10
$\begingroup$

Introduction

Last week, I was in the Atacama desert where I've seen many cacti. Some / many of them were seemingly suffering from predation. Most of predation seemed to be on cardón, often restricted (but not only) at the interface between the woody bottom part and the green spiny part. It looks like a big piece (maybe over 300 $\text{cm}^2$) of the flesh was bitten away. Unfortunately, I do not have a picture.

These cacti have very long spines and it was unclear to me what predator could maintain selection for cactus lineages to produce that many large spines.

In the desert, I have seen rabbits, guanacos, small birds, vultures, large black coleoptera and butterflies.

Question

In the Atacama region,

  • What species predate on cacti?
  • Is there a single species that causes most of the predation on cacti?
$\endgroup$
  • $\begingroup$ What does it look like? Are there pieces bitten/picked out, scratches? $\endgroup$ – skymningen Sep 8 '17 at 7:35
  • $\begingroup$ In North America, bighorn sheep are known to eat Ferocactus sp (barrel cactus) by "pawing and butting at the cactus" (according to Warrick and Krausman, 1989). Were there any animals around that could do that? $\endgroup$ – Gaurav Sep 15 '17 at 22:53
  • 1
    $\begingroup$ Guanacos probably! I just had a hard time to imagine so few guanacos making so much damage to so many cacti. Also it was surprising to me that guanacos could deal with those spines but I guess that if bighorn sheep can, why guanacos could not! $\endgroup$ – Remi.b Sep 15 '17 at 23:34
  • $\begingroup$ I agree with @Remi.b. I would just also note that I have seen similar damage on candelabra (Browningia sp.) in northern Chile, where an apparently similar-sized wound was effected by perching raptors (scarred by talons). I am pretty sure that one of them was a variable hawk and another a mountain caracara. Also, you likely saw vizcachas, not rabbits! $\endgroup$ – Plantaloons Feb 15 at 16:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.