Thursday, March 28, 2019

Closing In On The Lowest Count In 17 Years In A Remarkable Flower/Caterpillar Season

Leaders:March 21-March 28, 2019
Don White
Hal Cohen
Herb Stone
Laura Webb
Pam Albers
Rose Leong

Migration:
March 21-0
March 22-12 Swainson's Hawks
March 23-3 Swainson's Hawks
March 24-0
March 25-11 Swainson's Hawks
March 26-14 Swainson's Hawks; 10 Turkey Vultures
March 27-1 SW; 6 TV's
March 28-2 SW's

Discussion:
Since my last post we have had a total of 43 migrating Swainson's Hawks and 16 Turkey Vultures. This period of time traditionally yields thousands of migrants. This season we have had a remarkable flower bloom along with widespread caterpillars. The White-lined Sphinx Moth caterpillars can be found across several hundred square miles in Southern California and Northern Mexico. The Swainson's Hawks have most likely spread out to feed on the caterpillars. We should be grateful that the health of the hawks is probably pretty good with such an ample food source available.

Our evening watch has not been very exciting. Although occasionally we see a burst of activity to the east. A few nice kettles of hawks has been observed. Unfortunately the migrating hawks have moved much further away from the morning watch site. Will the hawks finally move through Borrego Valley after the caterpillar numbers dwindle? So far the number of caterpillars seems to be increasing and spreading throughout the region. Do not make the mistake of confusing the sphinx moth caterpillars with the huge number of Painted Lady Butterflies. Over 1 billion Painted Lady Butterflies have migrated through Southern California. The plant selection of the butterflies is different than that of the sphinx moths. The Swainson's Hawks evidently do not feed on the butterfly caterpillars as they are heavily armed with bristles and may not be appetizing.

Speaking of appetizing, a few hardy raptor watchers have finally participated in a traditional ritual that was very popular for hundreds of years by the native Cuhuilla Indians. Below is a narrative written by William Greenwood Wright in 1884.

“In an hour we came to the caterpillar pasture. The sand is dotted with mats and patches of a procumbent plant, much resembling in flower the common sand verbena, Abronia, on which vast armies of caterpillars are feeding; they are huge worms three and four inches long. Another small army of Indians—[men, women, and children]— are out gathering them as though they were huckleberries, for use as food. The Indians do not notice us, but go on with their gathering. Seizing a fat worm, they put off its head, and by a dexterous jerk the viscera are ejected, and the wriggling carcass is put into a small basket or bag, or strung upon strings and hung upon the arm or about the neck, till occasion is found to put them into a large receptacle.1 got three of these gathering baskets. One is funnel-shaped, holding a quart or two; another is like a large, flat saucer, and the third is similar but with a deep rim. At night, these Indians carry their prey home, where they have a great feast. Indians from a long distance come to these worm feasts, and it is a time of great rejoicing among them. The larvae that are not consumed at the time (and they eat incredible quantities), are put upon ground previously heated by a fire, and thoroughly dried, when they are packed away whole, or pulverized into a meal [Wright 1884:283].” 

We tried to perform the same ritual and found the worms to be very tasty. If I were served this delicacy in a restaurant, I would order more. 
Robin Roberts-White-lined Sphinx Moth Showing Proboscis
Sphinx Moth Caterpillar-Randy Lenon

Sphinx Moth Caterpillars Crowded Together-Randy Lenon
Sphinx Moth Caterpillars Cleaned, Broiled and Ready to Eat-HC
Painted Lady Chrysalis-HC
Painted Lady Butterfly-HC





Wednesday, March 20, 2019

Slow Season Thus Far-Very Slow Compared to the Previous 16 Years

Leaders: February 25-March 20:
Hal Cohen
Judy Davis
Rose Leong
Herb Stone
Laura Webb

Migration:
February 25-March 20: 607 Swainson's Hawks; 34 Turkey Vultures

Discussion:
Southern California is experiencing a remarkable flower bloom. With the exceptional bloom we are witnessing a White-lined Sphinx Moth caterpillar explosion. Because caterpillars are found in numerous locations, Swainson's Hawks have ample opportunities to feed during the northward migration. Borrego Valley is only one small area for hawks to feed in. I believe that the radically low numbers of SW's is a result of widespread feeding and not a diminished Swainson's Hawk population. To date (March 20), we have counted only 607 Swainson's Hawks from February 25 to March 20th. The total count for 2019 is 615 Swainson's Hawks. Traditionally by this period we should have counted a few thousand SW's. Regardless of the low numbers we have had some great views on occasion. Below are some photo's and movies. Check out the youtube of March 18. https://youtu.be/JRLgckvtcLQ


Ocotillo Wells-HC


                                           Blow Sands Area Near Borrego Springs-HC


5 Swainson's in Eucalyptus Tree-Borrego Valley Rd. David Nevett
Leaving the Roost-David Nevett
Rufous Morph Swainson's Hawk-William Carter

Subadult Intermidiate (Rufous) Morph SW's-Krisztina Scheeff

White-tailed Kite-Krisztina Scheeff

Sunday, February 24, 2019

Begin a New Season-2019-Possible Super Bloom Again

Leader:
February 21-Judy Smith
February 22-Laura Webb
February 23-Hal Cohen
February 24-Herb Stone

Migration:
February 21-1 Turkey Vulture
February 22-8 Turkey Vultures; 1 Swainson's Hawk
February 23-33 Turkey Vultures; 2 Swainson's Hawks
February 24-13 Turkey Vultures: 5 Swainson's Hawks

Discussion:
It has been a very cold rainy winter season. We've had over 7 inches of rain over a period of weeks. There are numerous flower hot spots surrounding Borrego Springs. With the warmup beginning Sunday February 24 we could experience another super bloom, lots of caterpillars and thousands of hawks. So far only a handful of hawks has migrated through the valley. However it looks like more Turkey Vultures are venturing into the valley.

Evening Watch:
No hawks and one TV were evident this evening (Feb 24th). There are TV's roosting in the usual spot in the Roadrunner



Early February Flowers Along Near Arroyo Salada-S22-HC






Entering Borrego Springs From Ranchita-February 23, 2019








Thursday, April 5, 2018

End of Season Posting-March 30-April 1, 2018

Leader:
March 30-Laura Webb
March 31-Don Wilson
April 1-Don Wilson

Migration:
March 30-Swainson's Hawks-31
March 31-Swainson's Hawks-25; Turkey Vultures-1
April 1-Swainson's Hawks-391; Turkey Vultures-5

Discussion:
We ended the season with a nice SW number. Several large kettles of hawks provided great looks for folks. Occasionally we will monitor the evening site just in case a large number of hawks arrives. However the official count is complete for the 2018 season.

This season we did not experience a wildflower bloom. This might be the single most important factor determining the number of hawks that utilize Borrego Valley as a stop-over destination.

We logged only 81.75 hours in 2018, our lowest number by far. The average number of Swainson's Hawks for 16 years is 4,737. This season we observed 4,172 SW's.

Here are several shots of hawks taken by our photographers.
Adult Male SW-David Nevett

SW-David Nevett

Dark Morph SW-David Nevett

Dark Morph-David Nevett

David Nevett

Adult Light Morph and Light Intermediate Morph-David Nevett
SW Unusual posture-David Nevett

In Palo Verde-also unusual-David Nevett

Adult Dark Morph-David Nevitt

Light Intermediate-David Nevitt

Subadult Dark Morph Swainson's Hawk-Dave Clark

Adult Female Light Morph-Dave Clark

Nice side shot-Dave Clark

Adult Female Light Morph-Dave Clark

Intermediate Morph-Dave Clark
Dark Morph SW-Tom Lawrence



Thursday, March 29, 2018

Nearing the End of the Count-March 29,2018

Leader:
Hal Cohen

Migration:
Swainson's Hawks-3

Discussion:
Yesterday evening we did not see a hawk drop into town. With this ominous sign we began today's watch. Only 3 Swanson's Hawks migrated today, one very close to the watch.

The hawkwatch will officially close after the count on April 1, 2018. We will continue to monitor hawks at the evening site on Borrego Valley Rd. If a number of hawks arrives in town we will inform folks.

I have been asked where the Date Farm (Evans Ranch) is located. The evening site as we call it is 1.7 miles north of Palm Canyon Drive on Borrego Valley Rd. We meet there from around 5:30pm until dark. We will be winding down soon as the watch comes to an end. If you look at data from the past-Hawkcount.org you will see some action in early April. When accesses Hawkcount.org, hit monthly and then scroll down to Borrego Valley. You can check out our data starting in 2003.

Evening Watch:
Only 5 Swainson's Hawks observed this evening (March 29)

Prediction:
Light wind is predicted for tomorrow. Lift-off the few hawks in town will be late (8:30-9:30am).
Ready to Take Off-David Nevett

Windblown-David Nevett

Light Intermediate Morph-David Nevett
Very Early Kettle-6:40AM-David Nevett

Large Kettle-David Nevett

Wednesday, March 28, 2018

March 27 and 28th, 2018-A Banner Day-470 Swainson's Hawks Up Close and Personal March 27th-Surprise on March 28th

Leader:
March 27-Pam Albers
March 28-Hal Cohen

Migration:
March 27-Swainson's Hawks-470
March 28-Swainson's Hawks-153; Turkey Vultures-11

Discussion:
As predicted the hawks began migrating before 7am. However a few hundred hawks flew low and west for 2 more hours. We established the count a mile north of Palm Canyon Drive on DiGiorgio Rd. For 3 hours hawks moved past us 20 yards above. A few hundred were perched in trees and on the ground. Kettles from the Date Farm and Roadrunner continued to form for our watch period.

March 28th was a surprise as the evening before yielded only a few SW's. The day started with a few hawks on the ground and one in the tamarisks near the count site. By 8:45am kettles began to form to the east. Before the day was finished 153 Swainson's migrated.

Evening Watch:
TBA

Prediction:
TBA

First Light-6:30am-HC







A Closer View-Janet Lyons

Nice Rufous (Intermediate) SW-HC



First Big Kettle-Janet Lyons



Monday, March 26, 2018

Huge Kettle in Town-Monday Evening March 26, 2018-Estimates from 200-500 Swainson's Hawks

Leaders:
March 22, 2018-Herb Stone/Judy Davis
March 23-Pam Albers
March 24-Herb Stone/Judy Davis
March 25-Rose Leong
March 26-Herb Stone

Migration:
March 22-Swainson's Hawks-2
March 23-Swainson's Hawks-1
March 24-Swainson's Hawks-145; TV's-6
March 25-Swainson's Hawks-8
March 26-Swainson's Hawks-3

Discussion:
Finally we had an evening fly-in on March 23rd. After 7pm 30-40 Swainson's Hawks were observed coming into the Date Farm. On Saturday March 24 most took off early with a stiff wind. Fortunately some remained in the area for some of the watchers. The total was typically more than the observed the evening before.

Note-The blog is not posted every day. You are welcome to join the ALERT System by emailing me at Raptorhal3@gmail.com to be put on the list. You may also find info at Sandiegoregionbirding@yahoogroups.com

Evening Watch:
Monday March 26-A large kettle of SW's was spotted to the east. They formed kettles, streamed and reformed. They began to settle down near the airport and rose up again. Finally most dropped into the Date Farm (Evans Ranch). Do not climb the gate to get photos. We are estimating between 200 and 500 Swainson's Hawks are in the valley.

Prediction:
Tomorrow Tuesday March 27th may have some breeze early in the morning. It is possible that hawks will begin to kettle up by 6:30 or 7am. Hopefully the breeze will hold off and the hawks will move later. Our experience in the past has shown that not all of the hawks will leave early. So some may be taking off around 8:30am. Viewing from DiGiorgio Rd near Big Horn and at the day count site (just south of Henderson Canyon Rd on DiGiorgio Rd might be good. Also with the sun to the east, the evening site on Borrego Valley Rd near the Date Farm would be an alternate.

Dark Swainson's Hawk-David Nevitt

Adult Light Male Intermediate Morph-David Nevitt