Wel­come to Subirdia by John M. Mar­zluff, Yale Univer­sity Press, 303 pages

Pasatiempo - - In Other Words -

Bird lovers may need a lift after read­ing the Na­tional Audubon So­ci­ety’s re­cent re­port that cli­mate change could drive 50 species from New Mex­ico by 2050. A new book writ­ten by or­nithol­o­gist John M. Mar­zluff and beau­ti­fully il­lus­trated by his Univer­sity of Wash­ing­ton col­league Jack De­lap of­fers a small mea­sure of com­fort.

While ris­ing tem­per­a­tures and the as­so­ci­ated con­se­quences threaten the most frag­ile avian pop­u­la­tions, other birds are evolv­ing phys­i­cally and so­cially in re­sponse to the stresses of in­dus­tri­al­iza­tion, dis­ease, ur­ban­iza­tion, ha­rass­ment, noise, light, traf­fic, and pol­lu­tion. This is es­pe­cially true in “subirdia,” the sub­ur­ban green­belts that Mar­zluff, a pro­fes­sor of wildlife sci­ence, calls “com­pact mi­cro­cosms of the plant world.” Where dif­fer­ent habi­tats meet, as they do in the wildlife-ur­ban in­ter­face, birds en­joy more di­ver­sity in their di­ets and hous­ing, and their pop­u­la­tions are larger and health­ier. But this is true only where the hu­man touch is more cre­ative than de­struc­tive.

The lawns, gar­dens, trees, and vari­able land­scapes of subirdia at­tract a mélange of the hardi­est birds — adapters and ex­ploiters, as they’re known to sci­en­tists. The “fab five” of the lat­ter group — Canada geese, rock pi­geons, house spar­rows, Euro­pean star­lings, and mal­lards — oc­cupy most of the world’s large ci­ties and need no as­sis­tance to sur­vive, Mar­zluff writes. Adapters ben­e­fit when we mod­ify the en­vi­ron­ment — homes, neigh­bor­hoods, parks, and ci­ties — to nur­ture birds, am­phib­ians, and other crea­tures that are sym­bi­otic with our species. Avoiders, though, ex­ist only in spe­cific habi­tats, many of which are dis­ap­pear­ing. The sage grouse needs vast tracts of its name­sake shrub­bery, just as the wood thrush thrives only in ma­ture de­cid­u­ous forests with leafy un­der­sto­ries. Th­ese birds, among many oth­ers, are ill-equipped by bi­ol­ogy or habit to find work­able al­ter­na­tives or de­velop com­plex cop­ing be­hav­iors. Sav­ing th­ese birds from ex­tinc­tion re­quires that peo­ple act with de­lib­er­a­tion.

Mar­zluff pro­poses 10 ways in which peo­ple can en­rich com­mu­ni­ties for birds and other wildlife. He frames them as com­mand­ments. Two of them, “Do not covet your neigh­bor’s lawn” and “Do not light the night sky,” dove­tail with lo­cal ef­forts to re­duce wa­ter use on non-na­tive lawns and with New Mex­ico’s Night Sky Pro­tec­tion Act. Ad­mon­ish­ments to “keep your cat in­doors” and “make your win­dows more vis­i­ble to birds that fly near them” ad­dress two of the most sig­nif­i­cant ways to avoid bird mor­tal­ity. Mar­zluff en­cour­ages peo­ple to pro­vide food and nest boxes and de­sign vari­abil­ity in lawns and land­scapes. We can co­ex­ist with na­tive preda­tors, such as bears and moun­tain lions, by build­ing bar­ri­ers around homes and out­build­ings and do­ing less to lead large car­ni­vores into temp­ta­tion, such as not leav­ing food and garbage out­side.

Other guide­lines re­quire col­lec­tive po­lit­i­cal ac­tion, with com­mu­ni­ties build­ing bridges or un­der­passes for an­i­mals where high­ways in­ter­sect with mi­gra­tion paths and re­serv­ing undis­turbed cor­ri­dors that link land and wa­ter. By fol­low­ing th­ese com­mand­ments, ur­ban and sub­ur­ban dwellers can re­cover from “en­vi­ron­men­tal am­ne­sia” — an alien­ation from the nat­u­ral world that en­cour­ages ap­a­thy about its ne­glect, mis­man­age­ment, and de­val­u­a­tion.

The re­wards of re­con­nec­tion are enor­mous — and mea­sur­able. Ac­cord­ing to an eco­nomic anal­y­sis by the U.S. Fish and Wildlife Ser­vice re­leased in 2009, birds are the foun­da­tion of a multi­bil­lion-dol­lar tourism in­dus­try in the United States alone. Be­sides en­tic­ing peo­ple out­doors to ad­mire them, birds scav­enge road­kill, dis­perse seeds, aid in pol­li­na­tion, and help us mon­i­tor the planet’s health. They feed on in­sects that spread dis­ease, de­stroy build­ings, and dev­as­tate crops. Any many of them sing like opera di­vas.

“As the birds of a for­est ad­just to hu­man set­tle­ment, the en­tire com­mu­nity is reshuf­fled,” Mar­zluff writes. “The chang­ing abun­dance of one species may rip­ple through the full web of life. The web is re­fash­ioned, as new strings are added and old ones are di­min­ished or re­con­nected into a new ar­chi­tec­ture.” The pace of evo­lu­tion is ex­plo­sive among birds and other an­i­mals that live close to hu­man set­tle­ments. Birds are mor­ph­ing into new species within a few gen­er­a­tions, and the evo­lu­tion is cul­tural, not just phys­i­cal. City birds, for ex­am­ple, raise their voices to be heard over traf­fic and other ur­ban and sub­ur­ban noise and lower their pitch on week­ends and hol­i­days. They rise ear­lier than their coun­try cousins and stay up later to ac­com­mo­date rush-hour racket.

The mea­sured op­ti­mism of this book is based on ex­haus­tive re­search and field­work, in­clud­ing the band­ing and mon­i­tor­ing of thou­sands of birds. “The life we cre­ate does not re­place what we have de­stroyed,” Mar­zluff writes, “but … all de­struc­tive forces in na­ture have a cre­ative side; fires cre­ate unique ecosys­tems and di­ver­sify for­est struc­ture, earth­quakes cre­ate lakes, vol­canic erup­tions en­rich the soil. Ur­ban­iza­tion too has the abil­ity to cre­ate biological di­ver­sity.

“Na­ture is frag­ile, but it does not al­ways break when bent: some­times it evolves. Evo­lu­tion is not some­thing that hap­pens only in the ab­stract eons of ge­o­log­i­cal time. It is hap­pen­ing right now, in your own back­yards. You are a force, as po­tent as the glaciers of the last ice age, shap­ing your feath­ered neigh­bors.”

— Sandy Nel­son

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