Let me start out by posing a question: What do the following horses have in common? Pictured up top is a 2009 foal, with the mother in the background. These horses live on the mountain and are part of Duke’s harem. On the bottom is a mare and her two year old colt. They are Starbuck’s harem, and they live down in the desert.


The answer to this question also answers another question, which is why haven’t I been putting up a lot of blog posts lately? Well, I’ve been working on developing the next phase in a project I’ve mentioned before – My horse lineage project.
So now to answer the question. The foal up there’s mother is the daughter of the mare whose mother (photo below) had a son that is the father of the bay mare and the grandfather of the bay colt. Complicated, right? Basically, all the horses pictured above share the fact that they are all descendants of a mare that was born in 1972. She is again shown right below here. (The similarity between the mare and the foal above is pretty obvious, huh? These patterns of inheritance are something interesting I’ve seen with the project.)

Well, how do I know this? I know it due to a project that the Pryor Mountain Wild Mustang Center is doing. Our project seeks to compile information on the herd from different years and different sources so that we can determine the relationships that exist between the horses in today’s herd. I frequently travel to the range so that I can collect different data. One thing I collect out there is information on who the parents of the foals each year are. This isn’t anything new. In fact, I am still pretty new at this when you think about the people before me who have made all this possible. It all started back in the 1970’s with the original BLM employees working with the herd. These guys were keeping track of all the horses as best they could, and they did an amazing job given the technology and knowledge they had to work with. Eventually, Hope Ryden, along with Reverend Schwieger and other locals, also collected data through the years. By the mid 1990’s, the BLM and USGS-BRD were largely collecting the data. Now, the PMWMC is continuing to collect data comparable to that collected by these earlier people. USGS-BRD is currently collecting some data as well, and so we work together to allow for the development of the most thorough collection of observations.
The idea of these horse lineages dates back to the 2006 gather, when we realized that by removing a particular horse, a particular mare wouldn’t have any genetic representation on the range. When we realized this, we started looking at all the other mares; and thus the first lineage was born. We were only looking at mares because there is some uncertainty with fathers sometimes; with few exceptions we can always say for certain which mare is the mother of which foal. This first lineage set went back to around 1994. During the 1994 roundup, there was a pretty comprehensive horse list developed; and so we were able to easily use the Reverend’s records and BLM records to determine relationships. We did have horse lists back to 1990, but we didn’t really know how to extend our data back with it in all cases. There was a lot going on in the early 90’s that made it all confusing. As I told more people about this project and asked if they could remember anything that could help me, I was often referred to a collection of notebooks from these early BLM wild horse people. (For locals, there was a great story on some of this history in a recent Lovell Chronicle article.) I did a lot of asking around to determine what happened to these notebooks, but I ended up concluding that they had been thrown away at some point. However, this winter the notebooks were located by the BLM’s Billings Field Office; and I have been able to borrow them to make the lineages even bigger. The tricky part was to match up horses over time. Though I had built this collection of lists from over time, they were from different people who were often using different descriptions of the same horse. Matching up the data took a long time, and there are still a few horses that I haven’t matched up yet. Last time I counted, though, well over 90% of the horses could be taken back to ancestors born in the late 60’s or early 70’s. (These early horses are my “founders.”) With this, I had a ton of data (photographs, lists, etc) that was organized but not archived and easily accessible. An Excel spreadsheet had been helping with the early lineage, but I was just dealing with way too much for this little spreadsheet. Due to the generosity of a supporter and a grant, though, I was able to obtain archival materials and software that is allowing me to handle this huge collection. Lately, we have been organizing and archiving everything; and I have been focusing a lot on the lineage project in preparation for the possible gather this summer. At this point, over 700 horses have been put into the database; but it will definitely get a lot larger as I continue to build it.
I guess the obvious question now is why our organizing has invested so much into this project. Well, we are very much into the conservation of the Pryor Mountain Wild Horses. With this herd, conservation must come through innovation – This is because we have a finite amount of land out there that can hold a finite amount of horses. Management will thus happen, but smart decisions can be made that allow for management decisions to be made that don’t cause some bloodlines to become too big at the expense of other bloodlines that may be small or even extinct. This is reality; this is the current trend with this herd. Decisions have been made that have led to a dramatic imbalance of genetic representation among the horses. Keeping the herd healthy basically depends on the herd having a high level of genetic variation. In other words, we don’t want the herd to get too inbred. If lines are made too big, then the probability of two close relatives breeding increases. With this comes a good chance that the herd has lost some variation.
Now I am not trying to cause any alarm; the last time the herd’s level of variation was measured, it was high. Presumably, it is still fairly high. The PMWMC is focused on proactive planning that will allow for it to remain high, and we feel that this lineage data set will be a tool that can allow for this to occur as it will allow for management for kinship to be possible.