An Interview with Katherine Zeller


Welcome back to Corridor Conversations, and the next interview in our series on women working in connectivity conservation.

Today, Harshad Sambamurthy speaks with Dr. Katherine Zeller, Research Biologist with the Aldo Leopold Wilderness Research Institute.

Dr. Katherine Zeller

How has your journey in conservation been thus far? What drew you to this field?

I feel incredibly lucky to have had the opportunity to work in different parts of the world, with different species of wildlife, and on important conservation questions. And in my current position, I get to work on research questions related to wilderness and other similarly protected areas, which is very rewarding. I was drawn to this field from almost the moment I set foot in Alaska. I was there for my first field technician job after I obtained my B.S. – it was my first experience with truly large and wild places (along with truly large wildlife!) –  and I was immediately hooked. From that point on, I knew I wanted to work in, study, and maintain these large wild places. That began my journey studying large scale conservation networks and spatial ecology, a large part of which is assessing connectivity and wildlife corridors.

Have you faced challenges as a woman working in conservation? What are some of the stereotypes you have had to fight against/ negotiate?

I think women in many STEM fields can relate to the sexism that is inherent in science, and I have certainly faced challenges in my career. Representation of women and other underrepresented groups in conservation is, thankfully, growing, but earlier in my career I was often the only woman on research teams. My contributions were often dismissed or ignored, forcing me to work harder for my ideas to be heard and for team members to regard me as a peer and respect me.

What are some valuable lessons you’ve learnt that could benefit early-career women conservationists?

For me, I found women mentors to be extremely valuable. They taught me lessons they learned through their own experiences and were great sounding boards for questions or advice. It is always nice to have someone to talk with who has had a similar path and can relate to your experiences.

I also found that, if you can build a good community of people to work with who respect each other, that goes a long way for supporting each other’s work and elevating each other’s accomplishments. For example, many times when women propose ideas, they aren’t really heard, or don’t immediately get taken seriously. Having people who support you and your contributions and who can amplify your voice in a room (and vice versa) is incredibly valuable and can shift negative power dynamics. 

Lastly, I feel like we don’t take enough time to acknowledge and celebrate accomplishments. There’s a sometimes overwhelming amount of work to be done in the field of conservation so often we just move onto the next project, but there is such value in taking some time to celebrate accomplishments and wins – no matter how small. We should all be proud of the work we’re doing.

In the filed, gathering data from a camera-trap

In your research, what are some of the best-practices you’ve identified for assessing connectivity and mapping corridors?

I’m glad you asked this, because this question has actually inspired a lot of my research. In the early to mid 2000s, I was working on the Jaguar Corridor Initiative, using the best-practices at the time to model jaguar connectivity. We were mapping connectivity at broad scales — across the entire range of the species. Before on-the-ground implementation work was initiated, I wanted to obtain some field data to validate these corridors. Essentially, I wanted to be sure that the mapped corridors were actually the best places for jaguar connectivity and that we were spending conservation dollars wisely. When I started to conduct the field validation, we were sometimes finding that the mapped corridors didn’t align exactly with what we were finding on the ground. This is not totally surprising since the broad scale corridor models might not totally reflect reality, however, it did raise a red flag for me. Many conservation organisations at the time were using similar corridor modelling techniques and I was worried that conservation dollars weren’t going towards the best areas for maintaining connectivity. It actually inspired me to go back to school to obtain my Ph.D. to study this very question. We still don’t have a definitive answer, since we couldn’t look at every corridor model for every wildlife species and in different study areas, but what we’ve learned so far is that corridors modelled from GPS collar data, tend to capture animal dispersal routes better than corridors modelled from other data types. This is closely followed by using genetic data, which is followed by simple presence/observation data. In terms of the specific corridor model used, we’ve found models based on cost distance algorithms, like resistant kernels, sometimes outperform those based on circuit theory, like CircuitScape. But again, much more research is needed before we have any real rules of thumb that can be applied across species and situations. Plus, new methods are continually being developed, so it remains an important question and one I continue to explore in my research.

As you know, maintaining corridors can help connect habitats and populations so that they are less genetically isolated from one another; leading to overall increase in the robustness of a given species’ gene pool, and the overall area available to them. Species have sometimes been rescued from isolation through translocation of animals. In your experience, are there examples of establishing corridors that have aided in genetic rescue?

There are certainly studies that have demonstrated gene flow through corridors and road crossing structures. This question made me think of the population of mountain lions that I studied for my Ph.D. It was a relatively small population in southern California, right between L.A. and San Diego, so it was isolated from other mountain lion populations in the region by a lot of development. With only about 20-30 cats in this area in any given year, they were starting to show signs of inbreeding — both through their genetics and outward physical characteristics like kinked tails. The problem was that no new genes were making their way into the population because mountain lions from surrounding populations were not able to immigrate in. But then, one cat, M-15, finally did and just by the successful dispersal and breeding of this one male into this population, inbreeding declined, and genetic rescue was documented. Now, there are efforts to build a crossing structure for wildlife across one of the 8-lane highways that border this population. A crossing structure such as this, with appropriate fencing, will help wildlife move into and out of this area and help maintain mountain lion and other wildlife populations without the need for translocation of animals.

The last best chance at connecting the Santa Ana mountain lion population to other populations in southern California. This freeway is a stretch of Interstate 15 south of Temecula, CA (Image Credit: Katherine Zeller)

Your research in jaguar connectivity across the big cat’s entire range led to the establishment of the Jaguar Corridor Initiative. Can you tell us more about the initiative and the value of mapping connectivity across the entire range of a species?

The Jaguar Corridor Initiative (JCI)was born out of ideas of lots of people concerned about the trajectory of this species. First, there was a range-wide exercise in late 1990s, led by Eric Sanderson and others at the Wildlife Conservation Society that looked at where important populations of jaguars were, and how representative these populations were of different geographic regions across the range. From this information, they prioritised the conservation of these populations for the first truly range-wide assessment of this species. Not long after this exercise was done, a jaguar genetic study came out by Eduardo Eizirik and colleagues that showed there was a good amount of genetic exchange across the range of the species, indicating jaguars were regularly dispersing among populations and maintaining genetic viability. This was a lightbulb moment for Alan Rabinowitz, who realised, to truly conserve this species, movement routes or corridors needed to be maintained along with the populations. I then modelled the JCI, bringing together all of these ideas into a single conservation network for the species and highlighting priority areas for conservation for both jaguar populations and corridors. The value of taking this birds-eye view across a species range is that we’re able to identify important areas at this larger scale that you might otherwise miss at smaller scales – say a key corridor that might be the only link between populations in Central and South America, or a key population, that, if lost, will significantly impact the structure of the conservation network.

Linear infrastructure can often lead to instances of roadkill. What are some of the mitigation measures you feel to be effective, and think could be used in other landscapes as well?

There have been many studies done on this, and for large mammals at least, the evidence points to crossing structures, either underpasses or overpasses, built with fencing directing animals to the structure to be the most effective mitigation measure for getting wildlife safely across a roadway and keeping motorists safe. Various studies have looked at the effectiveness of these configurations and have shown that they can be over 80% effective at preventing wildlife vehicle collisions. In some study areas, for ungulates, the effectiveness can be over 90%, which is really promising. Other mitigation tools, like reducing vehicle speed limits, or large animal detection systems, have not been as effective. Wildlife crossing structures with fencing can be used in many landscapes and are, in fact, being implemented in many places around the world.

A lot of research and conservation efforts are focused on umbrella species, often large mammals, and their preservation. How can we highlight the importance of connectivity for smaller species?

More and more, people are recognising the importance of assessing connectivity at multiple scales, from the larger scales that are more appropriate for species that are capable of moving long distances, to the smaller scales that are more appropriate for species that may not be able to move as far. One challenge for modelling connectivity for smaller scales is the lack of highly resolved geospatial data. Smaller species may be responding to landscape features that are smaller than the resolution of the data we can put into the models, creating a mismatch in scale of the movement process. However, things are changing, and geospatial data is becoming available at finer resolutions, hopefully making it easier to model connectivity for smaller species and more easily incorporate smaller species into connectivity planning.

In your work on road ecology, you have used movement and genetic data to identify road crossing hotspots for large mammals. How easy or difficult is it to ensure that such research gets used by infrastructure engineers and planners? Are there any instances of mitigation measures being retrofitted based on research? 

Some of my work has been motivated by questions that transportation departments have had regarding wildlife and motorist safety. And, some of my road ecology research has been borne out of data from GPS collared animals. From these data we can identify and model road crossing locations where mitigation measures might be successful.

Several corridors are mosaics of fragmented forests and other land uses. From your work in these multi-use spaces, do you get a sense that the importance of these mosaics for connectivity is recognised by the stakeholders? 

If you had asked me this question 10 years ago, I might have had a different answer, but due to a lot of great work by scientists, non-profits, and others, I think that more and more, people understand the concept of ‘connectivity’, and that it isn’t just forest, or grassland, but as you say, a mosaic of different land cover and land use types. In fact, the importance of connectivity is now being recognised by many governments. For example, here in the U.S., there requirements to consider connectivity within different land management agencies, like the Forest Service and the Bureau of Land Management, and most recently, the Office of the President released guidance for Federal Departments and Agencies on Ecological Connectivity and Wildlife Corridors. This recognition of the importance of connectivity, from an individual landowner, all the way up to the federal government is very encouraging. 

What are the foreseeable challenges in maintaining habitat connectivity? Realistically speaking, can they be maintained in the long-term, or is the arm of socio-economic development bound to cut through this longevity? We could perhaps take Brazil as an example (i.e. development of the agriculture sector vs. preservation of jaguar habitat). Any other examples you would like to highlight?

Because the concept of ‘connectivity’ can incorporate multiple land cover types, land uses, and land ownership, it is a concept that is not only difficult to communicate, but also to implement. Connectivity conservation, especially initiatives that are larger than a single road crossing location, is not like conventional protected area conservation. It takes buy-in from many interests such landowners, partners, and jurisdictions. As you point out, some of those interests are commercial – or even as straightforward as a landowner wanting to increase grazing on their land to earn a better living – so it really is a balancing act between maintaining connectivity and these interests. Realistically, sometimes that balance will fall to development and sometimes it will fall towards conservation, but the magic is in areas where a successful balance on both sides is reached.

In my experience, one example of this is the Barbilla-Destierro Corridor in Costa Rica. It is an important area for jaguar connectivity and through the hard work of folks at Panthera Costa Rica and others, it has been a really inspiring example of connectivity conservation. The corridor was facing many threats, but there are two examples that I’ll highlight. One example was the hydroelectric dam that was proposed on a river through the corridor that was to flood a main area of the corridor. Panthera Costa Rica was able to work with the energy company to direct flood mitigation efforts to areas of the corridor that would benefit from forest conservation and reforestation, thereby mitigating the effects of the flooding and maintaining connectivity in the corridor that otherwise might have been lost. Another example comes from the many dairy farmers in this area. Their problems were two-fold. First, they were having trouble with predation on their herds, and second, due to the rugged nature of the area, they were having trouble getting their milk to market and selling it for a fair price. The connectivity initiative brought many of these farmers together for the first time and they were inspired to form their own dairy cooperative – setting fair prices and working together to solve their transportation issues. They were also amenable to predator mitigation efforts that made their herds safer and healthier, increased yields and profits, and encouraged more tolerance of jaguars. In addition to working with companies and land owners, there have been many education initiatives in the corridor, bringing communities together to educate young and old about the importance of their lands to jaguars and other wildlife and increasing their sense of stewardship of the area.

Working from the national level to local residents has proven to be a successful model, but the work must be continually ongoing. In conservation, you’re never done with a project, the work will always continue, but the parameters of that work might change because new challenges will always arise.

How can we map wildlife connectivity in a future that is likely to have more humans, and therefore more human-wildlife interactions? Is that a disaster waiting to happen or a global case-study in co-existence?

I think some success stories have been the return of grizzlies and wolves to areas of the U.S. where they had been extirpated – and this is at a time when more people are living in the area than ever before. So, I think there’s a lot of hope. One exciting development for research is bringing more socio-economic data into connectivity models. Recognizing that successful connectivity isn’t only about what species need but is also about how tolerant humans might be of a species living in or passing through an area. There’s been a lot of great work done on combining wildlife ‘resistance’ to movement to various landscape features (typically the layer upon which connectivity is modeled, for example, roads might have a high resistance, whereas forests have a low resistance), with ‘anthropogenic resistance’, that represents the impacts of human behaviors on wildlife movement. This can help identify areas where different mitigation or restoration efforts might be needed and what approaches to promote co-existence might be most successful in an area.