Baby Season
A Year to Endear
A story about the year 1997. This provides an
interesting insight into a year of raptor rehabilitation.
Baby season was quite something this year -- for one thing, five of our education birds laid eggs for the first time... ever! Including our 9 year old great-horned owl, our 11 year old red-tailed hawk, a kestrel, screech owl, and barn owl. With most of them, there was not a chance of their being fertile, but having the birds go through part of the breeding cycle provides an opportunity to use them as foster parents. Oddly enough, in captivity, it is more often males that are good foster parents, not females.
The leader of the pack was Burwell, a great horned owl ("GHO"). Last year, she had made a couple of scrapes in the gravel bottom of her cage - and I had actually put in a hollow bark ring as a potential 'nest' - but nothing had happened. This year, I saw her starting the scrapes and just shrugged... and then suddenly realized she had been sitting in one place for a full 24 hours. Sure enough! When I peeked under her, there was an egg. Four days later she laid another! (For some reason, with the four birds that laid at least 2 eggs apiece, all of them had a period of about 4 days between the first one and the second.) I was excited! Now Burwell, a human imprint, will not tolerate anyone but me in her enclosure at the best of times... now I became her mate in earnest, bringing food directly to her in the nest - and then leaving very quickly before she charged me! S he had laid the first egg on February 26th - great horneds are notorious for nesting very early, probably because their off-spring have a very long post fledging dependency period, with a lot to master before they are on their own. I let her sit on the eggs through March, well past a normal incubation period, and just as I was thinking of removing them, I got a call from Roseburg - fellow 'rehabbers' there had just gotten in a nestling GHO that they were unable to return to the nest. (They also brought up a nestling barn owl, as our male barn owl is a fantastic foster parent every year - but that's another story!)
Now the fun begins! They brought the owl up the next day - April 5th. Not knowing how the introduction was going to go, I fed the baby a small amount, then put her into a carrier and moved her into Burwell's flight. Letting them see each other for awhile, I noted that the baby was frantic to get to what she recognized as a 'Mom' - and that Burwell, though not leaving her eggs, was not reacting in any hostile manner. So - holding my breath - I reached under Burwell, while she was focused on the baby, and just as I opened the door to the carrier, I removed the eggs, without letting Burwell see them. Still keeping the carrier door between the baby and the adult, I watched again for hostility and then, while still standing close by, I handed Burwell some food and let the baby have access to the adult. Talk about love at first sight! The baby made a beeline for Burwell, grabbing at the food in her beak. I was nearly dying with (silent) laughter as the adult tried to do several things at once: stay brooding on the eggs she didn't know I'd stolen, protect her eyes from the baby's grabbing beak, and greet the baby with food. This last was the hardest - Burwell had the instruction manual somewhere in her genes but this was definitely her first trial run, and I had messed up the equation. Instead of the helpless, just hatched newbies she would normally be feeding, I'd slipped in a month-old one pound ringer who was more experienced at this feeding business than SHE was. The baby wasn't old enough to tear up food, but neither did she need to be fed tiny tidbits... Finally, the two worked it out, the baby was fed, tired, and wanted to go to sleep. She was leaning against Burwell's breast, who (still in brooding mode) tried really hard to push down on the baby with her 'chin' while pulling her in with a wing... trying desperately to get that way-too-large bundle of fluff UNDER her where she was supposed to be! Again, tears of laughter on my part. Burwell finally compromised by tucking the baby under one wing - and both of them had a nap.
Now Burwell's cage is on public display, so we hung screens all around the nest to keep human exposure to a minimum. I didn't want to move the pair out of that familiar cage until the baby had 'branched' (left the nest), which didn't happen until April 15th. By the 18th, the baby was able to get up on a high perch - so I moved them both to a rehabilitation cage. Shortly after, two more fledglings came in, and Burwell took them also under her wing (this time figuratively, as they were way too old to need brooding!) On June 2nd, after a little bit of live prey training (in which Burwell embarrassed me no end by trying to show the babies how to catch mice on FOOT and with her BEAK!), all three were hacked out on the property. We knew they would stick around, because 'Mom" was there, and we set up a feeding platform on the outside of Burwell's cage. During the summer, they have all taken turns disappearing for days, even weeks, at a time; currently one male has apparently truly dispersed, as he's only been back once in the last 7 weeks; the other two take turns going off for a week or two at a time.
(Editor's Note: Burwell died in 2004 at the age of 16.)
We didn't get any young red-tails in time to try Tomahawk with an orphan. I came back from teaching a class in Idaho, walked into her cage on March 26th and found a broken egg on the ground. I admit it took me a minute to figure out that it had to have come from the hawk... but when I did, I grabbed a heron nest I had lying around and placed it on her feeding platform. She immediately took up housekeeping; I cut her some evergreen bows, which she carefully arranged. She laid her second egg in the nest on March 30th, but didn't start incubating until she laid the 3rd on April 2nd. I finally pulled her eggs May 13th, after about 40 days - much to her relief, I believe! I had been feeding her on the nest and she would get up and stretch (I think I was supposed to take over for awhile, but what do I know?) At any rate, she had been leaving the nest for longer and longer.We got one young red-tail nestling in on the 25th of May and were able to return that to the nest, thanks to help from Longbranch Tree Service. We got another, older nestling in on the 7th of June and tried to introduce it to Tomahawk, but she was no longer in the mood! That one and one other we had to raise ourselves! This was a strange year for red-tails. We were getting a number of calls about screaming youngsters in the nest, or fledged and on the ground, but with parents still around. One of these situations was really a mystery.
We'd been called by a concerned person about persistent screaming from a nest that she'd been watching from the time the parents built it before the tree had leafed out; the caller hadn't seen an adult in several days. Another call to Longbranch, and as they and I pulled in the driveway, here comes an adult! Relief all around! (Longbranch really hadn't wanted to climb that huge old cottonwood!) However, a few days later, we get called again by other residents of that same apartment complex - a screaming youngster on the ground, unable to fly; another one on the roof-top. We pick up the one that isn't flying: extremely emaciated and weak, despite the presence of his parents.
This bird was fully and perfectly feathered; whatever malnourishment had occurred, had happened after feather development, as there was not a mark on his feathers. He was extremely anemic (9% red blood cells, where 35-50% is normal) and his serum protein indicated that he had not eaten for days. I have always believed that our best option in these cases is a blood transfusion, though sometimes, as was the case with this one, not even that can save them. He died shortly after we returned from the vet. Five days later, after a few unsuccessful attempts, we got hold of his sibling. Again, a parent was flying overhead, but the bird was on the ground, screaming, extremely emaciated and weak; this one, being down even longer, had 7% red blood cells in circulation and essentially no total solids in his blood at all.
Since a transfusion had not worked for his nestmate, this time I tried a protocol used by a long-time friend in Wisconsin. I started with very dilute solution of meat baby food and Pedialyte, gradually increasing the proportion of meat. Although he lost weight initially, his blood values improved steadily. Within four days I was hand-feeding him chopped up whole food; within 2 weeks he had gained almost a pound. We were able to release him at the end of July. I have no idea if the parents were just not able to find food; if they had been gone for awhile, if one of them had been killed.
What was odd was that I was hearing similar stories of screaming fledglings from many different parts of the country; no explanation, but one theory was that the spring floods may have destroyed the first nest attempts of prey species. Though the adult rodents survived, their off-spring, who would have been having young of their own to coincide with young raptors leaving the nests, did not. So though there was no shortage in the early nesting period, there was a shortage of food later. Just a theory.
We also had a record year for Coopers hawks! One nest came in when a large branch broke off a tree; the babies were just hatchlings. So young, in fact, that we could not definitively identify them - beyond the fact that we knew they were diurnal raptors, too small for eagles, definitely not falcons... not ground nesting, so not harriers. The accipiter foot was not apparent for several days, by which time they were growing so fast, we entertained a brief flurry of concern that they might be goshawks. But Coopers they were - despite an early identity crisis while they were being fed with a red-tailed hawk puppet...! We could not return them to even a substitute nest because we did not know where the nest tree had been - despite several messages, the finders did not call us back.
We can do the best job a human can do raising orphans - in effect, feeding them well and teaching them how to hunt rodents, perhaps, but we still can't come close to what their natural parents can teach them. We were able to find a falconer in Corvallis to take over their tutelage at fledging age - the best option, since Coopers hawks are designed for bird-hunting through dense cover, which is not a situation easily duplicated in a flight cage! We were able to return another nest-full of Coopers hawks to the tree from which it came - and have both parents in full attendance almost immediately. Another Coopers nestling came to us from eastern Oregon, in the aftermath of a wildfire. This one we placed in a hack box on our property as a nestling; fed her there for some time; then opened the box to coincide with her fledging. She returned to the box for food as she learned to hunt on her own. We spotted her at the bird feeders (!) and the hack box for some time. Other older fledglings came in - all in all, we received and released 11 Coopers hawks so far this year, a quarter of all those we've seen in the last 10 years!
The limitations of captive-rearing of raptors were never more evident than when we were presented with a nestling osprey in late July! This had been an osprey summer - we'd received 8, when we usually see only 1 or 2 a year - but this one was really a challenge! The Forest Service quickly found the nest from which he'd taken a dive - the baby had been found in the middle of the road, having fallen probably 165 feet. He must have bounced off just about every branch on the way down, since he didn't break anything, despite not having enough feathers to even slow him down! Unfortunately, this was a very big (6' diameter at breast height) tree, with the top 40' very dead and unclimbable; Tim Brown, master tree climber from Seattle, generously made an attempt to put up a substitute nest on a lower branch - an questionable proposition, anyway, as we didn't now if the parents would tend two nests. But the bark was dying and just splintering as Tim tried to find footholds. There were no other nests that we heard of, despite emails throughout the Forest Service network - all the other nests that anyone had been monitoring had already fledged their young.
This nest - obviously a second attempt, given the late date - still had two other nestlings in it, judged to be about 4 or 5 days older than the one that fell. We considered putting the baby in an unused osprey nest at Fern Ridge Reservoir as a hack site, but we would have needed to feed him probably twice a day (and would have needed a lift-truck to get to the nest each time!), and he'd have no parent to protect him from hot, wet, or cold weather or crows, ravens, GHO's, or whatever else might be attracted to him. After discussions with osprey folks around the country, we decided our best option was to wait until his two siblings fledged, then put this one up in a nearby tree. At that point, the parents are more programmed to feed any calling youngsters, and are not necessarily so focused on the nest site itself.
The Oakridge Forest Service biologists (who were incredibly caring and helpful throughout - in fact, we could not have done any of this without them!) monitored the nest, picked a nearby tree to put a nest platform in, and built a platform to Tim's specifications. Tim and USFS biologists felt the original tree's seasons were numbered, given its condition, and that by putting up a substitute platform now, the osprey pair would have an alternative nest site. The osprey siblings fledged, of course, when Tim was tied up, but within two days, he drove down again from Seattle, climbed the tree, established the platform, hauled up the baby, took lots of pictures, and came down again.
We could only cross our fingers and pray, as the nestling we had was now at fledging age himself and thus not guaranteed to stay on the platform for any length of time. The main drawback was that he had not had the hours of practice on the edge of the nest that his siblings had (next time I'll build an elevated platform, as he had shown no inclination to flap while I had him) and I was concerned that he wouldn't be able to maneuvre those incredibly heavy, long wings well enough to get up and over to the original nest, where the adults were still serving meals to their fledged youngsters. The baby definitely started his flight practice the minute he was on the nest... nothing like being 120' up in the air to give you room to FLAP!
The adult ospreys were definitely in attendance and started to hover between the two nests as soon as Tim was down the tree. By the next day, the baby was gone, but the biologist monitoring the nest was sure he had heard three youngsters calling each time he went to the site - though the two he saw at the original nest the day he brought his spotting scope were not banded. I hate these cliff-hangers, but I can truly say that this was his best option for this bird. I mean, how was I going to teach this guy how to snag fish? Much better that he get the chance to observe experts - his own parents! - who were also programmed to feed him while he was learning. We can only hope that we get a postcard from Baja California some winter... or eventually find a banded adult nesting in the area! It was definitely a delight to hear him calling to the adults, despite his more than 3 weeks in captive care.
This doesn't mention the kestrel babies, the screech owls, or the green-backed herons we got to host... but we had a particularly busy baby season this year. Getting in something like two birds a day throughout June, rather than our average one every two days, was definitely a challenge. But we love a challenge... and it was never so obvious as, just as we released the last of the screech owls which had come in as orphans, we started to get in the fledgling screeches that were injured in their first foray into independence. Definitely a year to remember! My sincere thanks to our outstanding crew of volunteers who helped me keep everybody straight and shared all the responsibilities so graciously.
