National Wildlife Refuges have been protecting habitat for wildlife and providing recreational opportunities for Americans for over a century. Founded by Teddy Roosevelt and currently administered by the US Fish and Wildlife Service, the National Wildlife Refuge system has over 500 sites encompassing 95 million acres of land. NWRs are great places to go for a nature hike, watch birds and wildlife, hunt and fish (in season), and even buy a bison. Yes, I said buy a bison. Go figure.
My favorite refuge in the state of Washington is Nisqually NWR, about an hour south of Seattle. Founded in 1974 on former farmland, Nisqually now is home to protected wetlands and estuary habitat where the Nisqually River joins Puget Sound. I spent a couple hours last week walking the trails and boardwalks there, enjoying the fall weather and the newly returning ducks and geese that have spent the summer up north in Canada and Alaska.
Geese flying in formation crossed the sky throughout the afternoon. It is thought that formation-flying reduces the drag of air resistance on the geese following the leader, and is thus an efficient way to fly long distances. A number of different species of geese were present on the refuge when I was there, including this chap:
If you recognize this as a Canada Goose, you used to be absolutely correct. But not anymore. Same with these birds:
The Canada Goose, formerly considered just one species, was split in 2004 into a pair of species: a physically larger one breeding primarily in the Lower 48 and eastern Canada, and a physically smaller one breeding primarily in northwest Canada and Alaska. The larger species retains the name Canada Goose, while the smaller one is now called the Cackling Goose. And while their summer ranges are mostly distinct, in the fall and winter these two species mix and mingle, especially in places like western Washington – site of Nisqually NWR.
Telling these two species apart isn’t always easy. In general, Cacklers have a smaller body, shorter neck, and shorter/stubbier bill. Some of them are barely bigger than a Mallard duck. But there is quite a bit of variation in both Cackler and Canada Geese, with a gradient of sizes, shapes, and colors represented in the field depending on the subspecies. For comparison, here are a few Canadas – note especially the longer necks and longer bills.
If you want more information on how to tell Cacklers and Canadas apart, David Allen Sibley has a great page with photos and maps here.
You might think that deciding which animals comprise a single species and which are really two or more species might be straight-forward. And sometimes it is. But often it is more complicated than you might think. Originally, animals that looked the same were considered the same species, while those that looked different were classified as a different ones. The problem is that some birds that look different (like all of the different color morphs of Red-tailed Hawks) breed with each other successfully, share most of the same habits and habitats, sound the same (songs and calls), and are genetically pretty similar. In contrast, some birds look almost identical (I’m looking at you, Alder and Willow Flycatchers!), but do not regularly interbreed, have different songs, and show notable genetic differences. And then there are cases like the (Eastern) Yellow-shafted Flicker and the (Western) Red-Shafted Flicker. They look similar, but the western (sub?)species has red feather shafts instead of yellow, and subtly different markings on the head and neck. Their calls and behaviors are pretty similar. But they have pretty distinct geographical ranges, so they don’t interbreed often. Where their ranges overlap, they do breed with each other producing hybrids with a range of intermediate or mix-and-match characteristics such as a “red-shafted” head on a “yellow-shafted” body. I once saw a pretty amazing “orange-shafted” flicker in Oregon.
Ornithologists sometimes have difficulty deciding which groups deserve status as full species, and which are just variations or subspecies. And sometimes they change their mind in light of new information (take note, politicians, that changing your mind about something is not always a weakness!). The two flickers mentioned above, once considered separate species, where “lumped” together into a single species a few decades ago, now called Northern Flicker. For the geese, the opposite happened. After decades of being considered the same species, Cackling and Canada Geese were “split” into two different species in 2004. Sometimes, there is real indecision. The California Towhee, once considered part of the “Brown Towhee,” was split, then lumped, then split again! The confusion is in part based on the fact that the simplest concept of a “species” is purely a human construct. We like to classify things as either/or and yes/no in a binary, black and white way. Nature, however, is more analog than digital. Changes in populations wrought by natural selection and evolution happen in a continuous curve, not in discrete quantum leaps. Speciation, the creating of new species from a common ancestor, is a process not an event. As such, we try to use our best judgment to decide where one species ends and where a new one begins, but sometimes it’s complicated. Look for more splits and lumps in the years to come!
The handsome fellow above is a Northern Shrike. It has not quite reached full adult plumage, as the mask isn’t completely black and there is still some brown wash on the belly. Shrikes eat small vertebrates like lizards and birds, and have a reputation for impaling their prey on thorns, sharp sticks, and barbed wire. The first Common Redpoll I ever saw became a Shrike meal about 4 minutes later.
Just past the Shrike, the Nisqually estuary was filled with ducks, ducks, and more ducks. This area is a protected zone that is surrounded by hunting areas on two sides. And the ducks are not as stupid as they look. These are male Northern Pintails. They are still in the process of growing in their very long “pin” tail feathers.
The northwestern part of the refuge features a relatively new boardwalk, which stretches most of the way to the Sound.
Nearby I found a Great Egret feeding. These elegant waders are common over most of the United States, but are quite uncommon in Washington state.
Nearby was a wader that is NOT uncommon – the familiar Great Blue Heron. Like the Mallards, GBH’s often don’t warrant a second look from birders. But they are pretty spectacular creatures.
As I turned for home, I meandered by the Twin Barns, a reminder of Nisqually’s farmland past. They are currently languishing in a state of majestic disrepair.
As the days grow shorter and colder, the Big Leaf Maples throughout the refuge have received the signal to stop chlorophyll production and drop their flat photosynthetic factories. Winter is coming.
My winter schedule is beginning to firm up. The week after Thanksgiving I’m traveling to New York and New England to see some schools (like the public Bronx High School of Science and the independent Groton School in Massachusetts). I’ll also be looking for Atlantic sea ducks, gulls, and alcids. I’ll post more from the Northeast!
Periodic Wanderings 