Photos and text by Nancy Barrett, VP, Friends of Sam Smith Park
|Chestnut-sided Warbler (male)|
Why do birds migrate?
The ancient drive to follow time-worn migration routes every spring and fall probably began as an adaptation to climate and food availability, but over time it became part of the birds' genetic makeup. Birds also incorporate responses to weather, geography, food sources, day length, etc. But why make such an arduous trip north in spring? One idea is that the seasonal abundance of insect food and greater day length allowed them to raise more young (4-6 on average) than their stay-at-home tropical relatives (2-3 on average).
Do all birds migrate?
Most birds fit into the following categories:
are able to find food supplies year-round
(example: Northern Cardinal).
Short- to -medium-distance migrants follow
the most variable patterns, often in response to abundance of food (example: Blue Jay).
How do birds navigate?
Migrating birds can cover thousands of miles annually, often travelling the same course year after year with little deviation. First-year birds often make their very first migration on their own. Somehow they can find their winter home despite never having seen it before, and return the following spring to their birthplace.
The secrets of their amazing navigational skills aren't fully understood, partly because birds combine several different senses when they navigate. Birds obtain compass information from the sun, the stars, and the earth's magnetic field. They also get information from the position of the setting sun, as well as landmarks seen during the day.
|Whimbrel flock passing Whimbrel Point|
Is migration dangerous?
|Palm Warbler with midge|
In recent years, long-distant migrants have been facing a growing threat from tall buildings of glass and steel. Many species are
|FLAP layout at the Royal Ontario Museum|
reflective surfaces and millions are killed each year in collisions with these buildings. FLAP (Fatal Light Awareness Program) is dedicated to rescuing injured birds and seeking solutions to this issue.
Have you ever gone to the park early on a May morning, expecting trees dripping with warblers and vireos, only to end up with a face full of midges and mosquitoes? That luck, good and bad, often takes the form of the weather patterns the birds encounter. Weather can delay, detour, or even speed up migrating songbirds, and the prepared birder can check several sources to get a better sense of when and where they might show up.
Wind speeds are an important factor: It's easier for birds to migrate with a tailwind than a headwind. A cold front with steady winds from the north can keep birds grounded for days. Check a good hourly weather app (I use WeatherCAN, on PlayStore and the App Store) for the latest conditions.
|Black-throated Blue Warbler during fallout|
|Marsh Wren during fallout|
|Yellow Warbler on the beach during fallout|
BirdCast is a very useful tool in tracking bird migration through North America into Canada.
|BirdCast Live Migration Tool|
Can I see migrating birds in the park?
Yes! Colonel Samuel Smith Park is known in birding circles as a "migrant trap". Not only is it located along a prime migration route, the shape of the park itself (largely constructed with lakefill) acts as a natural funnel, encouraging tired, hungry birds to touch down, eat and rest in the varied habitats found there. Woodlands, dense shrubs, meadows, beaches and wetlands all provide ideal places for the birds to pack on some weight before continuing further north--leaving behind those species which stay and nest there.
The Friends of Sam Smith Park are finalizing an updated park map, with input from all, that identifies prime birding areas, such as:
Large Bowl/Small Bowl
|Male Red-winged Blackbird, singing on territory, March|
|Male Song Sparrow, singing on |
Some people may groan in protest at this, but early mornings are simply the best time to see the most species in the highest numbers at the peak of their activity. Hungry birds that have just arrived need to eat and pack on body fat to fuel the rest of their journey. There is another burst of activity in late afternoon, but I will attest that getting outdoors in time to experience the "dawn chorus"--an incredible variety of newly-arrived birds all flitting about in the trees at the same time, filling the air with their songs--is utterly worthwhile. Midday, on the other hand, is sleepy-time for many bird species.
|Female Blackburnian Warbler foraging in early morning sun|
On cool, frosty spring mornings, the insects that songbirds depend on are often close to the warmer ground, so the birds may be down low and easier to spot--and often on the sunny side. On warm mornings, insects move up higher into the treetops, and the birds follow, creating afflictions such as "birder's neck" or "belly shot photo".
In breezy or windy conditions, migrants--and insects--will tend to congregate on the leeward side (protected from prevailing winds) of peninsulas or woodlands.
|Blackpoll Warbler taking insect from spider web|
This extremely useful chart was carefully compiled using eBird frequency graphs by Mike Burrell, originally published on his blog. Even going by my own observations in the park for 10 years, I have noticed that these average arrival dates generally hold true year to year. To capture the majority of songbird arrivals, the list includes March 14 through May 20.
|14 March -||Turkey Vulture|
|16 March -||Eastern Bluebird|
|17 March -||Pied-billed Grebe|
|18 March -||Wood Duck|
|20 March -||Red-throated Loon|
|21 March -||Great Blue Heron|
|22 March -||American Kestrel|
|25 March -||Northern Flicker|
|27 March -||Blue-winged Teal|
|28 March -||Pectoral Sandpiper|
|30 March -||Dark-eyed Junco|
|31 March -||Wilson's Snipe|
|01 April -||Bonaparte's Gull|
|02 April -||Double-crested Cormorant|
|03 April -||Great Egret|
|04 April -||Osprey|
|06 April -||Common Loon|
|07 April -||Cooper's Hawk|
|08 April -||Lesser Yellowlegs|
|09 April -||Caspian Tern|
|10 April -||Black-crowned Night-Heron|
|13 April -||Louisiana Waterthrush|
|14 April -||American Bittern|
|15 April -||Surf Scoter|
|16 April -||Broad-winged Hawk|
|17 April -||American White Pelican|
|Northern Rough-winged Swallow|
|18 April -||Virginia Rail|
|19 April -||Purple Martin|
|20 April -||Cliff Swallow|
|21 April -|
|22 April -||Black Scoter|
|23 April -||Willet|
|24 April -||Green Heron|
|25 April -||Long-billed Dowitcher|
|26 April -||Solitary Sandpiper|
|27 April -||Wilson's Phalarope|
|28 April -||Sedge Wren|
|30 April -||Common Gallinule|
|Black-throated Green Warbler|
|01 May -||Eastern Whip-poor-will|
|02 May -||Ruby-throated Hummingbird|
|03 May -||Great Crested Flycatcher|
|Black-throated Blue Warbler|
|04 May -||Black-bellied Plover|
|05 May -||Cape May Warbler|
|06 May -||Least Bittern|
|07 May -||Common Nighthawk|
|08 May -||Ruddy Turnstone|
|09 May -||Semipalmated Sandpiper|
|10 May -||Yellow-billed Cuckoo|
|11 May -||Brant|
|12 May -||Olive-sided Flycatcher|
|13 May -||Yellow-bellied Flycatcher|
|15 May -||White-rumped Sandpiper|
|17 May -||Red-necked Phalarope|
|18 May -||Whimbrel|
|20 May -||Red Knot|
Stay tuned for SONGBIRD MIGRATION: PART 2 for a pictorial guide to some of the species that pass through Colonel Samuel Smith Park.
Acknowledgements to the Cornell Lab of Ornithology for their valuable resources, and to Mike Burrell for his arrivals chart. Read the entire article here and check out his new book with Ken, his brother: Best Places to Bird in Ontario.