Birds

All posts tagged Birds

Ian Stewart

These are the opening words of the poem ‘To a mouse’, written by the legendary haggis-eating Scottish poet Robert Burns in 1785 (which also contains the famous line oft-paraphrased as ‘The best-laid schemes of mice and men go often askew’). Although this is an apt description of mice it is also used to refer to all manner of small, obscure and reclusive animals and feather mites fit perfectly into this category.

Most people have never heard of feather mites which is hardly surprising. They are tiny brown arthropods which spend most of their lives flattened along the vanes of bird wing feathers where they were assumed to scavenge on feather debris and oily secretions and perhaps even rasp away at the feathers themselves. However, a remarkable study published last summer (Doña et al. 2018) examined the contents of mites’ stomachs using high-power microscopy and DNA analysis and found that their main food was fungi, and perhaps also bacteria and oil produced from the birds’ preen gland. Whether this means feather mites harm their hosts or are simply commensal remains to be seen.

Birds are assumed to acquire feather mites through physical contact with their parents while they are still in the nest, although they could also pick up mites from bumping into other birds at feeders or sharing the same dust bathing sites. Mites are quite easy to see if you are holding open a bird’s wing although with the naked eye they just look like a cluster of small dots (shown below).

We gained a whole new appreciation for these creatures when Shannon Modla of the University of Delaware kindly photographed some Gray Catbird feather mites under a light microscope. The magnified views show that they are long and thin with two pairs of legs at the front of their body and two pairs at the back (image below). The darker mites on the left and below are probably older mites with a hardened exoskeleton while the paler one on the right is probably a younger mite that has just molted.

Shannon was then able to view them under a powerful electron microscope and got some incredible images of their head as well as an egg (below).

To try to gain some insights into the biology of these enigmatic creatures we have been scoring the number of feather mites present on birds handled during the Delaware Nature Society’s Bird Banding project. Our simple questions were which bird species are most likely to have mites and whether the number of birds with mites varies according to the time of year.

Our first finding was that feather mites are quite common. We examined 448 birds belonging to 48 species and found that almost half of them (203 birds from 37 species) had mites on at least one of their wing feathers. We also found the proportion of birds with mites varies a lot between species. Over 75% of the Slate-colored Juncos, House Finches and Downy Woodpeckers that we examined had feather mites yet fewer than 15% of Ruby-crowned Kinglets, Common Yellowthroats or House Wrens had them. We also found that the proportion of birds with mites stayed quite consistent across the year with a noticeable peak in May.

This year we will be gathering more data on mites from the birds we band and then try to figure out why some birds are more likely to have mites than others, and why some have lots of mites while others have very few. Is it related to their body size perhaps, or how social they are, or maybe whether their beak is small and pointed enough to preen away the mites? So watch this space for updates on this new and fascinating DNS research project!

DNS has plenty of birding opportunities coming up soon, so sign up and enjoy the outdoors!

The Great Backyard Bird Count ~ Coverdale Farm Preserve

The Great Backyard Bird Coount: Kent County Tour ~ Abbott’s Mill Nature Center

Owls and Other Winter Raptors ~ Ashland Nature Center

 

Story and Photos by Joe Sebastiani, Ashland Nature Center Manager

What happens on a Delaware Nature Society Eco-trip? This spring’s adventure to Montana and Yellowstone featured lots of Black Bear, Grizzlies, Bison babies, over 150 species of birds, and world-class scenery. Throw in a few overnights in haunted hotels, cute mountain towns, and great food, and you have the recipe for an eco-trip to remember for a lifetime.
Forrest Rowland from Rockjumper Birding Tours led the trip. Forrest leads groups around the world, but lives in Montana. Joe Sebastiani, Ashland Nature Center Manager, accompanied the Delaware Nature Society group to experience one of America’s most wild and beautiful areas.  Many fans of the Ashland Hawk Watch know Forrest as the first Hawk Watcher during our 2007 inaugural season.  Now he is in charge of New World Operations for Rockjumper, and a highly sought-after guide.

Richardson’s Ground Squirrel looks like a pint-sized Prairie Dog. This one is barking at our group!

Our trip started in the short-grass prairie ecosystem around Billings, and focused on finding the birds of the region.  Many prairie species are declining, and some of the rare ones take inside knowledge of where to find them.  Luckily, Forrest lives in the area, and is tuned-in to where pockets of decent prairie habitat remains that supports birds.

Some of the highlights include watching the breeding displays Sprague’s Pipit, McCown’s and Chestnut-collared Longspurs as well as Long-billed Curlews chasing Golden Eagles.  Curlew disdain for eagles is known right away, as they scold and chase the larger eagles, America’s most powerful predatory bird, across the prairie.  Rare prairie nesting species we encountered included Ferruginous Hawk and Baird’s Sparrow.  A few species I thought I would never see in my life.

Chestnut-collared Longspurs fly up in the air and parachute back to the ground on wings held high, impressing feathered and human onlookers.

We were lucky to encounter a Plains Hog-nosed Snake which allowed us some close-up looks.

After the prairies, our group ventured into the foothills of the Rocky Mountains in southwest Montana.  Our base was Livingston, and we enjoyed the town and hotel as much as the adventures.  The Murray Hotel, downtown, allowed us to experience an old, western, authentic establishment, that is famously haunted, especially on the third floor, where my room was!  After returning from an old burned-over woods containing Lewis’s Woodpeckers, and visiting a wonderful bird feeding station with Evening Grosbeaks, Cassin’s Finches, Red Crossbills, and many others, the Murray awaited.  The rooms were well-appointed in Western and Native American decor.  Old photos of folks dressed in long-ago outfits decorated the walls.  I did not have a supernatural experience that night, but others in the group might have been in touch with the spirit world.

We visited two fantastic feeding stations, allowing opportunities to view hard to find species such as the Evening Grosbeak, a large finch.

Forrest Rowland, our Guide, enters the Murray Hotel in Livingston, with its famously haunted 3rd floor, where my room was.

Our group eagerly awaited Yellowstone National Park.  Large mammals abound, not to mention otherworldly hot springs and geothermal features.  Our first stop was Mammoth Hot Springs, which bubbles up boiling water, creating a beautiful cascade of dissolved limestone that reforms when in contact with the air at the surface.  Said to look like an inside-out cave, Mammoth Hot Springs is a beautiful sight, combined with sulphury smells, hot steam, and swirling colors.

Mammoth Hot Springs

We took one of the longest hikes of the trip here, partially to find Dusky Grouse and Williamson’s Sapsucker.  We found the Grouse by listening for its soft, low, cooing calls, produced by pinkish air sacs on the side of the male’s neck.  Forrest heard it, located it, and had us making concentric circles around the bird, without making eye contact with it, until we were right on top of it, taking a seat feet from the bird.  It went about its business, unconcerned by our proximity, so it seemed.

This male Dusky Grouse allowed us to sit practically next to it, as it made low, soft cooing sounds from the air sacs on its throat.

Along the walk, a few of us were looking at a butterfly, trying to identify it, when a brown figure was seen walking up a side trail towards us.  EEEEK!  It was a bear!  We noticed it when it was about 25 feet away, which is rather close.  We quickly stumbled away from it, walking at first, then moved with a little more urgency towards Forrest, who had the can of bear spray.  Hearts were racing, and there might have been a little pushing, but it turned out to be a young male cinnamon-colored Black Bear, only interested in getting a drink at the nearby creek, and eating some flowers.

This mild-mannered cinnamon Black Bear certainly startled a few of us on the trail, as we did not notice it until it was very close to us.

After our Bear encounter, we moved on to some of the large, open valleys in the park to seek other large forms of wildlife.  One way to do this is to stop where other people are on the side of the road looking at something.  One of our first “wildlife jams” on the road was caused by a mother Grizzly Bear and her two cubs tearing apart an elk that she had just killed.  As we watched them feed (300 yards away through the scope), you could see them tearing meat off the carcass…a brutal reminder there are animals here that are one step higher up the food chain than you.

For many of us, it was the herds of Bison that made the show at Yellowstone.  These hump-backed, woolly cow-like creatures plod around grasslands, roll in the dirt, walk down roadways, butt heads, and move along with young calves, right in front of you.  The calves are extremely cute, and allowed us fabulous looks.

In early June during our trip, it was “Cute Calf Season” for the Bison.

During our last few days in the park, continued our search for wildlife.  Sightings included Coyote, White-tailed Deer, Mule Deer, Bighorn Sheep, Mountain Goats, Moose, Pronghorn, and many species of birds including Harlequin Ducks and Barrow’s Goldeneye which inhabit the fast-moving rivers in the park.  One thing we missed by 10 minutes, however, was Gray Wolf.  We gave it a good effort, but didn’t end up seeing them.

Coyote are apparently more difficult to see in Yellowstone that Gray Wolves. We missed the wolves, but had this Coyote walk right past us.

Finally, although it was early June, we couldn’t leave the Rocky Mountains without at least one shot of snow.  Beartooth Pass, at nearly 11,000 feet in elevation, was closed to vehicular traffic up until the day we needed to cross it.  Finally, on June 3rd, hours after it opened, we ascended to the top.  Snow was falling, as was the thermometer in the car as we climbed.  At the top, the temperature was 31 degrees, the wind howled, and we dressed in every layer we brought.  We drove through canyons of snow 20 feet deep, as the road snaked its way over the barren top of the pass.  Considered one of the most scenic roads in the Lower 48,  it was a perfect way to cap off the adventure to the Montana and Yellowstone National Park.

The weather at Beartooth Pass finally allowed for some blue sky and clouds, after 31 degrees, snow, and high winds earlier in the day.

The next Delaware Nature Society Eco-trip is to Ecuador to see hundreds of species of birds in the Andes Mountains, where you will have the opportunity to surpass the elevation on the Yellowstone trip.  From 13,000 feet down to about 5,000 feet, sample the best of birding, eco-lodges, food, and natural beauty in one of the world’s most bio-diverse countries.  Sign up today!!!

By Ian Stewart

Delaware Nature Society has over 200 nest boxes spread around the properties we own or help manage which we installed to provide nest sites for a variety of birds. Every summer these boxes are monitored by a team of volunteers who track over 100 nesting attempts by 5-6 bird species (and we are always looking for more people to help with this – please get in touch if you’d like to get involved!). You’d be wrong to think the boxes stand idle throughout the winter however – it’s just that most of the action now takes place at night!

Several birds often roost in them during the winter, including Screech Owls, Eastern Bluebirds and some woodpeckers, which they probably do to protect them from the elements such as wind and rain. It is likely several degrees warmer inside a nest box than outside of it and for a small bird on a very cold night this could be the difference between life and death. Bluebirds take this a little further and are famous for ‘bundling’, where several birds squeeze into the same box for the night, probably keeping each other warm with their body heat.

A male bluebird entering a nest box

A male bluebird entering a nest box in winter

This year we’re making a special effort to check our boxes during the winter too. Sometimes it’s obvious that birds have been roosting in our boxes as they leave their droppings behind. The droppings in the photo below were almost certainly from a bluebird that has been eating Oriental Bittersweet. Bluebirds usually eat insects but at this time of year these are hard to find so they switch their diet to berries, and this exotic invasive vine is one of the few local plants that still has berries on it in February. You can help bluebirds in winter by planting berry-producing native bushes and shrubs such as Winterberry, Viburnums and Hollies. We will be following these boxes all through the year to see if bluebirds end up nesting in the same boxes that were used in winter.

Bluebird droppings inside a nest box

Bluebird droppings show they have been using this nest box

It’s also worth checking nest boxes in winter for less-desirable occupants. About 10% of our nest boxes are occupied by white-footed or deer mice during the winter. These nocturnal mice build fluffy nests inside boxes and sleep in them during the day. We always dump out mice and their nests during the winter, which may seem unkind but if left in place their urine and feces can damage boxes or carry disease, and birds won’t use boxes already occupied by mice. If you do this yourself, don’t use your hands to dislodge mice and their nests in case you pick up any disease or get bitten, but instead gently ease out the box contents with a stout stick.

Two deer mice fast asleep in this box

Two deer mice fast asleep in this box

This box at Coverdale Farm Preserve contained a furry nest with no fewer than 15 uneaten hickory nuts, which was interesting as this is not a common tree at the Preserve. These had probably been stored in the box by a Flying Squirrel, a nocturnal mammal which does not hibernate and requires food all winter. The squirrel cached the nuts here to provide a food supply for later in the winter, so to be sure the little guy wouldn’t go hungry we left the nuts below the box.

Hickory nuts cached in this nest box by a flying squirrel

Hickory nuts cached in this nest box by a flying squirrel

So just because you never see anything going inside your nest boxes in winter, don’t assume they aren’t being used!

Ian Stewart, Ornithologist

Many visitors to Ashland Nature Center have been enjoying our newest attraction – a bird blind! The bird blind overlooks a cluster of bird feeders along Wildflower Brook and is the perfect place to view birds and other wildlife up close.

These excited campers look out from inside the bird blind. The blind was conceived by Joe Sebastiani and built by our ‘Dream Team’. Photo by Joe Sebastiani

These excited campers look out from inside the bird blind. The blind was conceived by Joe Sebastiani and built by our ‘Dream Team’. Photo by Joe Sebastiani

As long as you sit quietly you can watch dozens of birds come to the feeders, bathe in the brook, or just hang out in the trees nearby, and since they are so close you don’t even need binoculars. This makes blinds an excellent way to get children interested in nature since even youngsters can enjoy watching the birds going back and forth. Having said that, just a basic pair of binoculars lets you see a lot more details of the different birds like their beak shapes and feather colors so try borrowing a pair from the visitor center if you don’t have your own. Blinds are also excellent opportunities for photographers as the nearness of the birds means you don’t need an expensive camera with a super-zoom lens – all you need is patience! If you’re lucky you may also see a Red Squirrel visiting from the nearby hemlocks or perhaps a cute little Eastern Chipmunk, both of which are uncommon mammals in the Piedmont. Imagine how memorable it would be this winter to watch a Red Squirrel searching for food in the snow while you’re sheltered inside the blind!

A Purple Finch occupies every port of this popular feeder! Photo by Hank Davis

A Purple Finch occupies every port of this popular feeder!
Photo by Hank Davis

The blind looks out over several types of feeders stocked with different seed mixes and suet cakes which each attract different species of birds. This variety adds a fascinating insight into how different birds feed – some birds like House Finches and Goldfinches perch happily at the feeders and chomp away until they are done while others like Chickadees and Tufted Titmice zoom in and grab one seed before carrying it away to a nearby tree and hammering it open. Woodpeckers and Nuthatches have a remarkable ability to hang upside down on suet cake cages and peck away at the contents while bigger birds like Blue Jays can’t perch very well and prefer to grab whole nuts from table-top feeders.

This Carolina Chickadee feeds on a hanging-dish type feeder. Check out its leg – it’s banded! Photo by Hank Davis

This Carolina Chickadee feeds on a hanging-dish type feeder. Check out its leg – it’s banded!
Photo by Hank Davis

Visiting Ashland’s bird blind will inspire you to buy your own bird feeder or give one to somebody else (they make great Christmas presents for anyone regardless of where they live in the city or countryside). Just hang them from a tree or pole at least a meter from a window (to minimize window strikes) and see which birds you attract. It is probably best to fill them with black oil sunflower seeds since this will attract many birds although some species prefer millet or nyger (thistle). Wild Birds Unlimited in Hockessin is a great local specialty store for bird food and feeders though most supermarkets also sell seed and suet cakes.

This male Downy Woodpecker is hammering away on a suet cake! Photo by Hank Davis

This male Downy Woodpecker is hammering away on a suet cake! Photo by Hank Davis

For me, watching birds at feeders is both entertaining and soothing and a bird blind stocked with several feeders is the sum of human happiness, as well as a relaxing way to connect people of all ages with nature. Next time you have a free hour or so come and hang out at the Ashland bird blind and see what I mean!