A new feature of adaptive colouration in ungulates: the fibular flag, part 2: Alces alces (Cervidae)

...continued from https://www.inaturalist.org/journal/milewski/70368-a-new-feature-of-adaptive-colouration-in-ungulates-the-fibular-flag-part-1-raphicerus-bovidae#

The moose (Alces alces, https://www.inaturalist.org/taxa/522193-Alces-alces) possesses a fibular flag (https://www.gettyimages.com.au/detail/photo/bull-moose-moving-through-northern-tundra-calling-royalty-free-image/657485842).

In this large-bodied cervid, the fibular flag covers the inner, and often also the outer, surfaces of the hindleg above the hock.

https://www.inaturalist.org/observations/107522426

The fibular flag of the moose is individually and seasonally variable, and also depends on illumination.

In the summer pelage, the fibular flag is poorly-developed (https://www.inaturalist.org/observations/179584604 and https://www.inaturalist.org/observations/170204579 and https://www.inaturalist.org/observations/79012704 and https://www.inaturalist.org/observations/31202401).

The following illustrate the fibular fag in Alces alces shirasi:
https://www.inaturalist.org/observations/22730337
https://www.inaturalist.org/observations/165808747
second photo in https://www.inaturalist.org/observations/183755724
https://www.inaturalist.org/observations/73121671
https://www.inaturalist.org/observations/4482611
https://www.inaturalist.org/observations/4308293

Fibular flag in Alces alces alces:
https://www.inaturalist.org/observations/35274716
https://www.inaturalist.org/observations/183855765
https://www.inaturalist.org/observations/183819576
https://www.inaturalist.org/observations/153934473
https://www.inaturalist.org/observations/46595843
https://www.inaturalist.org/observations/2922305

In nominate A. a. alces, the pale feature in question can be so expansive that the term 'fibular flag' no longer applies (https://www.inaturalist.org/observations/112176729).

ADDITIONAL ILLUSTRATIONS OF FIBULAR FLAG IN ALCES ALCES

https://www.inaturalist.org/observations/116777704

https://www.inaturalist.org/observations/115702446

https://www.inaturalist.org/observations/115325363

https://www.inaturalist.org/observations/115314501

https://www.inaturalist.org/observations/114790758

https://www.inaturalist.org/observations/112619055

https://www.inaturalist.org/observations/135414451

https://www.inaturalist.org/observations/115470987

https://www.inaturalist.org/observations/125843310

https://www.inaturalist.org/observations/121343112

https://www.inaturalist.org/observations/120257251

https://www.inaturalist.org/observations/129646111

https://www.inaturalist.org/observations/119626107

https://www.inaturalist.org/observations/119092478

https://www.inaturalist.org/observations/116521066

https://www.inaturalist.org/observations/134851345

https://www.inaturalist.org/observations/116789745

https://www.alamy.com/stock-photo-moose-from-behind-142718462.html

https://www.inaturalist.org/observations/131879614

https://www.inaturalist.org/observations/126552983

https://www.inaturalist.org/observations/125993345

Why A. alces is unusual, in possessing a fibular flag, is worthy of further investigation.

Posted on September 18, 2023 10:08 AM by milewski milewski

Comments

The following of Alces alces americanus shows that some individuals, in some circumstances, do not show any fibular flag. This is despite the presence of a pedal flag on the foreleg.

https://www.inaturalist.org/observations/176492198

Posted by milewski 6 months ago

The following shows that the fibular flag appears at the juvenile stage in Alces alces alces:

https://www.inaturalist.org/observations/171011163

Posted by milewski 6 months ago

Shift

Clear illustration of semi cross-walk:

https://www.inaturalist.org/observations/133255783

Posted by milewski 5 months ago

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