Another of source of indigenous knowledge Castellano talks about is the empirical source. So that, again it's that knowledge that we take in with our senses and share with others, and becomes part of the, the collective resource of knowledge for the communities and even for the larger human community. I would say this is probably the source of indigenous knowledge that's the least contested among people outside of indigenous communities because it is stuff that they can also test with their own observations too. But increasingly, this kind of indigenous knowledge is being respected by the western scientific community. They're starting to see the value of, of communities' observations of changes to the land. And part of the, the reason that there is a respect for this knowledge is the long term occupancy of certain people in certain places. So, that they are, are able to, to observe these things from their very careful observation and close connection to, to the lands and resources in the place where they live. It's an acknowledgement that this form of indigenous knowledge is constantly changing. So in the way that traditional knowledge might have elements of the same story being told as it has been for generations, empirical knowledge is a wealth of knowledge that is continuously being adapted and refined through current, careful observation. So when that hunter goes out on the land and experiences a population depletion of a certain species, they know from having done that activity for years and years and years, and seeing changes and understanding what, what is a cyclical change and what is what is a more kind of a longer trend happening. And they do this not only through their own observation, but also taking those empirical pieces of information and weighing it against, in kind of traditional stories about relationship to those places and, and species say. So, in essence they are taking the, the record of traditional knowledge, updating it with empirical experiences of knowledge. And coming to an, another understanding or a more current, developed, informed understanding of knowledge in that time and place. It's, it's a record that's continually changing. There have been attempts to kind of define and describe this particular subset of indigenous knowledge as traditional ecological knowledge or TEK or TK. And I think this is a recognition that, that empirical source of knowledge is where there is some greater overlap some greater understanding that can be made between western scientific forms of knowing, and indigenous knowing. So, the empirical source of indigenous knowledge is an important source where we see indigenous knowledge getting some acknowledgement and recognition from western communities of knowing.