Wedge-rumped Storm-Petrel (Oceanodroma tethys), Canoa Ranch Rest Area, Pima County
This Wedge-rumped Storm-Petrel was found and photographed by David Vander Pluym
and Lauren Harter on 07 September 2016
Hurricane Newton formed roughly 220 mi southwest
of Manzanillo, Colima, Mexico on 4 Sep 2016 and reached
Arizona on 7 Sep 2016, bringing with it several notable
species, including three species new to Arizona and one
even new to the ABA area! This storm officially reached
hurricane strength winds late on 5 Sep 2016 and reached
peak intensity with wind speeds of 90 mph shortly before
making landfall at Cabo San Lucas, Baja California Sur.
Newton moved north and weakened over the Baja California
Peninsula. The eyewall fell apart before it made a
second landfall, after crossing the Gulf of California,
near Bahia Kino, Sonora where it weakened to tropical
storm status. Early afternoon on 7 Sep it crossed into
Arizona in a weakened state. Despite the weakened state
of the storm it managed to bring 5 species of
“tubenoses” to Arizona, typically associated with
stronger storms. Clearly we have a lot to learn about
how hurricanes affect birds in our area! To see a track
of the storm see here and
to see windspeeds see here.
For more information on the last tropical storm to bring
tubenoses to Arizona, Nora, see here.
Multiple Wedge-rumped Storm-Petrels (15+) were reported during and just after the hurricane. This is the first time this species has been recorded in Arizona and there are ~12 records for offshore California, about half of which were photographed. Due to difficulty identifying this species from Townsend's Storm-Petrel it is possible that some sight records from the 1970's and 80's may have been Townsend's. The species is uncommon to fairly common off southern Baja California and in the Gulf of California. These represent the first inland records for the United States (though one slightly inland in central California after a storm). There are two subspecies (which may actually represent two different species) with one population breeding in the Galapagos and the other in Peru. It is not immeditely clear which are represented here though. They differ in size and extent of white rump. Several specimens have been obtained (including this individual) from the storm and they should be identifiable to subspecies.
This individual was found at night under the lights
at the rest area and taken to a volunteer with Tucson
Wildlife Center, unfortunately this individual did not
survive. Storm-petrels are nocturnal and often become
disorientated by lights.
strom-petrel with a white rump. The extensive all white
rump, forked tail, and small size rules out other
similar species except for Townsend's Storm-Petrel, a
recent split from Leach's Storm-Petrel. Note especially
the extensive white rump patch which is wedge
shape and only slightly rounded where it meets the back,
the extensive white wrapping around onto the undertail
coverts, shallow forked tail and the stout bill, large foot
(it was missing one foot from an old injury), and pale
upper-wing bar that did not include the primary coverts
typical of the "Halocyptena"
storm-petrels (potential genus split including Least,
Black, and Wedge-rumped).
07 September 2016, photo by David Vander Pluym
07 September 2016, photo by Lauren HarterAll photos are copyrighted© by photographer
Submitted on 09 September 2016