Raptors of Winter

by Becky Swearingin MN 
 
About the time I think that bird photography is over until the spring migrations, I find some new raptors that wish to be photographed.

I was in St. Louis during the last weekend of January at a dog show and since I was done at about 10 a.m. at the show I randomly chose a conservation area to visit.  The one I chose was Leach Memorial Conservation Area, just north of St. Louis outside of the town of the town of Elsberry. I explored a bit, looking at the river and the remains of the flooding, watching a Kestrel hunt and the waterfowl on the many ponds. After sitting and watching two Savannah Sparrows for a while I decided to go to a different conservation area as nothing seemed to be happening.  As I drove down the main road, this landed in front on me on the road.

Of course, what went through my mind was “What the heck, I think that’s an owl!” As I was watching and photographing this owl, I noticed a group of people down the road with scopes and binoculars watching something. Suddenly a second owl flew right by the group.  The one I was watching flew off the road and landed on a small tree nearby.



This owl is one of our winter visitors, a Short-Eared Owl. These smallish owls breed in the northern U.S. and Canada. They are fairly abundant and have populations throughout North and South America and Hawaii. Missouri is one of their winter territories. While they hunt day and night, I have found in the population in Dade County that they come out closer to dusk. These owls were active starting at about 3:15 giving me plenty of photographic opportunities.  There were three or four that hunted all around the people watching, often landing on small tree right be the road or flying next to the observers. I found the flight shots challenging, but got a couple.



After driving to some other areas in the conservation area I returned to watch the owls one more time. This one seemed to want its picture taken.



The first Saturday of February, I headed to one of my favorite prairies outside of Lockwood in Dade County. When I’ve been there in the late afternoon I have found that there are areas active with Harriers, Hawks, and Falcons. I was hoping to get a picture of another winter visitor, a Merlin. I found a likely spot by Pennsylvania Prairie and waited (and waited and waited) but nothing was happening. I decided to turn around to check out Niawathe Prairie only to discover that right behind my car on a fence post was this lovely Merlin.



I took several shots and crept closer, stopping to take pictures until I was right beside the Merlin on the road. It seemed to be as interested in me as I was in it.



The Merlin is another winter visitor to Missouri. This small raptor, like the Short-Eared Owl, breeds in the north (Canada) but spends its winters in southern states, including Missouri, and Central America. Not much larger than a Kestrel, these raptors are a bit stockier.  Their primary prey is songbirds which they catch in midair, a hunting technique I have yet to observe. One of the birds they like to prey on is one of our more common invasive bird species, the House Sparrow, because of this they are becoming more common in urban areas.*

Keep your eyes open for those “snowbirds” who come south for the winter.

Editor's note:
The attack on the House Sparrow (HOSP) is especially welcome for those of us who maintain bluebird boxes on trails.  Bluebirds were a threatened species with declining populations from 1920-1970.  In 1978 the North American Bluebird Society (NABS) was formed and with bluebird trails and nest boxes, bluebirds are coming back with our help.  HOSP are major threats to bluebird populations as seen in these graphic photographs.  They are one of the most wide spread species on the planet, well adapted to cities where they can be a major annoyance.

Birds of Winter

Eastern Towhee - REK

I have been sitting by the fireplace at night with my annual re-reading of Bernd Heinrich's Winter World.  In it he follows the course of the tiny Golden-crowned Kinglet in Maine, using its winter survival as an example to think about the survival of birds, reptiles and mammals in the frozen Northeastern US.  The kinglet is a winter migrant to Missouri although I haven't knowingly seen one. 

While Missouri doesn't have the prolonged extremes of Maine, the lessons up there can be applied to our species.  Short of buying the book (which I would highly recommend) you can take a crash course in winter bird survival at this Audubon site.

This is also a reminder that this is the weekend of the Great Backyard Bird Count, which ends February 12-15th.  Just click on this link for simple steps to report what you see in your yard or hike.  You don't have to be a "birder."  As evidence,  we have done this for several years by watching our feeders on the deck for a few minutes.  It is fun and the data will go into a huge database which helps determine the overall health of bird populations across the US.

Carnivore Attacks

Noppadol Paothong - MDC

A recent study of carnivore attacks on humans is worth reading.  It focuses on attacks by brown and black bears, coyotes and cougars. which are increasing in frequency.  While the 24 hour reporting cycle of media with sensational video reports catches our attention, the attacks are infrequent and frequently preventable.

The species most likely to attract out attention in Missouri is the black bear which is actually an omnivore, carnivorous primarily when the exceptional opportunity presents itself.  Steven Herrero of the University of Calgary is an authority on bear attacks and safety, and he reviews the study's results at this link.*

As the human population climbs, we move further into landscapes previously the domain of coyotes, bears, wolves and cougars.  More outdoor activity in the wild and an emphasis on extreme adventure puts people at greater risk.  On the other hand attacks remain rare, especially when we consider the increasing numbers of humans out in the wild.  They found 700 attacks from all species in North America and Europe since the 1950s.  Their results are summarized below.

As more people enter the wilderness areas, there is an increasing need to educate the public on managing their risks.  Around half of well documented incidents were associated by risky human behavior, especially leaving children unattended, running and hiking alone at dusk.  Other factors included walking with a dog and dealing with a wounded animal while hunting.  Feeding bears and sleeping in tents with food supplies further encourages attacks. 

Click to enlarge - from Nature.com

It is important to understand relative risks of outdoor activities.  Statistics for the United States from Outdoor Life  list mortality from outdoor activities.  There are annually an average of 5 fatalities from venomous snake bites and 51 deaths from lightening.  This compares with 55 deaths from black bear attacks over the last 110 years.  Some Missouri figures are below.

Missouri Outdoor Mortality - MDC

Take home lessons:

1. Attacks by bears and carnivores are extremely rare.
2. Avoid feeding bears.
3. Become Bear Aware.

* The complete study with the data is at Nature.com.

He or She or It

Timothy Knepp - US Fish and Wildlife Service

Sex change is in the news a lot and now the fish are joining in.  National Geographic describes the findings in Vermont's Missisquoi National Wildlife Refuge.

"About 85 percent of male smallmouth bass collected in national wildlife refuges in the Northeastern U.S. had eggs growing in their testes. Pollutants that mimic sex hormones are the suspected culprit."

Eggs?  Well shut my mouth! - Bill Roston

Scientists studying fish in 19 national wildlife refuges in the U.S. Northeast have found that 60 to 100 percent of male smallmouth bass had testes growing female egg cells.  This condition called intersex is not new but the increasing frequency is alarming.  It had previously been described in a Science Friday story back in 2006 and examples were known from the 1990s.

The suspected culprits are endocrine disrupting chemicals (EDC) entering the watersheds.  These can be found in pesticides, electronics, personal care products and cosmetics.  Chemical contaminants of concern include estrogens from birth control pills, the plasticizer bisphenol A, and the herbicide atrazine.  Laboratory studies of the diabetes drug metformin, using levels found in Lake Michigan water, has been shown to produce intersex fish.

Intersex changes have previously been documented in alligators, soft-shelled turtles and frogs.  Studies in Europe have shown that fish with eggs in their testicles tend to produce less sperm which have reduced motility, leading to reduced reproductive rates.

We have no studies from our Ozark streams where our smallies reside.  Studies in Northeastern US waters have shown a much lower incidence of intersex fish among largemouth bass populations, a hopeful note for fishing on the White River lakes.  One more reason to keep our waters clean.

Keep up on the latest on the Upper White River status with Ozarks Water Watch.

Sundew Assassin Bug

Assassin bug nymph - Mark Bower

While photographing lichen on Monday, Mark Bower came across this insect trying to look inconspicuous on a lichen covered stick.  It had the typical morphology of an assassin bug nymph, but which one?  I sent it to Bugguide and got my answer within 30 minutes - the Sundew Assassin Bug,  Zelus luridus.

Prominent spines on pronotum - Mike Quinn

Z. luridus adults are basically green with a few color variations  (luridus = sallow, ghastly).  The nymphs can vary from bright orange to blended mixtures of green.  According to Bugguide "The best feature for recognition is the pair of delicate spines on the rear corners of the pronotum, which are rather long on the light colored individuals and shorter on the dark."

Z. luridis nymph - Mark Bower

Both adults and nymphs prey on a wide variety of insects such as weevils and leafhoppers but much of their diet is lepidoptera larvae including butterfly caterpillars and many economic pests such as cotton bollworm.   They can be considered "good" or "bad" from our perspective but as usual, it depends, and they don't seem to care what we think.

Adult luncheon date

A quick trip to a favorite insect site called Bugeric.blogspot.com* brought up lots of good stuff.  Z. luridus has a cool predation strategy, or should I say sweet one.  They secrete sticky substances from glands on the tibia of their front legs.  This covers the hairs allowing them to capture their prey rather than relying on stabbing them like most other assassin bug species.  After that it is the same old story - inject digestive juice, wait and then suck out the digested contents.  Not exactly gourmet dining but it works for them.

A leafhoppers nightmare, Z. luridis egg mass and hatchlings - bugeric.blogspot.com

The nymphs pass through 5 instars (stages) on the way to adulthood.  While they may commonly overwinter as eggs, Mark's didn't get the message and was moving about on a cold winter day.  Bugeric points out that the nymphs don't produce the sticky secretion but instead wipe them up from secretions that their mom left on the egg sac.  Details like this always make me wonder who bothered testing these tiny nymphs and how.  Here you can read the answer - C. Weirauch- 2006 described assassin bug methods of prey capture in detail.  Studies like this add up to the complete descriptions in field guides.


* Bugeric's blog is a great place to check for insect lore.  He is the author of my favorite insect field guide, Kaufman's Field Guide to Insects of North America.

Heavenly Bamboo

N. domestica leaves- Wikimedia

Invasive plants from "heaven" now comes in two plant species.  The more familiar species is Ailanthus altissima or "Tree of Heaven," a small tree that spreads like kudzu of the north and even grows in the cracks of buildings.  Now we have another species popping up around Springfield, Heavenly Bamboo, Nandina domestica.  It came down to us not from heaven but from Asia.

Heavenly Bamboo berries - Wikimedia

Not actually a bamboo but an evergreen shrub, it tends to grow around 7 feet tall and spread out to 5 feet wide.  Introduced as an ornamental in the 1800s, it can seduce gardeners with its young pink leaves in early spring, white flowers in early summer and bright red berries in the fall and winter.  Oh, and evergreen leaves that may be tinged with red in winter..... beginning to sound like invasive bush honeysuckle?  It should, as it spreads covering the same habitat.

There are clues to look for when planting exotic (think non-native) plants.  "Needs no care," "grows in sun and shade,"  "grows in any soil," should all be a warning that escape is likely.  "Heavenly" grows readily up to 6-8 feet although there is a dwarf variety of 3-4 feet.  It spreads out by rhizomes, seeking to grow beyond the gardener's plan, and can cover the ground quickly like bush honeysuckle.  Nandina can take heat and cold, from −10 to 110 °F.  It grows in sun or under forest canopies and near forest edges like bush honeysuckle and Arkansas is an epicenter for Nandina in forests.

All parts of the plant are poisonous, producing hydrogen cyanide.  They are listed as Toxicity Category 4, the category "generally considered non-toxic to humans," but the berries are considered toxic to cats and grazing animals.  They generally do not affect birds except when consumed in large numbers by voracious frugavores like cedar waxwings.  I recall sampling honeysuckle berries and neighborhood kids mashing them for "tea."  These berries potentially could sicken small children who sample them in excess.

Leaves - Invasive.org

They were planted in the Master Gardener's Xeriscape Garden on National Avenue in Springfield.  And a confession, we have had some planted in our yard for 20 years, although Barb suspected they might be a problem and has picked the berries off each year before they ripen.  For some time they have been classed as invasive in the southern states including  Florida, Georgia and Texas.  Now it looks like Missouri's turn has come.

Fayetteville has just banned planting 18 invasive species in major developments as described here.
Detailed information of Heavenly Bamboo control is at this Forest Service link.

Birdwatchers Unite!

Bird migration routes by eBird- New York Times

Studies of bird migration have always been complex and expensive, using an array of techniques such as traditional VHF, digital coded VHF, GPS transmitters, Argos satellite transmitters, geolocators, and GSM transmitters.  While giving good information these require capturing a bird and attaching a device.  The bird has to haul around the extra weight and when you are done, you have a path for one bird only.

The first migration study was by marking swans with a nick in their beak in 1560 England.  Other methods listed in Wikipedia (scroll down to "study techniques") have included "an older technique to quantify migration involves observing the face of the moon towards full moon and counting the silhouettes of flocks of birds as they fly at night."

A story in the New York Times describes an exciting new approach involving citizen science.  Ornithologists at Cornell Lab of Ornithology have compiled more than a million observations reported by amateur bird watchers through eBird.  Many of our own Master Naturalists have participated through GOAS* field trips and as observant birders.

Nocturnal migration is difficult to study as the birds tend to take off 30-45 minutes after sunset.  Cornell's Birdcast program is combining eBird data with two other high-tech data sources.  Flight calls of migrating birds are species specific, allowing species identification during nocturnal flights.

Weather Surveillance Radar (WSR-88D) network has over 140 sites dedicated to collecting meteorological phenomena.  These can also track the movement of masses of birds at night, "determining where flights are occurring, how many birds are aloft, and in what direction and speed they are moving." (Birdcast)  While not species specific, this can be correlated to flight calls and eBird data to describe species-specific bird migration routes.

Even if you don't read the article, this link is worth a click just to see the flow of  migrating species shown as moving dots over the year.

  * GOAS - Greater Ozarks Audubon Society.

 This story was contributed by my fantastic editor and wonderful wife.