{"id":1079,"date":"2018-11-27T22:42:25","date_gmt":"2018-11-28T05:42:25","guid":{"rendered":"https:\/\/blogs.ubc.ca\/communicatingscience2018w111\/?p=1079"},"modified":"2018-11-28T00:43:34","modified_gmt":"2018-11-28T07:43:34","slug":"interspecific-aggression-why-do-crows-attack-ravens","status":"publish","type":"post","link":"https:\/\/blogs.ubc.ca\/communicatingscience2018w111\/2018\/11\/27\/interspecific-aggression-why-do-crows-attack-ravens\/","title":{"rendered":"Interspecific Aggression: Why do Crows Attack Ravens?"},"content":{"rendered":"

Interspecific Aggression<\/h3>\n

Interspecific aggression is common in animals\u00a0(Peiman and Robinson 2010)<\/a> and well documented between species that are ecologically similar. There are generally five reasons why\u00a0heterospecific aggression occurs. The first reason may be a nonadaptive behaviour, where heterospecifics are mistakenly treated as if they belong to the same species. The rest assume that behaviour is adaptive and all differ in with benefits received is food, space, a mate or a predator-free space.<\/p>\n

Though competition for food resources and space is most commonly seen, interspecific aggression could be related to reproductive interactions and predation. Interspecific aggression toward a predator is called “mobbing”, which occurs when a group of individuals attack or harass a predator (Altmann 1956).<\/a><\/p>\n

crows vs ravens<\/h3>\n

Since crows and ravens belong in the same family (Corvidae), <\/em>the difference between them is hard to distinguish at first, but both inhabit distinct features.<\/p>\n

\"Image

A crow (left) and a raven (right) by Tom Grey<\/a>.<\/p><\/div>\n

The difference between the American Crow (Corvus brachyrhynchos<\/em>) and the Common Raven (C. corax<\/em>) are listed below:<\/p>\n

American Crow (C. brachryhynchos)<\/em><\/h5>\n
    \n
  • Straight beak<\/li>\n
  • Generally smaller<\/li>\n
  • Short rhythmic “caw”s<\/li>\n
  • Consistent flapping<\/li>\n
  • Fan-shaped tails<\/li>\n
  • Extremely social (large flocks)<\/li>\n<\/ul>\n
    Common Raven (C. corax)<\/em><\/h5>\n
      \n
    • Slight-point on beak<\/li>\n
    • Bigger<\/li>\n
    • Deeper raspy “croak”<\/li>\n
    • Soaring<\/li>\n
    • Wedge-shaped tails<\/li>\n
    • Not social (usually found as pairs or single birds)<\/li>\n<\/ul>\n

      Tune in on an episode of Animals and their Experts where the conflict between crows and ravens is explained.<\/p>\n