Tuesday, 8 August 2017

Some interesting bulls from Oostvaardersplassen

I have many articles in preparation at the moment, but today I have a short post for you - browsing around on youtube I discovered a recent video that shows some bulls from Oostvaardersplassen. In the past, I made a number of posts on how the OVP population is getting slowly more aurochs-like in many respects; body shape and skeleton as well as the horn shape seems to adjust in a way that moves the population to a more aurochs-like appearance. In the posts linked below I show many examples for that, and also give explanations why the wild-type traits seems to have a selective advantage for the very heterogeneous start population, and also supported it with a lot of photos. 

- Aurochs-like features at Oostvaardersplassen
- New aurochs head reconstruction and new photo from Oostvaardersplassen 
- Heck cattle at Oostvaardersplassen - A special population 
- Dedomestication Series 

Unfortunately, many of the linked photos are not displayed anymore because the html seem to have changed or because of an error by Blogger. That happens all the time and I cannot fix it. I apologize. 

After about 35 years of natural selection, the morphology of the bulls in particular noticeably changed. The steppe cattle-like bulls you see on old photos from 1983 (see Frisch, 2010) vanished. On this video, you see a bull (0:37) with a morphology that matches perfectly that of many very aurochs-like Lidia bulls or accurate aurochs reconstructions. This individual still has the diluted colour that is the vestige of steppe cattle descendants, but there are many examples without colour dilutions. In a number of individuals, you see horns with an inwards-curve starting to resemble that of the aurochs you find nowhere else in uncrossed Heck cattle (see the linked posts above). But those individuals are, surprisingly, cows exclusively. 
Today, I found this video: 
Have a look at the bulls at 2:33. They are of a lean stature, have a flawless aurochs bull colour and the horns are big and curved - surely not curved very strongly, but especially if you pause at 2:34 you see that the so-called "primigenius spiral" is starting to develop. And the horns are comparably large as well. It is not impossible that such bulls were found in the reserve ten or even twenty years ago as well, but one would have to have look to find five of them next to each other. It is evident when you look at older photos from OVP easily available on the net. From 4:29 onwards you see some more footage (they might be the same bulls or even more individuals of this interesting morphology and appearance). Their build is definitely no comparison to what Heck cattle of zoos look like, and phenotypic plasticity is not the sole cause for these differences as many of the bulls at OVP also tended to look very domestic for a long time. 
This video and many recent photos show in my opinion that the Heck cattle population at Oostvaardersplassen is definitely evolving on a genetic basis, and in a direction that approaches the aurochs in many respects, which is probably not a coincidence. That makes it a very valuable population that should be protected in any case, and not be removed for whatever blind reasons (not just because of horn shapes. Examining if the decades of natural selection also led to metabolic and behavioural changes could be very insightful). 
Unfortunately, it is not legally possible to take a bull from the reserve and use it for breeding because of veterinary reasons. However, perhaps it is possible to get semen from one of these interesting aurochs-like bulls at the start of becoming dedomesticated. 

It is also apparent that the bulls are not very large. I would not be surprised if Heck cattle actually become smaller at OVP due to limited size and food availability (island effect). It would be interesting to measure some of these individuals, many bulls might actually be below the 140cm mark already (personal guess). It is also suspected that Chillingham cattle, living semi-feral in the Chillingham park for centuries now, also got smaller with time (for my post on Chillingham cattle, go here). 

2 comments:

  1. It's a pity, that they don't cull individuals. With always enough food the natural selection would favor bigger bulls. AND the project maybe even would pay for itself by selling the meat, horns etc...

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    1. It's likely that the recent drop in numbers of the cattle at OVP is not primarily the result of overpopulation, but being outcompeted by horses and deer. Roe deer disappeared already. I'm planning to do a post on the state of the nature at OVP this summer.
      It would be impossible the sell the meat because of the legal issues, by the way. Trophies maybe...

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