Hummingbirds, praying mantis, bees at Texas feeder


This video from the USA says about itself:

Praying Mantis Visits Hummingbird Feeder In West Texas – June 25, 2020

A praying mantis drops down to the hummingbird feeders and scuttles from port to port, likely in search of an insect [bee] meal. In rare cases, larger mantids have been documented staking out hummingbird feeders and preying on the birds that visit, but this individual is too small to be a risk to the birds.

Butterfly, hummingbirds at Texas, USA feeders


This video from the USA says about itself:

Butterfly Visits West Texas Feeders Alongside Hummingbirds – June 17, 2020

Enjoy watching a cloudless sulphur butterfly sip nectar from the West Texas hummingbird feeders as hummers hover from port to port.

Hummingbirds see more colours than humans


This 2018 video is called Beautiful hummingbirds show off their breathtaking colors.

From Princeton University in the USA:

Spectacular bird’s-eye view? Hummingbirds see diverse colors humans can only imagine

Team trains wild hummingbirds to discriminate UV color combinations

June 15, 2020

Summary: While humans have three color cones in the retina sensitive to red, green and blue light, birds have a fourth color cone that can detect ultraviolet light. A research team trained wild hummingbirds to perform a series of experiments that revealed that the tiny birds also see combination colors like ultraviolet+green and ultraviolet+red.

To find food, dazzle mates, escape predators and navigate diverse terrain, birds rely on their excellent color vision.

“Humans are color-blind compared to birds and many other animals,” said Mary Caswell Stoddard, an assistant professor in the Princeton University Department of Ecology and Evolutionary Biology. Humans have three types of color-sensitive cones in their eyes — attuned to red, green and blue light — but birds have a fourth type, sensitive to ultraviolet light. “Not only does having a fourth color cone type extend the range of bird-visible colors into the UV, it potentially allows birds to perceive combination colors like ultraviolet+green and ultraviolet+red — but this has been hard to test,” said Stoddard.

To investigate how birds perceive their colorful world, Stoddard and her research team established a new field system for exploring bird color vision in a natural setting. Working at the Rocky Mountain Biological Laboratory (RMBL) in Gothic, Colorado, the researchers trained wild broad-tailed hummingbirds (Selasphorus platycercus) to participate in color vision experiments.

“Most detailed perceptual experiments on birds are performed in the lab, but we risk missing the bigger picture of how birds really use color vision in their daily lives,” Stoddard said. “Hummingbirds are perfect for studying color vision in the wild. These sugar fiends have evolved to respond to flower colors that advertise a nectar reward, so they can learn color associations rapidly and with little training.”

Stoddard’s team was particularly interested in “nonspectral” color combinations, which involve hues from widely separated parts of the color spectrum, as opposed to blends of neighboring colors like teal (blue-green) or yellow (green-red). For humans, purple is the clearest example of a nonspectral color. Technically, purple is not in the rainbow: it arises when our blue (short-wave) and red (long-wave) cones are stimulated, but not green (medium-wave) cones.

While humans have just one nonspectral color — purple, birds can theoretically see up to five: purple, ultraviolet+red, ultraviolet+green, ultraviolet+yellow and ultraviolet+purple.

Stoddard and her colleagues designed a series of experiments to test whether hummingbirds can see these nonspectral colors. Their results appear June 15 in the Proceedings of the National Academy of Sciences.

The research team, which included scientists from Princeton, the University of British Columbia (UBC), Harvard University, University of Maryland and RMBL, performed outdoor experiments each summer for three years. First they built a pair of custom “bird vision” LED tubes programmed to display a broad range of colors, including nonspectral colors like ultraviolet+green. Next, they performed experiments in an alpine meadow frequently visited by local broad-tailed hummingbirds, which breed at the high-altitude site.

Each morning, the researchers rose before dawn and set up two feeders: one containing sugar water and the other plain water. Beside each feeder, they placed an LED tube. The tube beside the sugar water emitted one color, while the one next to the plain water emitted a different color. The researchers periodically swapped the positions of the rewarding and unrewarding tubes, so the birds could not simply use location to pinpoint a sweet treat. They also performed control experiments to ensure that the tiny birds were not using smell or another inadvertent cue to find the reward. Over the course of several hours, wild hummingbirds learned to visit the rewarding color. Using this setup, the researchers recorded over 6,000 feeder visits in a series of 19 experiments.

The experiments revealed that hummingbirds can see a variety of nonspectral colors, including purple, ultraviolet+green, ultraviolet+red and ultraviolet+yellow. For example, hummingbirds readily distinguished ultraviolet+green from pure ultraviolet or pure green, and they discriminated between two different mixtures of ultraviolet+red light — one redder, one less so.

“It was amazing to watch,” said Harold Eyster, a UBC Ph.D. student and a co-author of the study. “The ultraviolet+green light and green light looked identical to us, but the hummingbirds kept correctly choosing the ultraviolet+green light associated with sugar water. Our experiments enabled us to get a sneak peek into what the world looks like to a hummingbird.”

Even though hummingbirds can perceive nonspectral colors, appreciating how these colors appear to birds can be difficult. “It is impossible to really know how the birds perceive these colors. Is ultraviolet+red a mix of those colors, or an entirely new color? We can only speculate,” said Ben Hogan, a postdoctoral research associate at Princeton and a co-author of the study.

“To imagine an extra dimension of color vision — that is the thrill and challenge of studying how avian perception works,” said Stoddard. “Fortunately, the hummingbirds reveal that they can see things we cannot.”

“The colors that we see in the fields of wildflowers at our study site, the wildflower capital of Colorado, are stunning to us, but just imagine what those flowers look like to birds with that extra sensory dimension,” said co-author David Inouye, who is affiliated with the University of Maryland and RMBL.

Finally, the research team analyzed a data set of 3,315 feather and plant colors. They discovered that birds likely perceive many of these colors as nonspectral, while humans do not. That said, the researchers emphasize that nonspectral colors are probably not particularly special relative to other colors. The wide variety of nonspectral colors available to birds is the result of their ancient four color-cone visual system.

“Tetrachromacy — having four color cone types — evolved in early vertebrates,” said Stoddard. “This color vision system is the norm for birds, many fish and reptiles, and it almost certainly existed in dinosaurs. We think the ability to perceive many nonspectral colors is not just a feat of hummingbirds but a widespread feature of animal color vision.”

North American rufous hummingbirds, video


This April 2020 video says about itself:

The Rufous Hummingbird is a priority species for us at American Bird Conservancy due to significant population declines. In spite of its small size, it’s the most aggressive of the North American hummingbirds, often attacking birds many times its size in defense of its territory. It reigns supreme at feeders and choice flower patches.

Video by Don DesJardin.

Ruby-throated hummingbird videos


This 24 April 2020 video from North America says about itself:

Ruby-throated Hummingbird, Gorget-Flasher

Video by Timothy Barksdale, Macaulay Library at Cornell Lab of Ornithology.

This 21 April 2020 video from North America says about itself:

Ruby-throated Hummingbird and Coneflower

Video by Justin Hoffman.

Black-chinned hummingbird in Texas, USA


This video from the USA says about itself:

Male Black-chinned Hummingbird Dips And Sips In West Texas – May 1, 2020

The West Texas Feeder cam is about to be aflutter with migrant hummingbirds this spring. Watch this male Black-chinned Hummingbird dip and sip while it hovers (as this species often does while foraging) at the feeder.

Hummingbirds and trees in Panamanian rainforest


This video says about itself:

Hummingbirds buzzing in sanctuary at Panama Rainforest Discovery Center

Extensive 22-minute compilation of stock footage in 4K of hummingbirds flying, feeding and perched at Panama Rainforest Discovery Center located at the end of Camino Del Oleoducto near the town of Gamboa about 20 kilometers north of Panama City filmed in November 2016. The hummingbird feeders at the Discovery Center are placed to attract a large variety of wild hummingbirds present in the jungles of the Soberania National park in a natural and unrestrained environment with no nets or cage.

Species seen in this compilation are Violet-bellied Hummingbird (Damophila julie), White-necked Jacobin (Florisuga mellivora), Rufous-tailed Hummingbird (Amazilia tzacatl), Long-billed Hermit (Phaethornis longirostris) and Semiplumbeous Hawk (Leucopternis semiplumbeus).

From the University of Illinois College of Agricultural, Consumer and Environmental Sciences in the USA:

Hummingbirds show up when tropical trees fall down

April 23, 2020

When the tree fell that October in 2015, the tropical giant didn’t go down alone. Hundreds of neighboring trees went with it, opening a massive 2.5-acre gap in the Panamanian rainforest.

Treefalls happen all the time, but this one just happened to occur in the exact spot where a decades-long ecological study was in progress, giving University of Illinois researchers a rare look into tropical forest dynamics.

“I’ve been walking around that tree for 30 years now. It was just humongous,” says Jeff Brawn, Professor and Stuart L. and Nancy J. Levenick Chair in Sustainability in the Department of Natural Resources and Environmental Sciences at Illinois. “Here we are, running around on this plot for years and all of a sudden I couldn’t even find my way around. We just lucked into it.”

What’s lucky is that Brawn and his colleagues had amassed decades of data on the bird community in that exact spot, meaning they had a clear before-and-after view of what a treefall could mean for tropical birds.

This particular gap meant hummingbirds. Lots and lots of hummingbirds.

“After the treefall, we saw a very large spike in the total number of hummingbird species,” says Henry Pollock, a postdoctoral scholar working with Brawn and lead author on a study published in the Journal of Field Ornithology. “Within the previous 25 years of the study, we had only documented three or four hummingbird species, and they were usually present in low numbers. There was one species, the snowy-bellied hummingbird, which we had never captured on either of our two plots in 25 years of sampling. The year after the treefall happened, we got 16 unique individuals of this one species, and total diversity of hummingbirds more than doubled.”

The gap also attracted fruit-eating birds. The researchers documented a doubling of this group compared to pre-treefall numbers, with certain species being more than three times as abundant. Other species, including the thick-billed seed-finch, which typically inhabits grasslands, appeared as if out of thin air.

“They just swooped in,” Brawn says. “It’s analogous to a backyard bird feeder. As soon as you put one in, you’ll see species you’ve never seen before.”

And then, almost as quickly, the birds disappeared.

Within one to four years, depending on the species, the birds returned to pre-treefall numbers or were not detected again.

“What that suggests is these birds are incredibly mobile and opportunistic,” Pollock says. “They are probably just cruising around the landscape prospecting for their preferred food sources and habitats. Given the sheer size of this gap, it acted as a sort of magnet, pulling in species from potentially kilometers away. I mean, 16 snowy-bellied hummingbirds and we’ve never caught one before? It’s pretty astounding.”

Treefalls are a common and necessary occurrence in forests all over the world. As sunshine streams in from above, trees hunkered down in the understory finally get their chance to rise. Basking in the suddenly resource-rich environment, tropical trees and other plants produce nectar-filled flowers and fruit, important food sources for birds and other animals.

Previous research has hinted at how important these food sources are for tropical birds, but no one had documented before-and-after differences until now. Instead, researchers typically compared treefall gaps with intact forest areas at a single time point. That approach has its uses, but it can’t capture what Brawn and Pollock found: just how quickly the birds arrived on the scene, and how quickly they left.

“I was just really just astonished at how quickly and how efficiently these birds seem to be able to find and exploit a new source of food,” Brawn says.

Gaps don’t stay open long in the tropics. Understory trees shoot up, elbowing each other out of the way to take the top spot. Soon, there’s no evidence a gap — or its riotous array of feathered occupants — was there at all.

As short-lived as they may be, treefall gaps represent critical opportunities for species turnover, especially in the tropics where forest fires are comparatively rare.

“This kind of periodic disturbance is probably necessary for these birds to persist in the landscape matrix,” Pollock says. “That’s true for many organisms and ecosystems; our study provides evidence to back that up in these birds.”