How to Observe Amphibians and Reptiles
As POINTED OUT IN the Introduction, reptiles and amphibians tend to be rather elusive and thus chance encounters are rare. They are generally small, cryptic and often tend to range over long distances during the active season, all of which make them rather difficult to locate. There are, however, certain ways in which the chances of encountering these animals can be increased. Obviously, reference to the distribution maps provided for each species will give some indication of areas where they are likely to occur, but these are not specific enough to locate particular sites.
Thus, what can be determined from these is that the vicinity is appropriate, but from there on the search is up to you. It is also imperative that permission be obtained from the landowner if the particular site is on private land, before you enter and make a search. It is also significant that we advocate here only observation, not collection of specimens. For identification purposes, individuals may be handled, if you know how to do so competently without injuring yourself or the animal, but they should always be gently released again at the same site. Most amphibians and reptiles are afforded some level of protection under appropriate legislative acts of the Fisheries and Wildlife departments of each province. In Alberta, the local Fisheries and Wildlife office should be consulted about current regulations and legislation. No animals should be handled or removed before the regulations in force at the time have been consulted. Remember also not to disturb any habitat or handle any animals in provincial and national parks.
The first thing to remember is that many of our native amphibians and reptiles have activity patterns that are different from our own. Frogs, salamanders and snakes are often active at night. While this does not preclude their activity during the daytime, for some species, the chances of encounter are greatly increased if you can look for them after sunset. For frogs and toads, your task will often be assisted by the characteristic calls that these animals emit. After sunset, anurans can often be approached much more readily than they can in the daytime and will reveal themselves by their calls. Patience is still required, but once the calls are heard, usually at a water body, the source of the sound can be approached.
This may cause the sound to cease, but if you stand still it should begin again fairly soon, and the singer can then be located with a flashlight. Once located like this, frogs and toads will often continue to sing while the beam of the flashlight is trained on them. This will give you an opportunity to observe the vocal sacs. Frogs and toads can also often be located simply by walking slowly around the perimeter of a likely body of water, again usually after dark, with a flash- light trained on the ground. Often frogs and toads will emerge into the vegetation to forage and will leap back into the water at your approach. The sound of the animal entering the water will enable you to locate the ripples with a flashlight, and again a short time spent waiting at the same spot may well see the animal come to the surface and attempt to exit the water once more. Toads often venture much further from water than frogs and so may also be encountered moving through the undergrowth along woodland paths.
Salamanders are a little more difficult to locate as they do not emit sounds. Often the best way of finding them is to walk the perimeter of likely ponds or sloughs, turning debris, such as logs and stones, as you go. Often they can be found hiding under such pieces of cover. Remember to always replace the turned item to its original position after investigating whether there is anything beneath it, and remember also not to injure the animal if there is one there when you replace the item.
Frogs and toads may also be located in the same way, often in daylight hours when they are at rest. Another sign of amphibian activity, especially in the spring and early summer, is the presence of eggs in bodies of water. To locate these, one must again walk the periphery of the pond and carefully examine the vegetation near the shore. Often, eggs can be found attached to such vegetation (see colour plates), or tadpoles can be seen swimming in and out of the vegetation near shore. In some instances, tadpoles can be located in relatively small isolated puddles where females lay the eggs to avoid the potential pressures of predation that may exist in the main body of the pond.
Amphibian activity may be particularly great after a heavy spring or early summer rainfall. In conditions of relatively high humidity, amphibians tend to emerge in great numbers, and such falls of rain may actually initiate the breeding activities for the year. Such effects may be particularly noticeable in the southeastern corner of the province, where water is rather scarce. Mating in species such as the spadefoot toad occurs after heavy spring rains, and activity may be very intense after dark. The temporary pools left by such rainfalls often serve as the sites for egg deposition, and the tadpoles may be present in them in very high numbers.
Reptiles may be somewhat more difficult to locate as they generally have no preferred sites of aggregation where they remain obvious for extended periods of time. Some species of snake occupy communal den sites during the winter. If these can be located, then either spring emergence or fall aggregation can provide very spectacular views of large numbers of animals. Very soon after emergence in spring, they disperse, however, and very soon after arriving at the den site in fall, they enter the hibernaculum and thus disappear from sight.
Garter snakes can often be located close to water bodies as they tend to eat frogs and toads. Walking the periphery of a pond can often turn up a garter snake. Many snakes will bask during the day on warm surfaces and are thus often seen along roads where they pick up heat from the road surface or from rocks at the side of the road. Rocks in other areas are also likely sunning sites. For the same reason, driving slowly along minor roads (not major high- ways!) after dark may result in the location of snakes.
They often emerge onto road surfaces to pick up heat being radiated from the road after a hot day. Such animals are most easily seen simply by an observer (a passenger) paying attention to the beam cast by the headlights and scanning this for the presence of basking animals. Snakes may also be found basking beneath sheets of metal and other man-made objects that have been left lying in fields. Always remember to be careful when turning such objects as, if you are in the right area, you may meet up with a rattlesnake!
Less direct ways of attempting to locate animals are by signs that they leave behind. Shed skins of reptiles (see colour plates) give a clue that you are in a likely spot, as do scats (droppings). Once you know what to look for, particular sorts of burrows may also give an indication of the likelihood of locating snakes. The only lizard and only turtle in the province are both very localized in their distribution and are extremely difficult to locate. For the lizards, walking along the tops of south-facing coulee slopes and staring at the ground is about the only method available, and you will usually see nothing. The only real way of locating turtles is to travel by canoe along the Milk River on its course in Alberta and to closely observe the banks and logs emerging from the water, on which the turtles may be basking.
It may often be difficult to approach amphibians and reptiles closely without disturbing them, so patience in your searches is very important. It is also good practice to record what you see in a field notebook. Minimally, such details as location, species, time of day and weather conditions should be recorded. Also helpful will be such aspects as behaviour and any pertinent ecological notes, such as habitat details. As your dossier of records builds, you will learn more about the circumstances in which a particular species might be encountered.
The following references provide information about a variety of techniques used in the study of amphibians and reptiles. Some are of general applicability, while others will be of use primarily for more advanced students of herpetology. In addition to the works listed here, the journal Herpetological Review regularly publishes descriptions of new or improved field and laboratory techniques in herpetology.
Significant references: Alberta Forestry, Lands and Wildlife, 1990; Anon 1988; Bull et al. 1983; Bishop and Pettit, 1992; Bury and Corn 1991; Cagle 1953, 1956; Camp and Lovell 1989; Clark, D.B. and Gillingham 1984; Corn and Bury 1990; Etheridge (no date); Ferner 1979; Fisher and Muth 1989; Green 1997; Gregory 1983; Guerra 1976; Haneline and Rhodin 1976; Hero 1989; Heyer et al. 1994; Hudnall 1982; Ireland 1986; Karns 1986; King and Duvall 1984; Lillywhite 1982; Lohoefener and Wolfe 1984; MacCulloch and Gordon 1978; Mazzotti and Brandt 1988; Mengak and Gwynn 1987; Olson et al. 1997; Parker 1971; Pisani 1973; Robertson 1984; Schueler 1981; Simmons 1987; Stanner and Farhi 1989; Stark 1985, 1986b; Vogt 1987; Zucker 1988; Zwickel and Allison 1983.
Date added: 2022-12-11; views: 201;