Red Squirrel

Red Squirrels cache food for the winter.  They do not hibernate, although they will remain inactive during inclement weather.  These squirrels also harvest maple sugar, biting into the tree, and allowing the sap to flow.  After the sap dries, the squirrel returns and consumes the maple syrup. A Red Squirrel nested in a hole only a couple of feet from the ground in a Hackberry tree in our backyard. After the young hatched, the parent carried the young to a secondary nest elsewhere in the neighborhood.

Bird Field Guide Recommendations

Beginning birders might find this bird difficult to identify.  During my 30 years of teaching ornithology, I am often asked to recommend bird guides. Here are some quick suggestions.

I believe the best book for beginners is Peterson's Eastern Birds.  Birders in western North America will want the Western volume (Minnesota counts as East).  The bird portraits in the Peterson book are large, accurate, and clear.  The patented Peterson system of arrows pointing to the most important field marks is also a plus.  Finally, Peterson's introduction presents a fine essay on how to identify birds.

Many advanced birders use The Sibley Guide to Birds.  Sibley also paints his birds large, but with much more detail than Peterson.  This detail is great for the more advanced birder, but may tend to confuse a beginner.  The Sibley book contains all the birds of North America, which is good for a traveling birder, but gives the novice more chance to make mistakes. When the Sibley book first came out, it was criticized for being too large to carry in the field.  Since then he has published smaller guides to eastern and western birds, but I feel the bird pictures in those two books are too small for effective identification.

I usually carry Sibley with me at all times, but lately I have been enjoying the National Geographic Illustrated Birds of
North America Folio Edition.  It is a coffee table-sized book that I keep in my house for when I return from the field.  The book is also effective for teaching to groups. For my old eyes, the large format is quite enjoyable.  In many respects this latest edition of the National Geographic guide is comparable to the Sibley guide, and most advanced birders own both.

Finally, during my later years of teaching, I assigned my students Thayer's Birds of North America DVD. Be careful to order the correct version for your computer, Windows or Mac (the lower link to Amazon.com is a Mac version). I never liked field guides based on photographs because I felt it hard for a birder to focus on the most important field marks.  This DVD, however, contains multiple images of most birds (which can be shown side-by-side), song files, range maps, videos, and even a short ornithology textbook.  Most importantly, you can build bird quizzes with the birds you want to learn.  After using these quizzes, my students commented that identifying birds was pretty easy.  I replied that most things become easy if you study as hard and as often as they did while using their Thayer bird quizzes.

The bird above?  A young Yellow-bellied Sapsucker--complete with dried sap on its chin!   Sapsuckers will drink sap from the holes in the trees they drill, and will also dip insects into the sap.  Perhaps they like their arthropods to be sugar-coated.

Pied-billed Grebe

Erika and I also photographed this Pied-billed Grebe during our recent Circle Lake trip.  This bird is another waterfowl that beginning birders sometimes mistake for ducks.  But grebes are not ducks.  Older bird books place them next to loons, but DNA research suggests that grebes are distantly, but most closely related to flamingos!  They lack webbed feet, having only their individual toes with webs and their bills are not shaped like a duck bill.

Grebes are one of the few bird families that lack tail feathers.  They have only downy feathers where the tail should be.  The lack of a tail may be an adaption for streamlining these expert divers.  To keep them dry, grebes have over 200,000 feathers, which have a unique waterproofing structure.  You can see water droplets on this bird's head.  Pied-billed Grebes eat fish and protect their gizzards from fish bones by eating their feathers, creating protective pellets around the fish bones.  Eventually the grebes regurgitate the pellets.

Much of this information is from the Handbook of the Birds of the World, a wonderful, lavishly illustrated resource for birders with deep pockets.  There are to be 16 volumes.  If you factor the price per bird family, however, the series' cost becomes less prohibitive.

American Coot

My friend George P. commented "American Coots are proof that God has a sense of humor."  The poor birds don't seem to be able to paddle and keep their heads still at the same time. Erika and I found this coot on Circle Lake in Rice Co. last Tuesday.

Many non-birders and beginning birders assume that coots are closely related to ducks.  On land, they look kind of like chickens.  They do not have webbed feet.  Each individual toe is webbed. In fact, coots are rails, distantly, but more closely related to cranes than they are to ducks or chickens.

Red-breasted Nuthatch

Red-breasted Nuthatches irregularly irrupt out of the North Woods.  I banded this nuthatch on Sunday. These irruptions are caused by shortages of spruce budworms and conifer seeds in the north.  This movement, when it does occur, can begin early--like in early July or August.  Be careful not to interpret these early migrants, which may include relatively young birds, as local breeders.

Also adding to confusing breeding records is the fact that Red-breasted Nuthatches will sometimes begin excavating their small, square nest cavities south of where the species breed.  Later in the spring, these early excavators continue their northward migration.  When this species is breeding, females usually choose the nest site and do most of the excavating.  Unmated males, however, often begin excavations, in hopes of attracting females (Cornell Lab of Ornithology).


Most Minnesota birders own a copy of Robert Janssen's Birds in Minnesota.  Although now somewhat dated, this book is a good resource on where and when to expect birds in Minnesota.
Many of us are also faniliar with Kim Eckert's A Birder's Guide to Minnesota.  This book gives directions to good birding spots in all Minnesota counties.  Some birders are less familiar with his review of Minnesota birds, complete with sophisticated identification tips.  Kim keeps his book updated on the web.

Bay-breasted Warbler 2

Because this bird clearly shows fairly bight chestnut sides, this Bay-breasted Warbler is readily identifiable.  Compare it to the drab bird that I've copied from my 5 September 2010 post.  Not only is this new bird, banded on Sunday, brighter than most fall birds, the sides of the face are also darker than most. Both of these birds were young of the year, although I assume the one above is a male. Most fall Bay-breasted Warblers show only a hint of chestnut on their flanks.

If you are interested in improving your warbler identification skills, the Peterson Field Guides Warblers is an excellent resource.  When I am banding, I always have it nearby. In future blogs, I will try to recommend other books for a birder's library.

Orange-crowned Warbler

On Saturday I caught a few Orange-crowned Warblers. This drab species is one of the last of the fall warbler migrants (and one of the first of the spring). I taught my ornithology students that the best field mark for this warbler is the lack field marks.  Generally they have grayish heads and white eye rings.  Faint breast streaking is the salient field mark.  Their orange crowns are seldom visible. Orange-crowned Warblers show variable brightness, with increasing yellow and less gray as you move west across North America. Orange-crowned and Tennessee Warblers might be easily confused.  DNA studies have found that, although clearly in the same genus, the two species are not otherwise closely related (Gilbert et al. 2010).

Red-sided Garter Snake

The Red-sided Garter Snake is a race of the Common Garter Snake.  The Red-sided is found in western Minnesota and is replaced by Common Garter Snakes in the east.  Range maps in Reptiles and Amphibians of Minnesota by Breckenridge (1944) shows overlap between the two races in southeastern Minnesota.  My brother and I encountered this individual on the Cannon River Bicycle Trail in Goodhue County about 4 miles east of Cannon Falls.

Our Red-sided Garter Snake aggressively stood its ground, striking at us as we approached.  Recently garter snakes have proven to contain neuraltoxins, although in non-lethal quantities to affect humans.  The snakes also lack an effective method of venom transmission.  Although garter snakes are known to coil and strike, our snake may have been run over by a bicycle, which might explain its unwillingness to flee.

Wikipedia also reports that male and female garter snakes produce distinctive pheromones that allow males to find emerging females in the spring. Swarms of up to 25 males mate with each female.  Some males, however, practice kleptothermy.  Kleptothermy is when you steal someone's heat.  In this case, these males release female pheromones, attracting other males to attempt to copulate with them.  This action warms up the female-pheromone-releasing males, and makes them more active.  Studies demonstrate that these "she-males" are more active than cooler males and are thus able to mate more often.  Females are able to store sperm for several years.  The fertilized eggs hatch inside the female. Three to 80 young are then born live in a single litter, a condition termed ovoviviparity.

Deformed Yellow-rumped Warbler

On Thursday I banded a dozen Yellow-rumped Warblers, including this bird with deformed feet.  I can only speculate about the cause of the missing toes.  Is this the result of a developmental deformity?  Is it a bird that recovered from avian pox?  Had it suffered frostbite (the bird was an adult, so it was alive last winter)?  Had it barely escaped from a predator? In my banding career, I have never seen anything quite like this.  One wonders how this bird perched.  Most deformed birds do not survive.

Asian Lady Beetle

Another winter home invader is the Asian Lady Beetle, Harmonia axyridis. This beetle has spread across North America during the last 20 years.  In an attempt to control Soy Bean aphids, this beetle was introduced from Japan, Korea, and other parts of Asia.  Introductions began as early as 1916, and many were unsuccessful.  Now the beetle is often abundant.

Most households do not welcome these beetles. Once inside, they are everywhere.  They smell bad and they bite.  They out compete and prey upon native lady bugs.  They also damage fruit crops.  They spoil the taste of some wines made from infested grapes.  A few people are allergic to these beetles.

On the other hand, Georgia peach growers now rely less heavily on pesticides after the farmers used lady beetles to control aphids.  You may not want to try to control a home invasion of Asian Lady Beetles with pesticides.  Asian Lady Beetles are preyed upon by Carpet Beetles.  If you wipe out the lady beetles, the Carpet Beetles, which also live in homes, move on to consuming your carpets and other linens. As in the case of Box Elder Bugs, vacuuming the invertebrates may be your wisest remedy.  Much of this information is from Wikipedia and the University of Washington.