Jim Shea's 1997 Personal Radiotelemetry Experience

November 4

Tracking of a juvenile female Cooper's hawk, code-named "Ohlone" had begun on October 31. In the first few days, she had gradually moved north and was located on the western side of Bolinas Ridge, just above Stinson Beach when I joined the hunt.

The plan for the day called for the team headed by Maura Eagan to monitor Ohlone from West Ridgecrest Blvd, which runs along the top of Bolinas Ridge. Maura was an intern working for GGRO for the 1997 season; her primary responsibility was to support the telemetry program. The chase leader, Cheryl Kraywinkel, cruised the Stinson Beach-Bolinas area, keeping close contact with the hawk, while Libby Rouan and I monitored signals from Mt. Tamalpais.

Jim Shea tracking Rex, a juvenile red-shouldered hawk,
from near the peak of Mt. Burdell, N of Novato, in Autumn of 2000.

We were unable to detect the signal from Ohlone from Mt. Tam because of the topology. Nevertheless, our position was important in case Ohlone decided to head east over Bolinas Ridge. In that event the other two teams would rapidly lose contact and with the limited roads in that area a considerable time would elapse before they would be in a position to receive a signal. We would be able to provide bearings that gave sufficient information for selection of a new high point for Maura's team and the best route for Cheryl to re-establish contact. Ohlone, however, stayed in the same general vicinity all day.

As dusk approached, we moved from Mt. Tam to a vantage point on the Panoramic Highway near to where it joins California Highway 1 just southeast of Stinson Beach. There we were able to pick up the signal and provide a third bearing for the roost location.

That evening the question was debated as to whether to continue to track Ohlone, who appeared to be a "local bird," or to begin tracking a new bird. Further, there was a question of whether or not to continue with Cooper's hawks, considering the tail feather issue. The decision was made to track a new bird; the first choice for a new bird was to track one of the less frequently trapped hawks (provided it met the minimum weight requirement). However, because it could take considerable time until the new bird was trapped and prepared for release and Ohlone was nearby to the Marin Headlands, it was decided to use two teams to continue following Ohlone until a suitable new bird was trapped.

Also, because Ohlone was close to the Marin Headlands, the telemetry teams camped for the night in the GGRO building at Ft. Cronkhite.

November 5

Cheryl Kraywinkel's team waited at Hawk Hill and helped the hawkwatchers while waiting for the new bird to be trapped. Maura Eagan's team started the day at their previous location on W. Ridgecrest Rd., while Libby Rouan and I started to track Ohlone from Stinson Beach in the early morning. As we entered the town of Stinson Beach at first light, we picked up strong signals on the omni antenna. We stopped at several points along Highway 1 and took bearings. Just after taking a bearing to the east, we were putting the equipment in the car when Libby looked up and said, "There goes a Cooper's hawk now." It flew over us and west toward the Stinson Beach spit. We got out the Yagi and took a new bearing - to the west. The hawk we saw was Ohlone. Further readings that we took from Bolinas told us that she was on the spit, which is mostly a gated development and inaccessible to us.

Mid-morning, in accordance with the plan for the day, we moved to the observation point on Bolinas Ridge, and Maura Eagan's team moved to the peak of Mt. Tamalpais to be in position to track a new bird. For the rest of the morning we continued to take bearings, and had an indication that Ohlone was possibly moving up the ridge. We lost her signal shortly after noon, and drove the length of W. Ridgecrest and back without re-establishing contact. Then we were told by radio that the new bird had been trapped, so we should move to our assigned observation point above Richmond on San Pablo Ridge . The new bird was a juvenile red-shouldered hawk, and was code-named "Xingu."

Morning fog over Stinson Beach from our observation point on W. Ridgecrest Blvd.
in Mt.Tamalpais State Park where we listened for 'Ohlone'.

We arrived on San Pablo Ridge in the middle of the afternoon and began to take bearings. We had two problems. First, there was a conflicting signal on the same frequency that made it difficult to pick out our hawk, especially when the Yagi antenna was pointing in directions between west and south. The wind was blowing so hard that it was difficult to hear the beeps from the speaker on the detector. The wind noise problem was easily solved by using earphones, but the conflicting radio frequency noise made it difficult to be certain we had an accurate bearing. Nevertheless, with Cheryl's readings from along Highway 101, and ours from San Pablo Ridge, we were able to establish that Xingu was on the Tiburon Peninsula.

After another night camping at the GGRO headquarters building, Cheryl Kraywinkel and I headed for Mt. Tamalpais, Libby Rouan's team went to Point Richmond, while Maura Eagan's cruised the Tiburon Peninsula. Cheryl and I encountered heavy fog on our way up the mountain, but we cleared the clouds as we neared the summit. We spent the day taking readings, but because of Xingu's location on the back side of the hill on the peninsula, we could not pick up the signal; but, we could hear the interfering signal loud and clear. Early in the day our view was mostly the top of the cloud layer, but we did occasionally see the parts of the bay where there were breaks in the clouds. After noon, higher clouds began to come in and a fine mist descended upon us.

Late in the afternoon, we headed down to help pinpoint Xingu's roost location - Xingu had remained on the Tiburon Peninsula all day. Cheryl worried a bit that the transmitter might have come off Xingu. She had attached it and had had some problems dealing with the fine feathers at the base of the tail and the epoxy took longer to set up than usual. Cheryl had not attached a transmitter before and this was the first red-shouldered hawk upon which this was done. As we drove down the mountain, it began to rain. Because we passed close to the observation location we had used on W. Ridgecrest Blvd, we made a slight detour and I used the Yagi antenna to listen on Ohlone's frequency. I was happy to pick up her signal, back in the area above Stinson Beach.

We joined Maura's team on the peninsula, where the rain had stopped, and coordinated our locations and end-of-the-day reading times for the roost-location bearings. Once again we camped for the evening at the GGRO headquarters building.

November 6

The day started with Cheryl Kraywinkel's team on San Pablo Ridge. Katie Fehring's team would cruise the Tiburon Peninsula, and Bill James and I would look for a suitable high point to track somewhere in the Marin Headlands. Bill and I tried two hills in the Marin Headlands, Slacker and Wolfback Ridge, and Yellow Bluff at Fort Baker without being able to get a signal from Xingu. Finally, we crossed the Golden Gate and at a point just above Crissy Field in San Francisco we were able to get bearings pointing to the tip of the Tiburon Peninsula. After about an hour the bearings suddenly began to move eastward - Xingu was on the move! Cheryl needn't have worried about her glue job. The bearings from Cheryl's location on San Pablo Ridge did not change much until when they shifted nearly 180 degrees as Xingu crossed the ridge.

Bill James tracking Rex, a juvenile red-shouldered hawk,
from near the peak of Mt. Burdell in Autumn of 2000.

Cheryl decided to head for Mt. Diablo; she sent Katie's team to the Altamont Pass. Bill and I were sent to find a high point in the East Bay hills and to chase from there. We crossed the Bay Bridge and took Fish Ranch Road to Tilden Park. We picked up the signal near the corner of Grizzly Peak Rd. and Park Drive. Happily, the signal that was interfering on our frequency was not a factor on the other side of the East Bay hills. We then moved down Lomas Cantadas and set up to take bearings on the hillside there. After several readings which shifted steadily south, we lost the signal. Bill tried unsuccessfully to raise Cheryl on the radio; but he did reach a mobile PGE crew chief who refused to believe that Bill was tracking a hawk. He was convinced that Bill was an errant member of his team. He told us in no uncertain terms that we were to meet him in Milpitas as fast as we could get there.

There were several possible routes through canyons that Xingu could have used to move south. We drove down to Orinda, to Moraga and then followed Redwood Road along the San Leandro Reservoir without picking up a signal. During this time, Bill commented to me that it was his experience that you could go all day without being able to contact the other teams, but that somehow at the end of the day everyone converged.

We then followed Crow Canyon Road to Blackhawk, turned east on Camino Tassajara and then east on Highland Rd, still without hearing Xingu. However, we re-established radio contact with Cheryl who did have a southern bearing from Mt. Diablo. In hopes of being able to get a reading that would let us triangulate and pin down the Xingu's location, we drove up Morgan Territory Road, a steep climb on a narrow, one-lane road. After gaining some elevation, we picked up the signal, stopped and got a bearing. Unfortunately, it didn't cross Cheryl's last reading, probably because of hill that blocked our view to the southwest. We were unable to make radio contact with Katie's team.

We then headed south on Livermore Avenue to I-580, where we headed west, so that we would cross Cheryl's last bearing. When we reached Dublin without hearing a signal, we headed up the hill, stopped on a bluff and successfully picked up the signal. It appeared that Xingu was headed south down the canyon where I-680 runs. We raised Cheryl briefly on the radio, but lost her almost immediately, and were uncertain if she got our message. Later, we found out that her batteries were dying and that she had to walk from the observation tower on the peak to the parking lot to get spares.

We then headed south on Foothill Road, stopping at Castlemont Country Club, which is up on the side of Pleasanton Ridge, where we again acquired a bearing to the southeast. When we reached Niles Canyon Road and turned towards Sunol, we attempted to radio Katie Fehring's team. They came back loud and clear. They were at the corner of Niles Canyon Road and Pleasanton-Sunol Road, about 300 yards ahead of us. They had been working their way west along Vallecitos Road.

After a short conference, we decided that they would take a last reading from a position back on Vallecitos Road, while Bill and I went to Sunol Regional Wilderness to see if we could arrange access to Rose Peak, the highest point in the area, for the next day; all would then rendezvous back at the same intersection. Bill and I went to Sunol which had officially closed, but the resident ranger kindly interrupted his backyard barbecue with his family to assure us that Ranger Dan Reasor would provide the necessary access when a team arrived in the morning.

Bill and I returned to the rendezvous point and found Katie's team there waiting for us. We then radioed for Cheryl. She responded that she was on I-680 approaching the Calaveras Road exit - just a few miles away. Bill's observation about everyone converging at the end of the day was right on the mark.

After a general discussion of plans and a phone call to Alan Harper, who along with Karen Scheuermann headed the 1997 tracking program, the trackers who were continuing the next day headed for Alan Harper and Carol Baird's place in Oakland to spend the night. The others went back to the GGRO headquarters and then home, with the exception of myself, since Bill could easily drop me off in Castro Valley on the way.

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