One AM early on during year two of the annual census of migrating Turkey Vultures (TUVU’s), a stranger joined us not long after opening the count site for the day on Buzzard Bluff (the “Hill”). Folks did drop by from time to time, however he had to be an itinerant for he had driven up the more difficult road at the north end of the ridge.
In a friendly manner, the fellow jumped from his car and asked if there was room for one more? Assuming he was a fellow birder, “Sure!” Curiously though, he asked what we were doing? “Counting Turkey Vultures.” “Doing what - isn’t this the Tehachapi Loop?” Passing along verbal and written instructions to the congenial train buff - off he went.
Over the four years of the Tehachapi Mountains Birding Club’s Turkey Vulture Census 130,000 of these birds were counted by 30 members on 176 days during 2,448 hours on the “Hill”. This citizen science project will probably not be repeated in the same manner. Thus, it is time to reminisce and put to the written word as much as space allows.
Only once was there a hands-on experience with any of the TUVU’s. Responding to the message of a Golden Eagle down, the team took off to the east. Reaching the reported site, a caravan of five cars circled through the mobile home park in search of an eagle. Residents warily watched the trespassers from their decks and peaked through curtains.
Dismounting, six birders with binoculars hanging from their necks began combing the neighborhood for a grounded eagle. None of the adults were helpful and were still apprehensive over this invasion. Then a friendly group of young boys ran up and led us to the bird. In back of a single-wide, squeezed between a shed and a fence, there was Junior!
Junior (TUVU boys and girls look alike) was not an eagle! He was a pooped-out “grey-head” (juvenile) Turkey Vulture on his first migration. Junior was rescued by members and then rehabed by FACT. Member Kristie Grubb released Junior on Mourning Cloak Ranch. Two nights later seventy TUVU’s flew in to roost overnight. In the AM Junior left with these birds on their way to Mexico, or beyond, on the last day of the count!
A “Big Day”(1000 plus birds) was hoped for everyday. September 29th 1999 was the first 1, 2, and 3,000 bird day (3174)! On October 6th 2000, 4761 birds! The first 5000-bird day occurred on October 2, 2001. There were 43 “Big Days”. The 11 O’clock hour was the “Big Hour” averaging 275 birds. Three times 3,000 birds were seen mid-day (11 to 1).
On a Big Day last year there were four experienced counters (usually there were three) on the “Hill”. While counting a kettle of 300 which had broken-out into a glide, I broke away from counting (a no no) to observe a single raven continually “mobbing” one specific vulture thus interrupting its glide and causing it to have to flap its wings (a waste of energy needed to reach its winter range).
After five or six “attacks”, two leading adults turned back to assist and send the raven rapidly row row rowing on its way. While observing vulture migrations here and in Weldon, this was the first time I had observed TUVU’s breaking ranks to defend another individual bird.
With the alignment of the Tehachapi Mountains being generally east-west, and since birds of prey prefer ridges and wind currents which will lead them in a more southerly direction, not many birds-of-prey migrate through the Tehachapi Valley. Although this was not a goal of the count, birders on the “Hill” could not resist recording those that did.
Each year eight to ten species would be observed in small numbers. Eagles were always memorable, as were Northern Harriers and Prairie Falcons. Swainson’s Hawks were seen each year. In 2001 four individual Swainson’s were seen, while on a Sunday a kettle of 37 were recorded by member Angela Guy from the count site.
During the early days of the count window each year, and in the early hours each day on the count site, we would watch for Ospreys. This eagle-like bird would come through with an obvious mission - that of migrating from lake A to lake B, or to wherever. The Ospreys would go right by at eye level. Occasionally though, so as not to miss a possible fishing opportunity, a bird would take one swing around the settling ponds below.
There always were lots of things to see and distract us from counting. Aircraft, other birds and “Sun-dogs”. One day a plane landed near the P.O., taxied to the gas station in and subsequently took off! Trains, trains and more trains of all kinds, which Alvin Aronson sorted out for us. Trucks on “58” would honk in salute to “Old Glory” blowing in the wind on the “Hill”. There were control burns, fire engines, ambulances, “Chippers” citing vehicles, and of course bridge construction. Suppose we missed any vultures?
How many birders does it take to set up a shade-cover on site? Six! Three to erect the tent, two to watch for birds, and one to take pictures. The shade-cover went through four years of evolution both in structure and erection methodology. David McNally was the chief design engineer, however, many members added refinements over the years.
Is it surprising or not, that for the 176 days and nights the shade-cover frame stood on “Buzzard Bluff”, it was only vandalized once? The morning after that one night, Gordon Black greeted me with, “We had visitors last night.” Gordon, a retired fireman, and knowing how to do everything, had it repaired before the day’s first birds appeared.
During the counts, various agencies asked observers to watch for vagrant birds-of-prey. That is, birds, although out of territory, that had been seen in California. A Zone-tailed Hawk was on the watch list each year. This is a hawk which has very similar field marks to a vulture. It also mimics the TUVU’s forging habits in order to fool its prey. Not seen.
An albinistic (partial albino) Turkey Vulture was seen one year on the Weldon count. This year, during the “TUVU-count-withdrawal” period (watching and counting TUVU’s is addicting), Jean and I hung out for a few hours on a historically Big Day (October 5th) at a site where birds entering the valley were eventually sure to pass over.
On that day we saw 4000 to 5000 TUVU’s. In one 200 bird kettle, an albinistic Turkey Vulture! No question, it was not a Swainson’s, nor a Zone-tailed. It had a white tail, large dorsal wing patches at the base of the primary flight feathers numbers 5, 6, and 7 on each wing. No, not a Golden nor Bald Eagle. A very attractive albinistic Turkey Vulture!
Weldon, in the Kern River Valley, is also a corridor Turkey Vultures exploit in making a relative low passage over the southern Sierra. Terri Gallion’s count is in its tenth year – a remarkable commitment. Between these two corridors, it has been firmly established that from 60,000 to 70, 000 TUVU’s cross over the mountains annually! Is there a third path?
Cloud cover, temperature, wind direction and velocity were kept on an hourly basis. Each kettle was recorded as to path used to pass through the valley, flight behavior, and altitude. These observations make it clear that under any conditions, east winds, west winds, whatever, TUVU’s have a matching flight strategy to reach their winter ranges.
As a result of these counts, there are many things we learned and now know. What is disappointing is what we still do not know. Where do these particular Turkey Vultures migrate from and to where? How and where do large kettles (800 to 1000 birds) form?
Fidelity to overnight stops, flight path, and migration behavior have not been studied.
All observers had their special experiences and have their indelible memories of those days in the sun – and those days in the cold (who needs a sun-cover, a wind break would be nice). Most of all, we’ll miss the camaraderie on the “Hill”. The famous Sunday Women’s Day team, Men’s day on Wednesday, Saturday’s weekender team, and all the observers over the years will not be forgotten. Until the fall of ’04, those shaggy thunderbirds soaring overhead will also be missed.
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