Posts tagged “garbage

Raven yanks another raven’s tail

The average adult raven is about 2.5 pounds and it’s hard to tell adults from juveniles.  The below video shows a power struggle between ravens at a food source.  At the very beginning you can see a raven on the far left grab another raven’s tail feathers with his beak and pull him or her away from the food.  Another seems to join in.  (By the way, if the video is blurry find the settings in the bottom right hand corner of the player and change it to a higher resolution.  Youtube automatically chooses a low setting so it will download faster.)

After reading Ravens in Winter, a book by Bernd Heinrich, I’m inclined to believe that the commotion going on in the video has to do with a power struggle (to gain access to the food) between the juvenile birds and the adults.  According to Heinrich, adults are usually silent at carcasses (dead animals in the wild), and juveniles are very noisy.  The juveniles “yell” at kills and make a commotion, possibly to attract more juveniles to the kill, in order to compete with the adults and gain access to the food.

Heinrich “proves” through observation and careful note-taking that ravens actively recruit other ravens to food piles.  He speculates, after studying raven behavior for many years, that this recruitment is not necessarily altruistic, or done in order to get the favor back some day.  Instead, it is probably related more to “gaining or maintaining access to the food than to sharing the wealth.”

Juveniles actively recruit, in order to overwhelm by sheer numbers, the adults at the carcass, so that the adults will give up defending the carcass, which they do when they are just too outnumbered.

So if we can extend this power struggle at carcasses in the field to city food (trash) then it’s possible the squawking raven in the video, the one being pulled from the food by his or her tail feathers, is likely a juvenile, being bossed around by the adults, who are not as vocal.

I strongly encourage any bird lover to read Ravens in Winter.  This bird that I see nearly every day of my life is actually quite mysterious and Heinrich helps us understand their possible and likely motivations.

Thanks for reading!  Happy New Year!

 


A Bridge to the Birds of Paradise

Sian Ka’an Biosphere Reserve was the single most heavenly tropical place I’ve ever been.  Even without the amazing birding experience, I would go back in a second.

Sian Ka’an is close to Tulum, Mexico on the Yucatan Peninsula – a dazzling coastal ecosystem.  My husband and I rambled along in our rented Jeep with no A/C on a long white gravel road that winds along the coast of the Caribbean Sea.  It was a drop dead gorgeous sunny hot day.  The shining white beaches were radiant even with the washed-up garbage strewn about.  I hopped over photo op after photo op, looking for pieces of beach glass (something I could do for days, weeks, months!).

If it had been our choice, my husband and I would have driven that road till the end. But as we all know, daylight is limited and vacation time goes especially fast.

Possibly the best part of Sian Ka’an was the old weathered bridge that stood alongside the newer bridge that we traveled on.  They cross a beautiful blue-green river that flows into the ocean.  You can see a video of them here.

Locals fished off the bridges, breezes relieved the heat, and I found bird after bird to photograph.   To the left are female and male Great-Tailed Grackles.  The gull, tern, and turnstone were firsts for me (below).

I’ll fondly remember this old weathered bridge for all my days, along with the fine feathered friends I met that day.