Welcome to Frank's Field Notes, a semi-regular look at what’s happening across the Prairie Pothole Region during spring migration and breeding season.

Part field journal, part migration report, and part window into duck country, Delta Waterfowl Chief Scientist and President Dr. Frank Rohwer offers firsthand observations from the field on ducks, geese, weather, habitat conditions, and the annual return north.

Swans with cygnets

This reflects rapid population growth

10/20/2026

Trumpeter Swans released in Minnesota have shown remarkable population growth.

Canvasback in flight

nice looking Redheads and Cans

10/19/2026

While working at the edge of Long Island Bay (Lake Winnipegosis) it was impressive how many birds we saw – thousands.

Springers

Happy Springers

10/18/2026

My two spaniels were in heaven.

Wigeon

adult males

10/17/2026

There are lots of Wigeon at the Delta Marsh this fall using the diked areas with shallow water

Young Gadwall

Surprising

10/16/2026

Gadwall and Wigeon males surprise me.

Pheasant Feathers

pheasants follow same rules

10/15/2026

Just like in ducks – display feathers are grown last.

White throated sparrow

Sparrow migration

10/14/2026

Many other species are also passing through Delta – like White-throated Sparrows

Fall in ND is glorious

10/13/2026

Cool fall colors, magnificent animals, and amazing scenery.

blackbird flock

flocking blackbirds

10/12/2026

We got a whisper of cold temperatures and that seems to have inspired the blackbirds to really flock up.

Pheasant in flight

Opening weekend

10/11/2026

For the first time in 13 years in North Dakota I made opening day for Pheasants.

Mallards in Flight

relatively late to molt

10/10/2026

This is an interesting time of year because of the variation in molt that is apparent in male ducks.

Monarch Butterfly

What a migration

10/9/2026

We all love the waterfowl migration, but the Monarch migration is really something.

3 flying male pintail

early fall Pintails

10/8/2026

You can clearly see the wings and see they are three adult males.

Swainson's adult and juvenile

10/7/2026

Typical of hawks – the juveniles are splotchy.

Yes, they eat ducks too

10/6/2026

I suspect Swainson’s Hawks (shown) and Red-tailed Hawks had good production years

Gadwall Male

nice Gadwall

10/5/2026

Gadwall are loving the shallow water areas created at Delta Marsh.

Goose flock

Flocked versus territorial

10/4/2026

Snapped this typical early October picture of a seasonal pond with a flock of big Canada Geese in foreground and Mallards in back

subtle differences

10/3/2026

This photo shows a male Pintail as seen by most hunters in September.

First day for arctic birds

10/2/2026

Today at Lake Winnipegosis I saw the first flights of Snow Geese and one set of Cacklers.

Lake Winnipegosis

10/1/2026

Beautiful colors this time of year – both on ducks and trees.

Great blue heron

close up

9/30/2026

Great Blue Herons are still at Delta Marsh working on the small fish.

Not what we want to see

9/29/2026

I have no huge problem with drain tile as long as they don’t drain wetlands.

Learning to forage can be hard

9/28/2026

In the bird world – ducks included – young birds almost always have lower survival than adults.

Winter vs. Summer - amazing

9/27/2026

The difference between winter and summer plumage in Long-tailed Ducks is simply amazing.

Longtails

Beautiful birds in breeding plumage

9/26/2026

Like many duck hunters, I have never seen Long-tailed Ducks (aka oldsquaws) in their breeding plumage.

Learning or just foraging

9/25/2026

Female waterfowl home; males do not.

1/2 & 1/2

9/24/2026

Nice mix of 4 BWT and 4 GWT

Flying ducks

Mixed Delta ducks

9/23/2026

Grey light, but many species. Can you get them all?

slough pump

9/22/2026

American Bitterns are common at Delta and across the PPR.

molt feather comparison

last tail feathers to replace

9/21/2026

Ducks hatched this summer carry notched tail feathers compared to non-notched tails.