Transient Identification in Eastern Box Turtles

Mistaking Transients, Mistaking Residents, and Transient ID

If found at the blue dot on 8/13/14 and tracked until 9/7/14 to a GPS distance of about 0.8 miles, this turtle might surely be identified as a transient traveling through the population.

The assumption might be that this transient has just crossed the road into the resident population, traveling east to west, coming from who knows where.

If the limited tracking is suspended at this point and not later resumed, this turtle would likely be recorded as a transient.

(This turtle is an adult female)

But this turtle is in reality M4, a large, old female that has, in this season (2014) , traveled 2.6 miles, and has been tracked as a resident member of this local population since 2009. Here are the graphics of her previous years travels.

For some reason, this season she decided to travel well outside of her normal primary activity area (the powerline ROW).

She traveled to the highway (but never crossed), reversed direction traveling over the ridgetop into the adjacent hollow and found a tiny perennial seep and soaked in a small 1/4" deep pool of water for 18 days before heading upslope and crossed the ridgetop into another drainage where she found another tiny pool of water to soak.

It was evidently too late in the season for M4 to make it back to her primary activity area, but she did return in 2015 and hibernated near her normal hibernation spot that fall.

EXAMPLE 2 (2014)

But this is really turtle M6 who has traveled 1.6 miles so far this season (2014) and crossed the highway west to east into the meadow to nest as she does most summers. M6's routes from all seasons shows she is a dedicated resident of this population.

If found at the blue dot in the dense thorny growth of the meadow on 7/10/14 and tracked until 9/12/14, a distance of 0.8 miles, this turtle might be identified as a transient, despite being a female.

EXAMPLE 3 (2014)

This small adult male turtle might have been found on 5/9/14 and tracked to 5/25/14 (a distance of 0.6 miles).

But this is turtle M21 who has traveled 2.0 miles this season (2014) and has been tracked for many seasons utilizing the same general routes. He has never yet been observed crossing the road.

EXAMPLE 4 (2014)

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If found at the blue dot location in the power line ROW, this small male might have been tracked 6/11/14 to 9/6/14 and traveled 0.8 miles, and identified as a transient.

But this is M14 who has been tracked since 2010 and has traveled 2.2 miles so far this summer. This season (2014) he has traveled far outside of his normal activity area and for the very first time, crossed the highway and eventually found a small shallow creek where he soaked for 27 days before moving on, and hibernating in the woods south of the pond.

EXAMPLE 5 (2014)

But this is turtle M19 who has traveled 4.4 miles this season (2014) and was tracked for 8 complete seasons and frequented the hollow and the ridgetop.

Or if found on 6/12/14 and tracked eastbound until 6/30/14, (0.5 miles)

If this male was found 5/25/14 and tracked westbound until 6/12/14, (0.4 miles), he might be identified as a transient.

The graphic and caption to the left was copied from a thesis: a 2010, single season study of 9 Box turtles at a site in W. Va. Influence of Season and Sex on Terrapene c. carolina Movements: An Observation of a Population in West Virginia, Nathalie Caroline Aall

Of 66 total locations recorded for turtle BT9 (red dots), only 9 were outside of an otherwise tight group of over 45 locations (at least 45 days), but BT9 was characterized as a transient and consequently "....home range data for this individual were not analyzed..."

This appears to have been a serious miscalculation, and unfortunately travel data for this potentially important local population resident was ignored instead of being followed throughout the season.

Even a basic understanding of a transient individual's travels through a local population would have eliminated the mistaken idenitification of of this resident member.

Continued tracking and observation of the 4 females, and other males in future seasons would likely locate turtle BT9 while mating or meeting with other residents.

'Resident individuals occasionally make off-area excursions lasting weeks to months, and return to their primary activity area and hibernate there.'

EXAMPLE 1 (2014)

Studying transient Eastern Box turtles is tough. The amount of time and energy expended in tracking transients can be enormous and detract from studying residents. But perhaps the most difficult job in studying transients is identifying them when they are encountered. There is probably no way to search for transients, and once identified as a transient a newly found turtle might already be long gone and out of tracking range. Some researchers have estimated that as many as 26% of turtles found in a study area could be transients, but a more realistic estimate might be around 6%.

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M17 "Superturtle"

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A composite of all turtle routes 2008 through 2020 in this study area showing the routes of transients leaving the resident population after traveling through.

Turtles M17, M20, M31 and M26 were lost after their radio signals could no longer be found. Other turtles recored and tagged and later lost and never re-found, may also be transients. Info labels and message vials are now being attached to suspected transients in case they are lost and later re-found.

For scale, this photo represents about 4300 acres

The tenacity of a transient to travel long distances, and in a particular direction has yet to be widely studied.

Turtle M31, M31A, M31B, M31C and M31D (all the same turtle) was found 7/30/14 in the power line ROW and was relocated back to the original location 5 times during the season. He was eventually lost when he out-distanced his radio's range.

Mistaken Identity: Real Life Examples