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WILDLIFE CAPTURE AND CARE

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Dr. Mark R. Johnson, D.V.M, Wildlife Veterianarian, Instructor

Mark R. Johnson, DVM

Wildlife Veterinarian, Instructor
Founder and CEO of Global Wildlife Resources

Dr. Mark's Resume
  • You capture and handle captive or free-ranging wildlife and always wish to do better.
  • You want practical, field-based information on equipment and protocols to maximize success and the safety of both humans and animals.
  • You care for the animals you are working with and wish to learn and share how to incorporate our caring heart-felt values into our tools, techniques, and mannerisms.
  • You are new to the zoo and wildlife professions and you wish to learn the highest standards in wildlife capture and handling.
  • You would like to read stories from the field about our joys, our success, our challenges and the issues facing our work.


This is your opportunity to learn and improve how we capture and handle captive and free-ranging wildlife. In this blog, Dr. Mark and his colleagues will share their stories, tools, techniques, protocols, and attitudes to improve animal care, efficiency in the field, and success as a wildlife or zoo professional.


Dr. Mark encourages us to learn from every animal, every capture event, and every colleague. As he assists with field captures or teaches a chemical immobilization course he also gathers new practical tools and ways for improving our chemical capture skill and field experience and shares them with you.

Dr. Mark invites you to be a guest author for the Wildlife Capture and Care Blog.

Share your field experience and knowledge.

Read our Guest Author Guidelines
Visual Guide to Wolf Dentition and Age Determination.
By Tyler Brasington 03 Feb, 2024
The Visual Guide to Wolf Dentition and Age Determination is the most comprehensive guide to date, focusing on wolf dentition, and the approximation of age based on visual wear patterns.
In the course of our work on the African continent, we are fortunate to work with a number of charis
By Dr. Joel Alves 23 Jul, 2022
In the course of our work on the African continent, we are fortunate to work with a number of charismatic species and none-more-so than the ones with sharp claws and teeth.
By Dr. Mark 17 May, 2022
Here is a great question sent to me from a wildlife biologist taking my online course, “The Foundations of Wildlife Chemical Capture”. Dr. Mark Colleen asks: Dr. Mark, I just finished Chapter 2 where you discussed the importance of accurate weight estimates to determine safe and effective immobilizing drug doses. I see you mentioned observing the ear size in relation to the body, but what are your other go-to observations for estimating body weight for bears? Dr. Mark’s reply: Great question. I have three predominant aspects that I consider when estimating body weight for bears: Ears give me a sense of how old the bear is. As bears grow, their head grows but their ears do not. So a big-eared bear is a small younger bear. A bear with little ears (relative to head size) is an older larger bear. We’re often estimating bear weights when they are in a culvert trap so I first notice if it is a large or small culvert trap because traps vary in size. A small culvert trap will make me think it is a larger bear and can skew my estimate. A larger trap will make a bear look smaller. My strongest reference is writing down my weight estimates on the drugging field form every time we do a capture. We also document actual weight as well. That way we are learning from every animal. When I have a partner at the capture, I ask them to also write down their weight estimate. After we weigh the bear, we know that whoever is least accurate buys the next coffee. It is interesting to note that we have always strived for being accurate with animal weight estimates within 10%. That is the professional standard. I realized that we strive to be accurate within 10% because when we work with ketamine/xylazine and Telazol combinations (which I have done for decades), small variations in dose really makes a difference in the downtime and depth of immobilization. Many biologists are now immobilizing bears with BAM and BAM is more forgiving. We can be 25% off in our weight estimates and not notice a difference in the immobilization. One major reason for this with BAM is that we have reversals to wake up an animal when we’re done. With ketamine/xylazine and Telazol combinations the anesthetics are not reversible. With Telazol, we have to wait for them to wake up and we must wait for ketamine to wear off before we administer the reversal for xylazine. So we don’t want to give them any more than we need to, but we want to be confident that we gave enough! In all cases, we still strive to be accurate within 10% for safe and successful wildlife immobilizations. To recap: Look at the ears Look at the culvert size Write down both estimated weight and actual weight on the field form so we learn from each animal. Care to learn more? Register for the online course, “The Foundations of Wildlife Chemical Capture“ .
Dear colleagues, it is a pleasure to have guest author, Dr. Liesel Laubscher of Wildlife Pharmaceuti
By Dr. Liesel Laubscher 30 Apr, 2022
Dear colleagues, it is a pleasure to have guest author, Dr. Liesel Laubscher of Wildlife Pharmaceuticals South Africa present this article on potent opioids. Dr. Mark
The Foundations Course Reviewed by Journal of Wildlife Diseases
By Dr. Mark 31 Oct, 2021
It is an honor to have the Journal of Wildlife Diseases (JWD) review our online course, The Foundations of Wildlife Chemical Capture. This is likely the first time JWD has reviewed an online course.
Collaring a lynx in Alaska
By Dr. Mark 21 May, 2021
Dr. Mark describes creating new drug combinations for immobilizing lynx Note: This blog article is a bit technical but it covers the basics for how to choose an immobilizing drug combination for a wildlife research or management program.
Wildlife Health podcast - Untold stories from 35 years of wildlife handling.
By Dr. Mark 15 Mar, 2021
Dr. Michelle Kneeland of WildlifeHealth.org is presenting a podcast interview with me as I share my stories and adventures from 35 years as a wildlife veterinarian. Listen to me describe a mountain lion capture in a severe winter storm. Hear what it feels like capturing grizzly bears.
wildlife pharmaceuticals
By George Carballo 11 Mar, 2021
Wildlife Pharmaceuticals and its subsidiary, ZooPharm, the legacy of retired Bill Lance, DVM, MS, PhD, are now part of the largest veterinary-compounding pharmacy in the U.S., Wedgewood Pharmacy, a respected name known to 9 in 10 veterinarians in the U.S. The acquisition was completed this past summer.
Capturing and chemically immobilizing bears is stressful for the animal. Therefore, it is imperative
By Tyler Brasington 12 Oct, 2020
Capturing and chemically immobilizing bears is stressful for the animal. Therefore, it is imperative that researchers and managers justify all capture events, thoroughly evaluating potential alternatives to a hands-on approach.
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