JANUARY 1980 • conse 10 ;.,or timber IOWA CONSERVATIONIST ar the grou MAGAZINE Tree Cavities ~edlogs January 1980 ~~to the ~ White-b STAFF ~'l.l'al cavrtJ Roger Sparks Edttor Home-Sweet-Home tith squ1rrels RoiX'n Runge Atlnaf1mg Edttor ~nneth formanel... A·V Coordmator ~chJCK Ron Johnson Photographer ~st ooxes d • luhu\ S,l!re Contnbutmg Edttor to Many p:cavatmg Junoe Gookon. Ctrculatton Manager ~on Burch Art Dtre<tor Je pa:!Ja:~ fil by Ken Varland ~as to en WILDLIFE MANAGEMENT BIOLOGIST CONTENTS Jt.e eas'e'll )atural cavrt1 2 TREE CAVITIES ~rgof 3 SHORTER QUAIL SEA ON " SAY, JOHN, I just got a new Just how important are these trees to K:attered sm fireplace. May I cut up that old, dead our wildlife? Several mammals utilize 4 IOWA FISH HATCHERIES ocao near oak standing in the timber's edge next tree cavities as den sites including a!ions a WORKING FOR ANGLERS to your lane? I could use the wood " opposums, raccoons, squirrels, gray fox. e.-range 6 IOWA'S FIRST FISH " Sure Ted, 1t's really not good for and vanous species of bats. The U.S. table 0 HATCHERY BUILT IN 1874 anything except maybe woodpeckers. Forest Service lists 28 cavity nesting bird · ~opetJ1JOO k 7 WARDEN 'S DIARY Bes1des, I think ff's an eyesore!" spec1es using the oak-hickory forest ~ 3uetx Conversations like this are occurring association in neighboring Missouri !Eoal hou 8 PRUNING BROADLEAF more frequently these days as growmg (Hardin and Evans 1977). The oak­ TREES numbers of people purchase fireplaces hickory association is the same type 10 BffiER CARE = BffiER and wood-bummg stoves for the1r that makes up the major portion of TROPH IES homes. As energy costs continue to Iowa's forest lands. It is interesting to 12 CLASSRO OM CORNER skyrocket, 1t has become more appealing note that all sizes of birds use tree for people to use wood as an alternate cavities. They range in size from the 12 LOOKIN' BACK source of heat. Wood from dead or dying turkey vulture with its 70 inch wingspan 13 ICE FI SHING THE UPPER trees can prov1de a source of good to the black-capped chickadee with only MISSISS IPPI firewood, but is it really not much good a 4 Vz inch wingspan. 14 NICK KLEPINGER, W ILDLIFE for anyth1ng else? Most of us know that woodpeckers ARTI ST As usual, nature has its own way excavate their own cavities by pecking of taking care of itself; in th1s case with the1r beaks. Each species uses the dead has its own way of providing trees in its own particular way. Red­ for the living. headed woodpeckers usually create a Dead or dying trees (often called cavity in the trunk of a dead tree near snags), trees w1th dead or broken the timber's edge or in a forest opening limbs, and hollow liv1ng trees can have while red-bellied woodpeckers prefer COVER photograph tremendous value to many species their cavities in dead limbs of live trees by Dock Casady of wildlife and for those of us who in mature stands. Common flickers nest .. appreciate all aspects of our natural close to the top of dead stubs in open world. They can add their own kind of country or only lightly wooded areas THE IOWA CONSERVATION rugged, diverse character to the timbered often excavating cavities 1n the same COMMISSION landscape. Some species of wildlife tree year after year. Flickers often feed Thomas Bates, Bellevue, John Brcphy, Lansmg, John depend heavily on decaying trees for on the ground in open habitats. Downy D Foeld Hamburg Richard W ~mler Marshallto"'n. their very survival and if we remove too woodpeckers have similar nesting D:mald I< "nudsen. Eagle Grove, Carolyn T Lumbard. Des M omes, Manan Pike, Whttmg many of these trees from our forests and preferences to flickers except they select woodlots, we would see dramatic open timber with a dense understory of ADMINISTRATIVE STAFF population declines of these species. young saplings and brush in which to William C. Brabham, Dorector feed on insects. Hairy woodpeckers Bob Fagerland, Deputy Dtrector Dead or damaged trees usually have cavities or holes which many wildlife occur most commonly in open wood­ I I DIVISION CHIEfS Allen Farns, Ftsh dnd Came, Stanley C Kuhn. DIVIsiOn of Admtmstratton, john M Stokes, species use as den sites. These cavities lands and excavate cavities in live trees l.dnds and Waters are usually created by the animals which have rotten centers. Pileated SfCTION SUPERINTENDENTS Tom Albright, Engmeer· themselves such as holes "pecked-out" woodpeckers, Iowa's largest and rarest mg. Joe W Bnll, Parks, Robert Barran Wildltfe; James by woodpeckers or those created by the woodpecker, require large tracts of Mayhew, Ftshefles, Roy Downong, Waters, lester natural decaying process such as the mixed woodlands and favor large, Flemong Crants·tn·Aid, Gene Henel, State Forester, dead trees with bone-like surfaces and Kenneth Kakac, Law Enforcement. Caryl Carstens, rotting away of an injured limb. Good l..tcense, larry Davos, lnformatton & Educatton, Gene cavity forming trees mclude maple, oak, few limbs. Getssonger, Accountmg. Doyle Adams, County Conser· hickory, ash, elm, basswood, aspen, The cavities created by these birds vatton Boards Amoe Sohn Pfanmng birch, and pine. Cavity users are often not only serve as living quarters for . blamed for reducing the economic value themselves, but later are used by a IOWA CONSERVATIONIST tiSSN·a121~nJ tUSPS268- of a forest by their excavation activities variety of other small birds including the 780J, Volume 39, Number 1 published monthly by the Iowa Conservation CommiSSIOn, Wallace State Office in trees marked for harvest. This criticism tree swallow, great crested flycatcher, Rutldmg OesMomes loKa 50J19 Ackkessal!maJ/fsub­ is largely unwarranted, however, as house wren, purple martin, screech owl, scnpttons change ofaddress . Form )579, manuscnpts woodpeckers, etc. usually make cavities and American kestrel (sparrow hawk). ma1/ilemsi to the dbove address Subscnpt1on pnce. one In trees that have been previously Other species prefer natural cavities ~ear at $2 IV, m o l'l'iJJS at D IV, lour ~eiJJS at JS IV, Se-cond class postage pa1d at Des Momes lo111i1 and damaged by disease, insects, storm, usually found in rotting limbs or trunks. I otherpomts or fire. Turkey vultures, common in the state's 2 jor timbered areas, frequently nest nuthatches, and chickadees are 1r the ground in hollow trees or especially important because they Cover Story Nned logs. These scavengers will exert constant pressure upon insect Jm to the same nesting site year after populations, even in winter. Wood-boring ir. Whita.breasted nuthatches prefer larval forms frequently fall prey to the ural cavities and will compete fiercely sharp, efficient beaks of these predators. h squirrels for nest cavities. Black­ If too many of these cavity users' nest )ped chickadees will nest in artificial sites are removed, their populations st boxes if allowed to do some decline, thus leavmg the way open for ;avating on their own. Boxes should economically damaging insect partially filled with peat and sawdust infestations; damage which not only as to entice the birds to use them. affects our wood-producing and e eastern bluebird prefers to nest in soil-conserving forests, but also our farm :ural cavities in savanna-like habitat groves, fruit trees, and ornamentals. 1sisting of pasture areas with It is difficult to say how many cavity 1ttered small trees and bushes usually trees should be left per unit area in order ated near bodies of water. Bluebird to be adequate for all wildlife concerned. oulations are low throughout most of Although much more research is tir range because of a shortage of needed, experts currently estimate that Pholo tyy /JfcJ< Casaay :eptable nesting sites and because of from five to seven dead snags per acre 11petition from other, more aggressive should remain in the timber. This is in ds Bluebirds will readily nest in addition to trees with dead or dying limbs Shorter Quail 1ficial houses if placed in suitable and liVIng trees with hollow trunks. This ations. Another bird that accepts number may seem h1gh, but it must be Season mcial nest boxes is the wood duck, remembered that there are several January 6 marks the end of va's most colorful and abundant species which require tree cavities and the quail season in Iowa this sting waterfowl species. This some maintain territories (i.e. 1 V2 acres om-eating duck has its highest nesting for house wrens, 4 acres for black­ year. Normally, quail seasons run nsities along our major timbered river capped chickadees). Fallen snags should through the entire month of rridors but they will readily nest near also be left as they provide homes for January offering quality, late >oded ponds and lakes. Other species many small mammals and add nutrients season hunting for ardent sports­ it use natural tree cavities include the to the soil through the decaying process. men. However) the Commission ted titmouse, barred owl, and bam If you have a fireplace or wood­ adopted a shorter season following 11. Dead snags are used by birds burning stove, keep m mind that dead the winter of '78-'79, one of the other ways such as perches and snags play a unique role in our wood­ worst in history. :>sting sites. lands and are vitally important to many Although this alternative was Just how important are the above wildlife species. Please do not remove popular with nearly everyone, the ds to us? Many are insectivorous or too many snags from any one area. ;ect-eaters.