The following text is from Best Management Practices (BMPs) prepared for forestry lands in Alberni Valley, Vancouver Island by Habitat Acquisition Trust. It expands and provides clarification for BMPs shown on the main Western Painted Turtle page.
Main Threats in Relation to Forestry Practices
• Road mortality of hatchling or nesting turtles, and possibly also of dispersing turtles
• Gravel extraction from sites used by nesting turtles
• Disturbance to habitat at nesting grounds or to nesting turtles by the public
• Change of hydrological regimes from road building or from beaver control
• Limited availability of natural nesting grounds encourages turtles to use roadsides and gravel pits, increasing risk of mortality and disturbance
Best Management Practices Guidelines for Forestry Activities
The following guidelines are general measures that are recommended before any maintenance activities, infrastructure development, or forest practices are undertaken:
1. General Guidelines (All Activities):
• Check for known Western Painted Turtle occurrences or nesting grounds on the work site on available GIS system or database.
• Conduct surveys for turtles or for signs of nesting, where recommended by guidelines for specific activities (see BMPs below).
2. Guidelines for Maintenance Activities:
a) Road repairs and grading
The main threat from road repairs and grading is inadvertent destruction of turtle nests located along the edges of gravel roads. Grader blades could destroy nests, and the wheels of machinery could crush eggs and hatchings in nests. It is, however, possible to minimize these risks, because nests are usually located on roadsides and the shoulder rather on the roadbed itself.
• Where turtles are known to nest on roadsides, conduct repairs and grade roads in late spring, when chances of harming turtle nests are minimal, and avoid grading road edges and shoulders.
• In other areas where roads are immediately adjacent water bodies with records of turtles, either take above precautions or survey for signs of turtle nesting activity on roadsides before starting work.
• Grade and repair roads in late spring, after hatchlings have emerged from nests but before egg-laying begins. There is a narrow seasonal time-window when these activities can be conducted safely in sensitive turtle habitats. The optimal period is probably in May – early June, but there is uncertainty about the exact timing of seasonal activities of turtles in specific areas.
• Surveys for signs of turtle nesting activity can be conducted anytime from about March to September.
• The BMPs apply to sections of roads where the Western Painted Turtle is known to nest, and where roads are immediately adjacent to lakes or wetlands occupied by this species
• Implement the actions to the road from about 200 m before to about 200 m after the occupied water bodies to ensure that no nests are harmed.
b) Gravel extraction
Gravel extraction from old gavel pits that are situated close to wetlands can result in destruction of turtle nesting areas. If new gravel pits are placed in natural openings used by turtles for nesting they could also result in destruction of turtle nesting sites. Therefore an important precautionary measure is to place new gravel pits away from prime turtle nesting habitat. Western Painted Turtles are known to nest in gravel pits in the Alberni Valley. Resumption of gravel extraction in such places could inadvertently destroy turtle nests. Turtles are attracted to these sites because of the exposed soil and sandy substrate suitable for nest building, especially where natural nesting areas are in short supply .
• Locate new gravel pits away from water bodies with records of the Western Painted Turtle; consult a professional biologist if a gravel pit needs to be placed near turtle habitat.
• At existing gravel pits in turtle habitat, survey for signs of turtle nesting activity before any material is extracted for road repairs, road construction, or other purposes. If signs of turtle nesting activity are found, use alternative sites for gravel extraction.
• Conduct surveys of existing gravel pits before any extraction takes place; best time for these surveys is from about March to August.
• The BMPs apply to areas adjacent (within about 500 m) from ponds, lakes, or wetlands occupied by the Western Painted Turtle.
The main threat from clearing ditches from vegetation and debris is from machinery crushing turtle eggs or hatchlings in roadside nests and from materials extracted from ditches covering them. Suggested BMPs are similar to those for road repair and grading.
• Where turtles are known to nest on roadsides, clear ditches in late spring, when chances of harming turtle nests are minimal.
• In other areas where roads are immediately adjacent water bodies with records of turtles, either clear ditches in late spring or survey for signs of turtle nesting activity before ditching.
• Avoid piling up dredged materials or cleared vegetation along edges of roads in turtle nesting habitat.
• Clear ditches in late spring, after hatchlings have emerged from nests but before egg-laying begins. There is a narrow seasonal time-window when these activities can be conducted safely in sensitive turtle habitats. The optimal period is probably in May – early June, but there is uncertainty about the exact timing of seasonal activities of turtles in the Alberni Valley.
• Surveys for signs of turtle nesting activity. The best time for these surveys is from about March to August.
• The BMPs apply to sections of roads where the Western Painted Turtle is known to nest, and where roads are immediately adjacent to lakes or wetlands occupied by this species
• Implement the actions to the road from about 200 m before to about 200 m after occupied water bodies to ensure that no nests are harmed.
There are three main types of threats to turtle eggs and hatchlings in roadside nests from snowplowing. One is the mechanical destruction of nests with the snowplow blade; a second is from removing the insulating snow layer. Snow insulates turtle nests from freezing and is therefore important for the survival of the hatchlings that are overwintering in the nests. A third threat is from high piles of snow on top of nests, which could delay emergence of turtles in the spring and trap hatched turtles.
• Take care to avoid scraping road edges and shoulders when plowing snow in turtle nesting habitat.
• Avoid high/large piles of snow along road edges in turtle nesting habitat. Note, however, that piling of snow along road edges as a result of regular snowplowing process (to depths of less than about 1 m) will most likely not harm turtle nests.
• Anytime when snowplowing takes place.
• Implement the BMPs in areas where the Western Painted Turtle is known to nest along roadsides and where roads occur adjacent to water bodies occupied the species.
e) Replacing and Unblocking Culverts
The threat from these activities is sudden and drastic drops in water levels that may expose turtles hibernating at the bottom of ponds, wetlands, or lakes to winter weather. In the Interior of B.C., the Western Painted Turtle hibernates in shallow (below 1 m in depth), well-oxygenated waters of lakes and ponds . Such shallow areas would be the first to be exposed if water levels decrease. On the Sunshine Coast turtles hibernate in areas with water depths of 2 or more meters (M. Evelyn, 2009 per com). Unfortunately, we know virtually nothing about hibernation habits of the turtles in the Alberni Valley. In the Alberni Valley, turtles probably hibernate during the coldest part of the winter, from October to March, but the exact timing is unknown. In the Interior of B.C., Western Painted Turtles hibernate when water temperatures are below about 10° C. A cautionary approach is recommended when working in turtle habitat until more information of hibernation locations and requirements by turtles become available.
• Avoid replacing and clearing blocked culverts that could dramatically decrease water levels when turtles are hibernating.
• Conduct work during the activity period of turtles from about March to September.
• Apply BMPs wherever the activities could result in drastic drops in water levels in ponds, wetlands or lakes with records of the Western Painted Turtle or where water bodies contain suitable habitat for turtles but are yet to be surveyed.
f) Beaver Control
The beaver’s industrious dam building creates shallow ponds favoured by turtles, and beavers appear to be important in maintaining turtle habitat in some areas. Beaver activity, however, can block culverts and cause roadbed erosion, flooding, and other problems. Therefore, it is often necessary to manage beaver activity to alleviate these problems.
When beaver dams are removed water level often drops. If the dams are removed during the winter, hibernating turtles might be exposed to the elements, potentially increasing mortality (see Replacing and Unblocking Culverts section).
Beavers and their dens and dams are protected by the B.C. Wildlife Act, Water Act and the Municipal Act, so ensure that any management practices conform to these regulations.
• Near water bodies where turtles hibernate or are suspected to hibernate, take out beaver dams including those that are blocking culverts when turtles are not hibernating.
• Rather than eliminating or reducing beaver numbers, use a specially constructed “beaver baffler” to discourage beavers from fixing leaks in their dams and blocking culverts.
• Remove or open beaver dams from April to September when turtles are active and not hibernating
• Apply BMPs wherever the activities could result in drastic drops in water levels in ponds, wetlands or lakes with records of the Western Painted Turtle or where water bodies contain suitable hibernation habitat for turtles but is yet to be surveyed.
Links to further information on beaver management:
Beaver Stop: http://www.fsiculvert.com/beaverStop.php
Beaver Flooding Control Booklet from Massachusetts: http://www.wildlifedamagecontrol.net/beaverfloodcontrolbklet.php
BC Ministry of Agriculture, Food and Fisheries, 2005, Constructed Ditch Fact sheet: Drainage Management Guide - No. 16 : www.agf.gov.bc.ca/resmgmt/publist/500Series/543110-1.pdf
3. Guidelines for Forestry Activities:
a) New Road Construction
Many impacts of forestry activities on turtles can be mitigated during the planning phase, including placement of new roads and cutblocks. Road building near a wetland poses potential problems for the Western Painted Turtle: it exposes migrating or dispersing turtles to road kill; it encourages turtles to nest at roadsides, potentially resulting in poor survival of eggs and hatchlings and wasted reproductive effort; and it may bring more public access and vehicle traffic into turtle habitats. Whenever possible, new roads should be placed away from water bodies where turtles nest, bask, or hibernate. Because current knowledge of the distribution and movements of the species in the Alberni Valley is rudimentary at best, it is important to conduct surveys for turtles when planning new roads.
Construction of roads and associated ditches might change precipitation run-off patterns that impact the hydrology of the water bodies inhabited by turtles. In addition to lakes, ponds, and wetlands, turtles probably use streams and creeks to move across the landscape. Turtles will use square culverts with dimensions of 180 by 180 cm (6x 6 feet) as passageways to cross roads, but may be reluctant to use small, round culverts. Until we have a better understating of how turtles move around in the Alberni Valley, waterways that connect habitats occupied by the Western Painted Turtle should be treated as potential turtle habitat.
• Avoid placing new roads in sensitive turtle habitats.
• If roads must be placed close to a water body in known or potential turtle habitat, conduct surveys for turtle nesting grounds so that they can be avoided, and do not encircle the entire water body with roads.
• Follow standard practices when crossing streams and creeks and installing culverts to minimize natural hydrological patterns in turtle habitats.
• Conduct surveys for turtles and nesting habitats before road routes are finalized.
• New roads can be constructed anytime of the year, provided that sensitive habitats identified during ground surveys are avoided.
• Apply BMPs to road planning in the vicinity of water bodies with records of the Western Painted Turtle and to other water bodies where the species might occur.
b) Cutblock Planning and Timber Harvesting
The main threat from timber harvesting is possible loss of nesting areas and damage to riparian zones along water bodies or movement routes. Terrestrial habitats of importance to turtles are riparian zones along wetlands, nesting grounds, and migration routes between foraging, breeding, and hibernation areas. Turtles also move across the landscape among water bodies, but very little is known about these longer dispersal movements. Movement patterns of Western Painted Turtles inhabiting coastal areas, including the Alberni Valley, are virtually unknown, and we must rely on information from other areas. In other areas in Canada, nesting grounds of the turtles were usually located within 150 m from water bodies. Similarly, movements of 10 species of freshwater turtles in the United States suggest that riparian buffer zone width of 150 m is necessary to protect terrestrial habitat around water bodies, and it has been suggested that turtles need at least 300 m of terrestrial buffer. On the Sunshine Coast turtles moved among lakes throughout the summer (M. Evelyn, 2009 per com), which could be the case in the Alberni Valley as well.
• Conduct surveys in water bodies with suitable turtle habitat in cutblocks slated for timber harvesting.
• Retain a wide riparian buffer zone along lakes, ponds, and wetlands occupied by turtles.
• Apply appropriate buffers to all water courses within the cutblock to retain landscape connectivity through riparian zones.
• Conduct surveys for turtles at the planning stage, before the cutblock configuration is finalized. Surveys of water bodies can be conducted anytime during the activity season of the turtles from late spring to early fall. Optimal times are in the spring on sunny days, when turtles are basking and most visible.
• Apply BMPs to cutblocks that contain water bodies with records of the Western Painted Turtle or those with suitable habitat but no precious records. Also apply BMPs to water courses that connect ponds, lakes, or wetlands where the turtles are known to occur.
c) Transportation of Logs
One of the main threats to the Western Painted Turtle associated with timber harvesting is potential road mortality of turtles during their seasonal travels or while dispersing. Turtles are particularly vulnerable to road-kill where a road is located between nesting grounds and water bodies, or where they nest along road sides. Hatchlings that emerge from roadside nests are also vulnerable. Turtles may also travel across roads when moving from ephemeral ponds to permanent ponds in the summer, when they move among water bodies in search of hibernation sites or new foraging area, or when dispersing.
Road mortality of adult turtles in particular may be a problem because turtle populations depend on high adult survival for persistence. In the United States, high road densities have been shown to be associated with male-biased sex ratios of Painted Turtle populations, probably as a result of mortality of females on nesting migrations.
Road mortality along logging roads is difficult to mitigate, especially in areas such as the Alberni Valley where migration routes and travel corridors of turtles are virtually unknown. Research into how turtles move across the landscape is urgently needed. The following guidelines are interim measures in the absence of detailed movement information. If road mortality is found to be a problem at a particular site, underpasses could be considered.
• When using roads that intersect known or suspected turtle migration routes, attempt to travel at seasons and times of day when turtles are not actively moving in the landscape; avoid dusk in June – July, when nesting turtles are likely to travel overland.
• Consider using alternative routes to and from cutblocks in areas where roads intersect important turtle habitats.
• Apply BMPs throughout the active season of turtles from about March to October. It is particularly important to take precautions during the nesting season in June – July, when females are migrating to and from nesting grounds.
• The most important areas are locations where roads intersect known migration routes between nesting grounds and water bodies. However, because so little is known of movements of turtles and the location of nesting grounds in the Alberni Valley, also take precautions and apply BMPs to roads that are adjacent (within 150 m) and parallel to water bodies inhabited by the Western Painted Turtle.
d) Reforestation and Stand Management
Stand management activities include site preparation, tree planting, thinning, fertilizing, and weed and pest management. As a result there will be an increase in people, machinery, and vehicles in the forest and on roads to and from worksites. Stand management activities are expected to have minimal direct effects on turtles. The main threat is from road mortality associated with increased traffic on roads and from machinery that can crush turtle nests if work is to be constructed in sensitive nesting habitats.
• Inform contractors and workers of the location of sensitive turtle habitats, and encourage them to exercise caution when working in or driving through these areas.
• Avoid driving on roads at dusk in the summer when turtles are most likely to be on land and crossing roads.
• Ensure that pesticides, herbicides, or fertilizers are used appropriately and do not enter water bodies.
• Apply BMPs when turtles are active from March to September, particularly during the nesting season (May – July).
• Apply BMPs in turtle habitat, including nesting grounds, occupied water bodies, and potential movement corridors.
e) Road or Site Deactivation:
The main threat from road or site deactivation is from road mortality associated with increased traffic and from machinery that can crush turtle nests if work is done on turtle nesting grounds. In the Alberni Valley, turtle nesting areas have been found on old spur roads and gravel pits located close to wetlands.
• Conduct surveys to locate signs of turtle nesting activity, if deactivation is to occur in known or suspected turtle habitat.
• Avoid disturbing the ground within areas where signs of turtle nesting activity are found during surveys.
• Conduct surveys before any ground disturbance takes place. Surveys for turtle nesting activity can best be conducted from about mid-March to August.
• Apply BMPs in areas adjacent close to water bodies with records of the Western Painted Turtle or where suitable aquatic habitat for turtles exists but is yet to be surveyed.
• There is an opportunity to enhance or expand existing turtle nesting grounds or create new nesting grounds along deactivated roads. Habitat enhancement can be done with relatively little additional effort while machinery is already on site. Enhancement activities would consist of exposing bare soil in suitable locations or by mounding up soil to create a gentle south-facing slope that enhances exposure to the sun. Consult a turtle biologist for optimal site-specific prescriptions.
4. Public Access Management
Threats to turtles from recreational activities and public access are from potential road mortality of turtles moving across the landscape and from disturbance to nesting grounds (see Transportation of Logs on page 52).Turtles are known to use spur roads and old gravel pits for nesting in the Alberni Valley (Engelstoft and Ovaska 2008 and unpublished data). There is evidence of garbage dumping, target practice, and burning at an old gravel pit where turtles nest communally, possibly resulting in damage or disturbance to nests, hatchlings and nesting female turtles. Parking and vehicles that are turning around at the site could damage nests.
• Close public access to old gravel pits and spur roads used by nesting turtles; gate off access or use barriers to these areas to prevent vehicular access.
• Use signage, such as “turtle crossing” where roads intersect known or suspected turtle migration routes; consider information signs to gain community support.
• Close vehicle access to sensitive nesting areas permanently.
• Display road signs only during the activity season of turtles, from March to September.
• Apply closures to areas where turtles are known to nest on old spur roads or gravel pits.
• Apply signage where roads are immediately adjacent to water bodies with records of the Western Painted Turtle or where turtles are known to use roadsides for nesting.
Very little is known of coastal populations of the Western Painted Turtle in British Columbia, although recent survey efforts on Vancouver Island and the mainland coast are starting to fill in data gaps. Information gaps that are most pertinent to forestry practices in the Alberni Valley include the following:
Distribution: Our knowledge of the distribution of the turtles in the Alberni Valley remains rudimentary. It is important to know where the turtles occur, so that BMP guidelines can be applied efficiently and appropriately. We suggest a habitat suitability analysis to identify water bodies with potential turtle habitat, followed by surveys in the most likely areas.
Movements: To mitigate road mortality and locate nesting and hibernation sites, it is important to know how turtles move across the landscape and where potential problem areas are located. We recommend radio-telemetry studies to follow movements of individual turtles at selected sites. In addition, we recommend surveys for turtle nesting grounds in the vicinity of each water body with records of the species.
Timing seasonal activities: The timing of nesting, hatchling emergence from nests, and hibernation are poorly known in the Alberni Valley. Although the general pattern is likely to be similar to turtles in other areas, we need more detailed information to apply mitigation measures more efficiently during an appropriate time-window. We recommend following seasonal activities of turtles through surveys of known nesting areas and through radio-telemetry studies of turtle movements (see above).
- ↑ Ovaska, K.& Engelstoft, C. 2009. Best Management Practices for Island Timberlands.
- ↑ Engelstoft C and Ovaska K. 2008. Western Painted Turtle Surveys on Galiano, Pender, and Vancouver Island, 2008, Including Surveys in Selected CRD Regional Parks. Report Prepared for CRD Parks and Habitat Acquisition Trust, Victoria BC. (Available at: http://www.hat.bc.ca)
- ↑ Taylor GM and Nol E .1989. Movements and hibernation sites of overwintering painted turtles in southern Ontario. Can. J. Zool. 67:1877–1881.
- ↑ St. Clair RJ and Gregory PT. 1990. Factors affecting the northern range limit of painted turtles (Chrysemys picta) – winter acidosis or freezing. Copeia 1990:1083–1089.
- ↑ Blood DA. and Macartney M. 1998. Painted Turtle. B.C. Ministry of Environment, Lands and Parks, Wildlide Branch. 6pp. Available at: http://www.env.gov.bc.ca/wld/documents/pturtle.pdf
- ↑ Kaye DR, Walsh KM, Rulison EL and Ross CC. 2006. Spotted turtle use of a culvert under relocated Route 44 in Carver, Massachusetts. IN: Proceedings of the 2005 International Conference on Ecology and Transportation, Eds. Irwin CL, Garrett P, McDermott KP. Center for Transportation and the Environment, North Carolina State University, Raleigh, NC: pp. 426-432.
- ↑ COSEWIC. 2006. COSEWIC assessment and status report on the Western Painted Turtle Chrysemys picta bellii (Pacific Coast population, Intermountain-Rocky Mountain population and Prairie/Western Boreal - Canadian Shield population) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 40 pp. (Available at: www.sararegistry.gc.ca/status/status_e.cfm).
- ↑ Bodie JR. 2001. Stream and riparian management for freshwater turtles. Journal of Environmental Management 62:443–455.
- ↑ Semlitsch, R.D. and J.R. Bodie. 2003. Biological criteria for buffer zones around wetlands and riparian habitats for amphibians and reptiles. Con. Bio. 17(5): 1219-1228.
- ↑ Sexton OJ.1959. Spatial and temporal movements of a population of the Painted Turtle, Chrysemys picta marginata (Agassiz) Ecological Monographs, 29 (2), 113-140.
- ↑ Tingley R. and Herman TB. 2008. The effects of agriculture and forestry on the distribution, movements and survival of wood turtles in an intensively managed landscape. Report prepared for the Nova Scotia Habitat Conservation Fund. (Available at: http://www.gov.ns.ca/natr/wildlife/habfund/Proposal/final07/Herman_woodturtle07.pdf)
- ↑ Steen, DA and Gibbs JP. 2004. Effects of roads on the structure of freshwater turtle populations. Conservation Biology 18(4):1143-1148.
- ↑ Engelstoft C. and Ovaska K. 2008. Western Painted Turtle surveys on Galiano, Pender, and Vancouver Island, 2008, including surveys in selected CRD Regional Parks. Report prepared for CRD Regional Parks and Habitat Acquisition Trust, Victoria B.C. (available at: http://www.hat.bc.ca)