Friday, May 31, 2013

I Found A Baby Bird...Now What?

You've found a baby bird. Does it need help? What should you do? The Ustream Decorah Eagle mods made me aware of a flowchart to help answer your baby bird questions. Since we've been watching fledgling birds in our yard for the past week, I thought I would share it.

This particular flowchart was made by WildCare in San Rafael, California, but you can substitute the name of a local rehabilitation organization if you find a bird that needs care. If you don't know of an organization near you, try searching this website. You can look by location, browse a large list, or filter by animal:

By animal:
By zipcode and location:
By state:

Thanks to WildCare for sharing this flowchart! Please pass it on!

Thursday, May 30, 2013

IR Reflective Feathers and Facial Disks

While creating owl highlights this morning for our Eaglecrest site, I came across some very close-up footage of a fledgling owl's face. As the capture above shows, the young owl has a lovely ring of IR reflective feathers around its facial disk. I was curious, so I did a little research. If owls can't see IR light, why would they have IR reflective feathers? Although I wasn't able to find much on IR and feathers, it seems most likely that the ring is produced by melanin, which fluoresces under IR light. Melanin not only produces colors ranging from dark black to reddish brown and pale yellow, it also makes feathers stronger, stiffer, and more resistant to wear.

While many birds have some amount of melanin in their feathers, especially stiff wing primaries, owls instead have porphyrin, a pigment that doesn't stiffen feathers. Soft, serrated feathers aid an owl's silent flight by breaking up turbulence. An angry peregrine falcon whooshes by you, but you won't hear an owl coming (cue creepy music here). Owls are the only birds known to use porphyrin in their wing feathers.

The rigidity of a material also impacts the way it reflects sound. Rigid materials reflect sound better and more quickly than softer ones. To quote: "The speed of sound in a medium is determined by a combination of the medium’s rigidity and its density. The more rigid the medium, the faster the speed of sound." A wall or canyon might produce an echo, but a pillow won't. I tried it myself, just to make sure.

So soft feathers are wonderful for silent flight, but they don't reflect sound nearly as well as rigid feathers. I am speculating that our little barn owl has a ring of stiff, melanin-producing feathers around its facial disk. The stiff feathers channel sound better and more quickly than soft ones would - absolutely crucial for an animal that hunts in little or no light. The contrast between the owl's porphyrin and melanin laden feathers produces a ring effect that might not be noticeable in a bird with more melanin. It is interesting to speculate that 'echoes' produced by the irregularly shaped ring might also aid directional hearing. Changes in the speed of sound might help owls gauge prey distance and location much as bats use echolocation (aside: this might be the most hilarious video about echolocation ever made).

We know that an owl's facial disk is special in many ways, and that barn owls in particular seem to be well-adapted for low to no-light hunting. This looks like another example of owl adaptation in action.

Thanks to the camera operators at Eaglecrest for the wonderful video! The following things helped me learn about this topic:

Wednesday, May 22, 2013

The Riverside Herons, Xcel Energy, and Rob MacIntyre

The herons return. Thanks to Nora for the cap
Two years ago today, Raptor Resource Project Board President Rob MacIntyre suffered cardiac arrest while assisting his neighbors with cleanup after a tornado in north Minneapolis, MN. He was just 53 years old. The tornado also took the life of Floyd David Whitfield and damaged or destroyed 3,700 properties, including a blue heron colony located in the North Mississippi Regional Park. 

On June 6th of 2011, Xcel Energy staff at the Riverside Plant in northeast Minneapolis informed Dan Orr that blue herons had shown up on a small island owned by the plant. The island, which is sited roughly 50 feet from the east bank of the Mississippi, is believed to be man-made. It may have been built to control water flow or timber floating down the river in the 1890s, when Minneapolis was home to many saw mills. The industry faded in the early part of the 20th century, and the small island quickly became covered with trees. 

The tornado had been devastating, but the re-establishment of the heron rookery provided a lot of hope. We were thrilled with the connection to Rob, his beloved north Minneapolis, and Xcel Energy. Since the Riverside plant already had a falcon cam, adding a heron cam was easy. We also added a kestrel nest box to the plant's reclaimed coalyard, which had been turned into prairie grass. We'll be checking that and the falcon box sometime next week. 

The herons returned in 2013 for a third season on the little island. We hope you enjoy watching them. Fly high, Rob, and know that people still love and care for you. We wish you were here to see the wonderful things that have happened since 2011. 
Rob installing a falcon nestbox at Greysolon Plaza in Duluth


In addition to being silent flyers, owls are remarkably cryptic. This photo shows a barn owl, possibly mother Tess, perched just outside the nest cavity. She has flattened herself against the tree and is holding one wing down. Her barred wings break up her outline, making her difficult to see against the tree's rough bark.

Camouflage exists in two basic forms: crypsis and mimesis. Cryptic camouflage makes animals hard to see, while memesis, or mimetic camouflage, disguises them as something else.

Visual crypsis can be achieved in many different ways. When Tess is perched as she is above, her colors and patterns resemble a natural background. Owls are adapted for exceptional camouflage when roosting and hunting. Many species have colors and patterns that mimic the bark of preferred trees, which may explain the incredibly variety of color and pattern morphs seen in many widely distributed owl species.

Disruptive patterns use strongly contrasting, non-repeating markings such as spots or stripes to break up outlines. Tess's barred wings, plumage, and dark spots help break up her outline, making her difficult to see. Her spots also make her more attractive to male barn owls, who exhibit a clear preference for spotted females. The bigger and darker the spots, the better!

Cryptic patterns and coloration don't work as well when an animal is moving. While the fledgling owls aren't acting particularly cryptic, adult owls have very cryptic behavior. They perch quietly and hunt stealthily. Their soft feathers reduce turbulence, muffling the sound of air flowing over their wings. As the young owls learn how to fly and hunt, they will become increasingly cryptic as well.

The combination of stealthy coloration, disruptive patterns, and cryptic behavior make owls very cryptic, or hard to see. But some people believe that kestrels practice mimetic camouflage. The picture to the right shows the kestrels nesting at Xcel Energy's Pawnee Station earlier this year. The male is on the left and the female is on the right. They are facing forward, so we can see the dark 'eye spots' on the back of their heads. This mimetic false face might confuse predators into thinking that the back of a kestrel's head is actually its front.

Like many ground-nesting birds, Killdeer lay very cryptic eggs. I find it extremely difficult to see the Killdeer egg in this video, even though she lays it right in front of us (it can briefly be seen about 52 seconds into the video). Both of the adults are quite cryptic against the gravel road. However, they also practice a distraction display that disguises a healthy bird as an injured one and helps protect the nest. When a threat approaches the nest, the killdeer holds it wing in a position that simulates an injury and emits a distress call. The 'injured' killdeer lures the predator away from the nest by appearing to be easy prey. Once the predator is far enough away from its nest, the killdeer flies away. This behavior also strikes me as mimetic, since a healthy bird is mimicking an injured one.

Can you see the Killdeer egg in this picture?

Tuesday, May 21, 2013

Barn Owls Fledging at Eaglecrest

The barn owls began fledge at Eaglecrest on 5/19/13, when the first barn owl decided it was time to leap from the nest. We wondered how fledge would work, since the nest was so tight. The internal diameter of the hole is roughly a foot and a half, yielding a total area of about 1.76 feet (A=pr2) for four to five rapidly growing owls. In general, the birds we watch spend time wingercizing and hopping before fledging, learning about their wings and building some muscle prior to their first flight. But the size of the nest cavity prohibited the young barn owls from getting wing practice in. Would the lack of wingercizing present a problem? The answer appears to be 'No'. After sticking its wing out of the hole and clambering back in, the fledgling owl stuck its feet outside the hole, looked around, lowered its head, and leaped out into the night. This video shows the owl rapidly winging away from the tree, while three or four siblings watch from the hole. Actual fledge happens at 8:35 into the video.

Over the last two nights, we have watched the young owls begin to learn the basics of flying. They hop on branches, clamber up and down the trunk, and spend time practicing on the former canada goose nest, hopping and flying from the trunk to the nest and back again. We've also seen them scanning, moving their heads back and forth as they look at and listen to the world around them. Earlier this year, I was talking to one of my children about her navigational skills. "Mom," she protested, "why would I know how to navigate?  I've lived in the same place my whole life, and I don't drive yet." I think the young owls may be having a similar experience. They've spent their entire lives to date in a small, crowded hole where their wings and directional hearing weren't really needed. They have roughly five weeks of diminishing parental care to learn  flying, pouncing, hovering, hunting, and capturing prey. While flying and hunting are instinctual, proficient flying and hunting must be learned. A few video highlights from the first couple of nights:

According to the Barn Owl Trust, the amount of food each owl receives from its parents diminishes to zero by 14 weeks. There is some disagreement about dispersal, which may or may not happen after 14 weeks. We'll see what this family does.

Not a night owl? I am freeing up video from each night on a daily basis. To watch video, go to  Eaglecrest's Ustream site. Social stream will most likely be open. Click the Video tab just left of the Social  Stream tab above SS to view video.

Friday, May 17, 2013

Happy Endangered Species Day!

While we are perhaps best known for our work with web cams, the Raptor Resource Project was incorporated as a 501c3 in the late 1980s to help return the then highly-endangered peregrine falcon to the wild. In honor of Endangered Species Day, I'm going to talk a little bit about peregrine falcon recovery and our work with peregrine falcons. Many, many people worked to recover the peregrine falcon, and I don't mean to short any of them. But this post talks specifically about our work.

The Setting

In the late 1940s, biologists began noticing precipitous declines in the populations of many predatory birds. The cause of these declines was not identified until the mid-1960s, at which point several raptor species, including the Peregrine falcon, were facing extinction. DDT, a widespread, extensively-used pesticide, was interfering in eggshell formation. Seemingly healthy birds were laying eggs so thin that they were literally crushed to death by the weight of the incubating adult. How drastic were the effects of DDT? In the early 1940s Joseph Hickey, a Wisconsin biologist, determined that there were more than 200 pairs of Peregrines east of the Mississippi River. But by 1968 there were no Peregrines east of the Mississippi river at all. By the mid-1970s, the population had dwindled to 19 pairs in the western United States.

Dan Berger's Notes
Project friend Dan Berger was deeply involved in charting the species' decline in the 1950s and early 1960s. Dan worked with Fran Hamerstrom, Aldo Leopold's only female graduate student and a great conservationist in her own right. The falcon-finding team drove slowly along the (then gravel) roads by the Mississippi in an old van that had been retrofitted with a large plywood platform. One team member would lie on it and look for falcons. When a falcon or likely cliff was spotted, the team stopped to explore.

Now we use 11 mm static ropes and a variety of climbing equipment to get to eyries. But none of that existed in the 1950s. The team purchased hemp rope from hardware stores and used it to build ladders, which they used to access nests hundreds of feet off the ground. Their work made it clear that the peregrine falcon was in decline.


The Peregrine’s return to American began with the formation of the prestigious Peregrine Fund at Cornell University. Led by Dr. Cade, the Fund pioneered techniques of captive breeding to produce young peregrines for release. Although many opposed the idea, Dr. Cade persevered and by the mid-1970s began releasing captively-produced peregrines using a falconry technique known as hacking. Following the lead of Dr. Cade, other groups in the United States and around
the world began to breed and reintroduce peregrines.

Bob Anderson became interested in falcon recovery in 1972, when he was working at the Science Museum of Minnesota. He produced his first falcon in 1975. Peregrine falcons were very highly endangered at the time, with only about a dozen pairs left in the wild in the United States, so he began breeding Prairie and Gyr falcons, which were more common. . In the early 1980s, he sold his home in White Bear Lake and all of his 3M stock to begin his breeding program. He often says that successful breeding required a 24x7 commitment. When I met him, he was feeding young peregrines every four hours around the clock.

Weighing an egg
Very little was known about how to successfully breed falcons and incubate eggs, so the people involved in it were creating a new discipline. They shared information on what did and didn't work, including artificial insemination, incubator conditions, semen collection, breeding birds, and caring for young. Eggs were measured to determine weight and measure water loss. Bob was checking the egg to assure incubator humidity was optimal for hatch. With only a handful of peregrine falcons left, any loss was a big one.


Young falcons were released using a technique called hacking, developed by falconers to improve the hunting and flying skills of falcons raised in captivity. Young birds are released from a hack box, which provides some shelter for them. Since the falcons don’t have the hunting skills they need to provide for themselves, food is put out on a hack board. As the young falcons become proficient hunters and flyers, they eat less of the food provided at the hack board, and feeding eventually becomes unnecessary. This mimics the care that parents provide in the wild.

In falconry, the birds are re-trapped. Since the goal in this case was release, none of the birds were re-trapped. All of the birds we watch in the midwest today are the descendants of captively-bred and released falcons. Without the people who bred them for release, we wouldn’t have falcons to watch in the wild. While many of the people who worked in falcon recovery were academic, others were enthusiasts who believed they could recover the species through hard work and diligent care. Working together - and a lot of people from all walks of life worked to recover the falcon - they did!

Very early releases in Minnesota and Wisconsin were done in wild places. There were attempts – some successful and others not – to hack birds at Maiden Rock and a nameless bluff just south of Nelson, Wisconsin, and at Weaver Dunes in Minnesota. Following a failed attempt at Weaver Dunes, it was decided that all releases would be done in the city.

In 1987, just two peregrine falcons were produced in the
wild  in the mid-continent. Banding season lasted
less than an hour. 
This is MF-1. Produced by Bob Anderson in 1985 for the Minnesota Falconer’s Association, in 1987 she became the first bird to return mid-continent and breed in the wild. She nested on the Multi-Foods tower in Minneapolis, MN from 1987 to 1994.  He attributes his production success to good breeding stock. The issue of breeding stock was somewhat controversial. Since the original population was almost gone, it had to be recovered from a variety of subspecies, including some that had never nested in the area. Bob acquired breeding stock that was as close to the original anatum as he could get, since he believed they were more likely to survive.

Power Plants

In 1989, an employee and falconer named Paul Simonette reported a falcon at Xcel Energy's Allen S. King plant. Bob verified the report and approached Xcel Energy about putting a falcon nest box on the stack, at the 400’ level (ring two). They agreed and the Utility-Peregrine Program was off and running.

Belinda currently lives on ring two. She's a real monster.
Peregrine falcons provide wonderful organic pigeon control, and the company quickly became interested in boxes at their other facilities. They were joined by many other power companies, including Minnesota Power and Light, Dairyland Electric Cooperative, and Alliant Energy. Since 1989, over 1,000 falcons have been produced from power plants ranging from MPL in Cohasset, MN near the headwaters of the Mississippi river, down through the  Portage de Sioux Power Plant in St Charles County, MO. Power companies also played a crucial role in returning the Peregrine falcon to the wild, and especially to the Mississippi river valley.

The River Valley

In the mid-1990s, Bob started to wonder why peregrine falcons weren't returning to historical cliff eyries. We witnessed falcons fighting to the death over nest boxes not far from historic eyries that were home to the original population. Why weren’t they using the cliffs?

Bob began to think that the falcons were imprinting to buildings. He proposed a series of cliff-based releases to address the problem. It was 1996 and the idea was controversial. Only 55 falcons had been produced in the wild in Minnesota, Iowa, and Wisconsin, and the species was still quite endangered. Pat Schlarbaum from the Iowa DNR was very interested in Bob’s hacking proposal, so Bob sold his place in Hugo, Minnesota and moved to Iowa to breed and hack falcons.

This is the eyrie, built into the side of a house
Bob and several friends and Project members, including John Dingley and Dave Kester, built a special eyrie on the side of his house in which to raise the captively-bred falcons for release. The eyrie was built to resemble a cave and looked out on a natural landscape. The young falcons were raised in this chamber with as a little human interaction as possible until they were ready for release.

After an initial test release in Bluffton, Iowa, it was time to work on the Big River. Bob chose Hanging Rock in Effigy Mounds National Monument because it met all of his criteria. It was along the Mississippi river, highly visible, and in a region that contained several historic eyries. However, it wasn’t in his back yard. We hacked falcons from Effigy Mounds National Monument in 1998 and 1999. It was an arduous process that required a 100-mile round trip and three-mile mosquito-infested hike along a muddy, narrow trail every day, for over 40 days each season. The young falcons were fed and counted every day.

I returned to Effigy Mounds in 2010 and hiked out to Hanging Rock. The trail is a lot nicer now.

Return to the Cliffs!

In the spring of 2000, Bob learned that one of the falcons we had hacked at Effigy Mounds had been spotted on Queen’s Bluff, a historic eyrie south of Winona, Minnesota. He was thrilled! Our experiment had been a success. Although we’ve now seen falcons from buildings go to cliffs, and falcons from cliffs go to buildings, crossover did not begin until we created cliff-imprinted falcons. By hacking falcons from cliffs, we’d created falcons who were programmed to return to them. Other falcons would follow.

This photograph shows the female perched on a snag. Bob and I hiked up the back of Queen’s Bluff when I was four months pregnant with my son, who is now 12 years old.

The returned population of peregrine falcons is probably the most documented the world has ever known. Every spring we work out a banding schedule, load up gear, and head out to power plants, stackhouses, water towers, buildings, and cliffs. In 1987, two peregrine falcons were produced at one site. This year, we will be banding at roughly 40 sites, including power plants, water towers, stack houses, and cliffs. We climb, rappel, and scramble like crazy to get all of the work done. Because of falcon banders, we have a life history on every bird we can identify that stretches back to the founding population. Organizations that band falcons in the midwest include the Raptor Resource Project, the Midwest Peregrine Falcon Society (who also maintains a wonderful database), and the Wisconsin Peregrine Society.

Helping Species

The peregrine falcon was removed from the federal Endangered Species List in 1999. Its recovery was a true success story, since it showed that dedicated, passionate people could make a difference for the better. However, other species are still in need of our help. Visit the Fish and Wildlife Service Endangered Species Day website for more information, or check out this map (thanks, Nora H!).

We can make a difference!

We stand on the shoulders of giants. I would like to encourage everyone to learn more about two relatively unsung American conservation heroes, Fram Hamerstrom and Althea R. Sherman  (I would be happy to see posts about conservation heroes everywhere in the comments). They made a difference. You can too!

  • Fran Hamerstrom (and Dan Berger and many others): A book: Mice in the Freezer, Owls on the Porch. You can buy it from Amazon. Fran Hamerstrom was amazing! 
  • Althea R. Sherman: A book: Birds of An Iowa Dooryard. Amazing observations from a woman who did not begin her career as an ornithologist until she was 50 years old. See also this website: