Serpente saettone, il rettile non velenoso che conquista anche le aree urbane
È un animale schivo che suscita spesso curiosità e falsi allarmi, con avvistamenti in aumento tra aree verdi, siepi e parchi cittadini, dove può comparire anche a pochi passi dalle abitazioni, diventando un simbolo della convivenza tra biodiversità e territorio antropizzato
Il Saettone (Zamenis longissimus) è un serpente non velenoso della famiglia dei colubridi, parente stretto del Biacco. È chiamato anche colubro di Esculapio, perché è ritenuto il serpente caro al dio della medicina; la sua immagine è ritratta sul simbolo dei medici e dei farmacisti, avvolto intorno a un bastone.
Caratteristiche fisiche e dimensioni
Questo rettile può raggiungere i 2 metri di lunghezza, ma un adulto è solitamente tra i 130-150 cm. Il colore è bruno verdastro, con due semilune giallognole poco evidenti nella parte posteriore della testa; la superficie ventrale è gialla o biancastra. La testa è lunga, affusolata e poco distinta dal collo, con occhi di medie dimensioni a pupilla rotonda.
Dimorfismo e aspetto dei giovani
Esiste un dimorfismo sessuale nelle dimensioni: il maschio è più grande e lungo, circa 800 g, mentre la femmina circa 600 g. I saettoni giovani hanno un aspetto più macchiettato ed è visibile una striscia scura dietro ciascun occhio.
Comportamento e abitudini
Non è aggressivo e morde occasionalmente solo se viene catturato, senza mantenere la presa. È prevalentemente diurno, anche se nei mesi più caldi compare al crepuscolo. È termofilo, ama esporsi al sole per scaldarsi ma nelle ore più calde si sposta in zone più fresche.
Alimentazione e predatori
Si nutre di piccoli vertebrati come roditori, lucertole, passeracei, predando anche uova e nidiacei. Non è velenoso, ma è un abile costrittore che soffoca le prede tra le spire. È predato da diversi mammiferi (mustelidi, volpi, cinghiali, ricci) e da varie specie di rapaci.
Riproduzione e ciclo vitale
Trascorre il letargo da ottobre a marzo in anfratti, muri, tane nel terreno o cavità di tronchi. È un abile arrampicatore, sia di alberi che di edifici. Tollera la presenza umana e si trova spesso vicino a paesi, parchi e giardini urbani.
Riproduzione e sviluppo
La maturità sessuale si raggiunge nei maschi a circa 75 cm e nelle femmine a circa 85 cm. L’accoppiamento avviene tra maggio e giugno e può essere preceduto da combattimenti tra maschi rivali; il corteggiamento consiste in una danza a forma di “S” con le code intrecciate. La femmina depone da 5 a 10 uova in detriti vegetali o cavità di tronchi. La schiusa avviene tra fine agosto e inizio settembre; i piccoli sono lunghi 15-20 cm e subito indipendenti.
Habitat e diffusione
L’età massima è di circa 15 anni. L’habitat ideale è costituito da boschi di caducifoglie, aree rurali con siepi e vegetazione arbustiva, ma anche zone rocciose e aree antropizzate. È presente dal livello del mare fino a circa 1200 metri di altitudine. È diffuso in tutta Italia, dal Nord alla Sicilia.
Distribuzione geografica
In Europa è presente in diversi Paesi tra cui Francia, Spagna, Germania, Polonia, Bulgaria, Romania, Svizzera, oltre alla regione anatolica (Turchia) e caucasica (Georgia, Azerbaigian) e nel nord-ovest dell’Iran.
Importanza ecologica e osservazioni personali
È una specie protetta e utile all’ecosistema per il controllo dei roditori. L’autore ha documentato avvistamenti in provincia di Bergamo, Lodi e Milano.
Testo e foto di Walter Ferrari
Category passione-natura not found
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FTL stack trace ("~" means nesting-related):
- Failed at: @get_category name=cat_name var="cate... [in template "dev.sevendaysweb.com/layouts/macro/utils.ftl" in macro "set_primary_category_color" at line 600, column 7]
- Reached through: @set_primary_category_color c [in template "dev.sevendaysweb.com/layouts/macro/content_suggested.ftl" in macro "hs_contents" at line 970, column 25]
- Reached through: @hs_contents ca, contents_preview, co... [in template "dev.sevendaysweb.com/layouts/macro/content_suggested.ftl" in macro "suggested_category_content" at line 461, column 17]
- Reached through: @suggested_category_content ca, last_... [in template "dev.sevendaysweb.com/layouts/macro/content_suggested.ftl" in macro "suggested_contents" at line 223, column 25]
- Reached through: @query name=name cache=false start=st... [in template "dev.sevendaysweb.com/layouts/macro/content_suggested.ftl" in macro "suggested_contents" at line 221, column 9]
- Reached through: @suggested_contents name=(mpName + "i... [in template "dev.sevendaysweb.com/layouts/macro/content_suggested.ftl" in macro "content_suggested" at line 81, column 41]
- Reached through: @query name="categories_area_sect" ca... [in template "dev.sevendaysweb.com/layouts/macro/content_suggested.ftl" in macro "content_suggested" at line 8, column 9]
- Reached through: @content_suggested bundle.OCDetail, "... [in template "dev.sevendaysweb.com/layouts/macro/content_details.ftl" in macro "content_details" at line 358, column 25]
- Reached through: @content var="c" show_last_content=ca... [in template "dev.sevendaysweb.com/layouts/macro/content_details.ftl" in macro "content_details" at line 118, column 9]
- Reached through: @content_details img_full_width=img_f... [in template "dev.sevendaysweb.com/layouts/default.ftl" in macro "contents_column" at line 9, column 13]
- Reached through: @contents_column [in template "dev.sevendaysweb.com/layouts/macro/skeleton.ftl" in macro "container" at line 412, column 49]
- Reached through: @query name="count_areas" cache=false... [in template "dev.sevendaysweb.com/layouts/macro/skeleton.ftl" in macro "container" at line 254, column 5]
- Reached through: @container context, "[left-mid-", "[c... [in template "dev.sevendaysweb.com/layouts/macro/skeleton.ftl" in macro "html" at line 111, column 33]
- Reached through: @cache sv=search_val [in template "dev.sevendaysweb.com/layouts/macro/skeleton.ftl" in macro "html" at line 66, column 9]
- Reached through: @html cat_layout="home" cat_title=tru... [in template "dev.sevendaysweb.com/layouts/default.ftl" at line 24, column 1]
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Java stack trace (for programmers):
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freemarker.template.TemplateException: [... Exception message was already printed; see it above ...]
at it.treis.utils.freemarker.BasicHeadingCategoryDirective.getCategoryByName(BasicHeadingCategoryDirective.java:63)
at it.treis.utils.freemarker.CategoryDirective.execute(CategoryDirective.java:65)
at freemarker.core.Environment.visit(Environment.java:445)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:101)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:372)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.IteratorBlock$IterationContext.executedNestedContentForCollOrSeqListing(IteratorBlock.java:291)
at freemarker.core.IteratorBlock$IterationContext.executeNestedContent(IteratorBlock.java:271)
at freemarker.core.IteratorBlock$IterationContext.accept(IteratorBlock.java:242)
at freemarker.core.Environment.visitIteratorBlock(Environment.java:642)
at freemarker.core.IteratorBlock.acceptWithResult(IteratorBlock.java:107)
at freemarker.core.IteratorBlock.accept(IteratorBlock.java:93)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:372)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:372)
at freemarker.core.Environment$NestedElementTemplateDirectiveBody.render(Environment.java:2900)
at it.treis.utils.freemarker.CategoryCachedQueryResultDirective.execute(CategoryCachedQueryResultDirective.java:202)
at freemarker.core.Environment.visit(Environment.java:445)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:101)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:372)
at freemarker.core.IteratorBlock$IterationContext.executedNestedContentForCollOrSeqListing(IteratorBlock.java:291)
at freemarker.core.IteratorBlock$IterationContext.executeNestedContent(IteratorBlock.java:271)
at freemarker.core.IteratorBlock$IterationContext.accept(IteratorBlock.java:242)
at freemarker.core.Environment.visitIteratorBlock(Environment.java:642)
at freemarker.core.IteratorBlock.acceptWithResult(IteratorBlock.java:107)
at freemarker.core.IteratorBlock.accept(IteratorBlock.java:93)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:372)
at freemarker.core.Environment$NestedElementTemplateDirectiveBody.render(Environment.java:2900)
at it.treis.utils.freemarker.CategoryCachedQueryResultDirective.execute(CategoryCachedQueryResultDirective.java:202)
at freemarker.core.Environment.visit(Environment.java:445)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:101)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:372)
at freemarker.core.Environment$NestedElementTemplateDirectiveBody.render(Environment.java:2900)
at it.treis.utils.freemarker.ContentCachedResultDirective.render(ContentCachedResultDirective.java:201)
at it.treis.utils.freemarker.ContentCachedResultDirective.execute(ContentCachedResultDirective.java:181)
at freemarker.core.Environment.visit(Environment.java:445)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:101)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:372)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:372)
at freemarker.core.Environment$NestedElementTemplateDirectiveBody.render(Environment.java:2900)
at it.treis.utils.freemarker.CategoryCachedQueryResultDirective.execute(CategoryCachedQueryResultDirective.java:202)
at freemarker.core.Environment.visit(Environment.java:445)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:101)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.Environment.visitAndTransform(Environment.java:495)
at freemarker.core.CompressedBlock.accept(CompressedBlock.java:42)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.Environment$NestedElementTemplateDirectiveBody.render(Environment.java:2900)
at it.treis.utils.freemarker.CacheDirective.execute(CacheDirective.java:102)
at freemarker.core.Environment.visit(Environment.java:445)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:101)
at freemarker.core.Environment.visit(Environment.java:366)
at freemarker.core.Environment.invoke(Environment.java:775)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:83)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:336)
at freemarker.core.Environment.process(Environment.java:309)
at freemarker.template.Template.process(Template.java:384)
at org.apache.struts2.views.freemarker.FreemarkerResult.doExecute(FreemarkerResult.java:223)
at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:193)
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:372)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:276)
at it.treis.smartmedia.navigation.interceptors.PrepareParametersInterceptor.intercept(PrepareParametersInterceptor.java:183)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at it.treis.smartmedia.navigation.interceptors.SubscriptionTokenMatcherInterceptor.intercept(SubscriptionTokenMatcherInterceptor.java:46)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at org.apache.struts2.interceptor.DeprecationInterceptor.intercept(DeprecationInterceptor.java:41)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:168)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:76)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at org.apache.struts2.interceptor.DateTextFieldInterceptor.intercept(DateTextFieldInterceptor.java:125)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:253)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:140)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:575)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142)
at com.thetransactioncompany.cors.CORSFilter.doFilter(CORSFilter.java:209)
at com.thetransactioncompany.cors.CORSFilter.doFilter(CORSFilter.java:244)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:166)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:88)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:481)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:83)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:643)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:72)
at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:763)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:344)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:398)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:935)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1831)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:973)
at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:491)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63)
at java.base/java.lang.Thread.run(Thread.java:829)
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