Seattle Waterfowl Management Committee
Fall 2023 Report
Submitted by:
United States Department of Agriculture
Animal and Plant Health Inspection Service
Wildlife Services
720 O’Leary St. NW
Olympia, Washington 98502
(360) 753-9884
Item No: 8b_attach_3
Meeting Date: March 26, 2024
Overview
The Seattle Waterfowl Management Committee (SWMC) was formed in 1994 and consists of 9 entities
in cooperation with the United States Department of Agriculture, Animal and Plant Health Inspection
Services, Wildlife Services (WS). Formulation of the committee was intended to create a partnership
between local municipalities that were impacted by the abundance of geese within the Lake Washington
region, with a goal of monitoring local abundances and working with WS to mitigate the impacts of a
growing population. Impacts consist of defecation in city parks, elevated coliform bacteria levels at local
swim beaches, aggressive behavior by geese towards humans when protecting nests, and frequent calls
and complaints by city residents regarding goose activity on their property. Additional risks to human
health and safety generally result from feeding by humans, such as food aggression and habituation.
Monitoring Surveys
Boat Surveys
WS conducts five boat surveys on Lake
Washington between March and August.
Surveys consist of driving the outer perimeter of
Lake Washington and along the perimeter of
Mercer Island, scanning the shoreline, rooftops,
docks, lawns, bridges, parks, and coves in search
of geese and recording the number of adults,
goslings (if present), and their location. Starting
in 2023, Lake Union is now incorporated into this
survey.
Vehicle Surveys
Surveys are conducted once per month from a
vehicle. Angle Lake, several city parks, and a retention
pond near SeaTac airport were added in 2023,
bringing the current total to 31 sites within the King
County and Lake Washington areas that are surveyed.
The same information as the boat surveys is recorded
during the driving surveys.
Figure 1 - Geese on dock at Lake Washington waterfront home.
Note: Geese habituated to coyote effigy.
Figure 2 - Geese at Gas Works Park.
Control Methods
Non-lethal Control
WS employs various tools to haze
geese loafing at city parks. These tools
consist of dogs, lasers, pyrotechnics,
mylar tape, and harassment by
firearms and paintball guns. It is
important to diversify the techniques
used throughout the year as geese
become habituated to tools that are
used routinely.
Figure 3 - Use of pyrotechnics to scare geese from a city park.
Figure 4 - Geese contained in a pen during a roundup.
Permitted Take
There are several methods employed by WS as approved take by the United States Fish and Wildlife
Service (USFWS). Methods consist of egg oiling, egg addling, shooting, and roundups. Some of these
tools require a permit from USFWS and assist in directly reducing the number of geese frequenting an
area. WS possesses the necessary permits for this work and renews these permits annually.
Observations
Boat Surveys
The number of adult geese and the number of goslings observed per survey from 2019 through 2023
were plotted against each other (Figure 5). When considering data over the past 5 years, the linear
trendline for adults observed per survey is on a slight decline, suggesting that current non-lethal and
permitted take methods are functioning in a manner to stabilize, and possibly slightly reduce, the
population of adult geese around Lake Washington. The linear trendline for juveniles is flat, implying
that these same methods, in addition to egg oiling, are proving successful in reducing the number of
juvenile birds being recruited into the adult population. It is important to note that juvenile geese are
generally born March – May and are recorded as adults when they become fully grown, typically by July.
Figure 5 - Lake Washington geese observed per survey with a linear trendline for adults and juvenile geese. NOTE: Lake Union
was added to this survey for 2023, likely resulting in a slight increase in the number of geese recorded in 2023.
While geese were
distributed
throughout Lake
Washington, a Kernel
density analysis of
observations
collected during this
survey was
conducted to identify
any locations in which
geese congregated in
numbers greater than
in other areas (Figure
6). Union Bay held
the highest numbers
of geese. This was
followed by the East
Channel, and then
the north end of Lake
Washington in
Kenmore and
Fairweather Bay in
Hunts Point.
Vehicle Surveys
Vehicle surveys
conducted in the Lake
Washington
area/King County
show an overall
increase in the
number of geese in
the surrounding areas
of Lake Washington/King County (Figure 7). While the data from 2020-2021 is absent, the increasing
trend remains. This suggests that goose populations are on the rise in areas outside the reaches of
roundups, egg oiling, and harassment conducted on/near Lake Washington. This highlights the
importance of permitted take and non-lethal actions to maintain a stable population on and in the
immediate vicinity of Lake Washington. If this increase continues in future years, the participating
members of the Waterfowl Committee should engage in discussions about increasing egg oiling
activities and roundups, as well as pursuing other municipalities, State agencies, and large businesses
that may be impacted by growing Resident Canada goose numbers to partner with the SWMC.
Figure 6 - Kernel density analysis of Lake Washington goose observations. These data are from
2022-2023 and are presented in the number of geese per 200'x200' area.
Figure 7 - Lake Washington/King County area vehicle survey observations conducted 2015-2019, 2022-2023. Due to park
closures and work restrictions resulting from the Covid-19 pandemic, vehicle surveys were not conducted in 2020 and 2021.
For questions regarding this report, please reach out to Brook Zscheile at 360-337-2778 or at
brook.zscheile@usda.gov.
