We observed the behavior of individual crabs in situ. In each habitat, we collected groups of five adult A. pisonii by hand and determined the sex and carapace width (to the nearest 0.1mm) of each individual. The groups of crabs were made up of the first five individuals that we encountered and could capture and were drawn from all accessible habitat. We then painted the carapace of each crab an identifying color with nail polish to aid in identification and visibility. Following a short period of observation to ensure normal behavior, we released the crabs onto a single tree within 10 m of the collection tree of all individuals (mangrove), onto separate S. alterniflora stalks within 10 m of the area of collection (saltmarsh), or onto the same piling (dock) of the dock where all individuals were captured. Release in the saltmarsh occurred during the rising tide when the crabs had no access to the sediment.
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We observed crabs in the mangrove and saltmarsh habitats from the time they lost access to the sediment until the receding tide once again allowed access to the sediment (~6h depending on site and day). In contrast, we observed crabs on docks from three hours before slack high tide until three hours after slack high tide. The total time of observation, in minutes, was recorded. We watched crabs from a distance using binoculars and monitored the individuals continuously throughout the observational period. Behavior was recorded every five minutes and at every change in behavior within those five minute intervals as one of four categories: feeding, sitting, moving, or not-visible. Feeding was defined as the crab actively moving its claws from a food item or substrate to its mouth. Moving was defined as the crab actively moving along a substrate and not feeding. Other energy expending non-feeding activities, such as ritual aggression, were also classified under moving as they represent an expenditure of energy. Sitting was defined as the crab not actively moving, feeding, or participating in any activity. Invisible was defined as the crab not being visible to the observer.
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We separated the observations into ebb and flood tidal periods.\u00a0
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To avoid biasing the data with crabs that were not visible for long periods, we removed data from individuals that were not visible for more than 66% of the tidal period. To calculate the proportion of time each crab performed each activity during each observational period we divided the minutes observed on that activity by the total number of minutes of the observational period.
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Locations: Florida East Coast.
\nRound Island Park: 27o33'33\"N 80o19'53\"W
\nPepper Park: 27o29'42'N 80o18'12\"W
\nBear Point: 27o25'48\"N 80o17'10\"W
\nNorth Causeway Park: 27o28'28\"N 80o19'12\"W
\nOslo Road: 27o35'14\"N 80o21'55\"W
\nAnastasia State Park: 29o52'40\"N 81o16'32\"W
\nGuana-Tolomato-Matanzas NERR: 30o0'49\"N 81o20'42\"W
\nPalm Valley/Nocatee Canoe Launch: 30o07'57\"N 81o23'08\"W
\nSt. Augustine Yacht Club: 29o53'09\"N 81o17'08\"W
This dataset includes behavioral observations of individual mangrove tree crabs, Aratus pisonii: the proportion of time spent sitting, moving, feeding, or not visible. Size and sex of the crabs, water temperature, and tidal period of the observations were also recorded. Crabs were collected near Fort Pierce, Florida from a dock area and released into one of three habitats: mangrove, saltmarsh or under the dock.
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These data are presented in\u00a0Cannizzo et al (2018).
BCO-DMO Processing
\n- added column for ISO_Date, joining year and month-day columns; removed display of Date (d-Mon) column
\n- reordered columns: Year, Habitat
\n- reduced\u00a0the decimal precision of behavior proportions from 9 to 2 places