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The EFM Notebook

Photo by Robert Badger and Nita Winter

A Commentary on What’s New and Newsworthy

The EFM Notebook is a resource for information about the environment and climate change. In each post I’ll bring you news and insights from experts, activists, and policy makers and I will suggest ideas for moving towards environmental sustainability. Subscribe to the EFM email list and we will send you new Notebook posts when they are published.  #EFMNotebook

by Susan Holloway | Bio


NOTE: EFM Notebook is best viewed horizontally, when using your phone.


The Plight of the Pond Turtle and Successful Efforts to Reintroduce Them in the West

31 Mar 2021 8:25 AM | Gayle Marsh (Administrator)

Time for a turtle quiz! True or False?

 
   
  A glimpse at turtle anatomy

1. Baby turtles are extremely cute.

Answer: True!

2. Turtle fossils have been found from the Triassic period.

Answer: True! Turtle fossils from 220 million years ago show that turtle anatomy in prehistoric times was nearly identical to that of modern turtles.

3. Turtles are among the only animals that can breathe with their butts.

Answer: True!!!! Many turtles can use their cloaca to breathe when they are underwater. Essentially the cloaca doubles as a set of gills, sucking in water and absorbing the oxygen within.

4. Native turtles are plentiful in California’s lakes, ponds, and rivers.

Answer: False! The only native freshwater turtle in California is rapidly disappearing and is now listed as a species of concern by the US Fish and Wildlife Service. The situation is also dire in Washington and Oregon.

How did you do on the quiz? If you are like me, you may have gotten the first two right but were dead wrong on the third and fourth. 

So let’s take a little time to learn about these creatures that are so familiar and yet exotic. And let’s find out what steps are being taken to save them from extinction. (Spoiler alert: I won’t be going further into the topic of cloacal respiration but you can look it up if you are interested.)


Status of Native Turtles in Northern California

Western Pond Turtle  

 
On the West Coast of the US, the only remaining native freshwater turtle is the Western Pond Turtle (Actinemys marmorata) and they are in deep trouble. The US Fish and Wildlife Service considers the Western Pond Turtle a “species of special concern,” and they are listed as an endangered species in Washington State.

Why are these once ubiquitous creatures disappearing?  One problem is competition from the red-eared slider (Trachemys scripta elegans). These are the turtles sold in pet stores; however, they are sometimes "released to the wild" by owners who can no longer care for them. Red-eared sliders are bigger and more aggressive than the shy pond turtle and compete ruthlessly with them for food. Also, they harm pond turtles by taking up their basking space. This is a problem because turtles depend on the sun to regulate their body temperature, and typically spend hours every day basking on rocks and logs.

  Red-eared slider: Nemesis of the pond turtle
   
Other invasive species are a menace as well. The small and vulnerable baby pond turtle is particularly at risk for predation by non-native bullfrogs as well as small-mouth and big-mouth bass. 

Habitat loss is another problem for the pond turtle in areas that are urbanizing. In addition to an aquatic environment, where pond turtles spend most of their time, the females need to access sunny, grassy areas for nesting. In Marin, fire suppression efforts have created a shadier environment, making it harder for them to find good nesting sites. The further they travel the greater their risk of being hit by cars. Additionally, agricultural and vegetation management activities can disturb the habitat and destroy their nests. 


  Adult turtles are secondary and tertiary consumers in pond ecologies
 

Head Start for Turtles

The absence of an important species like the pond turtle can have a profound effect on the surrounding ecosystem. Juvenile turtles provide a source of food for larger predators, and juveniles and adults feed on various invertebrates and insects. Moreover, as denizens of the water and the land, turtles are important indicators of the health of these ecosystems.

So, in addition to managing invasive species and preserving habitat, what else can be done to prevent the pond turtle from going extinct?

I recently attended a Golden Gate National Parks Conservancy webinar describing current efforts to reintroduce the pond turtle to southern Marin County, where it had not been seen since 1998. The Head Start Project, a joint effort by multiple local partners, began four years ago and will continue for one more year. It is one of many similar projects being conducted in all three Western states. 

Pond turtle in paradise  

The five-year project has proceeded in three phases: hatching and rearing young turtles, releasing them, and monitoring their welfare.

The first step was to locate nests and “borrow” eggs for relocation. Park staff in Pt Reyes, where there is a fairly stable population of pond turtles, searched high and low for turtle nests. This was no easy task because these turtles can roam as much as one third of a mile from their water source in search of a good spot for a nest. The nesting process begins with the female excavating a hole, depositing from 1 to 13 eggs, and then filling up the chamber with soil and plant material. To learn more, read this excellent article, which is accompanied by great photos and a video of the nesting process. 

  Pond turtle hatching at the Woodland Park Zoo in Washington State  
  Released turtle  
  Two-month-old turtle swimming at SF Zoo  
  Biologist Gabi Dunn releasing a turtle  
The second step was to take the eggs to Sonoma State University for their incubation period. In the wild, incubation takes about three months, depending on the conditions. Typically, juveniles that hatch in the summer make their way to water soon after emerging; those hatching in the winter may stay at the nesting site until the weather warms up. In any case they are on their own, with no help from mom.

In the Head Start project, the newly hatched babies were transmitted to the San Francisco Zoo where they were cared for by zoo staff for about a year. Under these protected conditions they were able to grow three times as fast as turtles in the wild, quickly becoming “bigger than a bullfrog’s mouth” and thus able to avoid the clutches of the most dangerous predators. 

To keep track of these precious creatures, staff glued a radio transmitter to the shell, each with a unique frequency so that the individual could be easily identified. The turtles also had an ID number painted on their shell.

When the release day arrived in this past year, 20 of the youthful turtles were transported to the Rodeo Lagoon Watershed and 14 were taken to the Redwood Creek Watershed (see map for location of these watersheds). Another 7 were released in several ponds in Point Reyes. Twenty turtles had already been released through the program in the Redwood Creek Watershed in a previous year.  

Each turtle was monitored on a weekly basis to be sure that it was adapting successfully to its new environment. Later in the year, the staff set out net traps to catch the turtles for weighing, measuring, and a general welfare checkup, as well as to repair the transmitter if necessary.

So far, thanks to all of this meticulous care, most of the turtles released for the Head Start project are doing fine. Monitoring will continue for the fifth and final year of the project. Similar programs in Oregon and Washington have resulted in the successful release of over a thousand pond turtles.


What Can You Do to Help the Pond Turtle?

Use iNaturalist to monitor wildlife

You can start by using the iNaturalist app to document the location of any and all turtles that cross your path. You can do this citizen science work on your own or in coordination with established projects. For example, visitors at the MidPeninsula Regional Open Space Preserve have been asked to record turtle observations for the Midpen Biodiversity Index on iNaturalist.

  Turtles on TV: Friendly, mellow, and funny….

Turtles aside, this app is very easy to use and a fun way to increase your engagement with the wildlife around you. Your kids might think it would be fun to identify a species commonly found in your area and then see if they can go out and find a member to photograph and add to the database. 

Think carefully before acquiring a pet turtle

If you are tempted to get a pet turtle (or any other pet for that matter) do a lot of research about its care before you take the plunge.  I learned this the hard way. When my son was 8 and in the thrall of four fun-loving cartoon ninja turtles, he asked for an aquatic turtle, and I naively agreed to get one. 

Turtles in real life: Grouchy introverts that live forever

Fast forward 26 years…the turtle still resides in my home, although my son himself has not lived here since 2005. First lesson learned: Turtles live a really long time if you take care of them properly. Second lesson learned: Taking care of them properly involves a lot of work. 

If you do have a turtle that you can no longer care for, don’t set it free where it will terrorize the native turtles. Instead, find a rescue organization like Creepy Critters Rescue that will care for it. 

Support programs to reintroduce turtles

Keep your eyes open for a turtle monitoring program such as that sponsored by the Marin Municipal Water District. In the past, MMWD volunteers have learned to monitor turtle habitat conditions, record their behavior, and educate the public during the spring when they are most visible. This is a flexible activity that families can do together, so it is a good opportunity to help children learn about wildlife in their area.




That’s it for this installment of the EFM Notebook! Thanks to Rob Badger and Nita Winter for sharing Rob’s beautiful image. Check out their award-winning book or visit their website to see more!



         
   



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