• Pacific Loon

    Common NamePacific Loon
    Scientific NameGavia pacifica
    Type of ReportRare Species
    Date of Observation01/03/2021
    MediaOther Documentation of Observation
    Number Observed1
    Reporting Observer's NameKenneth Cox
    Mailing Address28 North Puckerbrush Road
    South Reading, VT 05153
    United States
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    EmailEmail hidden; Javascript is required.
    Date Completed02/04/2021
    Names & Emails of Other Contributing Observers

    Jim Mead --
    Clem Nilan -- not known

    Latitude of Observation44.041289
    Longitude of Observation73.438961
    Place NameLake Champlain: Champlain Bridge/Chimney Point
    TownshipAddison
    CountyAddison
    Vermont eBird Checklist URLebird.org
    Time of Day08:00 AM
    Length of Time ObservedAbout 3 hours total split between four observation locations: Champlain Bridge, 1 hr. 25 min.; DAR State Park, 21 min.; Owls Head Bay, 18 min.; Tri-Town Water District Plant/Oven Bay, 24 min.
    Maximum Estimated Distance from Bird (in feet)10,560
    Minimum Estimated Distance from Bird (in feet)3,960
    Noteworthy Weather Conditions

    Cloudy, no precipitation, little wind. Conditions for lake observation were good, i.e. water surface was generally calm, no heat shimmer, no fog.

    Optical Equipment Used for Observation

    Spotting Scope: Kowa Prominar TSN-883 with 20-60X Zoom eyepiece.
    Binoculars: Swarovski Swarovision 8.5 X 42.

    Observer’s Previous Acquaintance With This or Similar Species

    I had no prior experience with this species nor Arctic Loon unlike my experiences with Common and Red-throated loons which are too many to recall.

    I certify that that attachments included with this report were captured during this observation event​​.
    Description of Habitat

    Lake Champlain with open water (ice free) north of the bridge. Other loon species present at the time of observation included Common Loon (2) and Red-throated Loon (1). For complete species lists see eBird records: Champlain Bridge/Chimney Point
    https://ebird.org/checklist/S78620516; DAR State Park https://ebird.org/checklist/S79201955; Owls Head Bay https://ebird.org/checklist/S78777088; Tri-Town Water District Plant/ Oven Bay https://ebird.org/checklist/S78777053.

    Behaviors Observed

    On water and diving (feeding). Not observed in flight. Occasional standing wing flaps were observed.

    Description of Vocalizations

    None heard.

    Verbal Narrative & Description of Observation

    We determined that the subject loon was likely an adult in basic plumage. Being that it (PALO) and the Red-throated (RTLO) loon kept “company” with one another throughout much of the observation time, this provided opportunities to directly compare species’ similarities and differences. The PALO (3.7 lb.) was noticeably smaller with a head profile that was smoother, more rounded than that of the Common Loons (9 lb.) present at the Champlain Bridge location. Weights, as given by Sibley (2000), are used only to provide a relative size reference for the three similar species discussed here. The PALO and RTLO (3.1 lb.) were similar in size, although the PALO appeared slightly bulkier (thicker neck). Both PALO and RTLO had white fore necks and dark (blackish, dark gray) hind necks. When viewed from the side the RTLO showed more white on the fore neck than the hind neck; the opposite was the case for the PALO. Both loons’ necks showed a sharp, straight demarcation between the white and the dark. At one point the PALO did a standing flap revealing a slight chin strap. The RTLO had more white on the face with the eye mostly in a field of white; in contrast the eye of the PALO was in the dark. The backs of both the PALO and the RTLO were dark with that of the PALO appearing blacker than the RTLO. The bill of the PALO was finer than that of a COLO and was held at a horizontal level rather than angled upwards as is characteristic of RTLO.
    The possibility that this bird might be an Arctic Loon was eliminated on the basis of extreme rarity of the species in the eastern U.S., larger size (5.8 lb.) than either PALO or RTLO, and absence of a prominent white flank patch that extends above white and dark straight water line interface.
    At the end of our observation time at the Champlain Bridge location both the PALO and suspicious RTLO together gradually worked their way up the lake and were seen in the vicinity of a large concrete structure (blocky building) on the New York side. To get a better view of them we went to DAR State Park. There at the observation deck we were able find that building and both birds. From that vantage point we got better views of the RTLO and were able to confirm it as such. Both loons continued moving up the lake and so we headed to Owls Head Bay, where Clem and Jim have access permission from one of the camp owners. The concrete structure was visible from there and again both loons were found. At that time they were a bit north of the concrete structure but in front of a blue camp with a deck and red lattice. The loons kept going north so we headed to Tri-Town. From there we relocated the blue camp and the two loons. From there, we had our best look at the PALO's chin strap when it performed a standing wing flap while facing us.
    The preceding entry is a composite of a write-up done by Jim Mead reflecting observations made by Jim, Clem and me and submitted to eBird, as well as additional details of my own.

    Relative Size & Shape

    See details provided under Verbal Narrative & Description of Observation above.

    Head

    See details provided under Verbal Narrative & Description of Observation above.

    Feet & Bill

    See details provided under Verbal Narrative & Description of Observation above.

    Upper Back

    See details provided under Verbal Narrative & Description of Observation above.

    Lower Back & Rump

    See details provided under Verbal Narrative & Description of Observation above.

    Wings

    No details recorded or recalled.

    Breast, Belly, Flanks, Under Tail Coverts

    See details provided under Verbal Narrative & Description of Observation above.

    Tail

    No details recorded or recalled.

    IMPORTANT: What similar species were eliminated when making the identification and how was this bird different?

    See details provided under Verbal Narrative & Description of Observation above.

    Other Notes & Comments

    Subject loon was likely an adult in basic plumage. Sex undeterminable.

    This report was written from notes taken:Immediately After

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