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Seasonal movements of western chorus frogs (Pseudacris triseriata triseriata) tagged with radioactive cobaltKramer, David C. January 1971 (has links)
The movements of Western Chorus Frogs (Pseudacris, triseriata triseriata) were studied from March, 1970, to March, 1971, at the Robert H. and Esther L. Cooper Woodland Area near Muncie, Delaware County, Indiana. The objectives of the study were to determine: (1) the time and rate of dispersal from the breeding pool; (2) the day-to-day movements, including the time and minimal distance traveled; (3) the preferred cover or microhabitat; and (4) the site of hibernation.Seventy-three Chorus Frogs were tagged with approximately 50 μc Co60 and toe-clipped, and each was released at its capture site. The frogs were then sought at intervals by surveying the area with a portable survey meter equipped with a scintillation probe. The location of each recovered specimen and a description of the recapture site was recorded.Sixty-two individual specimens were recaptured at least one time. The number of recaptures for each specimen was variable, and the maximum number of recaptures for a single specimen was 26 times. In all, 324 recoveries of tagged specimens were made. The tagged specimens graduallybecame lost to the investigator, and the last specimen was found on August 4. The longest period of contact for an individual frog was 134 days.Some Chorus Frogs began leaving the breeding pools soon after the first eggs were observed on April 1. The exodus appeared to be gradual as a few (one to eight) additional tagged specimens were found out of the pools throughout April and early May. Four of these specimens returned at least once to their original pool and seventeen frogs entered a second pool.From a single attempt to monitor the overnight activities of these frogs, it appears that they remain quiescent during the daylight hours and become active between dusk and dawn.The minimal distances traveled by the tagged, specimens during the study are more a function of the length of the contact period and the number of recaptures than of the activity of the frogs. The average rate of movement for all of the specimens over the entire study period was 11.3 feet/day. However, the fastest observed rate of movement for a single specimen between two recapture sites was 138 feet/day. The greatest straight distance any specimen was found from its original pool was 700 feet. Most recaptures were within 500 feet of the pools where the specimens were tagged.In 213 (91.3%) of the 234 recaptures made daylight hours after the frogs left the breeding pools,the frogs were hidden in the leaf litter of the woods or dead grasses of the grassland. In the remaining recaptures the frogs were hidden under small objects. The frogs seemed to prefer moist rather than dry or wet cover, but this is possibly more a reflection of conditions at the time of the study than a preference on the part of the frogs.The gradual disappearance of the tagged frogs from the study area, the woodland situation of the breeding pools, and the concentration of searching efforts in the vicinity of the pools prevented the determination of the preferred habitat type (woodland or grassland). Also, because of the loss of all tagged specimens by the end of summer, hibernating sites were not located.There is evidence that the gradual disappearance of tagged specimens may be explained by predation or movement of the frogs underground or out of the study area. Other frogs lost their cobalt wires and could no longer be located.
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