Why birds nest near alligators and hawks

This video from the USA says about itself:

Black-chinned hummingbird nesting

8 June 2015

Tucson Arizona. April 24-June 03

Momma building a nest, incubating eggs, feeding young and babies fly off.

One day I was looking out my skinny slice of a bathroom window and I saw a pine tree that had some busy hummingbird activity. I tried to rig up and video from the bathroom window but the vantage point was not good.

I did not want to intrude or cause stress to the mother so from the ground with a tripod set at the highest setting I used a Canon Vixia video camera, 37x zoom, fixed focus and daylight white balance, sometimes I had to adjust the exposure. Using a 64GB card I set up the camera at dawn and just hit record and walked away. When the card was full in a few hours I transferred to a Mac using Final Cut Pro X and selected the clips. Mostly nothing was happening. When all was done the video timeline was about two hours and then I started to eliminate redundant. At thirteen minutes it is still too long but people who like hummingbirds enjoy every minute.

One early morning I found the nest empty as they had already left. I examined the ground below to see if they had fallen out of the nest but that was not the case.

Out of the corner of my eye I spied some bird movement and there was a baby hummingbird on an oleander branch being nurtured by mom. The other baby bird was not to be seen.

Momma often pecked at the baby on the branch— at the head and body trying to encourage flight. And eventually they were both gone. But during the day and the next day there was much flight amongst the pine tree and oleander. Flight training I assume.

I opted to detach and delete the ambient audio as it is near our pool pump and it was annoying.

From the NestWatch eNewsletter in the USA, May 2016:

The Predator Next Door

You might think that a nesting bird would want to be as far away from a predator as it could get and, generally speaking, that’s true. However, it could be very strategic to nest near a predator that is two or more steps above you in the food chain (i.e., your predators’ predator). In this way, some birds derive protection from larger, more aggressive species that keep generalist predators at bay. This phenomenon is called a protective nesting association. Here are two of our favorite examples of nest-protecting predators:

Alligators and Wading Birds

In the southeastern United States, researchers found that wading birds such as herons, egrets, ibises, storks, and spoonbills appear to seek out alligator-inhabited waters above which they can nest. The alligators keep away (or eat) nest predators such as opossums and raccoons, and they cannot climb trees to rob nests themselves. However, the alligators certainly claim any chicks that fall out of the nests from time to time, making it likely that they are also benefiting from their avian neighbors.

Hawks and Hummingbirds

Black-chinned Hummingbirds nesting in southeastern Arizona were found to cluster their nests around the nests of Northern Goshawks and Cooper’s Hawks. Both species of hawk prey on birds, but would not normally bother with something as small as a hummingbird. Researchers found that hummers that nested within 300 meters of the hawks were much more likely to successfully raise young than those that nested farther away.

At least 92 such associations have been documented so far. It is unclear whether the recipients of the protection actively seek out these “protectors,” or if they are simply recognizing that an area has fewer nest predators. Either way, it can pay off to have a formidable carnivore for a neighbor…as long as you fly under the radar.