Mammal Research

, Volume 63, Issue 3, pp 277–283 | Cite as

Differentiation of craniomandibular morphology in two sympatric Peromyscus mice (Cricetidae: Rodentia)

  • Kaz Jones
  • Chris J. LawEmail author
Original Paper


In the Santa Cruz Mountains of California, dietary partitioning is believed to allow Peromyscus californicus (California mouse) and Peromyscus truei (pinyon mouse) to occur sympatrically; P. californicus feeds primarily on arthropods, whereas P. truei feeds primarily on acorns. To better understand how these species partition resources, we examine if these dietary differences extend to differences in craniomandibular morphology. We use a geometric morphometric approach to test the hypothesis that P. californicus and P. truei exhibited size and shape differences in craniomandibular morphology, in particular, regions of the skulls that pertain to biting ability and mechanical advantage of the jaw adductor muscles. We found that P. truei exhibited relatively wider zygomatic arches, relatively broader, more robust masseteric fossa and coronoid process, and a higher mechanical advantage of the masseter jaw muscle. These craniomandibular traits suggested that P. truei exhibits a relatively stronger bite force that is more suitable to access hard-shelled acorns despite its smaller body size.


Bite force Dietary partitioning Geometric morphometrics Mechanical advantage Skull morphology 



We thank the many mentors, staff, and students of the University of California, Santa Cruz (UCSC) Small Mammal Undergraduate Research in the Forest (SMURF) program who have worked with us and taught us about the natural history of deer mice. We would like to thank Tina Cheng (UCSC), Karen Holl (UCSC), and Gage H. Dayton (UCSC) for their support of this study.


Funding for the SMURF program was provided by the UCSC Department of Ecology and Evolutionary Biology, the Webster Chair Fund, the Kenneth S. Norris Center for Natural History, and the UC Natural Reserve System. CJL was funded by a National Science Foundation Graduate Research Fellowship.

Supplementary material

13364_2018_364_MOESM1_ESM.docx (105 kb)
Supplementary Data 1 (DOCX 104 kb)


  1. Adams DC, Otárola-Castillo E (2013) Geomorph: an r package for the collection and analysis of geometric morphometric shape data. Methods Ecol Evol 4:393–399CrossRefGoogle Scholar
  2. Alfaro ME, Bolnick DI, Wainwright PC (2005) Evolutionary consequences of many-to-one mapping of jaw morphology to mechanics in labrid fishes. Am Nat 165:E140–E154CrossRefPubMedGoogle Scholar
  3. Anderson MJ (2001) A new method for non-parametric multivariate analysis of variance. Austral Ecol 26:32–46Google Scholar
  4. Anderson RA, McBrayer LD, Herrel A (2008) Bite force in vertebrates: opportunities and caveats for use of a nonpareil whole-animal performance measure. Biol J Linn Soc 93:709–720CrossRefGoogle Scholar
  5. Bookstein FL (1997) Landmark methods for forms without landmarks: morphometrics of group differences in outline shape. Med Image Anal 1:225–243CrossRefPubMedGoogle Scholar
  6. Bulté G, Irschick DJ, Blouin-Demers G (2008) The reproductive role hypothesis explains trophic morphology dimorphism in the northern map turtle. Funct Ecol 22:824–830CrossRefGoogle Scholar
  7. Collar DC, Reece JS, Alfaro ME, Wainwright PC (2014) Imperfect morphological convergence: variable changes in cranial structures underlie transitions to durophagy in moray eels. Am Nat 183:E168–E184CrossRefPubMedGoogle Scholar
  8. Cox PG (2008) A quantitative analysis of the Eutherian orbit: correlations with masticatory apparatus. Biol Rev 83:35–69PubMedGoogle Scholar
  9. Dayan T, Simberloff D (1994) Character displacement, sexual dimorphism, and morphological variation among British and Irish mustelids. Ecology 75:1063–1073CrossRefGoogle Scholar
  10. Druzinsky RE (2010) Functional anatomy of incisal biting in Aplodontia rufa and sciuromorph rodents—part 2: sciuromorphy is efficacious for production of force at the incisors. Cells Tissues Organs 192:50–63CrossRefPubMedPubMedCentralGoogle Scholar
  11. Ferry-Graham LA, Bolnick DI, Wainwright PC (2002) Using functional morphology to examine the ecology and evolution of specialization. Integr Comp Biol 42:265–277CrossRefPubMedGoogle Scholar
  12. Goodall C (1991) Procrustes methods in the statistical analysis of shape. J R Stat Soc Ser B Stat Methodol 53:285–339Google Scholar
  13. Grant PR, Grant BR (2002) Unpredictable evolution in a 30-year study of Darwin’s finches. Science 296:707–711CrossRefPubMedGoogle Scholar
  14. Herrel A, Damme RV, Vanhooydonck B, Vree FD (2001) The implications of bite performance for diet in two species of lacertid lizards. Can J Zool 79:662–670CrossRefGoogle Scholar
  15. Herrel A, Joachim R, Vanhooydonck B, Irschick DJ (2006) Ecological consequences of ontogenetic changes in head shape and bite performance in the Jamaican lizard Anolis lineatopus. Biol J Linn Soc 89:443–454CrossRefGoogle Scholar
  16. Holmes MW, Boykins GKR, Bowie RCK, Lacey EA (2015) Cranial morphological variation in Peromyscus maniculatus over nearly a century of environmental change in three areas of California. J Morpho 277:96–106CrossRefGoogle Scholar
  17. Kalcounis-Rüppell MC, Millar JS (2002) Partitioning of space, food, and time by syntopic Peromyscus boylii and P californicus. J Mammal 83:614–625CrossRefGoogle Scholar
  18. Kardong KV (2014) Vertebrates: comparative anatomy, function, evolution Boston: McGraw-Hill EducationGoogle Scholar
  19. Kaufman DW, Kaufman GA (1989) Population biology. In: Kirkland G, Layne J (Eds) Advances in the study of Peromyscus Rodentia. Lubbock, pp 233–271Google Scholar
  20. La Croix S, Holekamp KE, Shivik JA, Lundrigan BL, Zelditch ML (2011) Ontogenetic relationships between cranium and mandible in coyotes and hyenas. J Morpho 272:662–674CrossRefGoogle Scholar
  21. Law CJ, Venkatram V, Mehta RS (2016a) Sexual dimorphism in craniomandibular morphology of southern sea otters (Enhydra lutris nereis). J Mammal 97:1764–1773CrossRefGoogle Scholar
  22. Law CJ, Young C, Mehta RS (2016b) Ontogenetic scaling of theoretical bite force in southern sea otters (Enhydra lutris nereis). Physiol Biochem Zool 89:347–363CrossRefPubMedGoogle Scholar
  23. Maestri R, Patterson BD, Fornel R, Monteiro LR, Freitas TRO (2016) Diet, bite force and skull morphology in the generalist rodent morphotype. J Evol Biol 29:2191–2204CrossRefPubMedGoogle Scholar
  24. Maki K, Nishioka T, Shioiri E, Angle TTT (2002) Effects of dietary consistency on the mandible of rats at the growth stage: computed X-ray densitometric and cephalometric analysis. Angle Orthod 72:468–475PubMedGoogle Scholar
  25. Mori A, Vincent SE (2008) An integrative approach to specialization: relationships among feeding morphology, mechanics, behaviour, performance and diet in two syntopic snakes. J Zool 275:47–56CrossRefGoogle Scholar
  26. Myers P, Gillespie BW, Zelditch ML (1996) Phenotypic plasticity in skull and dental morphology in the prairie deer mouse (Peromyscus maniculatus bairdii). J Morpho 229:229–237CrossRefGoogle Scholar
  27. Pfaller JB, Gignac PM, Erickson GM (2011) Ontogenetic changes in jaw-muscle architecture facilitate durophagy in the turtle Sternotherus minor. J Exp Biol 214:1655–1667CrossRefPubMedGoogle Scholar
  28. Pianka ER (1973) The structure of lizard communities. Annu Rev Ecol Syst 4:53–74CrossRefGoogle Scholar
  29. R Core Team (2017) R: A language and environment for statistical computingGoogle Scholar
  30. Reid REB, Greenwald EN, Wang Y, Wilmers CC (2013) Dietary niche partitioning by sympatric Peromyscus boylii and P. californicus in a mixed evergreen forest. J Mammal 94:1248–1257CrossRefGoogle Scholar
  31. Rohlf FJ (2005) TpsDig, digitize landmarks and outlines, version 25 Department of Ecology and Evolution, State University of New York at Stony Brook New York, USA, Available at:
  32. Rohlf FJ, Slice D (1990) Extensions of the Procrustes method for the optimal superimposition of landmarks. Syst Zool 39:40–21CrossRefGoogle Scholar
  33. Root RB (1967) The niche exploitation pattern of the blue-gray gnatcatcher. Ecol Monogr 37:317–350CrossRefGoogle Scholar
  34. Santana SE, Dumont E, Davis JL (2010) Mechanics of bite force production and its relationship to diet in bats. Funct Ecol 24:776–784CrossRefGoogle Scholar
  35. Schlager S (2016) Morpho: calculations and visualisations related to Geometric Morphometrics R-package version 24Google Scholar
  36. Schoener TW (1974) Resource partitioning in ecological communities. Science 185:27–39CrossRefPubMedGoogle Scholar
  37. Smartt RA (1978) A comparison of ecological and morphological overlap in a Peromyscus community. Ecology 59:216–220CrossRefGoogle Scholar
  38. Tanner JB, Zelditch ML, Lundrigan BL (2010) Ontogenetic change in skull morphology and mechanical advantage in the spotted hyena (Crocuta crocuta). J Morpho 271:353–365Google Scholar
  39. Timm-Davis LL, DeWitt TJ, Marshall CD (2015) Divergent skull morphology supports two trophic specializations in otters (Lutrinae). PLoS One 10:e0143236–e0143218CrossRefPubMedPubMedCentralGoogle Scholar
  40. Turnbull WD (1970) Mammalian masticatory apparatus Field Museum of Natural HistoryGoogle Scholar
  41. van der Meij MAA, Bout RG (2006) Seed husking time and maximal bite force in finches. J Exp Biol 209:3329–3335CrossRefPubMedGoogle Scholar
  42. Verwaijen D, Van Damme R, Herrel A (2002) Relationships between head size, bite force, prey handling efficiency and diet in two sympatric lacertid lizards. Funct Ecol 16:842–850CrossRefGoogle Scholar
  43. Wainwright PC (1991) Ecomorphology: experimental functional anatomy for ecological problems. Amer Zool 31:680–693CrossRefGoogle Scholar
  44. Wainwright PC, Alfaro ME, Bolnick DI, Hulsey CD (2005) Many-to-one mapping of form to function: a general principle in organismal design? Integr Comp Biol 45:256–262CrossRefPubMedGoogle Scholar
  45. Watt DG, Williams CHM (1951) The effects of the physical consistency of food on the growth and development of the mandible and the maxilla of the rat. Am J Orthod 37:895–928CrossRefPubMedGoogle Scholar
  46. Žagar A, Carretero MA, Vrezec A, Drašler K, Kaliontzopoulou A (2017) Towards a functional understanding of species coexistence: ecomorphological variation in relation to whole-organism performance in two sympatric lizards. Funct Ecol 211:1336–1312Google Scholar
  47. Zelditch ML, Swiderski DL, Sheets HD (2012) Geometric morphometrics for biologists: a primer Academic PressGoogle Scholar

Copyright information

© Mammal Research Institute, Polish Academy of Sciences, Białowieża, Poland 2018

Authors and Affiliations

  1. 1.Department of Ecology and Evolutionary BiologyUniversity of CaliforniaSanta CruzUSA

Personalised recommendations