Monday, December 17, 2018

Redhead Ducks

An aptly named Redhead Duck drake (male) on an inland lake in Alexandria, VA.

     Redhead Ducks (Aythya americana) are medium-sized (18"-22") diving ducks which visit the mid-Atlantic region in winter. Weighing between 1.5-3lbs, these are considered bay ducks, or pochards in some parts of the world, members of the duck tribe called Aythyini. We have 5 species of bay or freshwater diving ducks locally that are all winter visitors (Redheads, Canvasback, Ring-necked Ducks, and both Greater and Lesser Scaup), though there are some 16 species globally. Though often just called divers, pochards around the world (2 different Genera worldwide) share some similar traits. First of all, most do not inhabit oceans and swim using only their feet (which like other diving birds are placed well back on their bodies). Sea ducks use their wings as well as their feet when swimming. Most male bay ducks also have similar plumage patterns of dark patches with light colors, bright colored eyes, and very similar voices due to having the same voice box apparatus (called fenestrated bullae). They all share a common ancestor.
     Redheads are aptly named, the drakes (males) having a bright red head, along with a bluish bill with a black tip, and a black bib. The females are much drabber. They are sometimes confused with their slightly larger cousins the Canvasbacks, but they have a much more rounded foreheads. Like all members of the Genus Aythya, none have the metallic colorful wing feathers referred to as a speculum and have their feet (much more webbed than many other ducks) placed well back on their bodies. This makes them superb divers, but awkward on land. Like other diving ducks, Redheads need to run or patter along the water's surface before they can take off.

A partial raft of Redhead drakes and hens near Dyke's Marsh on the Potomac River.

     While considered diving ducks, they often do not dive very deeply and sometimes just dabble or feed on the surface like Mallards and other "puddle or dabbling" ducks. Aquatic vegetation makes up a good portion of their diets, but they will also feed on animal matter such as mollusks and crustaceans. This is especially true during their breeding season when they consume the most animal protein.

Aquatic vegetation, particularly in winter, makes up a good portion of a Redhead diet.

     Like other diving ducks, these do not normally nest around the DC region. The vast majority of them nest in the northern prairie pothole and Great Lakes regions. More of them nest within the U.S. as opposed to Canada than all the other diving ducks. They choose treeless wetlands with lots of emergent vegetation.
     Redhead nests are basket-like and lined with down. They are usually anchored to the surrounding vegetation. The hens lay between 9-13 pale buff eggs which take between 24-28 days to incubate. The drakes leave after incubation starts, hanging out in small bachelor groups where they molt and are flightless for a period of time. The young ducklings fledge from 56-73 days later, but the mother hen often leaves them before the young can fly, sometimes 2-4 weeks prior to obtaining flight.
     Redheads are well known for brood parasitism. This is an unusual reproductive practice where hens dump their eggs into other birds nests. While other ducks may do this, none to the extent of Redheads. These are usually other Redhead nests, but up to 10 other duck species have been documented as serving host to Redhead egg dumping. They've even been known to lay their eggs in such completely different birds such as American Bitterns and even raptors such as Northern Harriers (Marsh Hawks)! Now this is not always a successful strategy, and those who lay their eggs into nests that are not even ducks rarely survive. In some locales 50% of the eggs are dumped, often by young females who may not even build their own nests. That these ducks nest so close to each other facilitates this behavior as well.
     Redheads who dump into other Redhead nests have the best chance, and some of them don't dump eggs at all or dump only part of their brood. But those that dump into other duck nests may only have 30% success rate if at all. One abandoned nest had 87 eggs in it. The favorite host to dump their eggs into other than another Redhead are their close cousins the Canvasbacks. Perhaps partially due to the chance of being raised in a foster nest, Redheads may hybridize with other ducks, especially other divers like Ring-necks and scaup. If they hybridize with Canvasbacks, the young are actually fertile and can mate as well.
     We see Redheads during their migration. They spend the winter in the interior parts of the country more so than any other diving duck, though they can range as far south as Guatemala and the Caribbean. While we get some in our area, 80% of all Redheads winter in the Laguna Madre region of Texas and Mexico, where  winter flocks of hundreds are the norm. In our region, they tend to be mixed flocks with other ducks, especially other diving ducks, sometimes in small numbers and sometimes in very large rafts.

A Redhead swims away from a Canada Goose intent on stealing the food it just brought up during a dive.

     Populations of Redheads overall have been relatively steady since 1955, though these are well below historical levels. Population numbers tend to be over a million birds, making up about 2% of the duck numbers in North America. However some areas have had greater declines than others. The worst regional declines seem to be an 87% decline in the Great Basin region, and even worse a 99% decline in Idaho, but overall the populations seem to have been steady and readjusted to other areas.
     These declines are usually considered to be due to habitat loss and changes such as droughts. Hunting pressure on them is relatively low, as they make up less than 1% of harvested ducks. This despite their widespread nature and their mild taste (due to vegetable matter making up such a large portion of their diet). This is also surprising as they decoy very well, earning a nick name in some places as Fool Ducks, being easily tricked into hunting range. But game laws and conservation practices seem to make hunting losses negligible to the overall population.

A Redhead Duck drake preens its feathers among some of its Ring-necked duck cousins.

     In our area, look for Redheads mixed in with other ducks in large open waters. I seem to bump into good numbers mixed in with Scaup ducks along the shallow stretches of the Potomac. They may reach the age of 12 years or so, and the accepted record so far from a banded bird is 22 years. So when you're near open freshwater (though again they can tolerate salty bays and such as well) keep an eye out for large rafts of diving ducks. If you search those groups, you may be rewarded with seeing Redheads among their numbers before they head back to their normal breeding grounds in the late spring. I'll leave you with a short video clip from the Capital Naturalist YouTube Channel of a Redhead drake that showed up in Kingstowne Lake in Alexandria:

Monday, November 26, 2018

Great Pondhawk

A Great Pondhawk, photographed and posted to the Arlington Bioblitz and iNaturalist by David Howell.

      Bioblitzes are always neat ways for people to contribute to citizen science efforts. The second one ever conducted in Arlington Virginia was scheduled for September 15th as a much smaller scale effort to document the natural history of Glencarlyn Park on that particular day. The results were quite encouraging and help not just add to the biotic inventory of the County and park, but help staff know a bit more about their efforts at natural resource management, add data for the upcoming revision of the natural resource management pan for the County, and help people realize just how wonderful the natural treasures in Arlington, as developed as it is, can be. A brief summary of the event is available here:
while information on bioblitzes in general can be found here:    
     As the information as posted is crowd sourced and open for people to help identify and confirm observations, it can sometimes take a while to get all the results back. While bioblitzes always provide good information and data, this last one provided a bit more of a last surprise. After one of the photo observations made by David Howell which he posted on iNaturalist started making the rounds, several people noticed what they thought was something quite interesting. The photo was sent to several experts and dragonfly discussion groups and the consensus was that what had been photographed was a Great Pondhawk Dragonfly (Erythemis vesiculosa).
     This appears to be a new state record for this mostly tropical dragonfly. While it is a very large and powerful flying dragonfly, it rarely strays North of Florida in the East, with the only previous record I could find of the next northernmost record being of one being near Savanah, Georgia back on September 18th of 2013 (interestingly 3 days and 4 years earlier). In fact, while it's been known to go as far north as Kansas in the West, it is never common anywhere in the USA.
     The Great Pondhawk, as its name suggests is a large and powerful dragonfly, often eating other large insects including other dragonflies. It is not uncommon in Mexico and has a range into South America as far as Argentina. It is such a strong flyer that it often ends up on Caribbean islands, even being featured on a few island's postage stamps. But it rarely strays north in the East, even in Florida.
     Some are theorizing that it was carried along with the strong storms over a week earlier and found a safe habitat in Arlington. Regardless, it adds to the knowledge and range of this species. It also shows that sharp eyed volunteers can add to the collective knowledge of our natural world, the value of events such as bioblitzes, and now adding a new species not only to Arlington County, but to Virginia as well. If you'd like to help citizen science and maybe make some interesting discoveries of your own, I encourage you to do so using, for example, the free iNaturalist application. Also, please join us for the next big biotic inventory event, the City Nature Challenge scheduled for April 26 - 29 of 2019. The DC Metro area has done well in this event in the past and we hope you can join our team to make next year's even better, while providing much needed observations and making your own discoveries of the natural world. For a wrap-up of last year's fun event, please check this out: 

Friday, October 12, 2018

Arlington BioBlitz Summary

     The second ever Arlington Bioblitz scheduled for September 15th of 2018 had always been planned as a smaller and more focused event than the first one conducted last May 20, 2017. It was planned to be done at one park rather than several and over a shorter period of time. But it became an even smaller event when predicted stormy weather ahead of the day caused several team leaders to reconsider and less people to sign up. However, 38 people divided in several teams did participate. You can read more about the lead up to the Arlington BioBlitz and why these bioblitzes are conducted here:
Part of the 2018 Arlington BioBlitz team.
     Luckily, the weather held for us, and these folks tallied 762 observations of 362 different species, representing some interesting biodiversity for Glencarlyn Park where all the activities took place. While some observations still need to be added and some identifications still need to be confirmed, we do have some initial numbers.
The Arlington BioBlitz herpetology team with a Northern Ring-necked Snake.
     An early morning bird watching team saw 26 bird species, including some migrating warblers such as both Tennessee and Chestnut-Sided Warblers. Botany teams recorded 166 different plant species. While only two amphibians and 4 reptiles were seen, one was of a Ring-necked Snake under a snake board placed out there as habitat and to make surveys for wildlife easier. This snake is fairly uncommon in Arlington and had not been recorded in Glencarlyn before, so was a very good find.
Northern Ring-necked Snake found under a snakeboard in Glencarlyn Park
     Seventy-six insects species along with a dozen arachnids were also noted. These included two unusual butterflies for Arlington, the Fiery and the Ocola Skippers, which only are seen late in the season when they move through as they cannot survive our winters. The Ocola was a first for our Arlington County records.
Ocala Skipper on Pickerelweed taken by David Howell during the 2018 Arlington County BioBlitz

     Another insect, the Mile-a-Minute Weevil, is a recently introduced beetle that was released in an effort to manage numbers of the terribly invasive Mile-a-Minute Vine. It wasn't even an option to pick from in the iNaturalist application used to record and crowd source identifications, though after we pointed this out, it has since been added. Several years ago, Fairfax County had gotten approval for its release as a test biological control. When some showed up in Arlington, we purposely did not treat the Mile-a-Minute Vine where it was seen to let it get established. That seems to have worked quite well and we are finding it now wherever the invasive host plant is found.
Mile-a-Minute Weevil on Mile-a-Minute found during the Arlington BioBlitz.
   The mycology team of fungi hunters had a very successful search, finding more than twice as many mushroom species as the previous year, likely due to all the wet weather leading up the BioBlitz. They tallied 66 species. This along with last year's results will be used by them as the baseline for a "Fungi of Arlington/Alexandria" project they've been working on. For an interesting look at how they conducted their search, please check out this short video:

A Beefsteak Mushroom, oozing in its classic way that helps identify it.
The strange looking Dog-nose Asphalt Fungi, another Arlington first.
      All in all, a fun and hands-on way to collect a survey of the natural world. While it's only a snap shot in time, by doing enough of these snapshots using the observations of citizen scientists, we get a better picture of the natural world for that location. This is just one method of getting biotic inventory to get a better idea of what animals and plants live in Arlington. Knowing what we have of course is necessary for us to better manage what we have left of the natural world, as well allowing us to compare if what we're doing is working. This is all leading up to the next update of Arlington's Natural Resources Management Plan which will hopefully take place over the next year or more. If you'd like to contribute observations, please try the iNaturalist app at  and if you'd like to see more results for the Arlington Bioblitz, search under Projects for the 2018 Arlington County BioBlitz.
The BioBlitz Mycology (Fungi) team discusses a discovery.

Thursday, September 13, 2018

Arlington Bioblitz 2018

Part of the 92 people who participated in Arlington's first Bioblitz in 2017, which tallied 1245 observations of 468 different species, including this Giant Puffball Fungus
      A bioblitz is a quick, but intense, biotic survey completed within a 24 hour period. Consider it a snap shot in time of what plants and wildlife are found in a certain place during that period of time. While this is certainly not a complete record of what lives there, it provides a vital look at what is there during that period. If you get enough snap shots, then you can get a clear picture of what’s there.
     The Arlington Bioblitz is part of a much larger and longer survey of what we have in Arlington. Over at least a two year period, the results of this and even more surveys will help us know what we have, and compare it to what we have recorded before or what was historically present. This information will help shape the new update of the County’s Natural Resource Management Plan. You can’t manage and preserve what you don’t know you have, so this info is vital. You can see the previous County Board approved plan here:  If you’d like to see the technical report (granted also in need of updating using new survey information) that resulted from our previous county biotic surveys, please check here:
     The Arlington Bioblitz will kick off many more surveys where we will check on previous records and see how those plants and animals are doing (and get an idea of how our Natural Resources Management Plan has done). But we may also find new flora and fauna that can influence what the new Natural Resources Management Plan update will include. Some of this will be done by County staff, some by contracted experts, and much more with the aid of volunteers and citizen scientists.
     This is where the general public such as you comes in. We hope you can join us that day (and stick around to help with the surveys that follow) to record what you see. Join a Bioblitz survey team. Perhaps you have an expertise and can help lead a team. Perhaps you can help be an extra pair of eyes or help record what is seen. We plan to use the iNaturalist application to collect most of the data. This where regular folks along with experts can record sightings, often using a photograph that can serve as a voucher of what was seen and which can be verified by others. More on this neat process here: with a tutorial found here: 
     Please not that we will have our headquarters at Glencarlyn Park Picnic Pavilion #1 ( 401 South Harrison St, Arlington VA 22204) and will restrict our observations to that park. A project for this Bioblitz has been setup in iNaturalist, which will be our primary recording tool.
     Want to lead a team or get even more info? Check out the County web page:  or contact Arlington County Parks Natural Resources Manager Alonso Abugattas at either or by phone at 703-2287742. Participating in a bioblitz is not only a lot of fun, but provides some valuable citizen science. To join a team sign up here: Recording these nature discoveries helps us know what we have and how we can better protect them. But it is also a great hands-on way to learn from experts and one another, all in a social and informative manner.

Tuesday, May 8, 2018

City Nature Challenge 2018

         A friendly global challenge was issued this year: Which cities could engage the most people to record the most observations of wildlife and plants, and find the most species over 4 days, April 27-30? There were 68 cities worldwide who answered the call. These cities tallied 441,888 observations by 17,329 people. Of these, 63 cities used iNaturalist resulting in 423,845 observations of 18,116 species by 16,544 people.
        The free iNaturalist app is now the standard way for bioblitzes and other citizen science (the involvement of the general public in scientific research and data collection) projects to record information. The beauty of the app is that with a simple uploaded photo, crowd sourcing can then help identify the organism and the observation is recorded so that worldwide any researchers can data mine the info they need. You never know what piece of data you could be providing some researcher somewhere in the world. You don't even need to know what you're reporting (though the iNaturalist app has a neat suggested identification feature to provide likely ID possibilities) due to the crowd sourcing that allows other perhaps more knowledgeable people to provide their ID skills.

Two of the groups I led found cyanide producing Xystodesmid millipedes, Apheloria virginiensis
The DC Metro Area did very well indeed in this global event:
            Its 22,809 observations was 5th place overall, behind San Francisco which started the competition 3 years ago (41,737 observations), Dallas/Fort Worth (34,218 observations), San Diego (33,448 observations), and Klang Valley/Greater Kuala Lumpur (25,287 observations). Just behind DC were Houston followed by New York. Coming in last was Palmer Station Antarctica which understandably only had 36 observations (but 27 species with only 3 people in Antarctica of all places!), just behind Buenos Aires (170 observations of 96 species with 18 people) and El Salvador with 220 observations of 52 species using only 6 people. Globally 124 new species were added to the iNaturalist data base that had not been present before, with Hong Kong providing 57 of them.
            As far as participation, the DC region again did wonderfully! It came in 4th place overall with 876 participants  who made observations. This was behind San Francisco (1,532 observers), San Diego County (1211 observers), Boston (992 observers), and just ahead of Los Angeles (which also started the competition 3 years ago with San Francisco, with 855 observers). With over 40 planned DC regional events over the competition period, it turned out those group events really paid off.
            The DC Metro Area also did remarkably well with its species count, considering some tropical places have much more biodiversity. The DC Metro Area came in 8th overall with 1,855 species observed.

Among one of neat findings was this Southern Adder's Tongue Fern at Huntley Meadows Park
            Arlington had a good showing overall as well for the DC region it was included in. Of the over 40 DC Metro Area planned events, Arlington led or had a leading partner role in 25 of them. Within Arlington County itself, 134 observers tallied 3,957 observations and identified 644 species. The top observed species for Arlington were the American Robin (reported 46 times) and Virginia Creeper (reported 46 times). Some unusual sightings will need to be investigated and verified as they might prove to be very interesting. While some are positive, the observations of potential new invasive plants are also important to know about, and a few were indeed reported. Overall, a very respectable showing and demonstration of Arlington’s commitment to citizen science.
            This City Nature Challenge proved to be a fun and friendly competition that did show that the DC area has great diversity and interest in citizen science. While it will take a while to digest what these nature observations will add up to as far as research contributions, the overall interest and caring of the environmental community was front stage on a worldwide scale. This event was also a great dry run and warm up for Arlington’s BioBlitz scheduled for Saturday, September 15th, 2018. Hoping it can be great event with lots of participation and observations as well. So mark your calendars now so you can participate! As for next year's City Nature Challenge, we will hopefully learn more about that date soon so we can gear up and do even better next time around!
            On a personal note, the Capital Naturalist was proud to be a City Nature Challenge partner and to have led multiple events in the DC Metro Area. I’m even prouder to have had a good showing overall, with my 533 observations putting me in 5th place on the DC area leaderboard overall, and my 282 species identified placing me in first place in that category for the region. better yet, it allowed me ample opportunities to be outdoors with like-minded people having fun making nature discoveries. What's not to like about that? So here's to citizen science, future bioblitzes, City Nature Challenges, and all the other ways to make fun nature discoveries in our wonderfully diverse region!

The City Nature Challenge DC Leaderboard

Monday, February 26, 2018

National Invasive Species Awareness Week

    Please note the beginning of National Invasive Species Awareness Week (February 28 - March 4). Invasive species are non-native organisms that, often because they're free from natural controls they had in their native lands, cause ecological, economic or human harm in the new lands they've been introduced into. They often have several traits in common besides freedom from their original natural controls. They often for example reproduce very quickly and out compete native fauna and flora. Though some, such as many exotic invasive plants introduced for the horticultural trade, may look harmless, they can cause great harm. The National Wildlife Federation estimates that 42% of threatened and endangered species are at risk due to invasives. 
     Arlington County, like all our region's jurisdictions, recognizes these threats. In fact, page 21 of the Arlington County Board approved Natural Resources Management Plan has this statement: "Invasive plant species represent the greatest and most immediate threat to the continued survival of Arlington's natural lands and native plant communities." Arlington, like so many neighboring jurisdictions, has committed many resources and efforts to manage invasives. 

     Again like many jurisdictions, Arlington has an Invasive Plant program as part of our Natural Resources Management Unit. It has a dedicated budget and a rolling 10-year invasives management plan based on ecological priorities and citizen interest to maximize our limited resources. You can find out more about it here:
     Arlington's program uses mechanical, biological, chemical, and cultural methods to manage invasives. In addition to staff and contractual services, the County also depends heavily on volunteers to help. Called RiP (Remove Invasive Plants), the volunteer program has weekly events and dedicated, trained volunteers. We invite you to participate (through the link above) and also note that a great many other jurisdictions have similar programs, including many that call themselves Weed Warriors. 
     Many environmental groups also have their own programs they use to cooperate with local governments. One such program was launched by the TreeStewards and Arlington Regional Master Naturalists. It focuses on calling attention to the problems English Ivy causes. You can check out the "Choking Hazard" brochure here:

     There are also several regional efforts and resources available. One such resource is the Mid-Atlantic Invasive Plant Council (MAIPC) in which Arlington staff serves as the Virginia state representative. You can find out more about it here: and you can check out the excellent invasive plant lists they've developed here:
     Much more locally is the newly formed NoVA PRISM (Partnership for Regional Invasive Species Management). Arlington applied for and was awarded a matching $140,000 grant to form this multi jurisdictional partnership. Arlington hired and housed the coordinator and oversaw the grant. It includes not just governmental partners but also groups and businesses, such as master naturalists, Earth Sangha and Dominion Energy. It is centered along the whole 45 miles of the W&OD Trail. The grant aims to map habitats and come up with an invasives management plan for the trail. It featured multiple pilot projects to create meadows in Arlington and Falls Church and to foster cooperation between all the partners.
     Arlington is also on the steering committee for the newly forming NCR-PRISM (National Capital Region Partnership for Regional Invasive Species Management). This is the expansion of the existing DC Cooperative Weed Management Area to include more of the region and to expand its efforts beyond just invasive plants. It will focus its efforts on a new program sponsored by the Department of Interior's National Invasive Species Council (NISC) called  "Invader Detectives." Arlington staff was also involved with assisting in developing this program which will hopefully later on go nation wide if successful in the DC area. It will feature citizen scientists looking for potential new invasives of all types on watch lists so the principles of Early Detection, Rapid Response can be tried.
     To throw yet more terminology out there, EDRR (Early Detection, Rapid Response) is the principle that the best way to deal with exotic invasive species is to do so when they're detected early enough that they do not have a firm foot hold yet. Eliminating invasive species while they have not yet gotten established is the most cost effective way as the population is small and the odds of success in keeping the problem from spreading is best.
     This can really work. Here's an example. Arlington County has the dubious distinction of being the first location in Virginia for a potential new invasive shrub, Castor Aralia (Kalopanax septemlobus) in June of 2012. We however quickly eliminated it before it spread and got established (it had been in a 15' colony). We were lucky it had not spread more where control efforts could have been much more costly and the ecological damage done much worse. More on Arlington County's EDRR program can be seen here:

EDRR target species Castor Aralia. Photo taken just after a voucher specimen was collected and the colony was eradicated from an Arlington County Park. 
     Hopefully this blog article has helped to make you more aware of invasive species and the local efforts to manage them. As you can see there are lots of ways to get involved and get better informed. To find out even more about National Invasive Species Awareness Week, webinars and events check out the website:

Monday, February 12, 2018

Winter Stoneflies

     Most insects, being ectothermic or not being able to regulate their body temperatures internally, are not commonly seen in winter. However, being active in winter can certainly have its advantages. For one thing, there are much fewer predators about with most birds having migrated to warmer climes to search for invertebrate prey and most bats also not being active. Any insects having evolved to come out in the cold of winter would have less predators and competition. So it should come as no surprise that a few insects have indeed evolved to to take advantage of the situation.
     One such group of insects are the Winter Stoneflies. Winter Stoneflies are insects in the Order Plecoptera (from the Greek for "twisted or braided wing" due to a twisted region of their hind wings). The Winter Stoneflies are made up of two families within that larger group: Taeniopterygidae (sometimes called Willowflies) and Capniidae (also called Small Winter Stoneflies or Snowflies). Taeniopterygidae consists of 35 species in 6 Genera in North America while Capniidae are one of the largest families of Stoneflies with 60 species in 10 Genera being found in North America though over 300 worldwide. In my experience however most of the ones I encounter in the DC area seem to me to be Taenopterygiidae in the Genus Taeniopteryx. 
     Stoneflies are not actually flies but in their own order of Plecoptera as already stated. True flies have only two wings and thus their Order is called Diptera meaning two-wings. Stoneflies have 4 wings. While many other insects are also called flies it should be pointed out that when used properly in a common name, when the word fly is attached to the first word it is not a true fly. So dragonflies, damselflies, butterflies, caddisflies and stoneflies are not true flies. When the common name consists of two words then they can properly be called true flies when they have the 2 wings that all Diptera posses such as house flies, bee flies, fruit flies and crane flies. 
     Stoneflies in general are poor fliers and Winter Stoneflies are no different.They tend to stay down low where they also can find cover and warmer temperatures. They also are mostly very dark in color likely to help them absorb whatever heat there is. While most Stoneflies are nocturnal Winter Stoneflies are just the opposite and are most active on warm sunny days.Their greatest adaptations to cold however are the myriad of glycols, glycerols, proteins and sugars they posses which act as a sort of antifreeze within their bodies. 
     Stoneflies are associated with water. While adults like sitting on rocks and stones, giving them their common name, the young are completely aquatic (at least all those in North America) and are called nymphs. Stonefly nymphs are flat with what look like two tails (called cerci) and tufted gills near the base of their legs. They stay on the bottom and like to hide under and among rocks. 

a Stonefly nymph , note the two "tails"

     Stonefly nymphs in general like cool clean well-oxygenated water. Most do not tolerate pollution. They are thus considered good bio indicators of clean water. Those folks who have conducted macro invertebrate stream monitoring may may well be familiar with EPT. E= Ephemeroptera (Mayflies) P= Plecoptera (Stoneflies) and T=Trichoptera (Caddisflies). As all these macro invertebrate organisms are intolerant of polluted water their presence is a good bioindicator of clean water.  Stoneflies are among these indicator species looked for in stream surveys. Of course sensitivity makes them vulnerable as well and the Xerces Society lists at least 3 winter Stoneflies as seriously imperiled in localized areas in Idaho and Colorado. 
     Stonefly nymphs depending on the species can take from 6 months to 3 years to mature into terrestrial adults. Most only grow during colder months going into a dormant non -growing state called diapause during the the hot summer months. Although some Winter Stonefly nymph species are predatory on other aquatic insects such as mayflies, most feed on plant material and detritus, the typical 'shredders' and detritivores of fallen leaves in streams and rivers. Once the nymphs make their final molt into terrestrial adults, many species do not feed at all though some, especially Capniidae feed on blue green alga or lichen.
     Adult Winter Stoneflies for the most part have an interesting way to find mates. They drum their abdomens against surfaces. Males start the drumming, each species with its own beat and preferred locations and drumming surfaces until females like their beat and drum back. They drum to each other until they find the one with just the right beat. After mating, females deposit their eggs, up to a thousand per female, into the water to start the cycle all over again.
     Adult Winter Stoneflies can emerge in large numbers, often called a hatch. Though there are fewer predators around, these large hatches can also overwhelm those that are around, flooding the habitat and ensuring that not all can be eaten. This brief abundance of food though can also be a real boon for predators. I recall one winter watching a phoebe that had not migrated engorging itself when it suddenly found itself in a large hatch by the Potomac. I had wondered if it was going to make it through that winter but the huge influx of food seems to have been a life saver.
     Fishermen also know that large WInter Stonefly hatches are one of the things that can bring listless fish such as trout back into a feeding frenzy. As one of the first foods available to them in large numbers, many fly fishermen try to "match the hatch" in their best imitations of the floating insects. Around the country some dry fly ties (imitation floating feather and hair lures in such small sizes as 16- 20 size hooks so light they actually float on the surface) are tied to match the prevalent species "Hatching" that day. Some of these imitation "dry flies" have such names as Montana Stone Yellow, LIttle Black Stone, Skwala, and Yellow Sally. For fishermen who are dying of cabin fever this maybe the first hopeful sign that the spring fishing season is almost arriving. To me that maybe true as well, but I also just enjoy seeing a winter insect out and about in an otherwise often dreary season. Since they like to land on our warm bodies, they make their presence easily felt. So take a walk along a waterway on a relatively warm day and see if you can find some hopeful insect sign on a dreary day as well. 
A Winter Stonefly lands on my hand by the Potomac