Habitat Enrichment (or Basking Sites Go a Long Way)

Hello from Kelly at Think Turtle Conservation Initiative

One of my favorite sights during turtle season is catching a glimpse of turtles, most often painted turtles, basking on a log or piece of driftwood in a lake. Although they are not there for the purposes of entertaining me, I can’t help but smile and appreciate the peace of mind that comes with seeing them on a log in the water rather than attempting to cross a road. When there is a group of them on a log, known as a bale, well, that just makes my day! I bet you feel the same.

TEMPERATURE REGULATION


Basking logs and/or comparable basking sites are an important part of wetland habitats. Turtles, amphibians, birds, and many other animals use them to rest and/or temperature regulate. Basking sites are particularly important for turtles being ‘ectothermic,’ meaning they cannot maintain a constant body temperature and therefore rely on outside sources to regulate their body temperature. Their body temperatures changes with the environment around them. If the environment is cold, the turtle must move to a warmer place.

To aid in regulating their body temperature you will see turtles basking on logs in the sun and sometimes unfortunately on the warm pavement/asphalt of the roads.

Just as a point of interest, birds, mammals and some fish (eg. tuna, billfish, swordfish and some shark species) are ‘endothermic’ meaning they maintain a constant body temperature independent of their environment as do humans. You may be more familiar with the terms cold-blooded (ecothermic) and warm-blooded (endothermic) but the scientific community has moved away from this terminology as it suggests there are only two categories of body temperature which is not the case as animal temperature varies by species and even within species.

WHERE TURTLES BASK


Turtles source out locations for basking that often consist of fallen trees or exposed rocks, logs, dead heads, emergent vegetation, etc. A site chosen for basking would be selected because it is ideally positioned in the water to optimize sunlight exposure and it is not too far from the shoreline; open water will make turtles feel vulnerable. Turtles do on occasion bask on a shoreline or sand but this would be in circumstances of their choosing when they do not feel vulnerable to predators. Sometimes turtles get creative and bask on docks, rafts, driftwood, exposed culverts, discarded items floating in the water, etc.

Unfortunately, the roads hold heat and are viewed by snapping turtles in particular as an ideal location on land for gaining heat from the substrate they are in contact with through a process known as, ‘conduction’. As a turtle species that is not particularly comfortable on land and spends most of their time in the water the snapping turtle is more inclined to venture out of the water only in times of absolute necessity such as nesting, a habitat disturbance, mating season, perhaps travelling to a different seasonal habitat and on occasion basking.

At shallow water depths, the sun’s rays can reach a turtle underwater and solar absorption occurs. Some turtle species may even engage in surface basking, floating for more direct sun exposure. Absorption is more difficult in water, a compound that instead of sharing heat, likes to keep it for itself. Most turtle species would rely more on basking on a log or other such site.

Yes, turtles like natural elements for basking but they are known to bask on basking sites that property owners have constructed and invitingly provided. Just as an example of how turtles do seek out locations to bask even those that are not naturally sourced, a photo was recently posted of a painted turtle basking on a recliner someone irresponsibly disposed in a lake. It really isn’t funny but illustrated how a turtle will adapt and make use items available to bask on. Last I heard, efforts to extract the recliner were being arranged. There is no guarantee turtles will use a newly introduced basking site that is largely to do with where the basking site is positioned. If the turtles feel threatened by predators they will steer clear of the introduced basking site.

WHY TURTLES BASK


Turtles engage in water basking and also land basking as it enables them to absorb heat from the sun through their body. Turtles rely on the sun’s rays to help raise their body temperature, to get their metabolism moving and to produce vitamin D an essential nutrient for healthy living and keeping their shells healthy.

Basking in the sun allows turtles to dry out their shell which helps prevent parasites from attaching for a period of time. This can also help relieve them of ‘Ectoparasites’, the scientific term for harmful organism’s on the outside of an animal, such as leeches. Leeches are a blood-sucking ectoparasite that can cause anemia in turtles if they parasitise for an extended period of time. Drying out in the sun and the direct sunlight is not a hospitable environment for leeches, adios leeches!

Further to this the sun can also have a rejuvenating effect on the algae that has grown on their shell by causing algae to dry out and fall off, allowing the turtles shell some relief from any parasites that may have been present if the algae growth was abundant. On the plus side though algae growth on a turtles shell has benefits and plays a role in providing turtles with protection by way of camouflage. Algae growth has also been described as a garden providing food and protection for small fish and other aquatic organisms, thus contributing in some regard to maintaining the algae and parasites load present. As always the interrelations of an ecosystem unquestionably have it all worked out.

It is believed that turtles will bask together to gather more heat and pile on top of one another in an attempt to change angles and maximize exposure and/or get closer to the heat source. Turtles can be seen with their legs stretched out again to maximize heat absorption.

SYMBIOTIC RELATIONSHIP


Researchers have identified that Painted turtles and snapping turtles appear to be the the only reptile pairing that share a symbiotic relationship. This is a special type of interaction between species sometimes beneficial to one and harmful to the other or in this case beneficial to both. The painted turtles are known to eat the leeches that have attached themselves to snapping turtles and the snapping turtles benefit from this, all balances out in the end making for a harmonious relationship.

NO TURTLES BASKING


From time to time people tell me that they have noticed that the turtles that once basked in a particular area have disappeared. Through the years many lakes have become entirely devoid of basking logs, often to do with shoreline development or in some cases to do with natural elements such as flooding or storms dislodging otherwise perfect natural basking sites such as logs, etc.

If you have ever wondered why turtles at one time regularly basked at a particular site and then seemed to disappear this could alternatively be to do with a disturbance in the area such as land development or to do with animals that are possible predators moving into the area or it could be the result of increased human activity, e.g. recreational activities, construction or shoreline development. Sadly in some incidences this could also be attributed to a gradual population decline in the localized area if situated in the vicinity of a high risk road mortality location that turtles would access during their seasonal activities.

NEW BASKING SITES


So all in all, a little sunshine goes a long way for turtles! Property owners can help turtles by introducing basking sites into lakes or bodies of water on or adjacent to their property that are known to have turtle activity and little if any sites for basking. Sometimes what may be viewed as a decline in turtle population in a specific area may in fact be down to the absence of natural basking sites, perhaps a perfectly positioned log or piece of driftwood was removed or drifted away.

I have included a photomontage of various basking sites constructed by people looking to enrich turtle habitat. It is very important to think about the materials being used to construct basking sites. These considerations must take into account the effect the materials could have on the turtles coming in contact with them, e.g. treated wood should not be used, if using straw/hay make sure it has not been treated with pesticides, etc. Also, one must think about the effect the materials used will have on the body of water the basking site is introduced into as well as the aquatic ecosystem it supports.

Ideally using natural and/or untreated materials is best such as a log, a fallen tree or drift wood found in the vicinity of the basking site location is best if possible. Well thought out platforms and other basking installations can be constructed and be just as effective and appreciated by the turtles.

It will be necessary to anchor the basking installation in some way so it does not float away. Again, you should consider materials used. Options may include; natural jute rope, cinder block, concrete anchor/plug, duckbill anchor if you can afford, plastic 4 litre jugs with sand but there may be concerns about plastic. Researching anchoring materials and procedures for docking system online may provide additional ideas that would be helpful in such an undertaking.

So, keep in mind this is a ‘Do It Yourself’ type project with the the aforementioned offering some general information you may find helpful and importantly making mention of considerations to do with materials used whether purchased, re-purposed or natural sourced. You may find some ideas online, improvising and getting creative to help the turtles on this one me thinks. During your travels take note of the types of aquatic areas, distance from the shore, etc. turtles you observe basking seem comfortable with. I read about a gentleman that built a basking raft and lined the entire underside with cut up pool noodle pieces that he secured with nailing strips which also gave him a place to tie an anchor rope.

Note: Please make sure a basking site introduced into a lake for example is within an area you are allowed access, if not seek the necessary permission especially if shared access. Always consider safety as well, a basking site near a boat launch in some circumstances may not be practical for several reasons and could be a safety concern for boats.

Photos (left to right, top row) – Bale of hay, Turtle’s Barbie dream house basking site & rustic/driftwood platform. Photos (left to right, bottom row) – Cedar platform, sack of straw & naturally sourced log with cement weight.

TURTLES DO WHAT TURTLES DO


Please note that no matter how thoughtfully constructed or inviting your basking site may appear turtles may not use it. In some instances it may take time, hopefully that is the case. Turtles are weary and feel vulnerable in open water and for good cause. Something new introduced into their environment may be steered clear of until it has been sized up and in time transitions from being something new to part of the local aquatic landscape.

I’m thinking, adopt a modified ‘Field of Dreams’ outlook, “If you build it, THEY will come.” Anyway, my brand of optimism. In the end it is the turtles that will make the decision.

If anyone has photos of basking sites they have successfully introduced into turtle habitat please share your photos. Always great to see the ideas people have come up with.

It would be greatly appreciated if you could please share this information with your families, friends, neighbors, work colleagues and ask them to do the same.Thank you for reading this post and your efforts to help the Ontario turtles! Please be safe on the roads!

Kindest Regards,
Kelly Wallace
Think Turtle Conservation Initiative
Cell: 647-606-9537
E-mail: thinkturtle@yahoo.com
Facebook: thinkturtleci
Username: Wallace Kathleen Kelly
Post: #338

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