Fear causes an inability to thrive in humans. Now a new study shows this is true of birds as well.
As a grad student at University of Massachusetts in Amherst, Aaron Grade decided to parse out why urban nestlings are lower weight than their rural cousins. It’s well known that urban settings have poor habitat, altered food sources and more predators but the likelihood of predation is lower there because urban predators have so many other food choices.
Grade wondered if fear play a role so he set out 38 house wren nest boxes and loudspeakers in participants’ backyards in urban, suburban and rural western Massachusetts. During the nesting season participants played back the sounds of two predators of house wrens: Cooper’s hawks (pictured at top) and eastern screech-owls (below).
Though there was no actual danger, parent house wrens responded to the sounds by guarding their young and perhaps feeding them less. In the end nestlings in these playback settings were 10% underweight no matter what habitat they grew up in.
The study found that whether the birds are hurt or not, their nestlings are underweight and less likely to survive if the family lives in fear.
“These landscapes of fear,” says Grade, “can have a greater effect on behavior and survival than the actual predator itself.”
Mid-August is a quiet time for the Cathedral of Learning peregrine falcons. This year’s youngsters have left the area to begin their life adventures while the adults stay close to home and wrap up their annual molt.
Morela and Ecco rarely visited the nestbox in July but last Thursday 12 August they spent eight minutes bowing together. They were not courting. They were strengthening their pair bond.
Morela calls to Ecco, 10:32am 12 August 2021
Ecco almost leaves
but he returns
and Morela leaves
Ecco goes back and forth, 3 times
After 20 minutes, Ecco leaves
In other news, I usually don’t check the snapshot camera but when I did so on Monday 9 August at 4:44am Morela was perched there in the dark. This was a one-time event.
To check the snapshot camera scroll down on this webpage to see the 2nd image. NOTE: The first image is the streaming camera which is not functioning now.
When hummingbirds sip nectar it can change their external body temperature. The change is visible in this thermal video of an Anna’s hummingbird by Gary Nunn.
After waiting four months I finally got my Pulsar Helion 2 XP50 Pro thermal scope! This thing is amazing—can’t wait to get out in the field with it. Anna’s Hummingbird taking a sip of jet fuel ? pic.twitter.com/iJsgmG0AvC
Many would say the bald eagle is the king of birds but when it comes to attitude, actions and name the small songbird attacking this eagle is both King and Tyrant.
Attitude: The eastern kingbird is often fierce and angry. This one is showing the orange-red crest he keeps hidden beneath his head feathers until he’s very, very mad.
Actions: Eastern kingbirds relentlessly defend their territories and will (obviously) ride the backs of hawks and eagles to peck their heads.
Males and sometimes females are very aggressive in territorial disputes [with other kingbirds], often resorting to aerial fights in which they lock feet together, pull out each other’s feathers, and sometimes fall to the ground. Eastern Kingbirds also attack large nest predators like crows and Blue Jays. Such aggression has been shown to increase their breeding success.
"Hey Ecco!" Morela bows as Ecco arrives from top left
Shaking off the rain
Both at once!
18 July 2021
This spring Ecco and Morela successfully raised four young peregrines at the Cathedral of Learning. All four fledged in early June and became independent in the subsequent weeks. One or two stopped by for a handout in early July but Ecco and Morela were having none of it. “You’re on your own.”
Now that the “kids” are gone (wrong! see below), Ecco and Morela are molting and staying close to home. In the past two days they have visited the nest several times and bowed together for a little pair bonding.
p.s. In the slide with Morela’s open wings, notice that she is replacing her middle two tail feathers. The white tips are halfway down her tail.
UPDATE 18 July 2021 at 5pm: The “kids” aren’t all gone. One of the youngsters was circling and begging loudly at 5pm at the Cathedral of Learning.
The female goldfinch builds her nest in a shrub or sapling, laying a foundation of spider silk and adding rootlets and fibers. Then she lines the nest with soft down, often using thistle fluff.
She lays one egg per day for a clutch of five and starts incubation at the next-to-last egg. In 12-14 days her babies hatch.
It’s still July. Now the fun begins!
The parents make many trips back and forth from thistle fields to the nest where they feed by regurgitation. Sometimes the adults munch on leafy vegetables, even in gardens, which earned them the nickname “Salad Birds.”
On Wednesday Bob Donnan emailed me with photos of a tufted titmouse in a very odd posture: “Noticed a bird on the roof of our shed doing this just before lunch. … It seemed fine, since it flew away within a minute after I took these photos.”
On sunny hot days you may see a bird perched or lying flat like this titmouse with its wings spread, feathers fluffed, beak open, and one side of its face turned to the sky. This bird is sunbathing.