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What I did for my Earth Day, 1999

I didn’t realize it was Earth Day until we were halfway there. Morro Rock, probably the best-known peregrine eyrie on the West Coast, was in the process of failing for the second year in a row. Yes, the peregrine falcon as a whole is doing very well, but in certain regions, like coastal California, chronic reproductive failures are still occurring at some sites as a result of eggshell thinning. Reports from field observers Judy Sullivan and Steve Schubert had the pair beginning incubation in the traditional "diving board" eyrie in mid-March. Here it was April 22nd and instead of feeding little hatchlings, the pair had been copulating for over a week in an apparently vain attempt to lay an intact full clutch that they could incubate to term.

They would begin to incubate, then apparently break whatever eggs they had and proceed with laying more (peregrines are "indeterminate layers", meaning that they will continue to lay until they have a complete clutch of 3-4 eggs, the same phenomenon that keeps a hen chicken producing for months if her eggs are removed daily). Fortunately we were in a position to intervene. Something we hadn’t done since 1992, when our captive breeding project ended.

Three young peregrine chicks had been promised to SCPBRG for release by a private breeder, Val Fairman. They were slated to go to one of two hack sites (release sites staffed with 24-hour-a-day human surrogate parents) we were planning for this year. However, their parents had bred earlier than anyone had expected and the hack sites could not be staffed in time for the chicks’ quickly approaching release date. (For a hack site to be successful, the chicks must be released at the age, 38-42 days old, at which age they would normally fledge, or take their first flights. If released too late they may be over-developed and fly away from the hack site before learning that it is a safe place to return to for daily feedings while they develop the skills necessary to hunt and provide for themselves.) To solve this dilemma we, pardon the phrase, decided to kill two birds with one stone. Using the tried and true technique of Fostering, it was decided that I would play the Stork, swinging into the eyrie to deliver a precious payload of big downy chicks to the reproductively-challenged Morro pair. I called Val and arranged to pick up the chicks, now 23 days old, the next morning. I then notified Fish and Game and the interested parties in Morro Bay and the plan was set in motion.

Young peregrines grow at a tremendous rate, going from egg to 1000 gram flying bird in a little over a month. To keep up with this metabolic mad dash they consume approximately half their own weight in bird bits over three or four feedings each day. This makes a lot of work for the adult male, or tiercel, who does the majority of the hunting for his young brood. On pick-up day Val made sure the chicks had been fed in the morning by their biological parents, and then we boxed them up for the long trip to their new home. To avoid transporting them during the hottest part of the day, I took them home, intending to depart at 3:30 a.m. and arrive in Morro Bay shortly after dawn. This would give us all day at the Rock to make sure everything went well. This also meant that the chicks would have to be fed a couple of times before their foster parents could take over those duties. So while I was cruising down 680, Janet Linthicum was thawing a dozen organically grown coturnix quail at home.

When alarmed, peregrine falcons, adults and young alike, emit a piercing discordant vocalization that has apparently been evolutionarily engineered to drive the cause for alarm away, or if not, quite insane.  The loud, harsh, "Cack, Cack, Cack," is rendered at an insidious frequency which causes one’s eardrums to throb painfully. If forced to endure this cacophony for long, one’s eyes begin to water, thought patterns become muddled as the eardrums threaten to implode, and absolute imminent panic hovers on the periphery. Peregrine chicks that have been raised by adult falcons apparently think that humans are a clear cause for alarm, even if they’ve never seen one before.

Fortunately, food has a temporary calming effect on an alarmed chick. To feed a 24-day-old falcon chick one first cuts several quail into bite-size bits. Carefully open the box, trying not to alarm the poor little thing. Then, using a long pair of tweezers, you gently place a bit of quail into its open cacking beak, or allow it to bite the piece of quail in an attempt at self-defense if it so chooses. The chick, which is busy being greatly alarmed at having you only a short wing’s length away, will invariably utter something like, "Cack, Cack, Cack, blearb, blearb, blearb, gulp, <pause>". In mid-cack, a dull little light seems to go off in its little brain alerting the beak to the presence of food and that perhaps it had better swallow before it chokes. It may be thinking, "Huh, that wasn’t so bad, besides, life has gotten so weird in the last few hours, who knows when the next meal might come along." The chick then seems to quickly figure out, "Maybe if I appear to become alarmed again…that big biped just might try to calm me with another piece of quail." And so on until the bowl is empty. Sort of gives a new meaning to the term "bird brained." Anyway, I apologize profusely for this gratuitous anthropomorphicological digression, now on with the story.

At 0330, I picked up Craig Himmelwright, who graciously offered to assist on this mission. We got to the Rock at about 0700 and started to gear up. After a final chick feeding, Steve Schubert, Elizabeth Hoyt, and Martine Lynch helped us schlep the gear and chicks over the top of the rock and down to the tie-off. Judy Sullivan took the critical job of observing the adults’ behavior from below. As we were gearing up the pair was observed copulating. This was troubling because it probably meant they weren’t incubating a full clutch of eggs. However, during the feeding of the chicks, the adult male, who could clearly hear the chicks' alarm calls, kept flying over the truck and perching closer and closer. His evident interest was encouraging. At the tie-off we decided that I would rappel in first to collect the eggs, then Craig would bring down the chicks. We have used this method of exchanging chicks for thin-shelled eggs hundreds of times (several times with this exact pair) and never have the adults refused to adopt the young as their own. The eggs would be placed in a portable incubator, taken to a breeding facility, and if viable, the resultant young would be released later. When I got to the eyrie though, there were no eggs. The eggs were apparently being broken as fast as they could be laid. This would account for the copulations and the pair's persistent reuse of this same nest ledge (pairs generally move to a new ledge after breaking a full clutch). Craig brought the chicks down and after a short palaver we decided to place the chicks in the nest anyway. Given our experience with these particular individual adults, including fostering numerous young to them in years past, and their constancy in this particular eyrie, we were confident they would readily accept the chicks as their own. Of course, we would stay to make sure. The intensity of the female’s nest defense increased markedly when she saw the chicks in her nest and the humans beginning to climb back out. According to Judy, the female entered the nest ledge five minutes after we pulled the ropes up. The male joined her shortly thereafter as we began our hike down off the rock.

Within an hour and a half, the male came flying in with food. However, this proved to be something on the sparrow or finch plan, perfectly appropriate for newly hatched chicks but hardly enough to satisfy 3 nearly grown young. Within minutes the female left the eyrie for something more substantial and returned with a previously cached prey item. In the eyepiece of the spotting scope I could see small bird feathers wafting out on the breeze from the back of the nest ledge. Craig turned to me and said, with a bit of an affected drawl, "Well pardner, our work here is done."

Happy Earthday, Y’all!

- Brian C. Latta