Friday, March 25, 2016

A Search for Bendire's Thrashers in the Sulphur Springs Valley

Guest post by Tim Helentjaris
March 18, 2016


Bendire's by Muriel Neddermeyer
I was out today with my colleagues from Tucson Audubon, Matt Griffiths and Jennie MacFarland, to look for Bendire's Thrashers in the large valley south of Willcox. As part of this large survey this year, I had mapped a number of putative winter territories in both the Santa Cruz Flats and Avra Valley. Unfortunately, going back within the last few weeks, not one of these "territories" was still occupied by a presumed breeding bird and I also could not find any Bendire's in nearby areas. Similarly, volunteers searching random transects in the southern third of the state have been uniformly unsuccessful. Just this Tuesday, I found none on two random transects near Cascabel, AZ.

Rethinking this problem, I did some searching on eBird for summer observations of Bendire's and found very few in the southern third of the state, other than the occasional single bird here and there. There were two interesting exceptions, large clusters of summer observations in the Sulfur Springs Valley, especially around Elfrida, and another around Rodeo just east of the Chiricahua Mts. The three of us made plans to do a driving search in the valley today.

Typical habitat we found Bendire's in Sulphur Springs Valley

The intrepid surveyors

Starting this morning around Sunsites, we started working our way south and eventually passing through Pearce on the Ghost Town Trail. We stopped and used playback at interesting areas but didn't find any Bendire's. After turning east at Gleeson and heading towards Elfrida, we found our first territory just west of town. Wow, pretty exciting, and we were pretty jazzed in having any success. It wasn't another 0.2 miles that we heard another Bendire's singing from a tree in a residence's yard. Getting out, we found three birds at this territory and then in just another 0.2 mile, another pair! We continued through town, doing a rough grid search, sometimes using playback but on most successful stops, finding birds either visually or by hearing their songs before ever having to resort to playback. For the morning, we found six territories in the Elfrida area and another near White Water Draw for a total of eleven Bendire's Thrashers! Never dreamed we would be this successful and to me, it again proved the worth of eBird data in allowing us to efficiently target our searches to areas where our success was many times greater than random searches. No question, as suggested by eBird, that there are breeding territories for this species in the southern part of the state.


Wolfberry (Lycium sp.) was present at most of the sites we found Bendire's

There's Bendire's Thrasher at the top of that pole! They do not seemed concerned with human presence.

One major point of this survey is to understand the habitat requirement for this species and we all agreed, that we are probably now more confused than before we started. The other large concentration of breeding Bendire's in this state, west of Wickiup in the Chicken Springs area is a rich mixture of Sonoran and Mojave deserts while the winter territories around Tucson are in some of the most degraded habitats I have ever found birds in, mostly creosote and scattered mesquites with lots of bare ground. This morning, the predominant habitat was disturbed grasslands with scattered, dwarf mesquites. About the only common factor we can observed was the presence of bare ground with loose soil. Check the videos below of a bird running and another bird singing its lungs out!







A great day altogether, we also had some other neat observations, coveys of SCALED QUAIL, a zooming PRAIRIE FALCON, lots of RED-TAILED HAWKS and AMERICAN KESTRELS, but also a group of Javelinas grazing in a lush alfalfa field, proving once again that you can never imagine all the places you might see these animals and what they might be eating. A stop at Willcox Lakes on the way home produced a lot of ducks, predominantly AMERICAN WIGEONS and NORTHERN SHOVELERS, as well as 24 RING-BILLED GULLS.



The Arizona Important Bird Areas program is still looking for people to join the Bendire's Thrasher survey team this spring. The data show this species is in steep decline and Arizona is a large part of their remaining range. Citizen-science volunteer point count surveys have been established and we are looking for birders to help us do these surveys. You would adopt a route of three point count locations and do the survey on a morning of your choice until mid-May.

For more information and to sign up please visit aziba.org/?page_id=1783

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