Drivers of natal dispersal, causes of endangerment – two new KCRL publications fill key knowledge gaps in Mt. Graham red squirrel ecology and conservation

Two new publications by KCRL wildlife biologist Melissa Merrick and postdoc alum Emily Goldstein shed light upon important population processes that are unique to Mt. Graham red squirrels: natal dispersal, fecundity, and survivorship.  Compared to other North American red squirrel populations, Mt. Graham red squirrels exhibit sex-biased natal dispersal with mean dispersal distances that are up to 9x greater.  Juvenile natal dispersal distance is driven by food resources, the body condition of mothers, and individual behavior traits, which may provide a flexible feedback mechanism to adjust local sex ratios and density depending on environmental conditions. Adult Mt. Graham red squirrels also suffer much higher mortality, with adult life expectancies mirroring those of highly hunted squirrel populations.  Low adult survivorship means that most adult females only get to reproduce once in their lifetimes – a critical limiting factor in population recovery.

Read both papers:

Goldstein, E. A., M. J. Merrick, and J. L. Koprowski. 2017. Functional semelparity drives population dynamics and endangers a peripheral population. Biological Conservation 205:52-59.

Merrick, M. J., and J. L. Koprowski 2016. Altered natal dispersal at the range periphery: the role of behavior, resources, and maternal condition. Ecology and Evolution 00:1-15. doi: 101002/ece3.2612.

New publication offers evidence of natal habitat preference induction in a habitat specialist

New research from KCRL member Melissa Merrick’s dissertation research on natal dispersal in the endangered Mt. Graham red squirrel provides evidence that even habitat specialists tend to settle in places that look like home.  The decision of where to settle following natal dispersal is one of the most important decisions young animals make in their lifetimes.  Preference for habitat features that resemble those of the natal area by dispersing individuals is known as Natal Habitat Preference Induction (NHPI) and may be an important mechanism for habitat selection during natal dispersal, particularly in the face of rapid environmental change.  While most studies of NHPI demonstrate natal habitat preference by individuals born in contrasting vegetation community-types, we found evidence of NHPI in an endangered forest obligate that inhabits one vegetation community-type.  This finding has implications for understanding how juveniles in this population decide where to settle and for current and planned habitat management and restoration plans.

Read it here:

Merrick MJ, Koprowski JL. 2016 Evidence of natal habitat preference induction within one habitat type. Proc. R. Soc. B 283: 20162106.


New publication on chipmunk sexual size dimorphism by KCRL alum Allyssa Kilanowski

Congratulations to KCRL alum Allyssa Kilanowski, now a PhD student at the University of Kentucky, on the publication of work from her MS research on chipmunks entitled “Female-biased sexual size dimorphism: ontogeny, seasonality, and fecundity of the cliff chipmunk (Tamias dorsalis)” in the Journal of Mammalogy with advance access at:


KCRL student Sam Abercrombie wins best poster at the 13th annual RISE symposium

KCRL Master’s student Sam Abercrombie participated in the 13th annual RISE Symposium on Saturday 08 October 2016, in the Marley Building on the University of Arizona (UA) campus ( and received the Best Poster award for his efforts. The objectives of the symposium are to share recent results of scientific research in semiarid environments, with an emphasis on work conducted at the USDA-ARS Walnut Gulch Experimental Watershed (WGEW) and the University of Arizona Santa Rita Experimental Range (SRER), and to encourage future research and outreach activities.  A recent UA News story described the legacy of student engagement and research collaborations that have emerged from the previous 12 symposia.

Sam’s winning poster titled “Small Mammalian Herbivores Decrease Herbaceous Plant Cover in Shrub Invaded Grassland”, highlights his Master’s research at the Walnut Gulch Experimental Watershed where he is documenting how small mammals influence vegetation communities in this arid ecosystem.

Congrats Sam!


13th Annual RISE Symposium Best Poster Awardee Sam Abercrombie (right) and contest benefactor Malcolm McGregor (left).

Two new KCRL publications on Kangaroo rats and the endemic Mearns’s squirrel

Two great new publications highlighting research by KCRL alums have just been released.

KCRL alum and Catalina Foothills High School science teacher Kirsten Fulgham’s research on Kangaroo rat foraging behavior on a colony of reintroduced black-tailed prairie dogs has just been published in The Southwestern Naturalist.  Kirsten received her Master of Science in Natural Science for Teachers, a great program at the University of Arizona.

Read more here:

Fulgham, K. M. and J. L. Koprowski. 2016. Kangaroo rat foraging in proximity to a colony of reintroduced black-tailed prairie dogs. The Southwestern Naturalist 61:194-202.

A new species account on the Mearns’s squirrel (Tamiasciurus mearnsi) has just been published by Dr. K, Mike Steele, and KCRL alum Dr. Nicolás Ramos-Lara.  Nicolás did his PhD research on the endemic Mearns’s squirrel in the Sierra de San Pedro Mártir in Baja California Norte, Mexico.

Read more here:

Koprowski, J. L., M. A. Steele, and N. Ramos-Lara. 2016. Tamiasciurus mearnsi (Rodentia: Sciuridae). Mammalian Species 48:66-72.


189 pages on the Sciuridae in the Handbook of Mammals of the World

HMW-06_0More than you may want to know about squirrels, chipmunks, marmots and prairie dogs…KCRL members John Koprowski, Emily Goldstein (postdoctoral researcher), Kendell Bennett (doctoral student) and Calebe Mendes (visiting doctoral scholar) recently coauthored the 189 page section on the Sciuridae in Handbook of the Mammals of the World published by Lynx Edicions ( The section provides a species account for all 292 recognized species in the Family Sciuridae and includes a range map and a wonderful artist’s painting of each species on more than 10 plates in additional to copious references and a general overview of the species….now its on to the next project!