The First Survey
The first survey for the pond-breeding salamanders will occur in the late winter. This is the time when you are likely to capture the adult salamanders moving into the pond to breed, and may also capture larvae of the Marbled Salamander which hatched the previous autumn. Adult salamanders that you may expect to capture include: Jefferson Salamander, Blue-Spotted Salamander, Spotted Salamander, Eastern Tiger Salamander, Small-mouthed Salamander, and Eastern Red-spotted Newt.
The best time for the first survey will vary greatly from northern to southern Ohio and from year-to-year depending on local weather conditions. In general, salamander activity is highest during or immediately following rainfall and daytime temperatures that exceed 55o F. In northern Ohio this usually occurs in the first week of April, while areas in southern Ohio may experience such weather conditions as early as mid-February. Melting of a large snow pack or high humidity will sometimes suffice in place of precipitation to induce the salamanders to move to their breeding ponds.
Salamanders may stay at the ponds for several days after arriving, hiding in the substrate during the day and coming out at night to resume courtship. If you arrive at the pond and observe salamander egg masses or spermataphores (small gelatinous stalks placed by the male on the pond bottom) do not despair! Salamanders may continue to arrive and breed in the pond for several weeks. The first survey will be the most variable in terms of the results you collect, but the additional two surveys will help to give a complete picture of the salamanders utilizing the pond.
Arriving at the pond, walk around the perimeter placing one trap out from the shore at each of your previously marked locations. The traps should be placed straight out from the marked locations, as far from the shoreline as necessary so that the funnel openings are completely submerged and only a small area of the trap penetrates the top of the water to create an air pocket. Ideally, the traps should be flush with the substrate.
DO NOT MOVE THE TRAPS FROM THE PRE-DETERMINED LOCATIONS! It may be very tempting to move the trap to a nearby area that “looks better,” but this will violate the assumptions being used to interpret the data you are collecting. The only reason a trap should be moved is if a structure in the water makes it impossible to submerge the trap. In that case, try moving the trap further out into the pond (but at the same location in relation to the perimeter). Only if moving the trap further out is not possible should you change the trap’s location in relation to the perimeter, and then only as much as is needed to submerge the trap.
On your data sheet, record the date and time of the trap placement, the air and water temperature, and the names of all people involved in placing the traps. Air temperature should be recorded at waist height in the shade, and water temperature should be recorded at 2cm below the water surface. Also, any relevant observations (egg-masses, spermataphores, salamanders observed) should be noted on the data sheet in the section labeled “Comments.”
Ideally, the traps should be checked in the early morning of the day after their placement into the pond. No trap should ever be left unchecked for over 24 hours. To check the traps remove them one at a time, keeping the trap horizontal. On shore, invert one of the funnels and carefully shake the contents out into the sorting tray or bucket containing a ¼” of pond water in the bottom. All captured specimens other than salamanders and their larvae can be returned immediately to the pond. (You may wish to keep a separate notebook of the other organisms that you find in the pond for your own records.) For each trap, record the number and species of adults captured and return them to the pond. If a camera is available, photograph a representative animal of each species captured. Color slide film is the best choice for creating a photographic voucher of the species. Larval salamanders should be moved into a plastic “Ziploc-type” bag with pond water and clearly marked with the trap number. Leave this bag on the shore until all the traps have been checked.
Move to the next trap and repeat the process for removing animals and recording the specimens caught on the data sheet. Remember to keep all larvae captured in numbered plastic bags until you have finished checking all of the traps. Once you have checked all of the traps, collect all of the bags containing salamander larvae and carefully inspect the animals. It is unlikely that any larvae caught during the first survey will be a species other than the marbled salamander. Even so, you should carefully compare all of the larvae you have captured to determine if you have more than one species. It is not necessary for you to identify the larvae caught as a particular species. Instead, you should use the “morpho-species” concept to merely identify different species. For a complete description of the morpho-species concept, click here.
When you have determined the number of morpho-species you have captured, place one individual of each type into separate vials of alcohol for preservation. Each jar should already contain a tag identifying the specimen as “Species A,” Species B,” etc. Clearly write the date (including year) on the top of the vial with a permanent marker. On your data sheet, write each morpho-species identification and the number of each captured in each trap. Release the remaining larvae back into the pond.
Adult salamanders should be easily identifiable throughout much of Ohio. Refer to Pfingsten and Downs (1989), Petranka (1998), or Conant and Collins (1991) for help in identifying adult salamanders. Record the species and number of each adult salamander captured on the data sheet. If a camera is available, photographs of adult specimens are very valuable. Return the captured adult salamanders to the pond.
In some areas, salamanders with characteristics intermediate of two or more species (“hybrids”) may be very common. This is especially true in northwestern Ohio and the adjacent Lake Erie Islands. These salamanders usually have characteristics that are assignable to the Jefferson Salamander, Small-mouth Salamander, and/or the Blue-spotted Salamander. If you should encounter adult salamanders that you are unable to positively identify, check the box marked “Unidentifiable Ambystoma.” Photographs of any unidentifiable specimens are very helpful.
On your data sheet, record the date and time of the trap retrieval, the air and water temperature, and the names of all people involved in retrieving the traps and collecting the data. Air temperature should be recorded at waist height in the shade, and water temperature should be recorded at 2cm below the water surface. If any fish are captured or observed, note this in the appropriate box on the data sheet, and the species, if known. Also, any relevant observations (egg-masses, spermataphores, salamanders observed) should be noted on the data sheet in the section labeled “Comments.”