Data

Owner Advantage in the fiddler crab, Uca mjoebergi. Do owners win more contests than floaters because they are more motivated?

Australian Ocean Data Network
Fayed, Sarah ; Backwell, Patricia, Dr
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://catalogue.aodn.org.au:443/geonetwork/srv/api/records/744e7670-43d0-11dc-972b-00188b4c0af8&rft.title=Owner Advantage in the fiddler crab, Uca mjoebergi. Do owners win more contests than floaters because they are more motivated?&rft.identifier=https://catalogue.aodn.org.au:443/geonetwork/srv/api/records/744e7670-43d0-11dc-972b-00188b4c0af8&rft.description=Resource owners generally win contests against intruders, a phenomenon referred to as the 'Owner Advantage' (OA). Uca mjoebergi is a typical fiddler crab that is highly sociable, territorial and lives in mixed sex colonies on intertidal mudflats. Burrows are used in territory defence, for mating, and as refuge from predators and environmental stresses. Fights are common between owners and floating males who battle for ownership of the territory and burrow. Experiments were conducted from 28th Sept - 30 Dec 2006 at the lower reaches of Ludmilla Creek within East Point Reserve, 5km North of Darwin, NT. This experiment was designed to determine if owner advantage in the fiddler crab Uca mjoebergi is related to motivation. This was designed on the premise that at low tide owners are thought of as being more motivated than floaters in contests because they have invested in the territory. It was thought that as the tide comes in, the motivational asymmetry is likely to be reduced as both are increasingly motivated to win the contest and the territory. The results indicate that as the tide came in owners, not floaters, were more likely to win contests, and size difference also had a significant effect on who won. The result is interesting because it is the first direct test of the role of motivation in contests, and it is a direct contradiction to established theory.Maintenance and Update Frequency: notPlannedStatement: Fights were documented during the day from 2.5 hours before low tide to up to 4.5 hours after low tide, between owners and floaters (natural and artificial). Crabs which lost fights late in the low tide period were rehoused before the tide came in by placing them in empty burrows or in artificially created burrows. Major claw length (manus+pollex) and carapace width of each male were measured to the nearest 0.1mm using dial callipers. Fight duration was either timed in the field using a handheld stopwatch and recorded to the nearest 0.01s, or after the event using a Sony Digital Video Camera.Statement: 187 fights were documented during the day from 2.5 hours before low tide to up to 4.5 hours after low tide. Documented fights included naturally occurring fights between owners and floaters, and fights between artificial floaters created by capturing and releasing floaters or owners from their burrows. There is no difference in the fighting ability of these three types of floaters, so their fights were pooled. A standard set of data was collected for each fight. For each fight the date, time, the type of floater, and winner were recorded. Additionally, all crabs were measured, and figh duration and phases recorded. The winner is the male that owns the territory at the end of a fight. The loser is the crab which walks away at the end of the fight. A fight was considered over when: a) the loser walked >30cm away, b) travelled past two other males territories, c) entered another burrow, or d) started another fight. Parameters: Date, ltidet (time of diurnal low tide), hightideht (high tide height of the tide which follows the diurnal low tide), rtimet (time of the fight), tsltide (number of minutes since low tide), ctype (condition, NF=natural floater, RF=removed floater, RO=removed owner), winner, cara (intruder carapace width - mm), chel (inturder cheliped / claw length - mm), ocara (owner carapace width - mm), ochel (owner cheliped / claw length -mm), actions observed (P=push, B=burrow, G=grapple, F=flick, D=dig, TB=true burrow fighting), dura (duration of fight - seconds), digdura (dig duration - seconds), sizediff ( size difference between owner and intruder claws - mm).&rft.creator=Fayed, Sarah &rft.creator=Backwell, Patricia, Dr &rft.date=2007&rft.coverage=130.830175,-12.408046 130.830189,-12.408232 130.830413,-12.408210 130.830349,-12.407976 130.830175,-12.408046&rft.coverage=westlimit=130.5; southlimit=-13; eastlimit=131; northlimit=-12&rft.coverage=westlimit=130.5; southlimit=-13; eastlimit=131; northlimit=-12&rft.coverage=uplimit=0; downlimit=0&rft.coverage=uplimit=0; downlimit=0&rft_rights=Creative Commons Attribution 2.5 Australia License http://creativecommons.org/licenses/by/2.5/au/&rft_rights=The citation in a list of references is: citation author name/s (year metadata published), metadata title. Citation author organisation/s. File identifier and Data accessed at (add http link).&rft_rights=Please contact Sarah Fayed for access to the data.&rft_subject=biota&rft_subject=Biosphere | Ecological Dynamics | Competition&rft_subject=Biosphere | Ecological Dynamics | Dominance&rft_subject=COMMUNITY STRUCTURE&rft_subject=EARTH SCIENCE&rft_subject=BIOSPHERE&rft_subject=ECOLOGICAL DYNAMICS&rft_subject=COMMUNITY DYNAMICS&rft_subject=CRUSTACEANS&rft_subject=BIOLOGICAL CLASSIFICATION&rft_subject=ANIMALS/INVERTEBRATES&rft_subject=ARTHROPODS&rft_subject=Fiddler crabs&rft_subject=Uca mjoebergi&rft_subject=28960043&rft_subject=Owner Advantage&rft.type=dataset&rft.language=English Access the data
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The citation in a list of references is: citation author name/s (year metadata published), metadata title. Citation author organisation/s. File identifier and Data accessed at (add http link).

Please contact Sarah Fayed for access to the data.

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Brief description

Resource owners generally win contests against intruders, a phenomenon referred to as the 'Owner Advantage' (OA). Uca mjoebergi is a typical fiddler crab that is highly sociable, territorial and lives in mixed sex colonies on intertidal mudflats. Burrows are used in territory defence, for mating, and as refuge from predators and environmental stresses. Fights are common between owners and floating males who battle for ownership of the territory and burrow. Experiments were conducted from 28th Sept - 30 Dec 2006 at the lower reaches of Ludmilla Creek within East Point Reserve, 5km North of Darwin, NT. This experiment was designed to determine if owner advantage in the fiddler crab Uca mjoebergi is related to motivation. This was designed on the premise that at low tide owners are thought of as being more motivated than floaters in contests because they have invested in the territory. It was thought that as the tide comes in, the motivational asymmetry is likely to be reduced as both are increasingly motivated to win the contest and the territory. The results indicate that as the tide came in owners, not floaters, were more likely to win contests, and size difference also had a significant effect on who won. The result is interesting because it is the first direct test of the role of motivation in contests, and it is a direct contradiction to established theory.

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Maintenance and Update Frequency: notPlanned
Statement: Fights were documented during the day from 2.5 hours before low tide to up to 4.5 hours after low tide, between owners and floaters (natural and artificial). Crabs which lost fights late in the low tide period were rehoused before the tide came in by placing them in empty burrows or in artificially created burrows. Major claw length (manus+pollex) and carapace width of each male were measured to the nearest 0.1mm using dial callipers. Fight duration was either timed in the field using a handheld stopwatch and recorded to the nearest 0.01s, or after the event using a Sony Digital Video Camera.
Statement: 187 fights were documented during the day from 2.5 hours before low tide to up to 4.5 hours after low tide. Documented fights included naturally occurring fights between owners and floaters, and fights between artificial floaters created by capturing and releasing floaters or owners from their burrows. There is no difference in the fighting ability of these three types of floaters, so their fights were pooled. A standard set of data was collected for each fight. For each fight the date, time, the type of floater, and winner were recorded. Additionally, all crabs were measured, and figh duration and phases recorded. The winner is the male that owns the territory at the end of a fight. The loser is the crab which walks away at the end of the fight. A fight was considered over when: a) the loser walked >30cm away, b) travelled past two other males territories, c) entered another burrow, or d) started another fight. Parameters: Date, ltidet (time of diurnal low tide), hightideht (high tide height of the tide which follows the diurnal low tide), rtimet (time of the fight), tsltide (number of minutes since low tide), ctype (condition, NF=natural floater, RF=removed floater, RO=removed owner), winner, cara (intruder carapace width - mm), chel (inturder cheliped / claw length - mm), ocara (owner carapace width - mm), ochel (owner cheliped / claw length -mm), actions observed (P=push, B=burrow, G=grapple, F=flick, D=dig, TB=true burrow fighting), dura (duration of fight - seconds), digdura (dig duration - seconds), sizediff ( size difference between owner and intruder claws - mm).

Notes

Credit
Funded by The Ecological Society of Australia
Credit
Funded by The Australian Research Council (ARC)
Credit
The Australian National University (ANU)
Purpose
To determine if owner advantage in the fiddler crab Uca mjoebergi is related to motivation.

Issued: 06 08 2007

Data time period: 2006-09-28 to 2006-12-30

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130.83018,-12.40805 130.83019,-12.40823 130.83041,-12.40821 130.83035,-12.40798 130.83018,-12.40805

130.830294,-12.408104

131,-12 131,-13 130.5,-13 130.5,-12 131,-12

130.75,-12.5

text: westlimit=130.5; southlimit=-13; eastlimit=131; northlimit=-12

text: uplimit=0; downlimit=0

Subjects
28960043 | ANIMALS/INVERTEBRATES | ARTHROPODS | BIOLOGICAL CLASSIFICATION | BIOSPHERE | Biosphere | Ecological Dynamics | Competition | Biosphere | Ecological Dynamics | Dominance | COMMUNITY DYNAMICS | Community Structure | Crustaceans | EARTH SCIENCE | ECOLOGICAL DYNAMICS | Fiddler crabs | Owner Advantage | Uca mjoebergi | biota |

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  • global : 744e7670-43d0-11dc-972b-00188b4c0af8