Congrats to KCRL’s Jonathan Derbridge on a successful PhD Defense!

Congratulations to Jonathan Derbridge on his successful defense of his dissertation yesterday! Jonathan shared his research on the impacts of introduced Abert’s squirrels on the critically endangered native species, the Mt. Graham red squirrels.

Jonathan’s dissertation abstract:

Ecology and Conservation of Endangered Territorial Species Under Invasion

 Biological invasions threaten biodiversity globally, and degraded ecosystems increase the potential for invaders to compete with threatened native populations.  In natural systems, niche partitioning minimizes interspecific competition, but introduced species may alter expected outcomes by competing with ecologically similar species for scarce resources.  Where food production is highly variable, coexistence of native and invasive competitors may depend on dietary niche flexibility.  Territorial species under invasion face additional challenges in maintaining economically defendable territories.  From 2011-2016, we conducted removal and behavior experiments to determine effects of non-territorial introduced Abert’s squirrels (Sciurus aberti) on diet, space use, and territoriality of endangered Mount Graham red squirrels (MGRS; Tamiasciurus fremonti grahamensis) in disturbed and fragmented habitat in the Pinaleño Mountains, Arizona.  We collected comparative data from Arizona sites of natural syntopy between Abert’s and Fremont’s squirrels (hereafter, red squirrels; T. fremonti).  Stable isotope analysis revealed similar dietary partitioning among populations.  Removals did not affect MGRS diet but did affect MGRS space use.  Territory sizes and body mass of MGRS were sensitive to conspecific population density and food production.  Behavioral experiments showed MGRS were more aggressive than other red squirrels.  Dietary flexibility of Abert’s squirrels may have facilitated coexistence with MGRS, possibly due to coevolved resource partitioning with red squirrels.  However, aggressive territoriality toward Abert’s squirrels may incur fitness costs for MGRS especially during poor food production years.  Climate change may reduce the advantage of ecological specialist species globally, and where introduced species are better-adapted to novel environmental conditions, native species may ultimately be replaced.


Jonathan Derbridge


Dr. K participates in student-led documentary about the modern zoo

What will the zoo of the future look like?  John Koprowski, SNRE Professor of Wildlife and Fisheries Science and Associate Director, participated in the production of a documentary on the future of zoos produced by a UA Journalism course.   Expanded partnerships among universities, land management agencies and zoos/aquariums are likely to be required to successfully manage biodiversity in the future, especially for highly endangered species.

Read the U A news story here.

Watch the trailer now:


Dr. John Koprowski named 2017 AAAS Fellow

KCRL’s fearless leader Dr. John Koprowski has been named a 2017 AAAS Fellow.  Dr. K is recognized by his peers in the American Society for the Advancement of Science for distinguished contributions to biology, particularly conservation and ecology of mammals.  Dr. K’s research program (the Koprowski Conservation Research Laboratory) works to understand the ecology and conservation of rare vertebrates. He also serves as director of the Mount Graham Biology Program that is focused on conservation of the endangered Mount Graham red squirrel.

Read the full stories here:


KCRL members discuss challenges and current efforts to conserve Mt. Graham red squirrels following catastrophic fire

It was a pleasure to work with dedicated journalists at on a story by azcentral about conservation challenges and current efforts to protect the Mt. Graham red squirrel and understand how the Frye Fire has impacted this imperiled population. Several KCRL members met with journalists during the first week of November and the story features interviews with Dr. Koprowski at the University of Arizona, KCRL PhD student and Phoenix Zoo Conservation Director Stuart Wells, and Senior Wildlife Biologist Melissa Merrick on site in the Pinaleño Mountains on 7 November.

While we are extremely concerned about the fate of this unique subspecies, we are not giving up. We will continue to study how Mt. Graham red squirrels are impacted by the landscape-level alterations brought about by the Frye Fire and apply what we have learned from this and previous fires towards making positive and meaningful contributions to collaborative conservation and restoration efforts underway, both in the short term and into the future.

Read the entire story here:

MGRS by Melissa Merrick

Conservation of the USA’s rarest small mammal: SNRE involved in the conservation of the imperiled Mt. Graham red squirrels

The School of Natural Resources and the Environment (SNRE) in CALS has long been involved in the conservation of federally endangered Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis) (MGRS), found only in the Pinaleño Mountains of southeast Arizona. Dr. John Koprowski, SNRE Professor and Associate Director, and his research team of senior wildlife biologists, graduate student researchers, and undergraduate field technicians conduct regular counts of squirrel abundance and follow the movement of individuals fitted with radiocollars in several study areas within the mountain range. The research is aimed at learning as much as possible about the ecology of this highly endangered species. These techniques yield information on habitat use, nest sites, distances moved, litter size and eventually the cause of death.   Such information provides insight to the challenges faced by the species and can prioritize management needs.


Photo 1. High-severity burn in high elevation spruce-fir vegetation community type. Credit M. Merrick

While fire has long been a major factor shaping the forests of the Pinaleños and thus the habitat and ecology of red squirrels, recent large wildfires have been cause for concern. The Frye Fire started in the Pinaleños on 7 June and impacted over 19,600 ha (48,443 acres) by the time it was contained in late July. A recent interagency survey reported by Arizona Game and Fish Department (, indicated a precipitous drop in squirrel numbers from over 250 to only 35 individuals. Impacts of the Frye Fire were reported at about 95% of the locations surveyed in the interagency census with 44% of the squirrel locations severely damaged.

Following containment of the Frye Fire, we were allowed to safely return to the mountain range to assess the extent and severity of burn in our study areas, and how Mt. Graham red squirrels were coping with the changes. The fire impacted the majority of our study areas, including high elevation sites that contain the remaining spruce-fir vegetation community type (Photo 1). While some areas experienced severe burn that killed all living vegetation, many patches of low and moderate burn remain. Trees that did not experience severe burn and crown scorch are still alive and several species have produced cones this year, such as Douglas-fir (Pseudotsuga menziesii), Engelmann spruce (Picea engelmannii), and white fir (Abies concolor), and these trees are active feeding sites (Photo 1A)for both red squirrels and Abert’s squirrels (Sciurus aberti) (Photo 1B).


Photo2. High-severity ground fire at a red squirrel midden. Credit: V. Greer

Red squirrels that survived are dealing with the changes to the forest in several ways. Many territories were severely burned, and animals are moving in search of food and new places to nest, often in previously unused areas. One individual, whose territory had been completely consumed by fire, (Photo 2) moved over 1.5 km (~1mile) to establish a new cone scale pile (Photo 3).


Photo3. Active, undamaged midden that a displaced red squirrel moved to. Credit: M. Merrick

Unfortunately, these extra movements, combined with less vegetative cover, have resulted in increased mortality from avian predators (Photo 4). Some squirrel territories experienced low to moderate severity ground fire that did not completely burn the cone scale pile (Photo 5). Many of these partially scorched cone scale piles are still in use and squirrels are caching new cones in them (Photo 6).


Photo 4. Long eared owl in a corkbark fir tree with moderate scorch. Credit: M. Merrick


Photo 5. Partially burned cone scale pile, surrounding trees still alive. Credit: V. Greer

Some cone scale piles were completely consumed by the fire, but left a network of holes in the ground where the roots of young and dead trees once were. Red squirrels have been observed caching cones in these holes (Photo 7).


Our research noted similar responses of red squirrels to other recent large fires in the Pinaleño Mountains (2004 Nuttall Complex and 1996 Clark Peak Fires). MGRS continue to avoid areas of high or moderate burn for many years after the fire; however, low levels of burn actually seemed to have some positive impacts as indicated by smaller daily ranging behavior of individuals and continued persistence of animals in such burned locations. Introduced Abert’s squirrels, a non-native competitor on Mt. Graham, respond more positively to fire and pose a continued threat. However, the Frye Fire was much larger than other recent fires and the impact may prove more severe. Post-fire management of MGRS and the forest will be critical to persistence.

A pilot conservation breeding program is also one of the strategies to ensure survival of the species. In 2011, citing concerns about ongoing drought conditions occurring on Mt. Graham, the US Fish, and Wildlife Service (USFWS) biologists collected two male and two female Mt. Graham red squirrels from the wild and brought them to the Johnson Center. The ACNC – Phoenix Zoo’s Arthur L. and Elaine V. Johnson Species Conservation Center (Johnson Center), was established in 2007 to work specifically on


Photo 8. Mt. Graham red squirrel at Phoenix Zoo Johnson Species Conservation Center. Credit: ACNC/K. Krahn.

priority issues related to native wildlife species recovery. In 2014, as drought conditions continued USFWS partnered with the Johnson Center to further develop a breeding program for MGRS and added two individuals to increase the captive population to three males and three females (Photo 8). Conservation Center staff has been working, towards a goal of producing offspring for release into the wild. To this end, Stuart Wells – Director of Conservation and Science at the Johnson Center is in partnership with the University of Arizona SNRE, USFWS, Arizona Game and Fish Department, and the US Forest Service. Wells is studying the behavior of these squirrels and analyzing the hormone levels in their scat to determine when the females are cycling as part of his doctoral work in SNRE, in hopes of applying this information towards developing a consistent breeding program. The program has already discovered surprising details about this critically endangered squirrel, information that could only be obtained in a managed setting. Through further study and good fortune, the program hopes to produce young for release into the wild soon. The recent population decline as a result of wildfire, heighten the importance of developing a successful propagation for release program.

Mt. Graham red squirrels have persisted through past fires in their 7,000-10,000 years of residence; they are tenacious survivors and don’t give up easily (Photo 9)! However, that tenacity will be tested in the coming years and the scientists from SNRE will continue to collaborate with agency and zoo biologists to enable persistence of what is now one of the USA’s rarest mammals.


Photo 9. Red squirrel carries grass for nesting material in an area that experienced ground fire. Credit: M. Merrick

Arizona Senator John McCain’s letter in support of Mt. Graham red squirrel recovery:

Links to research on Mt. Graham red squirrels and response to fire:

Blount, S.J., J.L. Koprowski. 2012. Small mammal response to post-fire conditions: case of the endangered Mount Graham red squirrel. Southwestern Naturalist. 57:8-15. 

Gwinn, R. N. and J. L. Koprowski. 2017. Differential response to fire by an introduced and an endemic species complicates endangered species conservation. Hystrix doi:10.4404/hystrix-27.2-11447:1-7.

Koprowski, J. L., K. M. Leonard, C. A. Zugmeyer, and J. L. Jolley. 2006. Direct effects of fire on endangered Mount Graham red squirrels. The Southwestern Naturalist 51(1): 59-63. 

Leonard, K. M. and J. L. Koprowski. 2009. Effects of fire on endangered Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis): responses of individuals with known fates. Southwestern Naturalist 55:217-224. 

Below, please find a number of helpful links with more detail on MGRS and fire:

For detailed information on the Frye Fire:

For information on the Mt. Graham red squirrels and our research:

For information on fires in the recent past on Mt. Graham:

For fire history of Mt. Graham through the late 1900s, see Grissino-Mayer et al.s 1994 paper:

KCRL members represent at TWS 2017

KCRL members had a great time at the 24th annual meeting of The Wildlife Society in


Albuquerque convention center – home of TWS 2017.  Photo by Colin Brocka

Albuquerque, NM last week!  Seven graduate students Kira Hefty, Allie Burnett, Marina Morandini, Brian Blais, Colin Brocka, Amanda Veals, and Neil Dutt, our fearless leader Dr. K, Senior Biologist Melissa Merrick, and lab alums Mags Rheude, Seafha Blount, and Emily Goldstein did their best to represent KCRL with research presentations, posters, and involvement in working groups and professional development opportunities.


Brian Blais’s poster titled: “Tools of the Trade: Herpetofauna as Models for Conservation”


Colin Brocka’s poster at TWS 2017

Colin Brocka’s poster titled: “Home on the Range: Terrestrial Ecology of the Endangered Sonoran Tiger Salamander”




Allie Burnett’s poster titled: “Effects of Woody Encroachment on Anti-Predator Behavior and Communication in the Harris’ Antelope Ground

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Allie Burnett’s poster at TWS 2017





Marina Morandini’s poster titled: “An Endangered Species After Catastrophic Fire: Whatis Next?”




Marina Morandini’s poster TWS 2017









Amanda Veal’s presentation on her Master’s research: “Camera Trap Occupancy and


Amanda Veals presenting at TWS 2017

Habitat Selection of Gray Foxes to Inform Rabies Management”.

Dr K & Melissa Merrick’s presentations in the Wildlife are Individuals, Too symposium: “Wildlife Are Individuals Too: Considering Inter-Individual Variation to Inform Management”


“Individual Behavior Differences Are Important Predictors of Natal Dispersal Distance in an Endangered Small Mammal”


Melissa Merrick presenting at TWS 2017



Many KCRL members al attending workshops and TWS working group meetings, activities that advance the Society’s various missions as well as provide excellent opportunities to network work on professional development.


Kira and Allie check out the TWS International Wildlife Management Working Group’s booth.


TWS International Wildlife Management Working Group Meeting: Dr. K, Allie, Marina, Kira, and Melissa in attendance









Beautiful views above Albuquerque from Sandia Peak.  Photo by Colin Brocka




Dr. K presents research in Nepal, visits area parks, study sites, and universities

Our fearless leader, Dr. John Koprowski, presented a keynote address on 28 August at the South Asian Small Mammal Conference in Kathmandu, Nepal.  His talk was entitled “Ecosystem services and the value of small mammals in our changing world”.  Afterwards he visited field sites in Nepal associated with river dolphin research, talked with researchers at Chitwan, Bardia, and Banke National Parks, and with professors at the Institute of Forestry in Hetuada.