It will also do this if it is accidentally attacked by the lesser species, either by misguided attack or during mounting. Oftentimes if a group of Calliprey try to take a bite from the carcass the alpha is currently eating, the Callidrome will headbutt them as a warning. As alphas of the Calliprey, the lesser species will not huddle in a corner.Ĭallidrome leave behind Rock Dents on hard surfaces to claim their territory.Ĭallidrome have no special interactions with the locale to note. Will typically fight anything that it thinks its pack can take on. Predators, but are easy meals for many larger monsters. Like many other alphas, it rules with an iron fist over the Calliprey pack it leads, asserting its own dominance by landing heavier headbutts.Įcological Information Placement In Food Chain In addition, the retractable claws on its hind legs have turned dirt brown in colour. Along with this, its facial armour has taken over a majority of its head. "The young males or the older, more senescent males do it less because they're just less able to be successful if there is an aggressive contest that follows," Nowicki says.To mark their position as alpha, their horn-like growths have grown to a larger size, along with a small bump on it. But weaker birds don't have the wherewithal to fight a lot. The tougher birds fight them off, and after that, they're pretty much left alone. One reason could be that when the kites add plastic, their nest immediately draws attention and attacks by other birds looking for food or a new nest. That requires some capacity to self-assess, realize that the signal that you find on your nest is off and then adjust it," he says. "Some of the individuals actually did not want it at all they immediately removed it," Sergio says. In fact they actually rejected the plastic when scientists added it to their nests. The weaker birds - the youngest and the oldest - do not. Think Harley-Davidsons and tattoos.īut the bravado is real because only the stronger, tougher nesting pairs decorate this way. Sergio and his team think it's a construction that signals bravado. Stephen Nowicki, evolutionary biologist, Duke University But Fabrizio Sergio of the Spanish High Council for Scientific Research says this is a pose of a different color.Ī male who is in his prime is going to put more decoration on because he can back up his signal. Lots of animals do things to show either toughness or sexual allure - they'll dance or bellow or display some overgrown body part. Slowly, this decorating habit started to make sense: It was a signal by the strongest birds that they were tough and could protect their nests. So a research team set up in a national park in Spain and recorded and videoed kites in 127 nests for five years. It's not just any kind of plastic that works, though - it's only white plastic bits and pieces the birds scavenge and lay inside their nests alongside their eggs.īiologists wondered for years why these big predatory birds do this. The raptors decorate their nests with plastic - apparently to scare other birds off. Since the 1980s, researchers have been tagging birds in a population to track them through their life spans.īut scientists in Spain have discovered a very different kind of signaling by birds called black kites. An eight-year-old black kite watches an intruding individual from its perch.