Saturday, May 31, 2008

RAT POISON? How about some (gulp) sanitation? Fishing Red-tails and Mobbed Cooper's Hawk

Nice huh? But before we get to garbage, rats, and second generation anti-coagulant poisons here is something from Diane D'arcy in the NEVER UNDERESTIMATE A RED-TAIL category.

Hi Donna:

I met up with a bird watching friend today who has a home in Haymarket, Virginia, where he built a koi pond on his one acre. He tells me that the Red-tails regularly hunt the koi pond and have "knocked-off" about a dozen over time. He says they perch in a nearby tree, watch the water, and then pounce. Sometimes they fail to go off with their catch but he finds the koi bottom up after few days later with lacerations!

What to do you make of this one"


As I said never underestimate a Red-tail! I'm wondering if maybe just maybe one day, a Red-tail was sitting in a tree watching for prey and noticed some Eagles doing some fishing over in the river and thought, "Hmmm, those fish look tasty. But that river looks deep and fast. Hey there goes a vole!"

Then later when she saw those chubby Koi fish in their still pond, the picture of fishing eagles came back to her and ta da, fishing Red-tails! Of course it may have happened nothing like that, but I figure we could use a little whimsy before we get to the heavier discussion.

So back to unwhimsical poison, the top photo is from my Rat Watching Phase: The restaurant up the street from this little neighborhood park doesn't want to put their trash in front of their restaurant. ICK! So they put it here, down the street from the eatery toward evening.

As soon as it's dark, the rats scurry out for their feast, gnawing through those black plastic bags in a nano-second. Then when the garbage truck arrives, the rats momentarily scurry out of sight and as the bags are now full of holes, well, things fall out. Don't tell me that the garbage man cares, he doesn't. Does he get paid for scraping garbage off the curb? No he does not, so it stays there. The truck leaves and the rats say, "Hurrah!" and come out for the second course which doesn't stop until dawn. Yummy!

But you know, the patrons of the restaurant sitting at the sidewalk tables, come eight o'clock or so can see big fat rats hustling back and forth across the street. Geez, that isn't good for business.
Does the restaurant get rat proof containers for their trash. No they do not! Do they clean up the trash area? No they do not.

They have the licensed exterminator come with his poison pellets. Yes, the bait is supposed to be in bait boxes but, the guy is being pressured by the restaurant to get rid of the rats NOW. So he leaves the bait all over the ground.
TRUE STORY. Now there is no way someone would get away with this in places as visible as the parks in NYC but it does happen in other areas of the city.

This is why I'm concerned about the EPA's lack of monitoring in the below scenario. Which is a step in the right direction but were some children poisoned by the bait first? As I said, how about a little sanitation?



May 29th the U.S. Environmental Protection Agency (EPA) announced a landmark decision to control the sale and use of rat poisons throughout the United States. The decision is aimed at protecting children, pets, and wildlife.

The most toxic rat poisons will be removed from the consumer market and replaced with less toxic alternatives, which have been shown to be equally effective in controlling rodent populations in cities and farm settings.

All over-the-counter sales of these alternatives will be required to be in the form of bait stations to prevent accidental poisoning of children and pets. Licensed pest control operators and livestock ranchers will still be able to purchase the more toxic “second-generation” rodenticides for use only in areas where the products will not be accessible to children.

Dr. Michael Fry, Director of Conservation Advocacy at American Bird Conservancy and the Natural Resources Defense Council have been pressuring the EPA for years to address the threats to wildlife and human health posed by rat poisons.

The EPA began its evaluation of rodenticides in 1998. A lawsuit brought by NRDC over child poisonings, along with the threat of action by American Bird Conservancy and Defenders of Wildlife over the poisoning of San Joaquin Kit Foxes and birds of prey, convinced EPA to develop a mitigation plan for both ecological effects and children. The manufacturers of these chemicals fought back, pressuring EPA to accept less stringent, alternative plans, and threatening them with lawsuits.

The final decision is not as strong as the proposed mitigation plan presented by EPA in January 2007, which called for the second generation products (brodifacoum, bromodialone, difethialone and difenicoum) to be labeled “restricted use”, with sales only to licensed pest control operators. Instead, they will still be available through farm supply stores to ranchers.

American Bird Conservancy believes the final decision will be very helpful in reducing the exposure to birds and mammalian scavengers in suburban areas, where they may come into contact with poisoned rodents. Because of budget cuts and overall decreased funding for monitoring programs, the EPA will not have a monitoring program to evaluate the effectiveness of their final decision.

Manufacturers will have 90 days to agree to comply with the new regulations or to voluntarily agree to cancel the registration of their product and remove it from the market. Manufacturers will have 18 months to provide new bait station packaging and test results of package safety to the EPA, and EPA will provide an approval decision within one year.

This means registrants must agree to the above conditions by September 4, 2008, and have testing and packaging applications submitted by December 4, 2009. The final decision allows distribution and sale of current products until June 4, 2011. More information is available at To view the ABC press release, please visit

I'm concerned by the lack of monitoring by the EPA, as these second generation anti-coagulant products my still be bought a feed stores in ranching and rural communities and transported anywhere. The ruling may help Urban and Suburban wildlife but what about all the animals that will suffer secondary poisoning in the areas in which the poison will be sold.

As it turns out, dogs too are incredibly susceptible to these second generation poisons...

(Sorry this isn't as easy to read as it might be Folks, Blogger is acting up and won't keep the paragraphs and spacing when it publishes. D.B.)

Anticoagulant Rodenticide Toxicosis in the Dog and Cat
Todd W. Harrell, DVM; Kenneth S. Latimer, DVM, PhD; Perry J. Bain, DVM, PhD; Paula M. Krimer, DVM, DVSc
Class of 2003 (Harrell) and Department of Pathology (Latimer, Bain, Krimer), College of Veterinary Medicine, The University of Georgia, Athens, GA 30602-7388
Anticoagulant rodenticides are probably the most commonly used rodenticides in the United States today (Table 1). It has been estimated that approximately 95% of all rodenticides used are anticoagulant baits.4 Not only are these baits easy to use and readily accessible over the counter, they are extremely effective in killing rodents and other pests. However, they also are lethal to non-target species, including domestic dogs and cats. The most common route of rodenticide toxicosis is by direct ingestion of the baits. Capture and ingestion of poisoned rodents also can lead to toxicosis, especially with newer second-generation anticoagulant rodenticides.1,4 Physicians commonly prescribe oral anticoagulants to human patients with various thrombotic disorders,3 but there have been no case reports of coagulopathy in companion animals due to the ingestion of these oral medications.
Table 1. Commonly used commercial anticoagulant rodenticides
Commercial Names


Zep Commercial®


Exterminator's Choice®



Anticoagulant rodenticides exert their effect by inducing a secondary vitamin K-dependent coagulopathy leading to uncontrollable hemorrhage and death. Reports of natural anticoagulant rodenticide toxicosis are relatively common in dogs but have not been published concerning cats. One possible reason that more dogs than cats are poisoned by rodenticides is that lethal doses of many common anticoagulant rodenticides is much lower in the dog versus the cat.1

Veterinarians should consider anticoagulant rodenticide toxicosis in the differential diagnosis whenever any bleeding disorder is encountered, especially in dogs. Newer second-generation rodenticide compounds may be more lethal and have prologed effects on hemostasis after ingestion. Anticoagulant rodenticide toxicosis is a potentially fatal condition, but it may be treated successfully if the diagnosis is made quickly and appropriate therapy is instituted.

Pathophysiology of Anticoagulant Rodenticide Toxicity
Anticoagulant rodenticides exert their effect by interfering with the recycling of vitamin K1. Vitamin K is an essential cofactor in the post-ribosomal carboxylation of clotting factors II, VII, IX, and X by a vitamin K-dependent carboxylase that is synthesized in the liver (Fig. 1).1-4
Figure 1. Vitamin K is responsible for the carboxylation or activation of clotting factors II, VII, IX, and X in the liver. Vitamin K reductase enzymes keep the vitamin in an active (reduced) state.

Factors II, VII, IX, and X are proteins that serve as enzymatic factors (serine proteases) in the intrinsic, extrinsic, and common pathways of coagulation (Fig. 2).

Figure 2. Schematic diagram of the intrinsic, extrinsic, and common pathways of coagulation. The vitamin K-dependent clotting factors (II, VII, IX, and X) are shown in red. Factor IX is in the intrinsic pathway, factor VII is in the extrinsic pathway, and factors X and II are in the common pathway. These four clotting factors are not activated if the function of vitamin K1 is inhibited.

Each of these coagulation proteins is synthesized by the liver. Carboxylation of these clotting factors is necessary to bind phospholipid membrane surfaces in a Ca2+-dependent manner. The vitamin K-dependent carboxylase concomitantly converts the active vitamin K to an inactive epoxide, which is then recycled back to vitamin K by another enzyme, called vitamin K epoxide reductase. The vitamin K epoxide reductase is the enzyme that is inhibited by anticoagulant rodenticides (Fig. 3), blocking the turnover of vitamin K and rapidly depleting the liver of its active vitamin K stores.

With the depletion of liver vitamin K stores, coagulopathy occurs because factors II, VII, IX, and X are not carboxylated and remain nonfunctional. Because anticoagulant rodenticides do not block activated (functional or carboxylated) circulating clotting factors, there is a lag of approximately 12-24 hours between ingestion of the offending compound and the onset of clinical signs of bleeding.

Figure 3. Anticoagulant rodenticides inhibit the activity of vitamin K epoxide reductase (red arrow). If vitamin K1 is not maintained in a reduced state by vitamin K epoxide reductase, then clotting factors II, VII, IX, and X will not be activated via carboxylation. Clinical signs, including internal bleeding and respiratory distress, will occur if these four clotting factors are nonfunctional.

Currently, there are two families of anticoagulant rodenticides: the hydroxycoumarins and the indandiones.1 The hydroxycoumarins are further subdivided into first-generation and second-generation rodenticide compounds. The indandiones usually are grouped with the second-generation compounds because their properties are very similar to second-generation hydroxycoumarins. The most common first-generation anticoagulant rodenticides encountered in the United States are warfarin and coumafuryl. These compounds rarely are encountered today; they gradually are being phased out because of the emergence of rodents that are resistant to these first-generation compounds.

1,4 The newer second-generation compounds were developed to kill rodent populations that had become resistant to the first-generation rodenticides. Today, these second-generation compounds are largely implicated in rodenticide toxicosis. The most common second-generation compounds that will be encountered in veterinary practice are brodifacoum and bromadiolone (hydroxycoumarins), as well as diphacinone and chlorophacinone (indandiones).6

Although first- and second-generation rodenticides share the same mechanism of secondary vitamin K-dependent coagulapathy, they differ significantly in their duration of action and response to therapy. The first generation compounds are considered "short-acting" compounds and often require multiple doses to exert their toxic effects.1,4,7 Warfarin, for example has a half life of 14.5 hours in the dog. Its clinical effects last only 1 week, even at a high concentration.4 Second-generation compounds, on the other hand, have a much longer half-life (4-6 days) and their clinical effects can last anywhere from 12 to 30 days, depending on the amount of rodenticide ingested.4,7 They also differ from first-generation compounds in that only a single dose is needed to cause clinical signs of hemorrhage.1,4 Inandiones, in addition to their effects on vitamin K recycling, also interfere with pancreatic exocrine function, potentially altering the uptake of oral, lipid-soluble vitamin K.7 However, the significance of altered pancreatic exocrine function has not been determined. Secondary anticoagulant rodenticide toxicosis also can occur if poisoned rodents are captured and consumed. In such cases, a second-generation compound is most likely involved.

Certain drugs such as fluconazole, cimetidine, phenylbutazone, and sulfonamides may prolong or exacerbate the effects of anticoagulant rodenticides, as can anti-platelet drugs such as aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs).1,3,12

It is extremely important that veterinarians familiarize themselves with the common anticoagulant rodenticides, particularly the long-acting, second-generation compounds. Treating a case of second-generation rodenticide toxicosis with a treatment regimen indicated for first- generation rodenticide toxicosis often will be ineffective and may lead to fatal hemorrhage that may have been avoided.

Clinical Signs and Diagnosis of Anticoagulant Rodenticide Toxicosis
Animals poisoned with anticoagulant rodenticides often may be initially asymptomatic. Because anticoagulant rodenticides do not have a direct effect on activated vitamin K or active clotting factors II, VII, IX, and X circulating in the blood, there is often a delay of about 12-24 hours post ingestion before clinical signs develop.4 Initial clinical signs are rather nonspecific and include lethargy, weakness, and pallor.4 Signs of external hemorrhage such as melena, petechial to ecchymotic hemorrhage of mucosal surfaces, hyphema, hematamesis, epistaxis, and hematuria may or may not be apparent. With second-generation anticoagulant rodenticide toxicosis, internal hemorrhage is common and may include hemothorax, hemoperitoneum, hemomediastinum, hemorrhage into fascial planes, and ventral hematomas.4,9 Hemorrhage into the cranial vault also may occur, but is uncommon.4,12

Lethargy and respiratory distress of rapid onset are the two most common clinical signs reported in second-generation rodenticide toxicosis.5,6,9,10 Thoracic radiographs of these animals often reveal pleural effusion and pulmonary edema.4,5 Pericardial effusion with cardiac tamponade also may occur.9 Formation of large hematomas, persistent bleeding at venipuncture sites, and / or persistent bleeding during surgery strongly suggest anticoagulant rodenticide toxicosis.4,5

Because these clinical signs are not pathognomonic for anticoagulant rodenticide poisoning, a thorough medical history and appropriate laboratory testing are necessary to exclude other hemostatic abnormalities such as disseminated intravascular coagulation (DIC), autoimmune thrombocytopenia, and hereditary coagulopathy. While specific toxicologic (rodenticide analysis) and diagnostic laboratory tests (PIVKA, proteins induced by vitamin K absence) are available to diagnose anticoagulant rodenticide toxicosis, they are costly and, more importantly, too time-consuming to be of any benefit to the veterinarian, owner, or patient when faced with acute respiratory distress or hemorrhage.4,6,11 Thus, the veterinarian must rely on the clinical signs, medical history, physical examination, and response to vitamin K1 therapy to make a presumptive diagnosis of rodenticide toxicosis.

Laboratory findings in animals poisoned with anticoagulant rodenticides are rather nonspecific, but can provide critical information to guide treatment. The complete blood count will often reveal a normocytic, normochromic anemia that is either regenerative or nonregenerative, depending on the acuteness and severity of blood loss.4,5 Leukocytosis is commonly present,4 but thrombocytopenia may or may not be present.4,5 The routine biochemical profile shows no consistent pattern related to anticoagulant rodenticide toxicosis, although a hypoproteinemia commonly is observed 24 to 48 hours after acute blood loss.
Coagulation screening tests (one-stage prothrombin time [OSPT or PT], activated partial thromboplastin time [APTT or PTT], thrombin time [TT], and activated clotting time [ACT]) are necessary for the presumptive diagnosis of anticoagulant rodenticide toxicosis.4,5,7,8,12 The OSPT is the first test to be prolonged in anticoagulant rodenticide toxicosis.5,7,8 The OSPT detects deficiencies in both the extrinsic and common coagulation pathways (see Fig. 2). It is the most sensitive of the assays because factor VII, a component of the extrinsic pathway, has the shortest half-life of all the vitamin K-dependent clotting factors.4,7 The ACT and APTT assays both detect deficiencies in the intrinsic as well as the common coagulation pathways (see Fig. 2). The ACT is the least sensitive assay, as prolonged clotting times may not be evident until 3 days after rodenticide ingestion.8 The ACT is not prolonged until the activities of factors IX, X, and/or II are <5%>15 seconds), vitamin K1 therapy should be continued for two more weeks and then the OSPT should be rechecked. If the OSPT prolongation is mild, then a 1- week additional course of vitamin K1 is sufficient.4
Anticoagulant rodenticide toxicosis can present with a variety of acute and chronic clinical signs. However, with the introduction of second-generation anticoagulants, the presenting clinical signs will often be acute and severe. The most common clinical signs include lethargy, respiratory distress, and persistent bleeding post-venipuncture; external bleeding may or may not be apparent. Because the clinical signs are nonspecific and rapid diagnostic tests often are not available, the veterinarian must obtain a thorough history from the owner, including the identification of the offending anticoagulant rodenticide, if known. The best coagulation screening test to assist in clinical diagnosis and monitor treatment of anticoagulant rodenticide toxicosis is the OSPT. The treatment of choice is vitamin K1, although whole blood or plasma may have to be transfused in more severe cases of toxicosis. Oral vitamin K1 therapy should continue for up to 6 weeks (second-generation compounds) after the patient is stabilized, and a follow-up OSPT is recommended 2-3 days after cessation of therapy.
1. Petterino C, Paolo B: Toxicology of various anticoagulant rodenticides in animals. Vet Human Toxicol 43:353-360, 2001.
2. Furie B, Bouchard A, Furie B: Vitamin K-dependent biosynthesis of ?-carboxyglutamic acid. Blood 93:1798-1808, 1999.
3. Hirsh J: Oral anticoagulant drugs. New Engl J Med 324:1865-1875, 1991.
4. Mount M: Diagnosis and therapy of anticoagulant rodenticide intoxicants. Vet Clin N Am Small Anim Pract 18:115-129, 1988.
5. Schulman A, Lusk R, Lippincott C, Ettinger S: Diphacinone-induced coagulopathy in the dog. J Am Vet Med Assoc 188:402-405, 1986.
6. DuVall M, Murphy M, Ray A, Reagor J: Case studies on second-generation anticoagulant rodenticide toxicities in nontarget species. J Vet Diagn Invest 1:66-68, 1989.
7. Mount M, Feldman B: Mechanism of diphacinone rodenticide toxicosis in the dog and its therapeutic implications. Am J Vet Res 44:2009-2017, 1983.
8. Woody B, Murphy M, Ray A, Green R: Coagulopathic effects and therapy of brodifacoum toxicosis in dogs. J Vet Int Med 6:23-28, 1992.
9. Peterson J, Streeter V: Laryngeal obstruction secondary to brodifacoum toxicosis in a dog. J Am Vet Med Assoc 208:352-353, 1996.
10. Petrus D, Henik R: Pericardial effusion and cardiac tamponade secondary to brodifacoum toxicosis in a dog. J Am Vet Med Assoc 215:647-648, 1999.
11. Mount M, Kass P: Diagnostic importance of vitamin K1 and its epoxide measured in serum of dogs exposed to an anticoagulant rodenticide. Am J Vet Res 50:1704-1709, 1989.
12. Murphy MJ: Rodenticide anticoagulant poisoning. In: Tilley L, Smith F (eds.): The 5-minute Veterinary Consult. Lippincott Williams and Wilkins, Baltimore, 2000, pp. 1176-1177.

Goldfinch may be wary but he's not about to leave all those Sunflower seeds until it's an emergency.

And it did become an emergency. A male Cooper's Hawk was in a Maple tree next door, all the Grackles and Robins, around 75 of them, mobbed him until he headed out for quieter hunting grounds.

Donegal Browne
P.S. If the illustration in the NY Times Sunday Book Review is from the children's book about Pale Male, the illustrator seems never to have seen the 927 Fifth Avenue nest. Strangely the underpining of the nest in the picture looks remarkably like Junior and Charlotte's old nest corbel on the Trump Parc. Tsk.

Thursday, May 29, 2008

Pale Male and Lola's Eggs, Thunder, Reverse Sexual Dimorphism, Peregrines, and Fire Island Doves

Photograph D. Browne

Pale Male and Lola stand on the nest in the rain

I contacted Glenn Phillips the Executive Director of NYC Audubon and contrary to rumor Audubon does still plan for an egg retrieval of Pale Male and Lola's eggs as soon as the 927 swing stage goes into action for window washing and other building maintenance. That activity shouldn't be terribly long from now, and should still be within the window for trustworthy diploid test results.

(John Blakeman's essay on the Diploid Test and other relevant information coming up Friday, so stay tuned. )

I do hope that a very small sample of each egg,(keep fingers crossed for a male egg if they've been fertilized), can be collected in hopes of getting the DNA markers for Pale Male. Then we can compare his DNA with samples from other NYC Red-tails and once and for all find out who is related to whom. It's already too late to get a sample from Tristan, aka Pale Male III. Now, unfortunately, we will most likely never prove or disprove a relationship between Pale Male and Tristan. We mustn't waste anymore time.

Screen Captures of Thunder courtesy of R. of Illinois and KJRH TV

Thunder, looking somewhat peckish, scans the thermals looking for a parent bringing some dinner. Note that her crop is relatively flat so it's about time for a meal.

This eyass has the peachy breast that is often seen in the the Eastern United State. I'm very curious about the percentage of rufous to white breasts in Oklahoma. Of the urban hawks in NYC so far, most have the light rufous breast.

One eyass from the Fordham nest a few years back had the white feathered model. It's been suggested that perhaps the rufous morph might help the parents find their youngsters more easily.

The delivery arrives and it's a dead mouse which Thunder proceeds to kill soundly once again.

Practice makes perfect.

Food-- a fledglings chief delight in life.

Photo by D.B.
Red-tailed Hawks, Tristan and Isolde, 2006, of the Cathedral Nest.
A Grand Example of Reverse Sexual Dimorphism

Question: Are a female hawks toes always bigger than a male's toes?

All raptor species have reverse sexual dimorphism, ie. the female is larger than the male. Therefore it follows that the female's feet would be bigger as would the rest of her. But it's tough sexing a bird who is sitting alone. When seeing a bonded pair perched side by side then it's usually reasonably easy to decide their sex. Occasionally though you can have a big male and a small female and so they are close in size. The female will still most likely be bigger if one had them in hand and measured. The male and female also have a slightly different skull shape which some longtime watchers learn to recognize over time.

In Red-tails there is usually about a 25% difference in size. Though if you look at the Riverside pair they are much closer in size than Isolde and Tristan are in the above photo.

People like Jemima Parry-Jones can look at any raptor and tell you the sex and relative age. But then again she has worked hands on with raptors daily for many years. This is not to denigrate her expertise. I've seen her work and she has a spectacular touch and eye with these birds which is almost magical.

As to why raptors are reversely sexually dimorphic? There has been a tremendous amount of discussion as to why, as opposed to so many other species, that the female is bigger in raptors. Being larger for brooding has been discounted as has most of the other hypotheses.

Sexual dimorphism either way is a plus, for if one bird in the pair is larger than the other they can work the same territory and subsist on different prey. A Red-tail female can handily take rabbits but the males rarely do. But the male being smaller can live on fewer calories when prey is more scarce.

For instance, this was a very hard winter in the Midwest, at a certain point all the female Kestrels disappeared. They needed more calories than they could get in this area and went further south to find them, but as the males needed fewer, they stayed and looked after things on the home front.

I read a study done on a species of raptors in Australia, which for me held the answer to WHY ,REVERSE SEXUAL DIMORPHISM? Let me say though that there are others that do disagree but for me this answer does it.

I think that male Red-tails look around for a territory. They find something suitable and wait for a female to arrive. In the meantime there is a population of unbonded females looking around for a male with a good territory. If two females are interested in our male at the same time, I believe that the females fight each other for the male and his territory. The winner gets the guy and the goodies. It makes sense then that the bigger and stronger female would have a tendency to win, she gets the chance to reproduce and propagates larger females who in turn will likely win mates with territory in the future.

I found this reinforced at least for me in the behaviors of Pale Male and Lola. During breeding season, Red-tail intruders will fly near the nest area while Lola is brooding the eggs. In some cases, she keeps sitting and Pale Male will rather gently "herd" the visitor out of the territory. We surmise these visitors are their young from a previous season. They recognize the son or daughter and usher them away from the nest.

On other occasions, Pale Male will be more aggressive in chasing the intruder out while Lola looks on. But then there are the instances when a Red-tail will arrive, Pale Male goes after it, and suddenly Lola turns into a Valkyrie, comes off the nest like a rocket and seriously goes for the intruder. The poor intruder usually then high tails it out of the area in fear of live and limb. I surmise these visitors are female and Lola doesn't want another female anywhere near her mate or in her territory--at all, ever. She takes the appearance of another female very personally.

Rob Jett of The City Birder made an observation that also supports this theory as well. He has been watching a bonded pair of Red-tails in Brooklyn for some time. One day during the courtship season, there happened to be a Red-tail female, that was unreleasable in an avian enclosure topped with a roped covering not far from the hawks he watches.. The pair heard this enclosed female calling and both went to investigate. The male sat on the sidelines while the females attempted to go at each other through the netted top of the aviary. A mini-demonstration of the female vs female battles that may well go on frequently behind the scene.

Then there are the cases in which a pair of Red-tails encroach on the claimed area. In these cases, I assume, because two birds must be dealt with. Lola comes off the nest in her Valkyrie mode, both she and Pale Male screaming, while Pale Male makes for the nest to protect the eggs. Why? First of all Lola is bigger and because while Lola is dealing with one RT, the second might come and despoil the nest. Pale flies to the nest and stands over the eggs, while puffing up his feathers and even doing raking of the twigs with his talons in a very butch manner. If because of the vagaries of the fight, Pale Male has a better angle for attack or Lola is tiring and at some point needs a hand, he'll come off the nest, go after one of the pair and Lola will fly back to the nest for a breather. In a pitched battle these switches can happen numerous times. I take these instances as a possible invasion that is an attempt to steal the territory away from PM and L. It doesn't work. In fact it's never even been close

Photograph of Rochester Peregrines courtesy of Froona.

From contributer Karen Anne Kolling--"Why parents get tired... I'm guessing this is the Dad. "

Photograph by Brett Odom

I was out on Fire Island over the weekend and I took several photos of two Mourning Doves displaying. At first both doves were displaying exactly the same as the one on the right, but the left one changed his posture before I could get my camera out.

Have you seen your doves in WI do this?

Is this two males competing for a female off camera or is this a male and a female? Or are they just attempting to warm up in the sun? I was able to get photos of a few different postures, all of them with their wings and tail spread. I only saw this behavior once for the five days I was out there.

Hi Brett,

No, I haven't seen Mourning Doves in this exact posture before. As these two are hunkered down I doubt the feather position has anything to do with any aggression. Doves aren't much for aggression anyway. All I've seen two males in breeding season do in response to each other is that one will do a little hop towards the other and the second male then backs off a foot or two and they both go back to their business. Or sometimes at a feeding area, they just keep their backs to each and pretend they are the only male there.

I have seen other birds spread their feathers to dry them in a somewhat similar feather position but not in the snugged down posture. But then again doves are very prone to lowering their bodies onto their feet. Doves in Wisconsin, remember it's usually a little chilly if not downright cold, tend to dry themselves in the sun with one wing up and feathers raised instead of spread.

I'm wondering if these birds aren't spreading their wings and tails in the sun, not only for a sunbath but perhaps as they are on Fire Island which is very sandy, perhaps they spread their feathers so that any moist sand that has adhered to their feathers will dry and fall off?

Any other possible theories or similar sighting, anyone?

Donegal Browne

Wednesday, May 28, 2008


Hello All,

My computer has developed a major glitch, will try again to post the blog later tonight but at any rate the machine will be fixed tomorrow, or I'll borrow one. Lots of good stuff to come, including info on anti-coagulant rat poisons, More Tips on Finding Fledglings, Thunder has flown off the tower and is being trained by her parents, Pale Male and Lola Egg Retrieval, Blakeman on the diploid test that will tell us if PM and L's eggs were hatchable, and it just keeps coming.


Fledgling Nest Return, Blakeman on Raptor Urbanization,Thunder, and a Peregrine Report

The Cathedral nest in 2006--Why? The view will be useful in a minute. Keep reading.

We've been having a discussion about young birds returning to the nest. Red-tail eyasses have a grand urge to do so but often in the city they are unsuccessful due to the nature of the nest sites, though it is not for want of trying.

I ran across this sequence in my photos of the one of the Cathedral eyasses in 2006 who was trying very hard to get there. The eyass has made it to about the right level for a try at the nest but can't seem to branch any closer. It's quite a distance to the left and the nest site takes some expertise to enter. First a pillar has to be negotiated and then there is St. Andrew's head and arm as well. And to add insult to injury a parent has just flown past reminding the eyass that, as always, she feels hungry. Notice the bulging crop, it's not like she's starving or anything even near it. But it has also reminded her that perhaps if she were in the nest again she'd be fed.

What does a fledgling do in this situation?

She begins checking all the possible options that might take her to location of her dreams. Down? No, just came from there.

Perhaps someting on the wall might do it?

What about this pipe?

Perhaps the underside of something?

Defeated for the moment and looking a bit chagrined, she stares at the nest, so close and yet so far. Not to worry, in about an hour a parent made a food drop which she heartily consumed.

Next up John Blakeman corrects my statement that presents habitat depletion instead of increased population density as a source of the urbanization of Red-tails and other species.


You stated that, "Red-tails have made a grand adaptation to building nests in cities as their habitats have shrunk...."

Red-tail habitats have not shrunk. I see this dictum all the time, in reference to formerly wild and rural species now in urban and suburban habitats. There is more Red-tail habitat in America than ever before. The destruction of the massive forests that covered much of the Eastern half of the US opened the land to ideal Red-tail habitat. There are more Red-tails alive today than ever before -- because there is more useful Red-tail habitat than before, and because the species is no longer shot or trapped.

As in so many other areas, the suburbs of Cleveland, Ohio are now saturated with roaming herds of backyard deer. Wild turkeys are also now strutting through backyards and roosting in park trees.

This is all so easily explained by stating, as so many urbanites do, that, "The animals have been forced to come into the city because we've destroyed their rural habitats. They built all those houses out there where the animals once lived, so they had no place to go."

In the case of deer, there were no deer living in the 200 acres of rural row-crop fields of corn or soybeans that the developer purchased 10 years ago from the 65-yr old farmer, who wanted to get out of the exhausting and expensive farming business and retire to Florida. The farmer's sons had all seen the future 30 years ago, when they went down to Ohio State and majored in business, not agriculture. Today, both in Wisconsin and Ohio (and upstate New York), there are very few young people entering farming. The capital costs of starting a farming operation are monstrous. The hours are long, and the returns (at least until recently) were not great.

So the local farmer on the edge of an outer ring suburb sold his land to a developer, where fifty to a hundred over-sized "impressive" houses would be constructed and questionably financed. Today, residents of the development have two major concerns. Many are struggling to keep up with the mortgage, while at the same time trying to keep the deer from eating down all the hostas and other non-native landscape plants used to adorn the property.

To the point. The deer aren't wandering through the neighborhood because the house was constructed where the deer used to live. The deer aren't there because "They have no more habitat -- we destroyed it." Quite the opposite. The deer have learned, as the NYC Red-tails have, that human environments are free of predators, safe, and full of food.

Urban deer and hawk populations are thriving, not because we have "forced them" out of their formerly rural habitats, but because of two primal reasons. First, especially in the case of Red-tails, rural habitats are saturated with adult resident hawks. There just are very few un-occupied, open territories where a rising young adult Red-tail can set up house-keeping. That's because Red-tails are no longer shot or trapped in any appreciable numbers.

In the first half of the last century, hawks were known to kill free-ranging chickens on farms and wild game animals that small game hunters pursued. Today, chickens are raised in giant enclosed factories, and the number of small game hunters is plummeting. The only hunters left today are real sportsmen, who follow game laws to the letter. Poachers and "kill it if moves" types are sitting at home playing games and occupying their time with other nefarious computer endeavors.

In Ohio, deer populations have exploded and wandered into towns and cities. Instead of encountering destroyed habitats, deer have enjoyed the opposite. As farming lands have been abandoned to future development, former corn and soybean fields have reverted to weeds and brush, ideal deer habitat.

Deer reproduction has been extremely high -- higher than the deer hunters can control, so the deer walk right into town and have a nutritious breakfast on Mrs. Dorglemyer's hostas and other expensive landscaping plants.

No, urban deer and Red-tails are not inside cities because we have destroyed deer and Red-tail habitats. They are there because rural deer and Red-tail populations are extremely large and dense. Urban areas are the only areas left for these species to colonize.

--John A. Blakeman

Thunder of Tulsa Update— Tulsa is having wet weather and Thunder has been staying on the nest where it is drier, thank you very much. Meals provided courtesy of her Mom, Kay while Dad, Jay, does guard duty. And typically Thunder is spending a good bit of time begging because, well, that’s a fledglings job.

The TV folks attempted to tape her vocalizations while standing in two inches of water. Of course, she continued to beg up until they got the tape rolling in the machine and then she quit. No doubt Mom was out of sight by then and Thunder didn’t want to waste her breath.

Returns to the nest by smaller birds?

Speaking of Thunder’s return to the nest, a question had come up concerning whether any of the smaller bird species ever try to return to the nest in the manner of young Red-tails. I hadn’t seen it but as it turns out Betty Jo of CA has. Here is her wonderful sighting.

I am watching Thunder on the cam now and I was just
pondering the return to the nest question. Small birds don't really
have the luxury because if there are 4 scrub jay babies in the
nest--they don't really fit at fledging size--I saw one of "my
babies" come out of the nest--run along the ground and try to climb a
shovel handle which was leaning against a wall. To my shock, the
male scrub jay, who was so attentive, was on a wire above and didn't
even seem to see it. I picked it up, quite easily, and put in in the
crotch of the orange tree and it climbed back up to the
nest--amazing--how did it know where to go?

By the way, it was the male, and only him, who taught those babies to be jays, and you could see that he was actually training them--much like a chicken does with
chicks. They are all so much more than they seem at a glance.
Betty Jo

The Highbridge Eyasses – Rob Schmunk reports that the Highbridge nest appears deserted. What has happened to the two eyasses previously seen in that nest? Were they carried off by predators, disease, or were they too, victims of poison?

For the full report go to Rob’s site-

A Peregrine report from contributor Karen Anne Kolling

It's amazing to see the Peregrine family tree photos at:

There's a new male, Nick, at the Macomb County peregrine nest, and he and Hathor have produced three chicks, after Hathor and Nick's predecessor, Horus, had only produced two over the past three years, none of which survived.

Horus is okay, and hanging out elsewhere, poor guy.

They have a photo up of Nick as an incensed chicklet at his banding, and his parents.

No web cam yet, dunno why, that will happen when they band the chicks,


Tuesday, May 27, 2008

Guess Who Made It Back to the Nest!!

Screen Capture Courtesy of KJRH
Thunder did it! And look at her face, she's smiling!
From R. of Illinois: Thunder flew back up into the nest! First she preened and finished drying her feathers and now she is curled up in the nest asleep!

I was right the first time when I guessed 150 feet high....the tower nest area is 160 feet above the ground level (one observer said the same as a 16 story building). Thunder has been hanging out on the rings at the base of the tower, about 60 feet above the ground, since her fledge at dawn Saturday, and this (Monday) afternoon, flew from there up 100 feet, to the tower nest.

And what have Kay and Jay been doing all this time?

From BTOliver of the Tulsa hawk forum:

"When I made those pictures of Thunder this morning, (See two posts down for the mentioned photos. D.B.)
Kay & Jay were WAAAY up in the air. I have watched them about 6 hours today... the parents come and go, Thunder spends her time jumping up & down, see photos, and makes short ( 25 foot) flights out from the ledge and back. She was soaking wet when I got there this morning and spent about two hours drying out and preening.
Her chest IS rusty, the parents are cream colored. Both Kay and Jay still make visits to the nest.
Tomorrow we'll talk about rusty chest feathers on eyasses. :-)
Donegal Browne
P.S. Earlier Updates on Thunder from Monday are in the next two posts.

Urban Hawk Update: Thunder of Tulsa, Monday morning


R. from Illinois reports--

"The KJRH weatherman, George Flickinger, took these photos Monday morning in
Tulsa, a wide shot and a close-up. It appears that Thunder may not have been
on a satellite dish (my error) when first spotted by local watchers. A
watcher reported after going to the tower this morning (Monday) that Thunder
is in just about the same spot that she has been since first sighted after
her fledge flight. She said that Thunder "looks pretty wet" from the
overnight rains."

Photograph by George Flickinger

Look carefully and you can see a little teeny Thunder perched on the ring near the base of the tower.

The updates are a touch out of order. To find out what happened in the afternoon, scroll down to the next post.
Donna Browne

Urban Hawk Update: Thunder in Tulsa, Monday Afternoon

Photograph by B. Toliver
One of Tulsa's Cam watchers decided to try his luck in person and got these grand photos of Thunder.

Photograph by B. Toliver

1:30PM Unconfirmed: Thunder flies off the position she was spotted in yesterday at the base of the TV tower.
(More on Thunder has come in and will be posted soon!)
Here's my answer to the forum question as to whether all raptor fledglings attempt to get back to the nest, even though songbird young don't seem to have the same urge.
I can't say that all raptor fledglings have an urge to get back on the nest but Red-tail eyasses definitely do. During the branching phase in a tree nest the eyasses hop flap around in the tree and then attempt, not that hard usually, to get back to the nest for chow time and to roost. I suspect that like most young creatures it isn't easy to give up the comfort of mom and the siblings for the night right off.. Besides the nest has been the dining room since hatching and an eyass always thinks she's hungry when food appears.

At Fordham University in the Bronx, Hawkeye and Rose, a bonded pair of Red-tails have a building nest which has trees only a few feet from the ledge they nest is on. Their eyasses regularly branch to the trees, branch to other trees, eventually go higher and get on another building which is taller than the nest building. Then they swoop back down to the nest for meals.

As you say, with most songbird species, once they've fledged, they've fledged and their flight skills are not up to getting back to the nest. The parents tend them and the young hide in long grass or take cover in bushes for a day or two until their flight skills improve. In the meantime they are watching their parents procure food and they learn to get their own eventually by watching the parent.

With another raptor, Screech Owls, the Owlets continue to roost with the family for some time after fledging. Come sundown, the whole family flies off to "hunt" together. At first the parents hunt and the fledglings follow to each hunting spot, perch, and wait to be feed. First the spot with the yummy bugs, then the wet spot with the night-crawlers, etc. Therefore they learn the territory, what to look for in geography in terms of which food, and eventually they start hunting their own dinner.

Red-tails have made a grand adaptation to building nests in cities as their habitats have shrunk but there is a bit of a glitch in the system compared to their old nest sites. Often with building nests, if an eyass takes her first flight, there is no way to return to the nest without more mature flight skills. And a big skill that is often missing at first is the ability to gain great elevation.
Suddenly there is no way to branch back because most buildings don't lend themselves to climbing. Just think if there had been no way for Thunder to climb the tower, she would have spent time, sometimes days attempting to figure out how to do it. She would first attempt to hop fly, no good. Then attempts would be made to climb other things that might suggest another path to the nest.

There have been instances where a fledgling was stranded on a city sidewalk attempting to climb back to the nest by hopping at the building. Which rarely works unless they can climb it in some way. In these instances one can take up guard duty a distance away and give the eyass a chance to find a way. Sometimes a parent will appear with food in the air, gain the eyasses attention, and attempt to lead her where she can climb something, but a young parent may not know to try this. Or the eyass may not "get it".

Sometimes a grounded fledgling, if after watching a good while, you're convinced it's stranded, can be gently guided/herded to a green space that has bushes, small trees, and big trees if it's very close. Then they can hop flap into a bush, branch into a small tree and then the big tree where their parents will continue in their care. The parents will be watching the whole thing, never fear.

In 2007 because of Pale Male Jr. and Charlotte's new and rather unique nest site, there was no green space for blocks, their single eyass was downed in a concrete plaza attempting to hop up the building during the morning rush hour. Unfortunately no hawk watchers or rehabbers were on the spot and good Samaritans not knowing how to help the eyass, called the zoo, the police, the park service, and anyone else they could think of. Which caused a huge deal as various city agencies disputed who had authority over the eyass.
The upshot was, that the eyass went into a very good rehabber's care for several weeks while her parents went mad looking for her. Eventually she was given a clean bill of health, taken to Central Park where her parents heard her begging, snapped into parent mode, and took up where they'd left off. In the end all was well.

So what does one do in a case like that. It's tough. If one of the experienced hawk watchers had come across the eyass fruitlessly jumping at the building with no close green space, they most likely would have picked her up, looked her over for injuries, possibly called a rehabber for advice, if they aren’t one, and carried the eyass the couple of blocks to Central Park. Then the Hawk watcher would have put her into a small tree, watched to make sure the eyass was acting normally and waited to make sure the parent's knew where she was.

But technically that might not follow the letter of the law in every case. Any citizen can rescue an animal who is in danger, in this case a federally protected bird, but then they theoretically are supposed to take the animal to a rehabber. Even if the animal seems uninjured, and is just in a dangerous place.
If all turns out well, that technicality might be ignored, such as replacing a baby robin that has fallen out of the nest back into it. But I mention it so you will know the law, and are aware, just in case.
Donna Browne

Sunday, May 25, 2008

Thunder, New Riverside Nest,Illinois and Norfolk Eaglets, Peregrines,

Illinois Bald Eagle nest photos by John D. Steffen Jr.
1:39:22pm John Steffen who took the photos got the impression that the larger eaglet in the Illinois eagles nest, might have been feeding the smaller one and in the photos it does rather look that way.

There are confirmed sightings of certain species of parrot siblings that regurgitate food fed to them by regurgitation by their parrots into the beaks of smaller siblings. But I haven't found any observations so far of eaglets feeding their younger siblings. Red-tail nest mates sometimes tug on the same piece of prey but in their case they look like they are tugging. These bodies don't seem to be tensed for tug.

1:39:39pm Though has the smaller eaglet just pulled the tidbit away from the larger? And the larger is wondering what happened to it?
1:42:15pm Look at this. There is now another chuck of food between their beaks. If the bigger eaglet was being snitched from, wouldn't she just turn the other direction to eat? Thereby avoiding the bother of her smaller sibling?
1:46:15pm Parent eagle makes a crash landing with extremely large fish and knocks the eaglets over like a star member of the Wednesday Night Bowling League. See the fish tail?
1:46:28PM Parent catches her breath after hauling the fish. Eaglets recover from being bowling pins.

Will New Hawk Watchers in the Field Blossom in Tulsa? An Update via R. of Illinois
(R. of Illinois and I had been hoping against hope that some local folks who have been watching the KJRH Cam would get out there in the field and have the grand experience of watching the hawks in person. D.B.)
From R.,
Another local behind the scenes observer has popped up!

She wrote: "Couldn't stand the suspense so I drove down to Brookside with my binoculars and camera this afternoon to see what I could see. Thunder was perched on the third concrete ledge, about 75 feet above the ground, about 1/3the way up the tower. Both Kay & Jay were circling about 1/2 a mile away. They know Thunder is there.... one of them flew over and called her with a high pitched squeal, then flew off. I watched for about an hour .... feel a lot better now."

(This has lightened many a worried heart!)

Another on the forum said she was going to go tomorrow and watch.
This is soooo cool. They are starting to emerge and blossom into watchers!
(Indeed it is! The Tulsa Hawk Watchers look to be starting their own version of the Central Park Hawk Bench. We'll try to get photos of Thunder's new position as soon as they are available.)
Images courtesy of Rochester Falconcam

Good evening Donna-

I left off with Mariah and Kaver in Rochester having 3 hatches and 2 eggs to go. The final 2 eggs did hatch on May 10th & 11th. I've attached a picture of the first clear view of all 5 eyases on May 11th.

The second picture is from yesterday. It's astounding how fast they grow! The younger 2 are in front and will catch up to their siblings in short order. You can see the wing feathers starting to emerge on the elder 3 as well as the dark mask around their eyes. They spend most of their time right now sleeping in an large fluffy lump. This is Mariah & Kaver's 4th brood of 5 eyases, so they are well able to hunt and care for a brood this large, though the nest box will be getting very crowd very soon.

All the best,

Will wonders never cease Intrepid and Builder have built another nest since the death of their three eyasses and then their nest falling out of it's tree a few days after the deaths.

Though come to think of it we are dealing with Builder here who just can't stop with the nest building. Here's an alert and explanation from raptor expert John Blakeman about this young pair's activities--


Well, the Riverside Pair has learned its lesson, and is applying it sooner than expected. photos show that it's building a new nest, this time in the solid crotch of a plane tree. This is now a typical, normal Red-tail nest -- except for its construction time. Normally, the pair would have just terminated nesting activities this late in the season. But these birds still have some breeding hormones flowing.

Will the nest be used now? Will eggs be laid in a "double-clutching" event? Seems possible. Notice the speed with which this nest was put up. That's typical for Red-tails. Once a site has been selected, sticks are brought up and the nest appears in only a few days. Nice work.

Now, it has to be lined, which should be no problem. Copulation has to resume, and the female has to have the physiological resources to produce another egg or two. Can she do it? Probably, but it may take several weeks for all of this to come together.

Don't be discouraged if the new nest is eggless. Even without eggs, this really sets things up for next year. This rebuilding of the nest, in a so much better location, shows as much commitment to reproduction as a Red-tailed Hawk pair can have. Very, very positive.

Now, for the "blood-thinned" rats....

John A. Blakeman

I do hope they've learned a second lesson and somehow figured out which rats to stay away from.

Charlotte on the nest, by Brett Odom.
Just what are Pale Male Jr. and Charlotte up to? Here's the latest from Brett Odom--

Hey Donna.

I just wanted to let you know that I saw both C & J at the nest together on both the 19th and the 21st. On the 19th they flew in and rearranged the already existing twigs on the nest. On the 21st they did the same thing.

Both days they flew off the nest at the same time but went off in different directions so there is definitely still no incubation going on. Very strange behavior.

I just wish I knew that they visit the site because they instinctively know that its breeding season and that they are supposed to be at the nest as parents, or if Charlotte is aware that she is definitely gravid and just waiting to lay her eggs. However, the latter seems unlikely since it's getting to be late in the season.

I will be gone for the holiday until Wednesday so I won't be seeing any activity at the nest until then.

Brett B. Odom

Well, Junior and Charlotte have done a late successful nest before but the question still remains. why, as they have been copulating, building a nest, and doing all the other activities which are the prelude to eggs, have there been no eggs?

An update from Ellie on the Norfolk Eagle's nest with a video link--
Hi Donna,

Thought I would pass this along in case you weren't aware of it. The eaglet had to be removed from the nest. Hopefully, the little eaglet will be okay and able to fly free in the future. What an unfortunate year this has been for this Norfolk eagle pair.

Thunder Found!

Thunder discovered by a local hawk watcher on the dish below the TV tower.

From R. in Illinois who zoomed in and added the arrow to locate where Thunder was seen this morning.

The KJRH tower, see the dish? That nest is a ways up there now isn't it? The formel Kay has been watching over Thunder from the nest platform on and off since she took the leap yesterday.
More Thunder to come plus a Peregrine Update and, I hope, the Illinois eaglets.


Thunder courtesy of KJBH

Screen captures by Catbird courtesy of KJBH TV

Thunder does a last practice flap, spreads her wings and is gone. For much more on Thunder's fledging go to the second post down. The next post down is the toxicology results for the Riverside Eyasses.


The toxicology report is in and as suspected the three eyasses in the Riverside nest with lung hemorrhages died from eating poison mostly likely carried by a poisoned rat brought unknowingly to them by a parent. And the poison may have come from bait boxes placed inside the park.

A tragedy that has been much feared by the hawk watchers and that has been just waiting to happen.

See Lincoln Karim's site:
(Also posted today, the news of Thunder of Tulsa's fledge. See next post down. D.B.)

Thunder Rolls Out! And Here Comes a Tornado Towards Tulsa.


At 6:06 AM CST Saturday, May 24, with no drama at all, Thunder spread her wings, and flew away, straight into her future. Observers who witnessed the fledge write that she "just did some air lifts..hopped to the corner ledge facing the street, fully extended her wings, and flew off, straight hesitation at all, just launched herself.."An observer on the ground, walking the area and searching and asking folks, said that no one has seen her since.

Russell Mills of KJRH TV in Tulsa is posting the video of the fledge on their Hawk Page. He wrote: "We'll keep a sharp eye out in the neighborhood and try to spot her, but if you know the topography then you know the area's heavily wooded, especially over by the Arkansas River, and she'll be very hard to find."

Another observer wrote: "Thunder hatched march 3/1/08, Thunder fledged on 5/24/08 - 54 days is my estimation."

4:45 PM Saturday. Tornado on the ground currently heading toward Tulsa. Are we freaked? Of course we are! Hawk spotted on a telephone wire at the far stretch of a parking lot at the station. ? Thunder ? Hard to feed a baby on a telephone wire. Parents have been bringing food and greenery back to the tower nest site, and facing that direction and calling, maybe telling him - If you want it, come and get it"? More later.

And from Judy in MA, who watched Thunder fledge--

4:45 PM Saturday. Tornado on the ground currently heading toward Tulsa. Are we freaked? Of course we are! Hawk spotted on a telephone wire at the far stretch of a parking lot at the station. ? Thunder ? Hard to feed a baby on a telephone wire. Parents have been bringing food and greenery back to the tower nest site, and facing that direction and calling, maybe telling him - If you want it, come and get it"?

From long time blog contributer and hawk watcher Betty Jo in CA--

I am so glad that you mentioned there is a network in Tulsa; I was getting really worried, esp. when that film clip played with someone saying people should come out and yell jump and that she should have left a week ago.

I was afraid no one who was there understood baby hawks. For some reason, I can't post to that site-I really wonder why the parents are now on the nest, with prey. I can not believe they don't know where she is. Our urban hawk here in Camarillo (Red Shouldered) sure let her parents know loud and clear where she was at all times--they led her to the local Heatlh Food Store where the concerned clerks put out hamburger. I was chuckling because I am sure there were rats in their dumpster. The RS did not re-use that nest, sadly; but it was in the same vicinity of a very large crow roost.

Betty Jo

I'm very surprised that the very loud almost gull-like piercing begging sound that fledglings make hasn't alerted the parents to Thunder's presence as well. These seem to be young parents but not spotting their eyass or attempting to get her back to the nest with prey is, in my experience, very unusual. Do they know where she is and we just don't know it? If they are spending a lot of time on the nest, instead of tending to Thunder in various ways something seems out of whack somehow.

Some Cues For Local Watchers Looking for Thunder
1. Listen carefully as you walk for the begging call. Fledglings on a maiden flight rarely go further than a block or two. In fact often it's no further than just across the width of a street.

Though Thunder had a good bit of height going for her so she is may well be further than that but not by grand lengths. We're not talking miles.
2. Listen and watch for the many smaller birds, often Crows, Jays, Catbirds, even Robins that will mob young Red-tails with abandon. It's noisy and active. Go towards that activity.
3. Watch the parents and attempt to get cues from their activity. They will try to evade you but keep trying.

P.S. Don't be alarmed if you see the parents bringing prey and Thunder eating but she continues to beg piteously afterwards. She's not likely starving but eyasses are wired to beg, particularly as the days pass and they spot a parent.

Donegal Browne