Raptor Monitoring Update for May to June 2019

The breeding raptor season is in full swing at Pinnacles National Park, with many species finishing up their nesting efforts. Here is an update on raptor activity through May and June.

Prairie falcons (PRFA) and peregrine falcons (PEFA) are actively nesting. For most falcon nest efforts, young are fledging (or flying for the first time) right now, with a couple of nesting falcon pairs still rearing developing young for several late season efforts. Raptor advisories are in effect, and advisory signs are posted at Balconies, Hawkins Peak, and near Little Pinnacles.

For current advisories in effect, refer to the PINN raptor advisories page - and feel free to ask me for further clarifications.

For the 2019 season, ten pairs of PRFA and one single PRFA have been confirmed occupying territories, as well as four PEFA pairs. Of these, eight PRFA pairs attempted to nest and three PEFA pairs have nested. For information on territory locations and rock formations, refer to Brad Young's climber's guidebook to Pinnacles.

PRFA and PEFA breeding efforts for 2019 are listed below:

• Resurrection Wall: PRFA pair confirmed, successfully fledged 3 young
• The Egg (on west side of High Peaks): PRFA pair confirmed, currently nesting
• South Balconies: PRFA pair confirmed, nest effort failed
• Crowley Towers: PRFA pair confirmed, successfully fledged 4 young
• Citadel: PRFA pair confirmed, successfully fledged 3 young
• Little Pinnacles / Yaks Wall: PRFA pair confirmed, abandoned territory
• Piedras Bonitas Cliffs: PRFA pair confirmed, non-nesting
• Willow Spring Slide: PRFA pair confirmed, nest effort failed
• North Chalone Peak: PRFA pair confirmed, successfully fledged 4 young
• South Chalone Peak: PRFA pair confirmed, abandoned territory
• Drywall Slide: Single PRFA confirmed, non-nesting
• Little Pinnacles / Yaks Wall: PEFA pair confirmed, non-nesting
• Hawkins Peak: PEFA pair confirmed, successfully fledged 3 young
• General Balconies: PEFA pair confirmed, currently nesting
• South Chalone Peak: PEFA pair confirmed, currently nesting

For 2019, prairie falcon occupancy has been consistent with 30-year averages, and productivity - those that have nested (and are likely to nest) successfully - has been lower compared to the averages. In part this appears to be due to the increase in peregrine falcon pairs this year - in addition to the two resident peregrine falcon pairs at Hawkins Peak and at Balconies, two new pairs - at Little Pinnacles and at South Chalone Peak - have actively defended territories this year and likely pushed prairie falcon pairs out of those nesting areas. The South Chalone Peak peregrine falcon pair began nesting very late in the season, and represents the first time we have had 3 nesting pairs of peregrine falcons in a breeding season at Pinnacles National Park in over 50 years. Historically, records suggest that there was a more even distribution of PRFA and PEFA nesting pairs at the park more than 60 years ago. It will be interesting to see how PRFA and PEFA breeding numbers change in years to come as peregrine falcons continue to reestablish nesting territories in their historic ranges.

Here are a couple of photos of prairie falcon nestlings developing during the 2019 season:

Four nestlings huddled together, at 17-19 days old	PRFA nestlings (with one hiding behind the others) at 20-21 days old - note the additional juvenile feather development on the wings
Female adult prairie falcon in flight	Male adult prairie falcon perched on a cliff face

As noted above, climbing and hiking advisories are in effect for the 2019 season. The official park website reflects current advisories in effect, as do the Friends of Pinnacles and Mud 'n Crud websites. Let me know if you have further questions.

In addition to PRFA and PEFA, other raptor species actively breeding in the park early this year have included:

• American kestrels
• red-tailed and red-shouldered hawks
• owls (great horned, barn, and long-eared)
• Cooper's hawks.

Golden eagles nested at North Chalone Peak and just outside the west entrance to the park.

Here are some photos representing the varied breeding efforts by raptors at Pinnacles this year:

Red-tailed hawk adult perching with 3 nestlings at a stick nest	Juvenile red-shouldered hawk, within a few days of fledging from a gray pine nest site
Barn owl nestlings huddled together in a mass in a cliff cavity nest, within 1-2 days of hatching from eggs, and with one yawning	Great horned owl fledgling, perched on the nest tree from which it fledged

This year several people are assisting with raptor monitoring at Pinnacles - Megan Gnekow, Mike Baird, and Joseph Belli. All of them have been volunteering with the condor and / or raptor monitoring programs for years, and their assistance in confirming raptor status at the park this year has been greatly appreciated!

Thank you to all the staff who have continued to provide me with raptor observations; every detail on raptor behavior helps to provide a more complete picture of raptor breeding at the park. If anyone on staff wishes to report raptor or other bird observations, I would greatly appreciate it if you please fill out a wildlife observation card, and give it to me or deposit it in my box in the RRM Office.

If you have any observations within the park to report, or any raptor-related questions, please contact me through email or extension 276. Thanks!

GAVIN EMMONS • Wildlife Specialist
5000 Highway 146, Paicines, CA 9504 • 831-389-4486 x276
Pinnacles National Park