Mast Baharon Ka Main Aashiq | Mohammed Rafi | Farz 1967 Songs | Jeetendra, Aruna Irani (Mai 2024)
Must karu (Ursus americanus), keda nimetatakse ka ameerika karuks, kõige tavalisem karu (perekond Ursidae), mida leidub Põhja-Ameerika metsades, sealhulgas Mehhiko osades. Ameerika must karu koosneb ainult ühest liigist, kuid tema värv varieerub isegi sama pesakonna liikmete seas. Valged märgid võivad esineda rinnal, mõnikord V-vormingus. Sõltuvalt nende värvivariatsioonidest nimetatakse musti karusid sageli kaneelikarudeks, sini-halli või sini-musta liustikukarudeks ja valgeteks karudeks (leidub peamiselt printsessil) Kuninglik saar, Briti Columbia). Mustad karud, mis on tegelikult pruuni värvi, on kõige tavalisemad Põhja-Ameerika lääneosas. Neid nimetatakse mõnikord pruunkarudeks, kuid tõeline pruunkaru (Ursus arctos; Põhja-Ameerikas nimetatakse seda ka grizzly karuks) on palju suurem.
Must karu on suur ja jässakas ning lühikese sabaga. Täiskasvanute pikkus on 1,5–1,8 meetrit (5–6 jalga) ja nad kaaluvad 90–270 kg (200–600 naela). Isased võivad olla kuni 70 protsenti raskemad kui naised. Pea on väike, kuid seda toetab tugev kael. Kõrvad on väikesed ja ümarad. Kumerad küünised ei ole retraktiilsed ning erinevalt kassidest ja koertest kõnnivad karud jalgade tallal (plantigrade liikumine).
Ehkki mustad karud on liigitatud lihasööjateks, on neil kõigesööja toitumine. Kevadel tarbivad nad talvel surnud loomade tärkavaid taimi ja korjuseid. Suvel domineerivad dieedis puuviljad ning sügisesest toidust moodustavad suurema osa nii puuviljad kui ka mast, eriti tammetõrud ja mesilased. Oportunistlike toitjatena söövad mustad karud ka männikäbisid, juuri, sipelgaid ja mett mets- või kodulindudelt. Sellegipoolest on mustad karud tugevad röövloomad ja mõnes piirkonnas tapavad nad kevaditi sageli põdravasikaid ja hirvepoisid. Inimeste lähedal elavad mustad karud kohanduvad hõlpsalt alternatiivsete toiduallikatega, näiteks prügimägedest või kämpingutest pärit prügi ja turistide jaotusmaterjalidega parkides. Inimeste kohtumised mustade karudega võivad mõnikord põhjustada vigastusi või surma ning rünnakuid teatatakse igal aastal. Peaaegu kõigil juhtudelüllatuskohtumiste vältimine on parim kaitse, kuna mustad karud eelistavad inimesi vältida.
Throughout most of their range, black bears become dormant during winter. They spend the winter in dens located in rock crevices, in underground burrows, under tree roots, in hollow trees, in brush piles, or simply on open-ground beds. Prior to winter sleep, bears must accumulate large quantities of body fat during late summer and fall. Not only does this enable them to survive the long period of winter fasting, but it also allows them to have sufficient energy in spring when they emerge and food is rare. For females, the amount of fat stored before winter is linked with reproductive success: fatter females typically have more and bigger young than do leaner females. Accumulating fat for the winter is thus a strong drive, and it explains the constant search for food through the summer and fall.
Black bears are not territorial; they are mostly solitary, and the home ranges of both males and females may overlap. Home ranges typically are larger where food is less abundant and smaller where food is plentiful. Throughout Canada and the United States, home ranges of black bears extend from about 40 to 200 square km (15 to 77 square miles) for males but are considerably smaller for females. Breeding begins in the spring and peaks during June and July. Black bears are promiscuous, males and females often mating with several individuals. Implantation of the fertilized egg is delayed, occurring in November or December. Actual gestation then lasts 60–70 days, and one to four young cubs are born in January or February. Born blind, fully furred, and toothless, the cubs remain with the mother for 16 months, and the female breeds every second or third year. Although the mother is very protective of her litter, young cubs may be killed by coyotes, wolves, brown bears, or other black bears. Black bears can live for more than 20 years in the wild, but in areas near human habitation most black bears die sooner as a result of hunting, trapping, poaching, nuisance removal near campgrounds or dumps, and collision with vehicles.
In natural habitats, black bears are active during the day. However, in areas of high human activity such as dumps and campsites, black bears often become nocturnal to avoid encounters with humans. Even so, black bears habituate quickly to handouts given by tourists, and this lack of fear of humans often leads to conflicts. In parks, human-habituated bears often must be killed as they become hazardous around campsites. Not feeding wild black bears is therefore better for both humans and bears. The black bear may be tamed and taught various tricks, and it is a common performer in circuses and other animal acts.
The Asiatic black bear (Ursus thibetanus) is similar to the American black bear in size and appearance.
