have there been any formal studies not indoors but in the field?

Your question: "Have there been any formal studies not indoors but in the field? any animals birds insects reptiles any of these creatures take marijuana in regularly as a steady staple in their diet?"

Probably not. The only way that could be done would be where there is plentiful marijuana. That only happens where people grow it for profit. If animals were eating it the growers will do their best to get rid of the animals.

It is not unlikely that herbivores would eat marijuana just like any other plant.

Invertebrate pests are probably as common as on any other cash crop.

• http://www.theweedblog.com/how-to-protect-your-out...

• http://www.youtube.com/watch?v=00xxJIFGsUs

In that regard dope dealers are no different that tobacco farmers or opium farmers.

While on the subject of dope and animals:

Have you ever wondered what the tobacco industry and the so-called medical marijuana industry have in common? Both industries have paid doctors to claim that smoking some plant has medical benefits.

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"9 Reasons Why Sanjay Gupta Changed His Mind About Marijuana" | Robert Ferris April 20, 2014 | Yahoo! Finance Business Insider

• http://finance.yahoo.com/news/9-reasons-sanjay-gup...

"Ex-Mexico president praises Wash. pot businessmen… “[Vicente] Fox, a former Coca-Cola executive who was Mexico's president from 2000-06, specified that he's not involved in the venture. He appeared at Shively's invitation.” | By GENE JOHNSON | Assoicated Pres | May 31, 2013

• http://bigstory.ap.org/article/ex-mexico-president...

“The Impact of Substance Use Disorders on Families and Children: From Theory to Practice” | Laura Lander, Janie Howsare, and Marilyn Byrne | Soc Work Public Health. 2013; 28(0): 194–205.

• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC372521...

"How marijuana impairs memory... Marijuana's effects on memory are controlled by hitherto neglected brain cells called astrocytes" | Mo Costandi | Neurophilosophy | The Guardian

• http://www.theguardian.com/science/neurophilosophy...

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Tobacco:

• http://www.tobaccocampaign.com/american-medical-as...

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Dope:

"Profit motive. If there is a commercial pot industry, businesses will have strong incentives to create and maintain the heavy users who use most of the pot. To get a sense of what this could look like, look no further than the alcohol and tobacco industries, which have found ingenious ways to hook and reel in heavy users."

• http://www.rand.org/blog/2013/04/7-key-questions-o... 

what kind of question is that, do you have a life?