, L.L., Jordäo, J.M., Burford, F.L., Latruffe, C. & McGregor, P.K., 2000. Human exploitation of male fiddler crab claws: behavioural consequences and implications for conservation. Animal Conservation, 3, 1–5.Google Scholar
Skov, M.W. & Hartnoll, R.G., 2001. Comparative suitability of binocular observation, burrow counting and excavation for the quantification of the mangrove fiddler crab Uca annulipes (H. Milne Edwards). Hydrobiologia, 449, 201–212.Google Scholar
Skov, M.W., Vannini, M., Shunula, J.P., Hartnoll, R.G. & Cannicci, S., 2002. Quantifying the density of mangrove crabs: Ocypodidae and Grapsidae. Marine Biology, 141, 725–732.Google Scholar
Wolfrath, B., 1993. Observations on the behaviour of the European fiddler crab Uca tangeri. Marine Ecology Progress Series, 100, 111–118.Google Scholar
Zucker, N., 1978. Monthly reproductive cycles in three sympatric hood building tropical fiddler crabs (Genus Uca). Biological Bulletin. Marine Biological Laboratory, Woods Hole, 155, 410–424.Google Scholar