Are there sex differences in the body size of the Eurasian red squirrel in Slovakia?
DOI:
https://doi.org/10.1515/eje-2015-0002Keywords:
Eurasian red squirrel, body size, reproduction success, PCA Analysis, Allometry, SlovakiaAbstract
Sexual dimorphism of the Eurasian red squirrel on five somatic variables (head-and-body length, tail length, hind foot length, ear length and body weight) was evaluated on 55 squirrels. The overlap of values of the measured traits among sexes was high, but in all traits (with exception of the tail length) males seem to exhibit slightly higher mean values than females. However, these differences were non-significant, with the exception of a small significant difference in the tail length and tail-to-head-and-body ratio. Similarly, the results of discriminant function analysis show no differences between the sexes. Positive correlation analyses, together with PCA values, confirmed that tail length and hind foot length are traits that play a significant role in overall variability. We suggest that this relationship could explain their mutual importance in locomotion, where the feet are essential for movement in the trees. By contrast, the tail maintains balance on thin branches, or during jumps from one crown to another. Longer tails also demonstrate differential selection on males and females for a locomotor trait. Similarly, we discuss whether variations in tail length were connected to female reproductive success. Our results suggest that the non-significant results regarding SSD provide the benefit of the same size for both sexes in the protection of territory as well as inter- and intra-sexual interaction.
References
F. (Ed.), Die Säugetierfauna Österreichs, Grüne Reihe
des Bundesministeriums für Land- und Forstwirtschaft, Umwelt
und Wasserwirtschaft, Band 13, Graz, pp. 338-344.
Bonduriansky, R. & Day, T. (2003) The evolution of static allometry in
sexually selected traits. Evolution, 57, 2450-2458.
Bonduriansky, R. (2007) Sexual selection and allometry: a critical reappraisal
of the evidence and ideas. Evolution, 61, 838-849.
Čanády, A., Mošanský, L. & Krišovský, P. (2015) Cranial dimorphism in
Eurasian red squirrels, Sciurus vulgaris from Slovakia. Zool. Anz.,
257, 96-102.
Degn, H.J. (1973) Systematic position, age criteria and reproduction of
Danish red squirrels (Sciurus vulgaris L.). Dan. Rev. Game Biol.,
8, 1-24.
Fokidis, H.B., Risch, T.S. & Glenn, T.C. (2007) Reproductive and resource
benefits to large female body size in a mammal with female-biased
sexual size dimorphism. Anim. Behav., 73, 479-488.
Fokidis, H.B. & Risch, T.S., (2008) Does gliding when pregnant select for
larger females? J. Zool., 275, 237-244.
Green, A. J. (1992) Positive allometry is likely with mate choice, competitive
display and other functions. Anim. Behav., 43, 170-172.
Hammer, Ø., Harper, D.A.T. & Ryan, P.D. (2001) PAST: Paleontological
statistics software package for education and data analysis, Palaeontol.
Electron., 4, 1-9.
Hayssen, V. & Kunz, T.H. (1996) Allometry of litter mass in bats: maternal
size, wing morphology, and phylogeny. J. Mammal., 77, 476-490.
Hayssen, V. (2008) Patterns of body and tail length and body mass in
Sciuridae. J. Mammal., 89, 852-873.
Koprowski, J.L. (2005) Annual cycles in body mass and reproduction of
endangered Mt. Graham red squirrels. J. Mammal., 86, 309-313.
Koprowski, J.L. (2007) Alternative reproductive tactics and strategies of
tree squirrels. In: Wolff, J.O., Sherman, P.W., (Eds.), Rodent societies:
An ecological and evolutionary perspective. Chicago and
London: The University of Chicago Press, pp. 86-95.
Lindenfors, P., Gittelman, J.L. & Jones, K.E. (2007) Sexual size dimorphism
in mammals. In: Fairbairn, D.J., Blanckenhorn, W.U., Szekely,
T., (Eds.), Sex, size, and gender roles: evolutionary studies
of sexual size dimorphism. Oxford: Oxford University Press, pp.
16-26.
Lurz, P.W., Garson, P.J. & Wauters, L.A. (2000) Effects of temporal and
spatial variations in food supply on the space and habitat use of
red squirrels (Sciurus vulgaris L.). J. Zool., 251, 167-178.
Lurz, P.W.W., Gurnell, J. & Magris, L. (2005) Sciurus vulgaris. Mammalian
Species., 769, 1-10.
Matějů, J. & Kratochvíl, L. (2012) Sexual size dimorphism in ground
squirrels (Rodentia: Sciuridae: Marmotini) does not correlate
with body size and sociality. Front. Zool., 10, 1-10.
McPehrson, F.J. & Chenoweth, P.J. (2012) Mammalian sexual dimorphism.
Anim. Reprod. Sci., 131, 109-122.
Mori, E. & Lovari, S. (2014) Sexual size monomorphism in the crested
porcupine (Hystrix cristata). Mamm. Biol., 79, 157-160.
Nandini, R. (2011) Evolution of sexual size dimorphism in squirrels.
Ph.D. Dissertation. Auburn University, Alabama, USA.
Petrie, M. (1992) Are all secondary sexual display structures positively
allometric and, if so, why? Anim. Behav., 43, 173-175.
Scheibe, J.S. & Robins, J.H. (1998) Morphological and performance attributes
of gliding mammals. Va. Mus. Nat. Hist. Spec. Publ., 6,
131-144.
Schulte-Hostedde, A.I., Millar, J.S. & Hickling, G.J. (2001) Sexual dimorphism
in body composition of small mammals. Can. J. Zool., 79,
1016-1020.
Schulte-Hostedde, A., Millar, J. & Gibbs, H. (2002) Female-biased sexual
size dimorphism in the yellow-pine chipmunk (Tamias amoenus):
sex-specific patterns of annual reproductive success and survival.
Evolution, 56, 2519-2529.
Schulte-Hostedde, A.I. (2007) Sexual size dimorphism in Rodents. In:
Wolff, J.O., Sherman, P.W. (Eds.), Rodent societies: An Ecological
and Evolutionary Perspective. The University of Chicago Press,
Chicago and London, pp. 115-128.
Thorington, Jr.R.W., Koprowski, J.L., Steele, M.A. & Whatton, J.F. (2012)
Squirrels of the World. Johns Hopkins University Press, Baltimore,
Maryland, p. 459.
Wauters, L.A. & Dhondt, A.A. (1989a) Body weight, longevity and reproductive
success in red squirrels (Sciurus vulgaris). J. Anim. Ecol.,
58, 637-651.
Wauters, L.A. & Dhondt, A.A. (1989b) Variation in length and body mass
in red squirrel in two different habitats. J. Zool., 217, 93-106.
Wauters, L., Dhondt, A.A. & De Vos, R. (1990) Factors affecting male
mating success in red squirrels (Sciurus vulgaris). Ethol. Ecol.
Evol., 2, 195-204.
Wauters, L.A. & Dhondt, A.A. (1992) Spacing behaviour of red squirrels,
Sciurus vulgaris: variation between habitats and the sexes. Anim.
Behav., 43, 297-311.
Wauters, L.A. & Dhondt, A.A. (1995) Lifetime reproductive success and
its correlates in female Eurasian red squirrels. Oikos, 72, 402-
410.
Wauters, L.A., Zaninetti, M., Tosi, G. & Bertolino, S. (2004) Is coat-colour
polymorphism in Eurasian red squirrels (Sciurus vulgaris L.)
adaptive? Mammalia, 68, 37-48.
Wauters, L.A., Vermeulen, M., Van Dongen, S., Bertolino, S., Molinari,
A., Tosi, G. & Matthysen, E. (2007) Effects of spatio-temporal
variation in food supply on red squirrel Sciurus vulgaris body size
and body mass and its consequences for some fitness components.
Ecography, 30, 51-65.
Wiltafsky, H. (1978) Sciurus vulgaris Linnaeus, 1758 – Eichhörnchen. In:
Niethammer J., Krapp, F. (Eds.), Handbuch der Säugertiere Europas.
Band 1, Rodentia 1 (Sciuridae, Castoridae, Gliridae, Muridae).
Akademische Verlagsgesellschaft, Wiesbaden, pp. 86-105.
Downloads
Published
Issue
Section
License
Copyright (c) 2015 Alexander Čanády, Ladislav Mošanský, Peter Krišovský
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Authors retain copyright in their articles.
Articles in the European Journal of Ecology published 2020 and after are made available under a Creative Commons Attribution 4.0 license.
Articles in the European Journal of Ecology published 2015-2019 are made available under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 license.
