Telemetry study continues to look for clues

By JOHN K. FLORES
This past winter, Louisiana Department of Wildlife and Fisheries’ North American Plan Coordinator Paul Link just had finished banding 75 snow geese at a grist pit on Cameron Prairie National Wildlife Refuges Pintail Drive.
By all accounts, it was a successful day. But, the biologist wasn’t finished yet. He went to check another capture site, where he was hoping to also trap white-fronted geese to attach telemetry units to.
Observing from a distance, he could see that a large flock of the unsuspecting birds were resting at the trap site.
In that instance, Link fired his rocket net for the second time that morning and captured 23 white-fronted geese.
Just more than two decades ago, 80 percent of the midcontinent white-fronted goose population wintered in Louisiana.
But, according to January mid-winter survey data collected by the Louisiana Department of Wildlife and Fisheries, today, that number has dwindled to 32 percent in spite of an increase in overall population.
The midcontinent greater white-fronted goose population is the subspecies whose breeding grounds range from the North Slope of Alaska eastward through the boreal to Nunavut in northeastern Canada and reach the western edge of Hudson Bay.
What’s more, this group predominately winters in Arkansas, Louisiana, Texas and Mexico.
Reasons for the decline in winter numbers vary according to experts.
Most indications suggest post hurricane effects, coastal erosion, agricultural changes, urbanization, industrialization and even hunting pressure all have contributed through the years.
With this in mind, in 2015, the Louisiana Wildlife and Fisheries Commission assigned the department the task of investigating the possible reasons for the decline to better manage the species going forward.
The method utilized to study the trend would be via Global Positioning System and Global System for Communications (GPS/GSM) combined telemetry collars attached to the geese following capture and banding. Each communication device is solar powered to reduce weight and estimated to last 3 to 4 years.
Link is in his second year leading the project. Link said, “The goals of the study is to gain a better understanding of the white-front’s winter ecology, habitat use, local and long-range movement, fidelity and philopatry, plus migratory pathways. All of these are key to help us get a better understanding of the winter decline.”
Link says a couple of surprising things he has noticed so far is the exodus of white-fronted geese on or shortly after opening day of waterfowl seasons. The biologist pointed out that they appear to be highly sensitive to hunting pressure.
Secondly, there might appear to be a low rate of return to Louisiana, noting that only 1 of 7 birds collared the previous year returned to the state. The others stayed north.
Though telemetry provides dispersal details with precision accuracy, there are habitat factors that can’t be assessed accurately without boots on the ground.
Link tries to get technicians out to the fields that telemetry collared birds have utilized before weather and agricultural manipulative changes take place. Pulling water control structures and plowing impede technicians from collecting information such as vegetation type the geese have been using and water height and moisture content of the locations surveyed.
Data from telemetry showed one of the birds from the study’s first year nested on the North Slope of Alaska, some 3,900 miles from her capture location in Louisiana. However, like any technology, the GPS/GSM units have their moments.
Link points out that periodically, the collared white-fronted geese go offline, typically due to poor cell service. When birds eventually relocate to better service locations, all unsent data can be retransmitted.
Additionally, though rare, there have been occasions when batteries were too low to collect location data.
Waterfowl with neck collars also have had issues in the past with freezing weather conditions, where blocks of ice have formed causing mortality. Link says white-fronted geese are better candidates for telemetry collars, because they don’t frequently encounter ice or snow.
Hunters also present another problem. So far, Link mentions two geese have been shot and reported by hunters. Both hunters disclosed the birds were in excellent physical condition and showed no abnormal behavior, nor did they show any feather wear along their necks.
The biologist suspects others have been shot and were not retrieved by hunters.
“This past winter, four of the birds collared went offline the same day they were captured,” Link said. “As it turned out, white-fronted geese that were banded with them but did not receive collars were reported harvested by hunters. Interviewing each of the hunters, they all recalled knocking off feathers and cripples sailing off that were unable to be retrieved.”
In short, Link theorized given the semi-regular observation of banded birds in close proximity to radio-marked birds, he likely could assume they encountered gunfire. Essentially, if the geese go down in areas without cell service, go underwater or land with the solar panel down in the mud, they in all probability won’t be heard from again.
During the project’s first year, all 11 transmitters were donated by private individuals and organizations. In the current second year of the study, 11 of 21 telemetry units were donated.
Also noteworthy is the support from private landowners, who allow access for Louisiana Department of Wildlife and Fisheries personnel to capture geese. Without private lands, it reduces Link’s options for trapping sites as geese move about looking for desirable habitats.
The department plans to continue intensive study for at least one more year.
Afterwards, Link hopes to continue annually deploying a smaller number of transmitters to maintain a long-term data set to look for what he refers to as landscape level changes and understand year effects (i.e.: warm-wet winters vs. warm-dry winters vs. cold-wet winters vs. cold-dry winters).
White-fronted geese, fondly known as “speckle-bellies,” are a preferred species in a waterfowl hunter’s bag. No doubt, Louisiana’s hunters will be paying attention to whatever results are derived from the department’s studies.
During the 2015-2016 Louisiana waterfowl season, the commission opted out of an increase in daily bag limit from two to three white-fronted geese, in spite of overwhelming public support for the increase.
During the 2016-2017 waterfowl season, the bag limit went unchanged.
EDITOR’S NOTE: Flores is The Daily Review’s Outdoor Writer.