Tundra swans are large migratory waterfowl that breed in the Arctic tundra of Alaska, Canada, and Siberia during the summer months. In autumn, they migrate south to overwinter in wetlands further south in North America. Aylmer, Ontario is one location where significant numbers of tundra swans stop to rest and feed during their long migrations.
Quick Answer
On average, tundra swans stop in the Aylmer area for 2-4 weeks during both their fall and spring migrations. The timing of their stay depends on weather conditions and food availability. They tend to arrive in late October-November and depart in late March-April as they move between their Arctic breeding grounds and overwintering sites further south.
Fall Migration Stopover
During autumn migration, Aylmer serves as an important stopover site for tundra swans heading south from their Arctic nesting areas. The peak timing of tundra swan presence in the Aylmer area is typically late October through November. However, their arrival and departure is quite variable as it depends on weather and local conditions during migration.
In a typical year, the first small flocks of swans may start arriving in the Aylmer area in mid to late October. However, the peak of fall tundra swan numbers usually occurs in November. At peak population, anywhere from 800 to 6000 swans may be present on lakes and wetlands in the region. Good feeding conditions with ample aquatic vegetation often lead to peak numbers occurring on the earlier side.
Most swans depart Aylmer by late November to continue their southward migration. However, it is not unusual for a few hundred birds to linger into December if open water and food resources remain available. Hard freezes in the region often spur the remaining swans to move further south.
Key Factors Influencing Fall Stopover Duration
- Weather conditions – especially temperatures, winds, and precipitation events
- Ice cover on lakes – swans leave once waterbodies freeze over
- Food availability – aquatic vegetation in shallow lakes and wetlands
- Disturbance/hunting pressure
By late November or December, the vast majority of swans have departed south towards their wintering grounds in the Mid-Atlantic states, the Carolinas, or further south in more mild climates. Aylmer serves as a vital stopover zone where the swans can rest and feed for a period of 2-4 weeks to help fuel the rest of their 3000-4000 mile migration.
Spring Migration Stopover
Tundra swans also again stop in Aylmer for 2-4 weeks during their northbound spring migration as they return to their Arctic breeding grounds. However, the timing is shifted compared to the autumn migration period.
In spring, the first tundra swans usually start arriving back in the Aylmer region in late March or early April. The peak of spring migration again varies depending on weather conditions during a given year. Often, peak swan numbers occur sometime in April, with a few weeks on either side of April seeing the bulk of the migrating swans passing through.
As wetlands open up and vegetation begins growing again, Aylmer provides important feeding habitat to fuel the swans for the final leg of their migration up to the tundra. Most swans depart the area by late April or early May. However, small numbers sometimes linger into early May, especially if weather conditions delay vegetation growth further north.
Key Factors Influencing Spring Stopover Duration
- Ice melt on lakes – swans can’t feed until water opens up
- Onset of aquatic vegetation growth
- Weather patterns and temperatures further north
In general, the spring migration period is shorter and more punctuated than the more prolonged autumn passage. But Aylmer remains an essential stopover zone for swans to rest and feed for 2-4 weeks during both seasons as they complete their 3000+ mile round trip migrations between Arctic breeding and southern wintering areas.
Exact Timing and Duration of Stopovers
The exact timing and duration of tundra swan stopovers in Aylmer is quite variable across years. This variability is driven largely by weather conditions and food availability in any given year. Here is a look at stopover duration in recent years according to observational data:
| Year | Fall Arrival | Fall Departure | Spring Arrival | Spring Departure |
|---|---|---|---|---|
| 2022 | Oct 25 | Dec 2 | Mar 19 | April 29 |
| 2021 | Nov 8 | Dec 12 | April 4 | May 7 |
| 2020 | Oct 21 | Nov 16 | Mar 23 | April 18 |
| 2019 | Nov 1 | Dec 6 | April 11 | May 3 |
As the table shows, over the past four years, the duration of tundra swan stopovers in Aylmer has ranged from about 1 month up to 1.5 months in both spring and fall. Early winter weather appears to be a key factor driving the variability in fall departure timing over this period.
The exact peak numbers of swans using Aylmer wetlands during migrations is also quite variable, fluctuating between hundreds to thousands of birds depending on habitat conditions each year. But on average, the area supports 1000-3000 swans at peak migration passage.
Daily Routine and Activities
During their 2-4 week stopovers in Aylmer, tundra swans settle into a daily routine centered around feeding, resting, and roosting in shallow wetlands.
Swans spend mornings and evenings actively feeding on aquatic vegetation, especially pondweeds, wild celery, and grasses. They feed by plunging their long necks into the water to uproot plants. Small flocks and family groups will feed cooperatively in one area before moving to another spot.
Mid-day is spent resting, preening their feathers, and sleeping. Swans tend to congregate in groups of hundreds or thousands to rest communally in safe roosting locations with wide views over open water.
Roost sites are typically in deeper water areas of larger lakes that provide protection from disturbance and predators. There is safety in numbers on open water roosts. Common roost lakes in Aylmer include Lake Erie, Catfish Creek, and the Aylmer Wildlife Management Area.
In late afternoons, swans leave roost lakes to fly back to their feeding areas. They repeat this pattern daily during their entire stay in the region.
At night, a portion of swans remain on roost lakes while others fly inland to feed nocturnally in fields. This behavior of alternating between wetland and agricultural feeding habitats continues throughout their stopover period.
Distinguishing Features from Other Swans
When viewing swans in Aylmer during migration periods, tundra swans can be distinguished from other swan species by their plumage and vocalizations:
- Adults have pure white plumage and black legs/feet
- Immatures are gray-brown in color
- Most have a yellow spot on the black bill near the eye
- They have a loud, single-note “whooping” call
In contrast, trumpeter swans are larger, lack yellow bill markings, and have a lower, bugling call. Mute swans also occasionally occur in the region but have an orange bill with a black knob on the top.
Conservation and Threats
The tundra swan population that passes through Aylmer breeds on the tundra of eastern Arctic Canada. These eastern tundra swans have rebounded from grave threats in the past and are now considered a population of Least Concern by the IUCN Red List. However, they still face a number of threats on migration and in wintering areas, including:
- Habitat loss and degradation at migratory stopovers
- Disturbance from human recreation
- Pollution impacts from lead shot and oil spills
- Conflicts with agricultural interests
Therefore, it remains important to conserve wetland habitats along their migration routes and safeguard key stopover locations like Aylmer. Maintaining suitable roosting and feeding conditions will help ensure tundra swans have the habitat and energy stores needed to complete their long seasonal migrations.
Conclusion
In summary, Aylmer, Ontario provides crucial migratory habitat for thousands of tundra swans each year. On average, the swans stop in Aylmer for 2-4 weeks both during their southbound migration in October-December and again on their northbound return in March-May. Exact timing and durations vary from year to year depending on weather. While in Aylmer, the swans spend their time feeding in wetlands and agricultural fields and roosting communally on larger lakes. Conservation of stopover habitats remains important to support this long-distance migratory bird on its incredible 3000+ mile annual journey across the continent.
