Is there any trace of a forearm flag in the largest felids?


We have seen, in two recent Posts (, that at least seven genera and 15 species of felids share barring on the inner foreleg, which

All of these are small to medium-size except for the puma.

My explanation for this pattern is that small felids are vulnerable to large felids and hyenas. Where the predatory regime is most intense it may pay to express the latent conspicuousness of the inner foreleg in the form of warning colouration.

How can we test this explanation?

One way is to see if the largest felids, which are at or near the top of the predatory hierarchy, lack the aforementioned latency. For the explanation to be borne out, the 'big cats' should have patterns on the inner foreleg which

  • are completely congruent with the camouflage colouration,
  • lack any incipient/residual trace of barring, and also
  • are consistent with the inner hindleg.

The cheetah is low in the predatory hierarchy. However, we can include it here because it is as large as the leopard, the snow leopard and the puma.

Please see the photos below, which show that in most of the 'big cats' there is a slight tendency for the inner surfaces of the legs to be striped - or at least for the spots to be aligned - even where the colouration on the torso lacks any striping. This makes it important to compare fore- and hindlegs.

On this basis, I see no potential for warning colouration on the inner foreleg in lion or snow leopard.

There is slight potential in the leopard because of a tendency for the spots to be more aligned on the inner foreleg than on the inner hindleg (an extreme example is

In the tiger, the similarity between inner fore- and hindleg in striping might rule out any latency for warning colouration, were it not for the intriguing facts that

  • the ground-colour is white on the inner foreleg vs fawn on the inner hindleg, and
  • the outer foreleg tends to be free of striping.

All that would be needed for a forearm flag to be expressed in e.g. or is a dimming of the general striping and a widening of the dark stripes on the inner foreleg to form bold barring.

The jaguar is ambivalent in a different way. The pattern on the inner foreleg is more complicated and more individually (and regionally?) variable than in the closely-related leopard.

It is intriguing to find traces, however ambivalent, of a potential for warning colouration in both jaguar and puma (see and and and

This is because these species, across the Americas until about ten thousand years ago, were vulnerable to carnivores larger than not only themselves but also the extant lion in Africa and India. I refer to Smilodon populator, Panthera atrox and several particularly large, short-faced bears (Arctodus and Arctotherium).

The cheetah, perhaps surprisingly, shows little potential for any barred pattern on the inner foreleg: at best a slight alignment of the spots in some individuals.

In summary:

  • only lion, leopard, snow leopard and cheetah emerge as categorically lacking any latent pattern for the forearm flag, and
  • jaguar, puma and even tiger retain ambivalent patterns, notwithstanding the difficulty of imagining any biogeographical situation in which the tiger could have found itself low in the predatory hierarchy.

Lion and and

Tiger and and and and and

Leopard and and and and and

Jaguar and and and and

Snow leopard and and

Cheetah normal morph and and and and and and and

Cheetah 'king' morph and and and

Publicado el agosto 10, 2021 01:59 TARDE por milewski milewski


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