Turtle Conservation: should we focus on adults or hatchlings?

Jun 8

Conservation of any animal has a lot of questions related to how, where, when, and even why. For turtles, we know some of the things we need to do include: protect their habitat, decrease the adult mortality, and increase hatchling recruitment (aka number of hatchling turtles that survive and have a chance to make it to adulthood). But, which of these actions will make the biggest impact?

In this month’s blog post we are going to compare the last two points and explore how protecting adults vs increasing hatchlings helps turtle populations. Yes, this is a discussion with no clear answer except that the best approach is typically always an approach that combines many options.

The key but financially difficult approach

Given turtles have been around for over 200 million years you can imagine that they have a pretty good evolutionary ability to survive and their populations historically have been pretty stable. What they haven’t been able to evolutionarily deal with is our fast human growth, particularly of roads, and the impact we have on adult turtle survivability.

So, when it comes to what turtles are more sensitive to (aka what will impact their populations more), it is the loss of an adult turtle. We can think about this further. Turtle mothers leave their offspring to survive on their own in a nest that is not very deep under ground or protected in anyway. Thus, predators can easily find and eat those eggs before they even have a chance to hatch. In fact, it is natural for 50-80% of turtle nests to be predated in the wild.

Adult turtles have a natural protection, their shell, and not many predators. Thus, evolutionarily they haven’t needed to adjust for a declining adult population. That is until we came along. So, if we really want to help turtle populations ‘spring back’, one of the best methods is to decrease adult turtle mortality.

Example: research studies in Algonquin Provincial Park have shown us: a snapping turtle population hadn’t recovered even 20 years after a large predation event on adults; with less than 1% of snapping turtle hatchlings reaching sexual maturity (which occurs at ~20 years old), the math indicates it would take one adult snapping turtle ~59 years to have one offspring reach sexual maturity, effectively replacing itself in the population.

Of course, the biggest factor to adult turtle mortality will change from place to place. Regardless of where you are though, roads will always have a big and negative impact. How do we protect turtles from roads? Through mitigation involving exclusion fencing, crossing structures, and alternative nesting mounds (read more about road mitigation with this blog post). Things that require lots and lots of $$$$$.

While we advocate and fundraise for road mitigation what else can we do to help our adult turtle populations? BRAKE FOR TURTLES! Just like the bumper stickers say: when it is safe for you to do so, help move turtles off roads. TAKE INJURED TURTLES TO GET HELP! If the turtle you are helping has been recently injured then take them to a rehabilitation centre - turtles are crazy resilient and able to bounce back from large injures with some help (find groups helping turtles all over Ontario here).

Learn more about how you can help turtles you find on roads with our Turtle Trauma Response Program.

The ‘easier’ and public engagement approach

In some ways protecting turtle nests to increase hatchling recruitment can be considered easier than trying to protect the adult turtles. All you have to do is place a nest protector box on a nest you find and tada it’s protected from predators while for adults you have to install exclusion fencing and transport them to rehabilitation centres.

Yes, natural predation rates of turtle nests are very high (50-80%) so why even protect them? Well, many human populated areas we have artificially increased predator numbers, reduced nesting habitat, and caused predation rates to be closer to 100%. Thus, nest protection still has a place in turtle conservation where almost all nests are predated or where the adult population has become too small to adequately reproduce.

Now, combining nest protection with adult turtle protection is a win-win! Keep the adults alive so they can keep reproducing and help the next generation get a little bit of a head start. You could even go the next step and set up a ‘head starting’ program (where turtle hatchlings, under special permits, are incubated and kept for some period to help prepare them for life). However, when you start getting into incubation and head starting programs that is where money and time come into play (is that money and time worthwhile? that could be up for debate and really depends on your local situation).

A big pro to turtle conservation through nest protection is the public engagement side of things. Nest protection programs can be great on-the-ground volunteer opportunities to engage and educate the public.

The GOAL

What ever your approach to turtle conservation we are all trying to do the same thing - help boost their numbers where humans have negatively impacted populations! In our conservation efforts do you ever wonder if we are interfering with nature? If you have, then check out this previous blog post.