Another publication! Geographic Origins of Shorebirds Using an Alaskan Estuary during Migration

Geographic Origins of Shorebirds Using an Alaskan Estuary during Migration

Authors: Ulman, Sadie E.G., Van Wilgenburg, Steven L., Morton, John M., and Williams, Christopher K.

Source: Waterbirds, 46(1) : 47-56

Published By: The Waterbird Society

URL: https://doi.org/10.1675/063.046.0107

Abstract.—Chickaloon Flats, Kenai National Wildlife Refuge, is an 11,000-ha tidal mudflat complex in upper Cook Inlet, Alaska. One-third (23 of 70) of Alaskan shorebird species use this protected coastal estuary stopover during migration. We conducted an isotopic approach to estimate probable breeding, staging and/or non-breeding origins of six shorebird species, some of high conservation concern, using Chickaloon during spring and fall migration of 2009 and 2010. We analyzed stable-hydrogen (d2H), carbon (d13C), and nitrogen (d15N) isotope ratios from feathers and performed a likelihood-based assignment to infer North and South American origins. Estimated molting distributions for Greater Yellowlegs (Tringa melanoleuca) occurred in southwest Alaska, and south-central Alaska for Short-billed Dowitcher (Limnodromus griseus caurinus). Lesser Yellowlegs (Tringa flavipes) likely molted in western Alaska and a latitudinal band across Canada and wintered throughout the contiguous United States. Least Sandpipers (Calidris minutilla) wintered from Oregon and south in North America but showed an isotopically similar possibility in Ecuador, Colombia, and Venezuela. Long-billed Dowitchers (Limnodromus scolopaceus) molted primaries across western United States and Canada. Pectoral Sandpipers (Calidris melanotos) likely molted near Rio de La Plata in southeastern South America. These results highlight the overall value of Chickaloon Flats as a stopover for long-distance shorebird migrants. Received 29 Mar 2022, accepted 7 Aug 2023.

Read the full article here!

AWA Presentation: Using genetics to address conservation issues on the Kenai Peninsula

Click here or scroll below to view AWA Vice President, Dr. John Morton’s, presentation Using genetics to address conservation issues on the Kenai Peninsula for the Exploration Ecology course at UAA Kachemak Bay Campus, Homer, AK.

New Publication! The Dynamics of a Changing Lutz Spruce Hybrid Zone on the Kenai Peninsula, Alaska

Join us in congratulating AWA Vice President, Dr. John Morton, and co-authors Diana Wolf, Matthew Bowser, Naoki Takebayashi, and Dawn Magness in their recent publication in the Canadian Journal of Forest Research!

Click here to see the article

Abstract

We investigated the genetic makeup of Lutz spruce, a natural hybrid between white and Sitka spruce on the Kenai Peninsula, Alaska. Microsatellites indicate 72% of individuals sampled had predominantly white spruce ancestry whereas 14% had predominantly Sitka spruce ancestry; some individuals classified as white spruce had Sitka spruce plastid genotypes. As Picea mitochondria are maternally inherited and plastids are paternally inherited, it appears that white spruce was the ancestral seed parent of nearly all spruce on the peninsula, whereas Sitka spruce alleles originated from pollen. Pollen records show that white spruce colonized the western peninsula ~8,500 YBP from glacial refugium, whereas Sitka spruce arrived on the eastern peninsula ~4,000 YBP after migrating up the Pacific coast. Our data suggest that Sitka spruce migration onto the western peninsula may have occurred not via seed dispersal, but by long distance transport of wind-borne pollen and subsequent hybridization with established white spruce populations. Hybridization was an important mechanism that allowed Sitka spruce to expand the leading edge of its range in response to historical climate change. As the climate continues to warm, climate envelope modeling suggests Lutz spruce may ultimately displace white spruce on the western peninsula even as Sitka spruce is constrained to the eastern peninsula where it will continue to hybridize.