Trackable Travel Rates-Part 3, Attrition and Survivorship

[+shellbadger]

It is not surprising to anyone having trackables that some last longer than others. As mentioned in Part 2, I measure survivorship in terms of drops achieved.

 

Refer to the survivorship curve (blue line) in the figure below. The curve shows the percent of the total trackables released that have reached a specified drop. This curve is automatically regenerated as new drops are entered on spreadsheets…it was current as of this writing. The choice of a 30-drops minimum for study inclusion was based on the histories of my trackables. Circumstances influencing that choice are indicated by arrows on the curve.

 

There are two things that must be understood about the curve. First, every trackable released contributes to it. Secondly, at least two-thirds of those trackables are missing. A missing trackable is defined as one having no logged retrieval-, visit-, or release-log for three years. For this particular project, I ignore increasingly-bogus discovery-logs as they will sometimes continue for years after a travel bug has disappeared. I will discuss what constitutes “missing” in more detail in a project later this year, but for now the reader must accept there is a less than one percent chance a that one of my trackables will resume activity after three years (see the Drop Interval Table in Part 4). Thus, because most of the bugs are inactive, the shape of the curve is fixed and has not materially changed since about 2017, except for the attenuation of the number of drops achieved…now one trackable at 88 drops.

 

The shape of the curve is determined the by loss of trackables between drops, losses that incrementally reduce the sample sizes for subsequent drops. Note that 50% of the trackable have gone missing before the sixth drop, which is usually around 9-10 months.

 

Meanwhile, the rate of attrition declines through successive drops…see the dotted trend line on the percent attrition figure below. A trend line is a mathematically-derived track of the averages, expressed as a straight line. This figure is also automatically regenerated with new data.

 

Even with decreasing attrition rates, sample sizes at later drops are still reduced to nearly-unusable numbers. For example, Love Bugs (heart-shaped items), one of the oldest and largest series, has a total of 274 releases. However, only 11 trackables have achieved as many as 30 drops…this will be more completely illustrated in Part 5 of this post. Then, there are several series that have never had one trackable even reach ten drops, either because their original number of releases is too few to survive the rate of loss, or because the series is too new and there are no representatives old enough to have achieved 30 drops. The small numbers to reach 30 drops are what makes direct comparisons among all groups impossible at this time.

 

The next point of interest is the curve at 13-16 drops. That range is when half of the surviving trackables are located in the United States (US), while the other half are in other countries, mostly in Europe. Annually, beginning in 2014, I either dropped or sent trackables to Europe. However, they have always been a small minority, usually around 5% of the total released. Meanwhile, some of the trackables I released in the US from 2010 on, have been taken outside the US by other cachers. Those trackables are nearly double the number I have sent or taken abroad. The reason that trackables outside the US begin to dominate after 13-15 drops is, in part, because the attrition rate in Europe (4-9%) is approximately half that in the US (11-16%). Again, see the smaller figure below.

 

The last important circumstance on the survivorship curve is at 45 drops. Among my trackables that have never had a drop outside US, none have survived past this point. This means all trackables having made 45 or more drops either left the US or started in Europe. Thus, if I wanted any representation by trackables outside the US, I had to include drops out to at least 30. If the reader doubts that trackables survive longer, and move more frequently in Europe, particularly in the north, see my earlier forum posts on this topic.

 

Although my desire to compare travel histories among all my many series of trackables must be shelved for now, I am not prevented from pooling part of the trackable data to establish a baseline for my 30-drop trackable collection. Part 4 of this post will address the means by which the rate of trackable travels will be expressed.

[+1mech]

Nice charts, I have had some travel bugs which have gone missing after their first drop, others have been replaced to "keep them alive". 

The big question I have is, why do so many go missing? There is no monetary value to them, there should be no bragging rights, as to "I have the most stolen travel bugs"

Some cachers who are the last listed to have grabbed a bug are still active, so, if you have them, drop them or at least log them as visits if you want to hang on to them!

I realize some also go missing due to muggles being just plain mean! To all the bug stealers I say, may Signal the Frog constantly croak in your ears!!!

[+TeamRabbitRun]

21 hours ago, 1mech said:

Nice charts, I have had some travel bugs which have gone missing after their first drop, others have been replaced to "keep them alive". 

The big question I have is, why do so many go missing? There is no monetary value to them, there should be no bragging rights, as to "I have the most stolen travel bugs"

Some cachers who are the last listed to have grabbed a bug are still active, so, if you have them, drop them or at least log them as visits if you want to hang on to them!

I realize some also go missing due to muggles being just plain mean! To all the bug stealers I say, may Signal the Frog constantly croak in your ears!!!

 

Given current trends in the format of new cache, I've often picked up TBs with every intention of moving them along because I personally dig that portion of the hobby, BUT, I frequently don't encounter caches big enough to take them for months!

 

I end up keeping TBs for far longer than is reasonable.

 

[+CAVinoGal]

On 3/4/2023 at 3:25 PM, TeamRabbitRun said:

 

Given current trends in the format of new cache, I've often picked up TBs with every intention of moving them along because I personally dig that portion of the hobby, BUT, I frequently don't encounter caches big enough to take them for months!

 

I end up keeping TBs for far longer than is reasonable.

 

 

Same here.  I enjoy the travel bug aspect, I enjoy sending bugs out and watching where they go, and seeing pictures of my bugs on their travels.  So I try to reciprocate by taking photos as I'm caching with ones I have picked up (especially if I can get a photo in a spot that fits the theme or goal).  It slows down my caching partner(s) as they wait while I "pose" the bugs and get my photos, so I don't always get the photos I'd like...

 

The hardest part seems to be finding the best place to leave them to continue their journey.  Caches are too small, or not found very often, or not in great condition.  Thankfully, my son has an awesome TB Hotel on his front porch, a Letterbox hybrid complete with a stamp, a stamp book AND a logbook, and he keeps good track of what's there.  We visit often enough that I can drop bugs if I need to, and pick up some to take when we travel.

 

There are a couple of other nice TB hotels fairly close by too if I need to use them, but I prefer to find caches a bit further from home to drop off bugs.  So sometimes I end up keeping them for longer than planned, but eventually they do get dropped off, with photos of where I have taken them.

[+CAVinoGal]

On 3/7/2023 at 7:47 AM, CAVinoGal said:

Thankfully, my son has an awesome TB Hotel on his front porch, a Letterbox hybrid complete with a stamp, a stamp book AND a logbook, and he keeps good track of what's there.  We visit often enough that I can drop bugs if I need to, and pick up some to take when we travel.

 

This is so coincidental it's funny...we were visiting our son yesterday, I went through the travel bugs in his hotel and grabbed several as I will be able to help with some of the goals,  and I'll be headed to the East coast and can give them some miles.  One of the bugs I picked up  was released by .... shellbadger!!  I thought the name was familiar as I read the description and goals... and it looks like it was marked missing, then grabbed, and ended up in my son's hotel.  Now I have it!

https://coord.info/TB9FG5B

Edited March 10, 2023 by CAVinoGal

[+CCFwasG]

On 3/3/2023 at 9:15 PM, 1mech said:

The big question I have is, why do so many go missing? There is no monetary value to them, there should be no bragging rights, as to "I have the most stolen travel bugs"

Some cachers who are the last listed to have grabbed a bug are still active, so, if you have them, drop them or at least log them as visits if you want to hang on to them!

I realize some also go missing due to muggles being just plain mean! To all the bug stealers I say, may Signal the Frog constantly croak in your ears!!!

 

Agree. Not only have they got no monetary value, they cost something to the person purchasing them! (Although admittedly some are cute or nice and probably tempt those who don't really know or understand what they are.)

 

On 3/4/2023 at 6:25 PM, TeamRabbitRun said:

Given current trends in the format of new cache, I've often picked up TBs with every intention of moving them along because I personally dig that portion of the hobby, BUT, I frequently don't encounter caches big enough to take them for months!

 

I end up keeping TBs for far longer than is reasonable.

 

 

Same. I just will NOT drop a TB in a place with missing listed TBs, or in winter a place they won't stay dry... in fact (I've said this in the "what irks you" general thread) I almost never drop TBs in basic, non-premium caches. At least if I know the finders are paying for the game they are more likely to respect the TB thing. Exceptions are puzzle TB hotels/larger caches where there is a more discerning or educated (in GC etiquette) group of finders.

 

22 hours ago, CAVinoGal said:

This is so coincidental it's funny...we were visiting our son yesterday, I went through the travel bugs in his hotel and grabbed several as I will be able to help with some of the goals,  and I'll be headed to the East coast and can give them some miles.  One of the bugs I picked up  was released by .... shellbadger!!  

 

That's very funny! Where out here will you be visiting? And have you been to this TB hotel in CA that's been on my list forever? (I'm from CA originally, all my family is still there.)
Xtended Stay TB Hotel & Spa https://coord.info/GC3YZAB 
(Oh heck, I have driven past your son's TB hotel probably thousands of times... if only I'd known it was there. I always struggle when home in the Bay Area with TB drops. Sometimes I hand off to caching friends, but the one I have used conveniently - in a library - is the typical kind where the bugs disappear, sadly, so I stopped using it.)
 

Edited March 11, 2023 by CCFwasG

[+Goldenwattle]

On 1/24/2023 at 11:54 PM, shellbadger said:

The last important circumstance on the survivorship curve is at 45 drops.

Is there a way to count drops as against visits, other than to go through each page? 141 pages in this trackable's case. TB8NKBB

 

The only other one of mine that might be existing is TB6NBZD, which has 410 pages.

 

I recently found TB488XT here in Australia that went missing in Canada ten years ago. That's my record with finding missing TBs. The previous longest missing one I found I think was three years.

 

Then there is this one I found recently TBCFF9; travelling since 2003.

[+BirdSearcher]

11 hours ago, Goldenwattle said:

 

I recently found TB488XT here in Australia that went missing in Canada ten years ago.

I love hearing stories like this, gives me hope for my missing trackables 😀

[+Goldenwattle]

I should have mentioned this longish travelled one too. Published in 2005 and still out there. A Jeep TBM4F7 (White Jeep Travel Bug "Bemeere") I recently found, and now released again. Another published the same day, TBM7NJ (White Jeep Travel Bug "Morris"), is at HQ. I logged that too, but at HQ. It's not 'wild' like the other.