John K. Flores: Shining light on decline in goose population

A platoon of waterfowl biologists, field technicians and volunteers gathered outside of the entrance to Cameron Prairie National Wildlife Refuges’ Pintail Drive in mid-December waiting for lesser snow geese to show up. The group could see small flocks of snows drop into a flooded impoundment perhaps a quarter mile up the road, where they would eventually swim to a grist pile provided courtesy of refuge managers.
The intent of this early morning foray into the refuge was twofold. One was to capture midcontinent lesser snow geese and attach 25 state-of-the-art tracking devices to identify habitats, movements and seasons important to their overall survival and management.
The second purpose was to study and monitor avian influenza. In late December, the Louisiana Department of Wildlife and Fisheries issued a press release stating that this fall’s migrations have led to a resurgence of the virus in waterfowl and other wild birds. It went on to say that while many recover, some may show neurological symptoms that can lead to death. Moreover, scavenging birds such as raptors and vultures are highly susceptible to the disease.
The hope that morning was to capture as many lesser snow geese on the grist pile as possible using a rocket net.
The plan, unbeknownst to the geese, was while they stuffed their gizzards with sand to digest their food, LDWF Rockefeller Wildlife Refuge Research Program Manager Paul Link would fire the net in ambush-like fashion, making the capture.
The morning temperature hovered around the freezing mark, and everyone came dressed for the occasion as there was no shortage of winter gear being worn. But, despite having the appropriate apparel, some, including myself, had the shivers.
I could hear one guy mumble, “come on geese — let’s go,” as if he was speaking directly to the ancient waterfowl spirits of the flyway’s midcontinent light goose population.
Unfortunately, the spirits weren’t listening. The refuge marsh and surrounding rice fields were white from a hard frost that blanketed all of southwest Louisiana overnight.
I observed this before, where massive bodies of perhaps 5 to 10 thousand snow geese stood loafing in a green winter wheat field waiting for the sun to rise overhead. After the frost is long melted and the sun’s rays permeated deep into their feathers, they raucously leap all at once toward the sky. It’s a sight to behold.
I thought about my past experiences with these snow geese on this refuge. Having hunted both the Cameron Prairie NWR’s senior lottery waterfowl hunts and taking my grandson on the youth waterfowl hunts, we could expect these geese to show up between 9-9:30 a.m.
I wasn’t wrong. About 9:15 a.m. we heard the rocket charges detonate in one long burst. The entire group now mobilized, diving into ATV side-by-sides and pickups towing trailer loads of orange crates and floating sleds to the grist pile.
There was no time to think about the frigid cold and water now. Under the net was well over a hundred lesser snows that needed to be removed as quickly as possible, where they wouldn’t be further stressed from exposure to the elements.
Once crated, the whole operation went from a controlled chaos to a rhythmic banding process. Some of the birds would be collared with tracking devices based upon their sex and health, while others would go through swabbing and bloodletting to test for avian influenza.
The light goose story, which not only includes midcontinent lesser snow geese, but also greater snow geese and Ross’ geese, goes back a few decades, where their numbers reached unprecedented highs throughout the early to mid-90s.
In a collaborated article written by Mitch D. Weegman, PhD, Kevin Kraai, and Mike Brasher, PhD, published in the July 1, 2025 issue of Ducks Unlimited Magazine, the feature stated, “the rate of population growth was so extreme, biologists worried that feeding behaviors of hyper abundant geese would irreparably damage fragile arctic and subarctic ecosystems, threatening other populations of wildlife.”
The DU article takes a deep dive into the history of midcontinent light geese, discussing how the 1999 Light Goose Conservation Order was established in an effort to reduce adult survival.
The order allowed for a no holds barred approach to regulations, where everything from no plugs in shotguns, to electronic callers with amplified sound, and extended seasons were allowed and established.
The article mentions how light goose populations peaked at around 20 million in 2007. However, what’s important to note is light goose numbers have been in decline precipitously ever since. It’s estimated snow goose numbers have plummeted by 70 percent to 6 million as of 2022.
Weegman, Kraai and Brasher point out what became apparent was the LGCO had been unsuccessful in reducing adult survival, which was the primary rate it was designed to affect. Their article stated, since implementation of the LGCO, harvest rates of “adult” midcontinent snow geese as a percentage of the total population have changed little, hovering around 2 to 3 percent. Likewise, adult survival rates have barely budged and have even increased in recent years.
With the dramatic decline in light goose numbers, the focus has shifted to productivity. The question is, what are the things that are impacting annual changes in light goose productivity?
Link and his team have captured and banded 312 lesser snow geese on Rockefeller Wildlife Refuge and Cameron Prairie National Wildlife Refuge this winter. Some of the objectives they hope to achieve is estimating nesting propensity and reproductive outcomes based on locational and behavioral data. Also, quantify the habitat use and degree of inter- and intra-winter movements of adult snow geese within and among wintering sites.
In addition to these objectives, Link hopes to be able to describe the migration routes, speed and behavior of tagged individuals during the prelude to the nesting season. He hopes to quantify the extent to which variation in migration data attributes to things like staging and wintering habitat use and therefore explains variations in nesting propensity and reproductive outcomes.
Link, in listing the objectives, points out how the results can help biologists form a full annual cycle model for snow geese and quantify the relative importance of phases of the annual cycle to explain variation in productivity.
Link said, “We’re proposing to capture and collar 20 to 40 adult female snow geese during the next 5-plus winters. We’ll attempt to mark half in the coastal marsh of Rockefeller Wildlife Refuge and half in the rice prairie region of southwestern Louisiana. Multiple years of marked birds are needed to untangle the complicated carry-over effects, which is essentially what happens in one season carries over to impact subsequent seasons.”
Research Professional Deb Carter works for the Department of Pathology in the College of Veterinary Medicine at the University of Georgia/Southeast Cooperative Wildlife Disease Study Group. Carter has been involved in avian influenza research for well over a decade as she crisscrosses the United States annually.
Carter said, “This study has been going on for 4 years, where we have been monitoring avian influenza in these snow geese. Early in the study there was no highly pathogenic avian influenza and then when high path did come in, it became apparent that these snow geese were getting sick and dying and that the high path virus was still in them.”
Carter says UGA’s goal this winter was to sample 120 lesser snow geese. Samples of 60 were taken on separate occasions. What’s noteworthy, Carter mentioned that in her initial group of 60, 95 percent had antibodies to the flu, indicating the birds had contracted avian influenza at some point.
Avian influenza, particularly highly pathogenic H5N1, is extremely hard on juvenile snow geese. One of the things the UGA/SCWDS group is trying to assess is what the impact of highly pathogenic avian influenza has on snow goose populations.
During the two snow goose captures in December, Link shared that 85 adult snows and 7 juveniles were caught on Rockefeller Wildlife Management Refuge. On Cameron Prairie NWR, 153 adults were captured and only 19 juveniles. Though anecdotal, both numbers represent low numbers of juveniles compared to adult birds.
Link says he also saw large differences in age ratios with his own eyes in Saskatchewan in October and again in North Dakota in November where he suspects H5N1 was the likely culprit.
The Lincoln-Petersen method of estimating waterfowl populations differs by using band recoveries instead of traditional survey methods. Link says you have to go back to 1987-89 when midcontinent light geese populations were as low as the current L-P estimate of 4 million.
No doubt findings over the next several years, particularly if numbers continue to decline, will impact how wildlife professionals across all flyways approach managing light geese populations.
John Flores is the Morgan City Review’s outdoor writer. He can be contacted at gowiththeflo@cox.net.