Appendix D: Guidelines for conducting field investigations
Some seasonal concentration areas, and many rare and specialized habitats and habitats of species of conservation concern in the municipality probably have not been identified or evaluated. Also there may identified habitats currently considered to be “potentially significant wildlife habitat” because the information about them is either insufficient, vague, or outdated. Well-planned field investigations should enable the planning authority to collect sufficient information for the identification, evaluation, and ranking of specific wildlife habitats according to their relative importance.
The following guidelines will help the planning authority to:
- provide comprehensive terms of reference for any field work
- obtain the required information, in a form that is useful to the planning authority
- minimize the cost and time required to conduct field investigations by obtaining sufficient information from a minimum number of site visits
- ensure that proper documentation of important information (e.g., location of rare species and habitats) is obtained by the planning authority
- ensure that field investigations are scheduled to be done at the proper time of year ensure that private property rights are respected
Pre-field investigation
- Have clear objectives for any field investigations, preferably in written form (e.g., to determine the significance of a site based on the evaluation criteria provided; to record as thoroughly as possible, all the different habitats on the site; to accurately record observations; to accurately map vegetation communities on the site)
- Determine the detail and intensity of the field investigation. For example, it may only involve a quick reconnaissance to determine whether the site has changed considerably from some earlier description of it, or it may be very detailed (e.g., collecting species information about a rare habitat).
- Collect and review all information pertaining to the identification and evaluation of the site. Such information usually includes ministry Site District Reports and relevant literature, aerial photographs of the area, topographical maps, Ontario Base Maps, Ontario soils maps, the various atlases, and information from the Natural Heritage Information Centre. Consultation with local naturalists, ministry staff, scientists, and academics can also help the planning authority obtain relevant information on the area to be investigated.
- Determine specific priorities for site visits (e.g., to assess the nature and level of disturbance on specific portions of the site, to describe the ecological features of the rare habitat, to determine species presence)
- Provide a schedule for the field investigations that ensures that the required information can be obtained at the time(s) of year. For example, to evaluate the significance of a migratory shorebird stopover area, field workers will want to be present at peak periods when the greatest number and diversity of shorebirds will be observed on the site. Most wetland community identification and evaluation is better done in July and August because most wetland plants flower later than most plants of terrestrial/upland communities. Most breeding bird observations should be done between late May and the end of July, but observations of raptors and waterfowl breeding should be done in April and early May. Different seasonal timing is required for amphibian breeding, flowering plants, deer yards, etc.
- Provide operational guidelines for any field investigations on private property
Field investigations
- Assemble the necessary materials for work in the field. These include topographical maps (1:50,000 scale), Ontario Base Maps (scale 1:10,000, 1:20,000 in the north), aerial photographs (scale 1:10,000, 1:20,000 in the north) of the site; a compass adjusted for declination of the area; information about the site (e.g., existing species checklist, community maps); clipboard with sheets of Mylar; field notebook or small tape recorder; pencils, eraser, sharpener; and miscellaneous equipment such as binoculars and field guides.
- Have a list of basic information to record as field notes or observations. This list usually includes the following information: approximate size of site; level and type(s) of disturbance on the site or within specific communities; diversity of site (vegetation composition and structure, floral and faunal diversity; special or unusual ecological features of the site), and a description of as many site conditions as expertise permits (aspect, slope, soils texture, drainage, moisture regime, microclimates etc.).
- Prior to undertaking fieldwork, take a photocopy of the pertinent aerial photos (use the photo enhancement capability of the photocopier). If the planning authority has the capabilities, it is very useful to scan the aerial photos and print them off to take into the field. Original aerial photos may be used in the field, and erasable grease pencils may be used to write on them. If none of these facilities are available, an overlay of Mylar on the aerial photographs may be useful. Mark on the field map/photos the sites to be visited, your present location, and the location of your parked vehicle. Recording this information before entering the area to be investigated makes it easier to keep track of your location.
- On most aerial photographs, north is found at the top of the photograph, and 1 cm on an aerial photograph is roughly equivalent to 100 metres in the field at a scale of 1:10,000 and 200 metres at 1:20,000. Field workers should measure their pace to determine approximately, how many steps are taken to cover a measured distance. This knowledge can provide a reasonable estimate of the distance covered on foot in the field, help field workers know where they are, and even provide rough estimates of the size of areas covered on foot.
- Keep track of your location on the site in order to accurately describe and map it. On sites greater than 100 hectares, pay constant attention to the maps, aerial photographs and compass bearings. Use a compass and prominent landmarks, preferably ones that are visible on both aerial photographs and maps (or at least on aerial photographs) as reference points to travel to desired points of interest. Be sure to record all compass bearings, these reference points, and approximate distances travelled, in a field notebook or on a small tape recorder. For future reference and any mapping, it also helps to sketch simple maps in a field notebook, noting due north and any prominent landscape features.
- Use triangulation to find out where you are in an unfamiliar area. To do this, first locate two recognizable reference points on the distant landscape that are also visible on the aerial photograph (or map). Take bearings from your position to one of these landmarks. Place the compass on the aerial photograph, with the cover opened wide so that the long edge intersects the landmark and the cover is towards the landmark. Rotate the compass edge about the landmark until the parallel meridian lines on the compass are roughly parallel with the vertical edges of the aerial photograph (or meridian lines of the map) and fixed North indicator on the rotating bezel (not the compass needle) is on the North side of the aerial photograph or map. Then starting from the landmark, draw a line on the aerial photograph or map, along the edge of the compass. Repeat this for the second visible landmark. The intersection of the two lines is your position.
- Consider using photography to help further document the overall character, unique features and various communities of the site, for future meetings and discussions.
The above discussion focuses on material and background information to take to the field, and how to determine where one is. It does not provide any information on how to actually collect pertinent data. In many instances, planning authorities may not have in-house expertise for collecting field data and may have to hire consultants or rely on proponents to provide relevant data. There are, however, some planning authorities that have their own environmental staff or that have agreements with conservation authorities or other conservation groups.
Following are some general guidelines for conducting fieldwork for specific natural features:
- A basic requirement is identification of habitat types. The most recent version of the Ecological Land Classification system for southern Ontario should be used (Lee et al., 1998). Similar classification systems are available for the north. Personnel completing this analysis should be capable of identifying tree species, dominant species that occur in the understory, and have an understanding of soil properties.
- A qualified botanist is usually required to identify plant species and also their habitat requirements and the amount of habitat that should be protected to ensure their continued survival in the planning area. It may be necessary to conduct fieldwork during early spring, summer, and early autumn to ensure that most species have been detected (there is no such thing as a “complete inventory”).
- The Canadian Wildlife Service has prepared protocols for monitoring amphibian populations. These are not very useful when working on a site-specific basis. However, they do provide a tape so that one can identify the songs of calling frogs.
- There is no standard protocol for sampling reptiles. For snakes, when a species of conservation concern may occur in the planning area, distributing hiding sites may give an excellent indication of where these species occur. Placing boards and other cover may reveal the location of species and give an indication of their relative abundance.
- For breeding birds, there are several standardized techniques. Fieldworkers should be able to identify birds by song and visually. For most birds, the breeding season extends from very late May until the first week of July. Surveys should be done starting shortly before dawn and ending by 0900 or 1000 at the latest. Calm days with no rain should be selected for surveying. Shorebirds, waterfowl, and raptors nest earlier through April and May. For difficult to detect species (marsh birds, certain hawks, owls) tapes of their calls may be played to elicit a response. There are also special protocols for sampling marsh birds, certain owls, and Red-shouldered Hawks.
- Most mammal observations rely on checking for signs such as tracks, scats, dens, etc. When surveying for a specific species, it is necessary to know its habitat requirements before designing the field methods. Appendix G gives the general habitat requirements of the mammals that occur in Ontario.