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SpATS Study Methods 
Ducks Unlimited Canada (DUC) uses science and research to guide, evaluate and target conservation programs. In order to ensure that findings are based on accurate data, DUC’s team of scientists use a certain methodology, or process, when conducting studies like SpATS.
Some of the methods used during SpATS are:
- Breeding pair surveys
- Nest searching
- Wetland habitat classification
- Upland habitat suitability
- Brood observations
- Habitat classification
Breeding Pair Surveys
On each study site, two waterfowl surveys are conducted to determine the density of breeding waterfowl. The first count is conducted in late April or early May. The second count is conducted in mid to late May.
Research crews set out early in the morning with spotting scopes and binoculars and visit all wetlands on each focal quarter, recording waterfowl species, number of ducks and social structure of the birds.
Nest Searching
Nest searching involves looking for waterfowl nests in a given area. It provides estimates of nest density and nesting success among different study sites, types of cover and duck species.
All potential nesting cover (except for planted cropland, woodland and flooded wetland vegetation) is searched on each focal quarter within each study site. Three successive searches are conducted at approximately three week intervals.
Nest searching involves two all-terrain vehicles driven in a parallel course through potential nesting cover. The two ATVS drag a long cable with loops of chain attached. The cable-chain rides up on the vegetation and flushes out nesting hens as it passes over their heads, revealing the nest location.
Nests are also found by walking and striking vegetation with long willow switches, or by using hand-pulled rope drags. Nests are not considered unless they have eggs in them.
Once a nest is found, it is marked with a flagged stick, which is placed four metres north of the nest. Each nest location is recorded on site maps and with a Global Positioning System (GPS).
Researches use a process called field candling to find out the age of the eggs and the nest. Field candling involves putting an egg in a small plastic tube and holding it up to the light, which allows researchers to see inside the egg and determine how old it is. Nests are revisited every 10 days until the nest hatches, or until it is destroyed or abandoned.
Nest searches are conducted with great care to avoid hurting birds or damaging their nests.
Wetland Habitat Classification
On each study site, all wetlands within focal quarters are visited and classified. Classification is done using the Stewart and Kantrud wetland classification system.
Water level, plant cover type, permanency (ie. whether it’s a temporary wetland or permanent wetland) and flooding of vegetation are recorded.
Upland Habitat Suitability
One of the things SpATS researchers record is how vegetation changes over time during the nesting season. The height of vegetation is measured, as well as the visual obstruction of vegetation (VOR), which reflects how well it acts as cover for waterfowl.
Vegetation is measured along permanent transects (imaginary lines along which researchers collect samples of data) in all habitats searched for nests. Transects are 40 metres long with sampling stations every five metres.
Vegetation height is estimated using a 30 cm clear Plexiglas disc. VOR is estimated using a 3 x 150 cm pole painted with alternating colors at 10 centimetre (1 decimetre) intervals. When viewed at a distance of four metres, this pole provides a measure of the how “thick” the vegetation is.
At each nest site, vegetation height and VOR are measured once at the beginning and end of the nesting season.
Brood Observation
SpATS researchers keep track of waterfowl broods (hens and their ducklings). Species, the number of ducklings and age class are recorded for all broods seen during a single survey of all focal quarter wetlands in July.
Each wetland is scanned for broods when first approached. Brood observation provides valuable data on waterfowl nesting success in a given area. It also helps to confirm data gathered during nest searches.
In addition, some waterfowl species nest either in holes in tree trunks (for example, buffleheads and common goldeneyes) or in nests constructed by weaving bulrush or cattail into platforms above standing water (for example, canvasbacks, redheads, and ruddy ducks). This means that their nests cannot be found during standard nest searches. Observing broods is another way to gather information on these species.
Habitat Classification
During the field season, each study site is regularly surveyed to identify habitat types (ie. cropland, hayland, grassland, woodland, open water, etc.). Current land-use for each major kind of habitat is also recorded.
Black and white aerial photographs are taken of each study site, along with habitat classification information. These photos are put into a Geographical Information System (GIS) and digitized. This means that different habitat types are identified in each photo, separated and assigned a colour.
The digitized information is then combined with other data gathered in the study, such as nest surveys. This process allows researchers to get a better understanding of how different habitat types are related to waterfowl (ie. nesting, population, etc.)
Disclaimer:
SpATS data presented on this Web site cannot be used without written permission from the authors.
