Northbound

The story of bird migration is the story of promise – a promise to return.

~the movie, Winged Migration

A week ago, we had a snow storm that crippled much of the south. Today, the temperatures soared into the 70’s. Less than two weeks ago, I stood in awe as thousands of Snow Geese swirled overhead and then landed amongst thousands of Tundra Swans feeding in a field at Pocosin Lakes National Wildlife Refuge. Two days ago, I could only find 8 Snow Geese amidst a flock of a few hundred swans. And even more telling was the view from the observation platform when we arrived.

Pungo Lake with no birds

Pungo Lake after the birds have gone (click to enlarge photos)

Where thousands of white specks had dotted the lake only a couple of weeks ago, there was now not a single one. No duck, goose, or swan could be seen anywhere on the lake. We altered our plans to hike and drove through the refuge looking for birds. A few swans flew overhead, but we only saw two eagles – on my last visit there had been over twenty. The eagles follow the flocks of large birds when they are on the refuge…no eagles, no flocks.

We drove to Mattamuskeet to see if that refuge was more to their liking. Crossing the lake, we could see a few Canada Geese, but no swans. But the impoundment along Wildlife Drive was full of ducks, more than I had seen in there all winter.

Pintails in impoundment

Large flock of ducks in impoundment at Mattamuskeet

Most were Northern Pintails, although there were also large numbers of American Wigeon, Northern Shovelers and Blue-winged Teal. A few Tundra Swans were mixed in, but it appears as though most have headed out from here as well.

Swans at Mattamuskeet

A few remaining swans at Mattamuskeet

Driving through Mattamuskeet, we spotted several Great Egrets, Great Blue Herons, Black-crowned Night Herons, more ducks, a few more swans, and a sizable flock of White Ibis.

Immature and adult White Ibis

Immature and adult White Ibis

Most were actively feeding, probing the soft mud and shallow waters with their long bills, looking for small fish, or crayfish, worms, and other invertebrates.

White Ibis and reflection 1

White Ibis feeding

A few were off by themselves and were busy bathing and preening.

White Ibis bathing

White Ibis bathing

White Ibis bathing 1

White Ibis splashing and bathing

Ibis scratching

White Ibis scratching

White Ibis preening

White Ibis preening

White Ibis in flight

After preening, a White Ibis flies off to feed

Driving back to Pungo on the way home, we saw a few flocks of swans returning to the lake for the night, but no Snow Geese. Looking back at my notes from the past few months, I found that I had seen the first of the Snow Geese back on November 23. That was a lone bird mixed in with a flock of Tundra Swans, who had started arriving a few weeks earlier. Thousands more arrived soon after, providing myself, and many other visitors, with incredible sights and sounds all winter. Now, in mid-February, most were gone. They are returning to their nesting grounds in northern Canada and Alaska, a few thousand miles from here.

Another amazing season of wildlife spectacles at Pungo and Mattamuskeet has drawn to a close. And a new season begins. This morning I heard a loud dawn chorus of birds in the woods outside my house. Last night, the calls of Upland Chorus Frogs filled the night air. It is one of the things I love most about this region, the progression of the seasons and the accompanying ebb and flow of life. I’m sure I will find something to keep me occupied until next winter when the first Snow Goose wings its way south and lands at Pungo Lake. Just as the waterfowl are flying north, our spring is moving north and will be here soon, bringing a new burst of life to my woods. Be sure to make some time to get outside in the next few weeks and enjoy its return.

Marbled Salamander eggs

Marbled Salamander eggs

Marbled Salamander eggs under log

Two friends from the Museum, Megan and Melissa, invited me to tag along with them yesterday, as they did some fieldwork for a future workshop. Megan made a great find as she and Melissa were turning over logs at the edge of a vernal pool, looking for salamanders – some viable Marbled Salamander eggs. It seemed really late to us for this species to still have viable eggs (when she looked closely, she could see the well-developed embryo moving inside the eggs) so she grabbed a couple to photograph.

Marbled Salamanders have an unusual reproductive strategy compared to many other species in that the eggs are laid in the fall (usually October and November in this area). The female often scrapes out a little area near or at the edge of a vernal pool.  Vernal pools are fascinating and important habitats that may be dry much of the year and then fill with autumn and winter rains. The key is they have no fish, which makes them critical habitats for a number of species of amphibians, invertebrates and other animals. She then will stay with the eggs for some time (often a month or more) waiting for the water to rise so the eggs will hatch. If it remains dry for an extended length of time, she may abandon them and return to her underground burrows in the nearby woods until the next breeding season. Studies suggest that egg clutches where the female remains with them until they are covered by water have a higher offspring survival, perhaps because she helps protect them from predation or getting too dry.

Marbled Salamander eggs

Marbled Salamander eggs

The 50 or 60 eggs Megan found were under a log at the edge of a large vernal pool. It was very moist under the log but the standing water was still a few inches away from the eggs. Embryos develop to the hatching stage within a couple of weeks after being laid, but do not hatch until covered by rising water. So these eggs were very well developed. You can see the front legs and feet, the larval gills, some of the diagnostic lateral spots, and the eyes in the waiting “larvae”. My salamander reference (Salamanders of the United States and Canada by James W. Petranka) states, “when covered by water the embryos become oxygen stressed…this triggers the release (from hatching glands on the snout) of digestive enzymes that dissolve the egg capsule and allow the embryo to escape”. Amazing!

Marbled Salamander eggs

A closer look

We put a couple of eggs in some water in a bug box so I could photograph them. Megan called Jeff Beane, a herpetologist at the Museum, and told him about the find. He said he did not recall seeing any viable eggs this late in the spring so he wanted to document the location. We walked down into the woods to show him, photographed the eggs and then walked back to the car. In those 40 minutes or so, the two eggs had hatched. The reference said it usually takes a few hours to a couple of days after flooding for the eggs to hatch. Guess these guys had waited long enough. The last picture is one of a larva from last year that I pulled from another pool. It was much older and larger than the ones from yesterday.

Marbled salamander larva

Large Marbled Salamander larva