Project Updates
More frequent updates will be posted on our Facebook page:
September 5, 2016--Hungry hungry turtles.
Our first publication relating to the Project was just released yesterday. Sasha Tetzlaff and Nicholas Schiltz published a note in the peer-reviewed journal Herpetological Review on an observation of a female box turtle scavenging a gravid Eastern Hog-nosed Snake (Heterodon platirhinos) at Fort Custer. Hog-nosed snakes have a fascinating repertoire of behaviors. For example, if they feel threatened, they flatten the skin around their neck to appear larger and more intimidating. This is similar to the "hooding" behavior of cobras, though a bite from a hog-nosed snake poses no real danger. They also inflate their bodies and make a loud puffing sound, which has given them the local name of puff adder in some areas. Again, unlike cobras, hog-nosed snakes are nowhere near as dangerous as the African Puff Adder that is highly venomous. If intimidation doesn't work, they play dead to confuse would-be predators, but that clearly didn't work in this case. Box turtles love their protein, and a dead snake is an easy and risk-free way to get it. We think the snake was killed by a predator (likely a raccoon) while looking for a nesting site, as it had at least seven eggs inside of it. Why the predator only ate half of the snake and also didn't consume the eggs is somewhat puzzling. Hog-nosed snakes and box turtles both dig their nests in somewhat elevated, dry, and sandy habitat. So we assume she took advantage of an easy meal after also nesting in the area, as we found a depredated box turtle nest just over a meter from where we found the turtle eating its meal. Events like these may seem strange or even disgusting to some. However, it's just nature doing what nature does, and small bits of information like this are valuable to science. Knowing what animals eat and how that may influence their interaction with other species is useful to understanding whole ecosystem processes. |
August 28, 2016--Home sweet home.
All of the turtles have now been placed in either an enriched or control environment and are doing well. The turtles are cared for daily and weighed and measured once a week. They're growing fast! Our goal is for them to get as big as possible before we release the first wave of turtles at Fort Custer next year. Many are voracious eaters and will eat anything and often, while others are still deciding what their favorite food is. For the gluttons, mealworms (which are actually beetle larvae) are a favorite. Some of the daintier turtles haven't quite graduated to mealworms just yet and prefer the much smaller and wigglier blackworms. We calculated a body condition index for all turtles in each treatment (enriched or unenriched) as soon as they were moved into their new living conditions. Not surprisingly--but good for the project from a statistical standpoint--we found no difference in body condition of turtles in either treatment. However, now we have baseline data to compare body condition of turtles in each treatment as they grow, and if we find differences in the future, we may be able to attribute it to their rearing condition. So, the turtles will sit tight in their houses as we provide excellent care for them and prepare for running behavioral trials on them in the coming months. |
August 12, 2016--Lots of baby turtles!
The incubation regime worked! We have 32 baby turtles in total awaiting to be moved to their new homes where they'll reside for the next 10-22 months. They came much earlier than expected. Most Eastern Box Turtles have an incubation period in nature as short as 60 days to over 100 days, but ours hatched in an average of 55 days, with a range of 51-58 days! Many of the eggs didn't make it, which is completely natural and expected. For those that did hatch, most are relaxing in their eggs absorbing the remainder of their egg yolk that nourished them in the later stages of development. They'll live on the yolk reserves for a week or more, and then they'll hopefully start taking to eating live prey such as mealworms or blackworms, as hatchlings are quite carnivorous. |
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June 30, 2016--Lots of eggs.
The good news: We hit our mark for finding enough eggs for the project. The "bad" news: None of the pen girls obliged us by laying their eggs in their outdoor enclosures. Nick was finding copious amounts of other turtles around Fort Custer naturally nesting in the early mornings or late evenings in June, but none of our girls were laying around that time. So, we decided to let them go and do their thing on their own, and did they! As each female was released, they marched one by one from the area of the pens to a sandy, elevated area only a hundred meters or so from the pen. We didn't want to disturb them more than we already had, so we didn't follow them. But we knew exactly what they were headed to do: dig a nest. When we returned to the field site the next morning, many of our girls were either in the process of digging a nest or actually laying eggs. The unfamiliarity of the pens may have led them to resist laying in there, and wild reptiles are such creatures of habit. Nick is highly-skilled at finding subtle cues of the presence of a recently dug nest in prime nesting habitat (elevated, dry areas with loose soil) and found nearly all of the eggs we needed for the project in that manner. Way to go, Nick! Our eggs are now being incubated in, of all things, a chicken egg incubator. If we're lucky, we should have adorable little hatchling turtles emerging in 60-90 days! |
June 15, 2016--Lots of females.
We hit the mother load for turtles and have captured well over fifty turtles this field season so far. 13 of those are gravid. We're patiently awaiting them to lay their eggs. They are residing in swanky outdoor enclosures that Sasha and Nick spent hours and hours in the heat and fighting biting flies building for them. Box turtles are notorious diggers, so the framework of the pens are made of aluminum flashing buried about six inches or more into the ground. Another layer of chicken wire buried into the ground as well should prevent them from reenacting Tim Robbins' escape from Shawshank Prison. The pens are about a square meter each, complete with food, water, shelter in the form of leaves, logs and covers to keep predators out; raccoons are amazingly adept at using their nimble paws to break into tight places, and the girls are sitting ducks, so we're taking every precaution to keep them safe and sound. So far, the "pen girls"--as we've aptly named them--seem content in their new, temporary homes. They're eating earthworms and fresh produce daily (though they much prefer the earthworms), basking and hiding--all things wild turtles should be doing. We even provided them each with a nesting box full of sand to lay their eggs in when the time comes. While they're in their micro natural environments, we're attaching small temperature loggers about the size of a couple of dimes stacked on one another so we can record their body temperatures. The logger is taped to the top-rear of their shell and records a temperature every ten minutes. Since they have eggs developing inside of them, they should all maintain pretty high body temperatures to facilitate proper egg development. |
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May 23, 2016--The Project begins.
We're off! The turtles have been emerged from their overwintering sites since mid-April and are crawling all around Fort Custer Training Center. Sasha Tetzlaff, Ph.D. student at University of Illinois, along with field assistant Nick Schiltz are scouring open and edge habitat for gravid (carrying eggs) female turtles. Despite mortality from prescribed fires and an assumed over abundance of raccoon predators, Fort Custer seemingly has a rather robust population of box turtles. They have been much easier to find than we expected. Still, conditions have to be right to find turtles. Warm temperatures--but not too warm--with a bit of an overcast sky and a somewhat moist ground seem to be perfect times to find turtles. When we find a turtle, we take a GPS point of its capture location, measure its carapace (top shell) and plastron (bottom shell) length and width, weigh and permanently mark the turtle's outer edge of its shell with a file. Marking a unique combination of spots on the shell using a numbering system lets us know who is who. The majority of captured turtles have been previously marked by researchers working at Fort Custer in years past, so it's great to see them surviving into subsequent years. However, many are also missing back feet or are badly scarred on their shells--likely from those pesky raccoons. If we find a male, we put them right back where found after processing them. If it's a female, we feel around in their abdominal cavity for the presence of eggs. If she doesn't have eggs, she gets turned loose as well. If she does have eggs, we'll temporarily hold her in an outdoor enclosure until she lays her eggs, which will be incubated and hatched for captive rearing. Our goal is to capture around 12 gravid turtles which should provide around 50 eggs (clutch size is normally 3-5 eggs per female) for this study. |
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