2003 Peter Green Award 2nd Place - Jon Jonsson

Peter A.W. Green spent two terms as the president of the Delta Waterfowl Foundation. During this time he led Delta to the forefront of the conservation movement and heightened awareness of waterfowl and wetland issues. The Peter A.W. Green Communications Award was established in 1994 by the Delta Board of Trustees in honor of Peter’s six years of outstanding service (1988-94).

This award is presented annually "to the Delta student who best exemplifies the characteristics required to be an effective communicator for the well being of North America’s waterfowl resource. These skills are to include the ability to communicate in both a written and oral fashion, and to present information in a manner which is understood by layperson and professional alike".

by Jon Einar Jonsson
Ph.D. Candidate

A pickup truck approaches and stops next to mine. The window rolls down, and a smiling man wearing camouflage from head to toe asks: “What’s ya doing? You watchin them birds?” Most of the time the geese do not mind another parked vehicle, they stay on the ground and continue their daily routine. But sometimes the entire neighborhood takes flight. This is another day at the office in southwest Louisiana. I watch the geese. I compare snow geese between coastal marshes and rice-fields. I compare the behavior of snow geese and Ross’s geese.

Snow geese in Louisiana use two habitats. Only a few snow geese used rice-fields roughly half a century ago, when the population was one-fourth of its present size. Snow geese wintered in coastal marshes back then, where they fed on chordgrass roots they dug from the ground. Snow geese began using rice fields some 60 years ago, and the population increased simultaneously.

Snow geese winter in both habitats in our day. Dr. Ray Alisauskas compared the bill size and head size of snow geese from marshes and rice-fields, and he found that snow geese from the marsh had larger bills and skulls than birds from rice-fields. Therefore, he hypothesized that larger bills were beneficial for geese digging for chordgrass roots, whereas bill size was less important to snow geese eating rice plants. But are the two groups of snow geese separate populations, or do snow geese with smaller bills prefer rice-fields to the marsh? I answer this question by observing the movements of snow geese neck banded in both habitats.

Not many things are more exciting than capturing snow geese with rocket-nets. You wait in the blind, watch the first geese land and walk in front of your net. Hope and pray that no airplanes or helicopters arrive. Hope that nothing happened to the wire. The net goes off; the geese are in, much to your joy and relief. Your people arrive and the processing begins. With the help of volunteers, I neck banded 432 snow geese at 3 banding locations from 14 November 2001 to 17 February 2002, and I banded another 539 at 4 locations from 20 November 2002 to 5 February 2003. My field crew scanned flocks for neckbands with spotting scopes, and we recorded locations of neck-banded birds with GPS units. We have so far sighted 207 of birds that we banded, yielding 563 total sightings.

My banding effort allows me to measure bill size, body size, and skull size of both adults and juvenile snow geese. As in the previous study, adults from the marsh had larger bills and skulls than adults from rice-fields. However, bill size and skull size of juveniles were not different between habitats, although overall body size was larger in the marsh. Snow geese do not reach full size until they are one year old, so it is possible that the larger “marsh” bills are not yet fully developed in juveniles. My findings indicate that adult snow geese select their habitat based on their own bill size, and juveniles must make do with the habitat their parents choose.

Ross’s geese are a new species in Louisiana. Historically, Ross’s geese wintered only in California, but their wintering range expanded eastward into Texas and Louisiana as the population increased. Surveys by Louisiana Department of Wildlife and Fisheries estimated over 100.000 Ross’s geese wintering in the state in 2000-2001. Snow geese and Ross’s geese are closely related and they share a special relationship; they nest side by side in nesting colonies in the Canadian Arctic, and they winter together in the rice-fields of Louisiana.

Ross’s geese are two-thirds the size of snow geese, and the two flock together and eat the same foods. Therefore, comparisons between the two species are free from any environmental effects, such as different food selection, migration distances, and weather. Therefore, the two species are ideal for testing the body-size hypothesis, which states that smaller species burn more energy per gram of their weight, and larger species are better able to carry reserve energy in the form of fat. I test the body-size hypothesis by comparing the behavior of snow geese and Ross’s geese. I collected 780 time-budgets in Louisiana 2002-2003. One time-budget is an observation of a single bird that lasts 10 minutes, during which all behaviors are recorded. I use these data to compare the percentage of time snow geese and Ross’s geese spend feeding, resting, walking, and standing alert. Ross’s geese spent more time feeding than snow geese, on average 47.2% to 41.8%, respectively. Snow geese spent more time resting than Ross’s geese, on average 26.6% to 16.1%, respectively. These preliminary results are consistent with the body-size hypothesis.

Snow goose families remain together from one breeding season to the beginning of the next. Families dominate pairs and lone birds; therefore, juveniles in families are able to feed more than lone juveniles, and parents profit from juvenile assistance when competing for food. I recorded family size of the white geese I observed for time-budgets. Ross’s geese were never observed in family units, whereas 22% of all snow geese observed were birds in families. Half the snow geese and two-thirds of the Ross’s geese were lone birds, and 26% of the snow geese and 30% of the Ross’s geese were paired adults with no offspring.

Most goose species tend to keep a distance between one another when they use the same fields, i.e. snow geese and white-fronted geese. By contrast, Ross’s geese and snow geese always hang out together in southwest Louisiana. I recorded all fights among white geese during my time-budget observations. Any given white goose had the chance of encountering snow geese and Ross’s geese of 93% and 7%, respectively. Snow geese won 98% of all fights between the two species. Snow geese fought Ross’s geese in proportion to the chance of encountering them; 6% of all fights recorded for snow geese were with Ross’s geese. By contrast, 51% of all encounters recorded for Ross’s geese were with other Ross’s geese. Ross’s geese encountered each other more often than expected by chance, which indicates that Ross’s geese compete with one another for spots where they can feed without being harassed by snow geese. Ross’s geese probably benefit from hiding among snow geese from hawks, falcons, and hunters.

I have completed two field seasons, 2001-2002 and 2002-2003. My final field season will be November 2003 – February 2004. My Ph.D. dissertation will also include chapters on data collected at Karrak Lake, Nunavut in 1993, 1996, and 1999. Dr. Alan D. Afton collected these data, which are on time-budgets and incubation constancy of breeding snow geese and Ross’s geese. Incubation constancy is the percentage of time each female spends sitting on her nest, which is highly variable between waterfowl species. I use films of incubating geese to measure incubation constancy. If these films have taught me anything, it is how immensely patient creatures incubating birds must be.

My conversation with the hunter continues. “Say, you ain’t from around here, are ya?” So I tell the man I am from Iceland. “You are a long away from home” is the reply. And what made me come to Louisiana? I came to the States to study waterfowl and to see new waterfowl species. Geese particularly fascinate me because they are the Arctic specialists of the family. Snow geese (in spite of them wintering in Louisiana) are possibly the greatest Arctic specialists of them all. And they are the coolest birds.

The School of Renewable Natural Resources and the Fish and Wildlife Coop Unit, Louisiana State University, Delta Waterfowl, Canadian Wildlife Service, Louisiana Department of Wildlife and Fisheries, and the Rockefeller Scholarship Program support this study.