該圖片由注冊用戶""提供， 反饋已知最(zui)早的(de)(de)(de)(de)松(song)(song)(song)鼠(shu)(shu)(shu)類(lei)物(wu)種(zhong)(zhong)的(de)(de)(de)(de)化(hua)(hua)石(shi)來自(zi)始(shi)新(xin)世(shi)的(de)(de)(de)(de)地層。那是(shi)距(ju)今(jin)6500萬年～3500萬年前的(de)(de)(de)(de)久(jiu)遠(yuan)時(shi)代。那時(shi)恐龍剛剛滅絕不久(jiu)，哺乳動(dong)物(wu)尚未在陸地上取得控制權，青藏高(gao)原尚未成為(wei)(wei)陸地，歐(ou)洲(zhou)和北(bei)美(mei)(mei)洲(zhou)仍然有(you)陸地相連，南美(mei)(mei)洲(zhou)則是(shi)一(yi)個巨大的(de)(de)(de)(de)島嶼(yu)。最(zui)原始(shi)的(de)(de)(de)(de)松(song)(song)(song)鼠(shu)(shu)(shu)生活在北(bei)美(mei)(mei)洲(zhou)，形(xing)態與今(jin)天的(de)(de)(de)(de)鼯鼠(shu)(shu)(shu)接近。在北(bei)美(mei)(mei)洲(zhou)晚(wan)始(shi)新(xin)世(shi)的(de)(de)(de)(de)地層中還發(fa)現了一(yi)系(xi)列松(song)(song)(song)鼠(shu)(shu)(shu)類(lei)物(wu)種(zhong)(zhong)的(de)(de)(de)(de)化(hua)(hua)石(shi)，不同于現在的(de)(de)(de)(de)任何一(yi)類(lei)松(song)(song)(song)鼠(shu)(shu)(shu)。北(bei)美(mei)(mei)洲(zhou)異常豐富的(de)(de)(de)(de)化(hua)(hua)石(shi)松(song)(song)(song)鼠(shu)(shu)(shu)種(zhong)(zhong)類(lei)顯示，松(song)(song)(song)鼠(shu)(shu)(shu)科(ke)起源于始(shi)新(xin)世(shi)的(de)(de)(de)(de)北(bei)美(mei)(mei)洲(zhou)，并在之后(hou)的(de)(de)(de)(de)漫長歲(sui)月中輻射(she)到了大洋洲(zhou)以外的(de)(de)(de)(de)各(ge)(ge)大洲(zhou)，在這(zhe)個過程中演化(hua)(hua)出了形(xing)態各(ge)(ge)異、適應各(ge)(ge)種(zhong)(zhong)環境的(de)(de)(de)(de)物(wu)種(zhong)(zhong)。在現存的(de)(de)(de)(de)嚙齒目(mu)松(song)(song)(song)鼠(shu)(shu)(shu)亞目(mu)物(wu)種(zhong)(zhong)中，主要分(fen)布于歐(ou)亞大陸的(de)(de)(de)(de)睡鼠(shu)(shu)(shu)科(ke)和分(fen)布于北(bei)美(mei)(mei)洲(zhou)的(de)(de)(de)(de)山河貍科(ke)與松(song)(song)(song)鼠(shu)(shu)(shu)科(ke)有(you)較近的(de)(de)(de)(de)親(qin)緣關系(xi)。而松(song)(song)(song)鼠(shu)(shu)(shu)科(ke)是(shi)最(zui)為(wei)(wei)人熟知的(de)(de)(de)(de)松(song)(song)(song)鼠(shu)(shu)(shu)家(jia)族成員，也是(shi)分(fen)布最(zui)廣、種(zhong)(zhong)類(lei)最(zui)繁多的(de)(de)(de)(de)一(yi)個類(lei)群。
廣布于古(gu)北(bei)界(jie)溫(wen)帶和(he)寒溫(wen)帶森林生態(tai)系(xi)統中(zhong)，西(xi)起伊(yi)比利亞(ya)和(he)大不列顛島(dao)(dao)，東(dong)至堪察(cha)加半島(dao)(dao)、俄羅斯薩哈林島(dao)(dao)和(he)日本的北(bei)海(hai)(hai)道，南至地(di)中(zhong)海(hai)(hai)、黑海(hai)(hai)、蒙古(gu)北(bei)部、中(zhong)國的西(xi)北(bei)和(he)東(dong)北(bei)地(di)區。
松(song)(song)鼠主要分布在由(you)(you)松(song)(song)屬(shu)(Pinus)、落(luo)葉松(song)(song)屬(shu)(Larix)和云杉屬(shu)(Picea)樹(shu)種(zhong)構成的針(zhen)葉林或針(zhen)闊混(hun)交(jiao)林中。由(you)(you)于食物(wu)來源相(xiang)對較為豐富和穩定，松(song)(song)鼠在針(zhen)闊混(hun)交(jiao)林中可(ke)以維持較高的種(zhong)群(qun)密度，并可(ke)以利用城(cheng)(cheng)郊甚(shen)至城(cheng)(cheng)市中的小片林地，成為伴(ban)人(ren)動物(wu)。
歐(ou)亞(ya)大(da)陸北部溫帶針葉林帶廣泛(fan)分布的(de)(de)歐(ou)亞(ya)紅(hong)(hong)松(song)(song)鼠(shu)（也(ye)(ye)稱北松(song)(song)鼠(shu)）是(shi)松(song)(song)鼠(shu)的(de)(de)典型代表，也(ye)(ye)是(shi)大(da)眾熟知的(de)(de)松(song)(song)鼠(shu)形象的(de)(de)原型。分布在歐(ou)亞(ya)大(da)陸東(dong)端(duan)的(de)(de)歐(ou)亞(ya)紅(hong)(hong)松(song)(song)鼠(shu)冬(dong)季背毛(mao)黑而腹白(bai)，夏(xia)毛(mao)灰(hui)間棕(zong)紅(hong)(hong)色(se)(se)；而分布在歐(ou)亞(ya)大(da)陸西端(duan)的(de)(de)歐(ou)亞(ya)紅(hong)(hong)松(song)(song)鼠(shu)背毛(mao)全年均(jun)為(wei)棕(zong)紅(hong)(hong)色(se)(se)。灰(hui)間棕(zong)紅(hong)(hong)色(se)(se)也(ye)(ye)是(shi)北美洲(zhou)森林中多(duo)數松(song)(song)鼠(shu)的(de)(de)主要色(se)(se)調。歐(ou)亞(ya)紅(hong)(hong)松(song)(song)鼠(shu)在分布范(fan)圍內(nei)從東(dong)至西不同地(di)理群(qun)體毛(mao)色(se)(se)的(de)(de)變化(hua)也(ye)(ye)是(shi)歷史上(shang)松(song)(song)鼠(shu)從北美大(da)陸起源，輻(fu)射(she)進(jin)入(ru)歐(ou)亞(ya)大(da)陸這(zhe)一過(guo)程(cheng)的(de)(de)反映。
在(zai)中國，東北(bei)地(di)(di)區(qu)和(he)(he)新疆的(de)(de)泰加林是歐(ou)亞紅松(song)鼠(shu)(shu)(shu)的(de)(de)天然分布范圍。而(er)華北(bei)等(deng)地(di)(di)的(de)(de)闊葉林和(he)(he)針闊混(hun)交(jiao)林中分布更(geng)為廣泛(fan)的(de)(de)松(song)鼠(shu)(shu)(shu)是巖松(song)鼠(shu)(shu)(shu)。巖松(song)鼠(shu)(shu)(shu)體型較歐(ou)亞紅松(song)鼠(shu)(shu)(shu)小，耳朵(duo)上不具(ju)有長(chang)毛簇，色偏灰黃，更(geng)多(duo)地(di)(di)會(hui)下到(dao)(dao)(dao)地(di)(di)面上活動(dong)，尤其(qi)在(zai)多(duo)巖地(di)(di)帶(dai)，因(yin)此得名。而(er)花鼠(shu)(shu)(shu)也(ye)(ye)是中國溫帶(dai)地(di)(di)區(qu)常見的(de)(de)松(song)鼠(shu)(shu)(shu)。這種背(bei)部長(chang)有黑白(bai)相間縱紋(wen)的(de)(de)小動(dong)物(wu)會(hui)花更(geng)多(duo)的(de)(de)時間在(zai)地(di)(di)面覓食，并常捕食小動(dong)物(wu)，還嗜(shi)啃食樹皮。赤(chi)腹松(song)鼠(shu)(shu)(shu)甚為膽(dan)大(da)，且可(ke)適應受(shou)到(dao)(dao)(dao)干擾(rao)的(de)(de)林緣(yuan)生(sheng)(sheng)境，因(yin)此也(ye)(ye)能很好地(di)(di)生(sheng)(sheng)活在(zai)城(cheng)(cheng)(cheng)市公園(yuan)綠地(di)(di)中。在(zai)上海(hai)、廣州、成都和(he)(he)昆明等(deng)大(da)城(cheng)(cheng)(cheng)市的(de)(de)城(cheng)(cheng)(cheng)市公園(yuan)及周邊(bian)地(di)(di)區(qu)都生(sheng)(sheng)存著赤(chi)腹松(song)鼠(shu)(shu)(shu)，也(ye)(ye)是中國南方城(cheng)(cheng)(cheng)市居民最(zui)易見到(dao)(dao)(dao)的(de)(de)野(ye)生(sheng)(sheng)哺乳動(dong)物(wu)。
松(song)鼠(shu)全年(nian)活(huo)動(dong)(dong)(dong)，不(bu)(bu)冬(dong)眠(mian)，為日(ri)(ri)行性(xing)動(dong)(dong)(dong)物，每日(ri)(ri)開(kai)始活(huo)動(dong)(dong)(dong)時(shi)(shi)間(jian)與(yu)(yu)日(ri)(ri)出時(shi)(shi)間(jian)有關，而結束活(huo)動(dong)(dong)(dong)時(shi)(shi)間(jian)與(yu)(yu)日(ri)(ri)落時(shi)(shi)間(jian)無明顯(xian)關聯。松(song)鼠(shu)的(de)(de)(de)日(ri)(ri)活(huo)動(dong)(dong)(dong)節(jie)律受(shou)氣候條(tiao)件的(de)(de)(de)影(ying)響(xiang)，大風、暴雨和(he)嚴寒(han)酷暑都(dou)會(hui)(hui)減少松(song)鼠(shu)的(de)(de)(de)活(huo)動(dong)(dong)(dong)時(shi)(shi)間(jian)。覓食需要和(he)留(liu)在(zai)(zai)(zai)巢(chao)中保(bao)存能量的(de)(de)(de)權衡(tradeoff)影(ying)響(xiang)著松(song)鼠(shu)冬(dong)季的(de)(de)(de)活(huo)動(dong)(dong)(dong)格(ge)局(ju)。冬(dong)季日(ri)(ri)活(huo)動(dong)(dong)(dong)節(jie)律呈(cheng)單峰型，在(zai)(zai)(zai)嚴寒(han)天氣條(tiao)件下也(ye)會(hui)(hui)留(liu)在(zai)(zai)(zai)巢(chao)中幾天不(bu)(bu)活(huo)動(dong)(dong)(dong)。夏(xia)季則在(zai)(zai)(zai)上午(wu)和(he)下午(wu)各(ge)出現一個(ge)活(huo)動(dong)(dong)(dong)高峰,。春季和(he)秋季的(de)(de)(de)日(ri)(ri)活(huo)動(dong)(dong)(dong)格(ge)局(ju)介(jie)于冬(dong)、夏(xia)之間(jian)。
松(song)(song)鼠(shu)70%～80%的時間都用(yong)于覓食(shi)(shi)(shi)(shi)活動，傾(qing)向于在針葉林中覓食(shi)(shi)(shi)(shi)和貯(zhu)食(shi)(shi)(shi)(shi)。秋(qiu)季松(song)(song)鼠(shu)將堅果分(fen)散貯(zhu)藏(zang)于地(di)面(mian)，將真菌貯(zhu)藏(zang)于樹枝上。秋(qiu)季貯(zhu)食(shi)(shi)(shi)(shi)有利于松(song)(song)鼠(shu)越冬和第(di)二年的生育。松(song)(song)鼠(shu)貯(zhu)食(shi)(shi)(shi)(shi)微(wei)生境(jing)選擇及(ji)貯(zhu)食(shi)(shi)(shi)(shi)重取機制得(de)到(dao)了深入的研究，成為當前國內(nei)松(song)(song)鼠(shu)生態學研究的熱點。
松(song)鼠大(da)(da)(da)部分時間獨居。社群結構建(jian)立在同(tong)(tong)性(xing)間和(he)兩(liang)性(xing)間的(de)(de)優(you)勢(shi)序列基礎上，優(you)勢(shi)個(ge)體(ti)體(ti)型(xing)通(tong)常較其他個(ge)體(ti)大(da)(da)(da)。等級(ji)優(you)勢(shi)通(tong)常僅在生殖(zhi)季(ji)節才(cai)得以(yi)體(ti)現。松(song)鼠會用尿液和(he)下(xia)頜腺的(de)(de)分泌物(wu)在樹干和(he)樹枝(zhi)上涂抹,以(yi)標記家(jia)(jia)域(yu)(homerange)。松(song)鼠的(de)(de)家(jia)(jia)域(yu)大(da)(da)(da)小(xiao)與(yu)生境質(zhi)量、季(ji)節、性(xing)活(huo)動及食(shi)物(wu)豐度相關，不同(tong)(tong)分布區家(jia)(jia)域(yu)大(da)(da)(da)小(xiao)差別很大(da)(da)(da)，但通(tong)常雄性(xing)家(jia)(jia)域(yu)大(da)(da)(da)于(yu)雌性(xing)，優(you)勢(shi)個(ge)體(ti)家(jia)(jia)域(yu)大(da)(da)(da)于(yu)次級(ji)個(ge)體(ti)。在食(shi)物(wu)豐富的(de)(de)地區,家(jia)(jia)域(yu)會出現小(xiao)范圍的(de)(de)重(zhong)疊。
松(song)(song)鼠營巢(chao)(chao)居(ju)生活，也可(ke)以利(li)用(yong)樹(shu)(shu)(shu)洞和(he)鳥(niao)巢(chao)(chao)。每個(ge)(ge)個(ge)(ge)體通常同(tong)時占有(you)2～3個(ge)(ge)巢(chao)(chao)。由(you)于(yu)杉樹(shu)(shu)(shu)枝(zhi)葉相(xiang)對松(song)(song)樹(shu)(shu)(shu)更為濃密，在(zai)(zai)(zai)人(ren)工林(lin)(lin)中，松(song)(song)鼠通常選(xuan)擇在(zai)(zai)(zai)杉樹(shu)(shu)(shu)上(shang)營巢(chao)(chao)。天然(ran)林(lin)(lin)中的(de)(de)(de)(de)巢(chao)(chao)址選(xuan)擇問題未見報道。巢(chao)(chao)大(da)部分(fen)營建(jian)在(zai)(zai)(zai)距地(di)面8～16m的(de)(de)(de)(de)樹(shu)(shu)(shu)枝(zhi)上(shang)，靠近樹(shu)(shu)(shu)干或者(zhe)位于(yu)樹(shu)(shu)(shu)枝(zhi)分(fen)叉處(chu)，分(fen)為日間(jian)使用(yong)的(de)(de)(de)(de)休息(xi)巢(chao)(chao)和(he)夜間(jian)使用(yong)的(de)(de)(de)(de)睡(shui)眠巢(chao)(chao)兩種類(lei)型(xing)，通常呈球形，直徑約(yue)30cm，外層(ceng)由(you)細枝(zhi)、松(song)(song)針和(he)樹(shu)(shu)(shu)葉筑成，內(nei)徑約(yue)12～16cm，覆以苔(tai)蘚、樹(shu)(shu)(shu)葉、松(song)(song)針、干草(cao)和(he)枝(zhi)皮(pi)等柔軟的(de)(de)(de)(de)材料。冬(dong)季(ji)松(song)(song)鼠巢(chao)(chao)內(nei)形成一個(ge)(ge)微氣候環境，溫度能高出巢(chao)(chao)外20～30°C，從而減(jian)少(shao)(shao)了機(ji)體體溫調節所消耗的(de)(de)(de)(de)能量，減(jian)少(shao)(shao)了暴露在(zai)(zai)(zai)巢(chao)(chao)外低溫、大(da)風(feng)中的(de)(de)(de)(de)時間(jian)，這是(shi)生活于(yu)北溫帶(dai)地(di)區的(de)(de)(de)(de)松(song)(song)鼠冬(dong)季(ji)生存(cun)策略之一。在(zai)(zai)(zai)寒冷(leng)的(de)(de)(de)(de)冬(dong)季(ji),也會出現幾(ji)只松(song)(song)鼠分(fen)享同(tong)一個(ge)(ge)巢(chao)(chao)以維持體溫的(de)(de)(de)(de)現象。
松鼠沒有明(ming)顯的(de)(de)(de)遷徙，但有短距離的(de)(de)(de)擴(kuo)(kuo)(kuo)散(san)行為，包括由越冬地(di)向(xiang)外的(de)(de)(de)擴(kuo)(kuo)(kuo)散(san)和由出生(sheng)地(di)向(xiang)外的(de)(de)(de)擴(kuo)(kuo)(kuo)散(san)。本地(di)競爭決定了(le)種群松鼠生(sheng)態(tai)學研究現狀(zhuang)與展望擴(kuo)(kuo)(kuo)散(san)距離。研究表明(ming)，不(bu)同性別在(zai)(zai)(zai)擴(kuo)(kuo)(kuo)散(san)季節上存在(zai)(zai)(zai)差異，大部(bu)分雄性個(ge)(ge)體在(zai)(zai)(zai)春季擴(kuo)(kuo)(kuo)散(san)，而雌(ci)(ci)性通常在(zai)(zai)(zai)秋(qiu)季擴(kuo)(kuo)(kuo)散(san)。雌(ci)(ci)性個(ge)(ge)體的(de)(de)(de)擴(kuo)(kuo)(kuo)散(san)受食物的(de)(de)(de)影響，雄性的(de)(de)(de)擴(kuo)(kuo)(kuo)散(san)則取決于(yu)雌(ci)(ci)性的(de)(de)(de)分布。
松(song)鼠(shu)的生(sheng)殖(zhi)狀(zhuang)態與(yu)食物獲取(qu)(qu)狀(zhuang)況密切相關。每(mei)年(nian)可以(yi)有(you)兩(liang)次生(sheng)育(yu)，分別在2、3月和7、8月交(jiao)(jiao)配(pei)，妊娠(shen)期(qi)約為38～39d。但如果食物獲取(qu)(qu)不足(zu)，則春季交(jiao)(jiao)配(pei)會被推遲或消(xiao)失。婚配(pei)制度(du)是一雄(xiong)(xiong)多雌(ci)(ci)(ci)制或混交(jiao)(jiao)制。交(jiao)(jiao)配(pei)前有(you)求偶行為，通常優(you)勢(shi)雄(xiong)(xiong)鼠(shu)會擁有(you)更多的交(jiao)(jiao)配(pei)機會。初(chu)生(sheng)雌(ci)(ci)(ci)鼠(shu)通常第二(er)年(nian)開(kai)始生(sheng)育(yu)，其(qi)生(sheng)殖(zhi)能力與(yu)體(ti)重(zhong)密切相關，只有(you)超(chao)過一定(ding)體(ti)重(zhong)閾的雌(ci)(ci)(ci)性松(song)鼠(shu)才具備(bei)生(sheng)育(yu)能力，而(er)且體(ti)重(zhong)越(yue)大(da)能夠生(sheng)育(yu)的后代越(yue)多。幼(you)仔(zi)由雌(ci)(ci)(ci)鼠(shu)單(dan)獨哺育(yu)，哺乳期(qi)超(chao)過10周。
