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:  https://projects.arlingtonva.us/natural-resources-management-plan/  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: https://projects.arlingtonva.us/wildlife-arlington/
     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: http://www.inaturalist.org/ with a tutorial found here: https://www.youtube.com/watch?v=KGj8gGGxs68&feature=youtu.be 
     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:
 https://environment.arlingtonva.us/events/arlington-bioblitz/  or contact Arlington County Parks Natural Resources Manager Alonso Abugattas at either AAbugattas@arlingtonva.us 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: https://www.signupgenius.com/go/60B0B4FA8AB22A31-20181 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 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


    Today marks the beginning of National Invasive Species Awareness Week (February 26 - March 2). 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, 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 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 them here: http://www.maipc.org/ 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 houses the coordinator and oversees 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 will feature four pilot projects to create meadows in Arlington, Falls Church, Reston and Loudoun and foster cooperation between all the partners.
     Arlington is also involved in 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 10' colony) and we have not seen it again since. 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:
     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: https://www.nisaw.org/.

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

Friday, December 29, 2017

Juncos - Snowbirds

Dark-eyed Junco

     Juncos are common winter visitors throughout much of the USA. These woodland sparrows are quite variable in appearance, especially out West and by region, where some 15 different subspecies and races are recognized. Formerly many of these were recognized as different species, but now they've mostly been lumped together in the East to one species. What were sometimes called Northern, Eastern, or Slate-colored Juncos now are all called Dark-eyed Juncos (Junco hyemalis). 
     While living most of the year in forested portions of Canada and at higher elevations, they migrate over to become our winter residents. This winter time appearance has given them another common name: Snowbirds.


An aptly named Snowbird.

     Once they do arrive though, they're all over. Project Feeder Watch has listed them as the most commonly reported winter bird. They're considered among the most abundant forest birds, with a population estimate of 630 million. Juncos are commonly found in mixed flocks (often accompanying white-throated sparrows and bluebirds in particular) of 10-30 birds. Where the different ranges overlap, several subspecies of different juncos may flock together for the winter. There are definite hierarchical orders to juncos which play out when they're feeding, with those juncos who arrive earlier to a winter territory ranking higher than later arrivals. By the way, there are several accepted names for a flock of sparrows such as juncos. These include calling them a crew, a flutter, meinie, quarrel, or (my favorite) a ubiquity of sparrows/juncos. Be aware though, that few actual birdwatchers use any of these terms, simply referring to them to them as a flock. 


A Junco and White-throated Sparrow feed together.

     While somewhat variable in appearance, juncos tend to be gray and dark along their top half and light colored below, with pale beaks. Their most distinguishing feature though is the flashing of their white tail feathers as they pump them when they fly. The flashing is supposed to serve as both a warning device to fellow juncos and as distraction to any predators following them.
     Some dark-eyed juncos do not migrate at all, including some in the Appalachian mountains. These year-round resident birds, like many non-migratory birds, have shorter wings than the ones who fly so far away for the winter. Of those who do migrate, males tend to stay farther North, and the same individuals tend to go to the same wintering grounds each year. 
     Juncos feed in typical sparrow fashion: hopping along, pecking and scratching for food. They're mostly ground feeders, with 75% of their year-round diet made up of seeds. They're not too picky about the seed types, eating chickweed, sorrel, and lambs-quarters for example. At bird feeders, they usually go for the spilled seed on the ground, preferring millet over larger sunflower. They eat most of their insect food during the breeding season. In fact, like many other primarily seed-eating birds, they feed their own young almost exclusively an insect diet. Interestingly, the insect food at first when given to their young tends to be regurgitated prey. 
This short video shows juncos feeding:

Another Dark-eyed Junco, showing some of the variability typical of juncos. 

     Once they're back at their breeding grounds, males get very territorial in defending their woodland homes. Females pair up with them, preferring the ones with the flashiest white tails. Nests are normally built on the ground and are well concealed. They tend to be covered over, but can be very variable in appearance. The female incubates the eggs, though both parents feed the 1-2 (rarely 3) broods of young the high protein insect diet they crave. Three to five whitish eggs (with dark smudges on the larger end) are laid, with later nesting attempts having fewer eggs. After 11-13 days, the eggs hatch. The young develop quickly, and though they do not usually fledge and leave the nest until 9-13 days later, can in an emergency run very quickly to escape danger. If all goes well, they may live 3-6 years, though the record  is one that was 11 years and 4 months old that was noted in 2001.
     I enjoy the antics of these snowbirds. The flocks are very active and noticeable while they're foraging. They add a lot of liveliness to what can sometimes be a very drab landscape in winter. 


Thursday, December 21, 2017

Crows - Of Mobbing and Murder


     We have two species of crows in the DC area: the common American Crow (Corvus brachyrynchus) and the slightly smaller Fish Crow (Corvus ossifragus), which is usually associated with water. The two are tough to differentiate (apart from the nasal like calls of the Fish Crow) and often flock together. Fish Crows have been expanding their range inland along waterways. American Crows are the largest of the true crows in North America at 16-20 inches, compared to the 14-16 inch Fish Crows. The rest of this article will be about American Crows, though much is also true of Fish Crows.
     All crows (called corvids because they're in the Corvidae family, the crows, ravens, magpies and jays) are considered among the smartest of birds, with good reason. American Crows are incredibly adaptable creatures with some amazing natural history allowing them to thrive.
     First of all, crows will eat just about anything. While they prefer animal protein (they love worms for example), they will eat quite a bit of plant material as well. And they won't be fooled by such scare tactics as scarecrows or fake owls to keep them away, being much too smart for that. The lengths corvids will go to get food are legendary, with some types of crows worldwide using tools, stealing fish caught ice-fishing, cracking nuts under car tires, using water to soften hard foods, and such. But our own crows are also very adept at getting food. Here's a short video of crows taking advantage of red cedar fruits:



     While they love to eat meat, crow beaks are not always strong enough to make them great scavengers. But they will take advantage of road kill, letting the car tires help them to not only kill their food, but break the skin open to allow them access to the softer insides. Crows will also raid bird nests, eating both eggs and young. This is one of the reasons you see birds gang up and mob them all the time. As they sometimes target poultry, this does not always endear them to many farmers. 
     They will also eat young animals, though again, it isn't easy for crows to dispatch potential prey with their beaks. It sometimes takes some great effort and time for them to finally kill their food. They will occasionally cooperate in order to do so. I've seen several crows all ganging up on a young rat, pecking at it, chasing and cornering it among each other until it finally died. Crows will also raid pet bowls, scavenge garbage and go after baby turtles. They will sometimes follow the edges of forest fires to catch whatever the flames force out into the open. I've seen them patrolling the edges of vernal pools, intercepting frogs as they make their way to the ponds to lay eggs. When they have enough food, they may cache leftovers for later use. If they eat something indigestible such as feathers, fur or bone, these get coughed up in pellets similar to owls. 


Crows are curious, and that occasionally gets them into trouble. We had to untangle this one when it got tangled up in line. 

     Some people think that curiosity is a sign of intelligence. Well, crows certainly are curious, but their inquisitiveness is tempered by lots of caution. Still, they do go out of their way to check out novel developments. I think it humorous when I see a crow sitting next to a fake owl meant to scare it away, for instance. They love to investigate shiny objects as well it seems. We had some who would regularly walk through our Arlington County native plant nursery and pull most of the plant tags and labels out of the pots and discard them on the ground. Here's a short video of them doing just that: 



     American Crows will also make use of tools, a trait most other animals don't share. One example is of a captive crow who learned to use a shallow container as a cup to carry water over to its dish to moisten the dry mash it was fed. Another involves one that shaped a stick so it would fit into a fence post to pry food out. Others have learned to pick up mollusks and drop them from great heights to break them open. In another example, a captive crow would use a slinky toy as a head-scratcher. One learned to drop pine cones and other tree parts onto the heads of climbers getting too close to its nest. Some crows use another bird behavior called "anting" where they stir up an ants' nest and let the ants swarm them, or pick up individual ants in their beaks to preen their feathers. The belief is that the ants not only kill parasites on the birds, but by spraying formic acid also reduce the presence of pests on their bodies. In what may be a unique use of a "tool", a crow was famously photographed hitching a ride for a while on the back of a flying bald eagle. Crows are capable of learning and even teaching one another, as some examples below will show. Some crows have even learned to be mimics, including saying some words and copying voices. 
     Crows have a very complex communication system. They make many other sounds in addition to the common "caw", but the same "caw" can mean a variety of different things based on how quickly it is repeated, how many times it's made, and the context as well. Many people are most familiar with the 3 sharp caws given by sentry crows that are keeping watch over the flock. It also seems that each crow sounds different enough from one another that they can tell individuals apart. Crow calling is a favorite study subject among researchers studying animal communication due to its complexity. 
     Crows not only learn, but appear to have remarkable memories and can teach one other. One experiment showed that when researchers captured crows, once they returned to the area, the crows could recognize them and tell them apart from other people. They would harass the researchers and warn each other of their presence. They did this even 9 years later, and amazingly birds who had not been handled themselves learned to recognize the researchers and warn others years later. Hunters and farmers have even tried to accustom crows to their presence, carrying broom sticks as gun-props in the hopes that they would learn not to fear them. But the crows are able to tell the difference of when they are carrying a gun instead of broomsticks. Many hunters and farmers have tried to trick crows with fake-gun props, and the crows always seem to figure it out. It is little wonder that scarecrows, fake owls and other scare tactics are useless, even when changing their clothes or imparting motion. 


Crows love to bathe and will do so almost daily even in winter, frequently in large numbers.

     Mobbing is a common defensive behavior among birds, and crows use it quite often. This is when birds gang up and harass a potential predator. They may not actually strike their perceived enemy, but they don't let it rest or hunt, eventually causing it to leave the area. Crows may use this as a means to teach their young what predators to avoid as well. 
     I've used crows mobbing as an educational demonstration many times. My set-up is a bit more elaborate in order to trick them, if only briefly. I use a fake owl that I place out there as the predator (sometimes a large great horned owl puppet, sometimes a stuffed taxidermy mount). At its feet, I place a crow puppet, usually on its back with feet up in the air and wings spread in as dramatic a death-pose as I can achieve. I then hide nearby and use a mouth call along with a recording of crows mobbing. The first few are apprehensive when they appear, and I need to be well hidden or they quickly notice something is amiss. But as their numbers increase, so does their daring. It is sometimes like a scene from Alfred Hitchcock's "The Birds" movie, so many aggressively gather and scream bloody murder. But this is very short-lived. Soon they see through the ruse and leave. I can rarely get away with dong this in the same area more than a couple of times a year before they get wise that it's a trick.
     It appears that crows also learn how to be good parents. Crows normally are not sexually mature until after their second year, and many don't breed until their fourth year or even later. During the interim after they themselves leave the nest, most assist their parents in raising their younger siblings. Each year, the previous years' young assist in feeding and protecting the nest. In this way some think they learn the best ways of being successful as parents, and the extra helps helps more young crows survive. It is not uncommon for families of up to 15 crows covering 5 generations to all be present raising young.


A pair of crows

     So during the late winter and early spring, crows pair up, often with the previous year's same mate and often mating for life. While they have interesting courtship displays, (preening one another, males bowing and spreading their wings for the females, and showing off with diving and circling), this is not often seen. Once the pair has bonded, they tend to not have as many courtship displays anymore in the years that follow. 
     Once paired up, the pair builds a nest, preferring evergreens as a nest site when they're available. It is often hidden, with the normally noisy birds keeping quite quiet around the nest. From 3-9 (though 4-5 is most common) dull bluish green eggs are laid, incubated solely by the females, hatching about 18 days later. With lots of help from their older siblings, young leave the nest 3-5 weeks later. The young crows tend to have bluish eyes at first. crows only nest once a year, but after their first successful attempt, they tend to be fairly successful in raising young most years that follow. Being so smart and adaptable, they have been recorded as living over 16 years in the wild, and the record is of one that lived 59 years old in New York as a captive.
     While their extended families and clans form the basis of their flocks, and while they tend to use a set family territory, this can be quite variable. Crows living in urban areas have much smaller territories for instance. During the day, family members may leave and join larger flocks before coming back to join their families. While in the larger flocks, family members also don't seem to hang out together very much either.
     Crow behavior changes quite a bit in the winter though. Crows tend to join flocks more, particularly before dusk. These can be huge aggregations, some 2 million strong per roost have been recorded, though of course numbers are usually much smaller. Some historic roosts have also been around for over 100 years. There's safety in numbers. 


A murder of crows...

     There are quite a few generally accepted names for flocks of crows. The most popular is to call them a murder. But they're also sometimes called a congress, a cauldron, a muster, or a horde. These noisy (and sometimes messy) aggregations may be very unpopular near people, leading to some jurisdictions trying harassment tactics to discourage them in certain areas. Crows being as smart as they are, these are not always very successful, leading to more lethal means of controlling numbers and trying to break up roosts. Dynamite has even been used in the past.


Attempted murder of crows...

     Recently, crow numbers in some areas took a dramatic drop, with some surveys showing a 45% drop in their population numbers. West Nile Virus when it was accidentally introduced into our area took a huge toll on them. Crows are more susceptible to it than any other bird, with most infected birds not lasting even a week. But those that survived, due to their adaptability and intelligence, have made a huge come back. A 2014 survey estimated there were 27 million crows in North America. 
     Crows may not be every one's favorite bird, and indeed to some they're a nuisance or even a pest. but there's no denying their adaptability and intelligence. People may grudgingly admire these large, common birds. Around the world, corvids have been part of folklore and legend, be it the crows in Aesop's fables, or the mythical ravens in Norse mythology. I'll leave you with one tale of our own crows, a legend attributed to the Delaware tribe, the Lenni Lenape. Back in my stoyteller days, my version was part of a much longer creation story, but here are the elements at least regarding crows.  One of many versions, the story of the Rainbow Crow:
     It starts with a long, bitter and dark winter. The deep snow and darkness finally worried all the animals, who were tired of stumbling in the darkness and suffering from the cold. They all gathered to see what they could do about it. In the most common version of the tale, it is decided that a messenger should go to the great spirit and ask for help. The journey would be long and dangerous with the darkness and snows. As they were fearful of disturbing the spirits, and since only a very intelligent creature would be able to find the way, there were not a lot of volunteers. But the most beautiful of all birds, the Rainbow Crow, volunteered to speak on their behalf and ask for aid. Having one of the most elegant of voices, this was seen as fitting as well.
     After a perilous voyage, Rainbow Crow eloquently made his point, asking for help on behalf of all the animals, and providing a gift to the spirits of his song. The great spirit provided a magical gift called Tindeh (fire) for him to take back as a present for the animals, to provide light and warmth until the season changed. It was burning at the end of a stout branch for the beautiful messenger to carry.
     Rainbow Crow grabbed the fire stick by the end in his strong beak and returned to the people. Again, the journey was a long one. Soon the fire stick started to burn down to the end he was holding, yet he could not let go lest he lose this precious gift. So he ignored the heat and smoke and flew on. Soon the flames were scorching his beautiful feathers. He could not help but breathe in the fumes. When he arrived back at the animal village, his beautiful feathers had burned black, covered in soot and ash. When he tried to speak, his speech  was hoarse from the smoke, his eloquent voice forever gone. 
     All the other animals rejoiced for Rainbow Crow's sacrifice had provided them with a great gift providing light and warmth, All rejoiced that is except for Rainbow Crow, who had gone from the most beautiful of voice and feather to now being among the ugliest. But the great spirit appeared to him in a smoky vision. He reminded Rainbow Crow that his daring deed had saved the people, and he would always be remembered for his bravery and intelligence. He added that he also would not be hunted for food, for the smoke had made his flesh burnt and ill tasting, no one would want to eat crow (more on how this saying came to be in the comments below). Since his voice was also not attractive anymore, few would want to cage him for he had no song to offer rather than a hoarse "caw". But seeing that Rainbow Crow was still suffering, the spirit gave him another gift. His black feathers were not just dull black any longer, but under the right light would have a beautiful iridescence all their own. So it would ever be for the descendants of Rainbow Crow: always to be admired, if sometimes grudgingly, for all their remarkable abilities for those who take the time to look for them. 


Friday, October 27, 2017

Mangy Foxes

Red Fox with Sarcoptic Mange (wikimedia commons by Juan Lacruz)

     Several times a year the topic of mangy foxes comes up. Mostly this is by well-intentioned people who want to interfere. Since I end up explaining so often why that shouldn't be done, I decided to put together a blog article I can refer people to each time it happens. Of course, many people may not read all the way through all this information and there are others who just don't want to listen, but this is my attempt to let people know a few things about this. 
     First of all, let's make something clear: it is illegal to treat foxes with medication for mange. Period. This is true in most jurisdictions everywhere, including all of Virginia and Maryland. Here's the Virginia Code for example: 
29.-1-508.1 Use Of Drugs on Vertebrate Wildlife
A.   With out a written authorization from the Director or his designee, it is unlawful to administer any drug to any vertebrate wildlife, except in accordance with a permit issued under the provisions of this title or regulations adopted by the Board. This prohibition shall include, but not be limited to, drugs used for fertility control, disease prevention or treatment, immobilization, or growth stimulation. Nothing in this section shall prohibit the treatment of sick or injured wild animals by licensed veterinarians or permitted wildlife rehabilitators. This section shall not limit employees of agencies of the Commonwealth, the United States, or local animal control officers in the performance of their official duties related to public health, wildlife management, or wildlife removal. For the purposes of this section, the term "drug" means any chemical substance, other than food, that affects the structure or biological function of wild species.
B.   The Department may take possession and dispose of any vertebrate wildlife if it believes that drugs have been administered to such wildlife in violation of this section.
C.   Any person violating this section is guilty of a Class 2 misdemeanor. (2004, c. 171.)
     There are numerous good reasons for this law. Even assuming that the correct dose is known and administered (not giving a correct dose may of course result in additional issues and there may be possible side effects regardless), the most common drug used, Ivermectin, is not meant to be used for treating foxes. Any such use is outside its scope. Wildlife rehabbers have even had their licenses revoked for assisting in such illegal activities as helping others treat wildlife using this medication.
     The usual method it is administered is by hiding it inside the food that is offered to the fox. This then assumes the fox gets all the medication and that other creatures don't consume it. If they do, that may also cause additional problems. For instance, some dog breeds, such as collies, can be sickened and even die if they consume Ivermectin. Since it hasn't been tested and is therefore not approved for use on other wildlife, how it affects them is not always known. For example, it will also kill certain species of turtles. Now you may say that turtles don't eat such foods (and you'd be wrong), but also don't forget that the medication can get into the environment through fox feces and urine and perhaps into the water ways. Such are just some of the unintended consequences that are possible. 
     But there's lot more to this. For instance, sarcoptic mange (the most common form of mange, caused by a mite) is one of the only population controls for red foxes. Red foxes by the way, are not native to the DC area, having for the most part moved in to the region, with a small amount of English red fox thrown in from attempts to introduce them for hunting purposes. So they're not supposed to be here. Our native fox is the Grey Fox, which is now severely declined in our area, with some thinking this may also be partially to blame due to competition from the naturalized red fox. Here's more on red foxes from a previous Capital Naturalist Blog:  http://capitalnaturalist.blogspot.com/2016/02/red-foxes.html
     Sarcoptic mange affects red fox disproportionately from other creatures, including other canines. Grey Foxes for instance are much less likely to be affected, as are coyotes and dogs, though they can be, as can very rarely even humans. My own dog for instance was affected by mange, picked up from a mangy fox that was being attracted to my yard thanks to a neighbor unwisely feeding it, and then later I found out, also treating it with Ivermectin. By the way, feeding such creatures not only concentrates them and thus allows for easier disease transmission, but may cause them to lose their fear of man and lead to other confrontations or misunderstandings. By the way, red foxes who have had mange are also more likely to get it again, as the medication does not give immunity. It may just be postponing the inevitable.
     But let's say that a red fox is treated and the mange goes away (though perhaps just temporarily). By choosing to try and help this predator, you affect other wildlife. You affect the prey base and the other predators who now have to compete with a predator who isn't even supposed to be here in the first place and has been given an unfair advantage by being fed. Many of these other predators themselves are declining in numbers. The red fox eats their prey (and they eat more than just rodents) and may even prey on them as well. This can include hawks, owls, shrews, snakes, weasels, bobcats, and so many more. Since in many places we have very large populations (too many?) of red foxes already, their numbers can really impact native wildlife.
     This not only means ground nesting birds, but of course rodents and such small creatures as rabbits. When fox numbers decline, their numbers expand, feeding other small predators and helping these small creatures themselves. But red foxes also eat fruits and other plant matter as well, directly competing with herbivores and other omnivores. So its not just quail, waterfowl and other ground nesting birds, but also raccoons and possums among so many others. By choosing to help one charismatic nonnative predator like a red fox, you have countless effects on so many others.
     While it may help you feel good, in the end you did not do nature a favor by interfering. The difference you actually made is often a negative one to other native wildlife, even if the things affected are not as charismatic or as easily noticed. So nature can be cruel, but its more important to think about the native natural community rather than an abundant and charismatic individual. Letting nature take its course is a wiser thing for the ecology and other wildlife. Sorry to be a downer, but thinking of the larger implications and doing so in a balanced and non-emotional way is how we should make wildlife decisions. If nothing else, please follow the law, as it is in place for good reasons.