Rhinoceros Hornbills: Romance Blooms

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A male, left, feeds his mate.

This is Chapter 2. Be sure to read Chapter 1, Rhinoceros Hornbills: A Fairy Tale.

January 6, 2010, the male and female rhinoceros hornbills moved into their new home. Once again, keepers were ready to break up any fighting. Once again, the birds showed us just how much they liked being with each other. With hardly a squabble, the male picked up a piece of food, hopped over to his new enclosure mate, and offered it to her. She daintily took the food and swallowed it. Over the next few weeks, the male solidified his bond with the female by bringing her the best food items in their pan. He may not have been just trying to be “nice,” though: food sharing is an extremely important part of the courting process.

In many bird species, the male may offer food to the female to show what a good provider he would be for any young that they may have together. With rhino hornbills, this is especially true because of their unique way of protecting their nest. As with many hornbills, the female rhino hornbill finds a cavity in a large tree that serves as her nest. By using food, saliva, and feces, the female makes a “wall” that seals her in the nest. This wall helps to keep her safe during the long egg laying, incubating, and chick-rearing process. She does leave a small hole by which the male can pass food to her, but she is then completely dependent on the male for both her and their chick’s survival.

March 10 was the day the female finally stopped exploring her enclosure and instead sat in her nest all day long. The keepers were both ecstatic and guarded. The female might have been too old to reproduce (she had not successfully reared a chick since 2001). What were the chances that this new pair would get it right only months after first being introduced? The female went into the nest box, and over the course of a few days she sealed herself into the nest. With the male diligently bringing the majority of the food to the nest box, keepers were confident that the female was getting all the grub she could have asked for. It got quiet for a while in that aviary: the morning honking had stopped. There was just the quiet, predictable routine the male had established to keep his mate well fed.

For a few months the male was mostly aloof toward his keepers and stayed out of our way during servicing. That all changed in early May. It was almost like a light switch had been flipped. The aloof male became something of a food monster! He couldn’t get to his food pan quickly enough, he couldn’t eat fast enough, he couldn’t get to the nest speedily enough! We couldn’t be sure, but it looked like our new male hornbill was a new daddy!

Check back soon for the next chapter of this tale!

Mike Grue is a senior keeper at the San Diego Zoo.