...Sense, is it??? Birds of a feather,...
...Sociological Studies Show: Birds of a feather,...

...eaten by the birds that are the...
...other herbivores. The birds benefit, increasing their...
...benefit because the birds are opportunistic feeders...
...the herbivores. The birds may also warn...
...No mammals or birds were harmed by...
...and feces of birds. Most of these...
...effects on wild birds but cause more...
...symptoms in domesticated birds, the most common...
...that quarantine domestic birds or monitor their...
...movements of wild birds. From 2003 to...
...for infected wild birds to enter the...
...and testing migrating birds in Alaska, trying...

...of speedy fishes, birds, and marine mammals...
...animals, such as birds and mammals, use...
...in mammals and birds is insulation: hair,...
...Land mammals and birds react to cold...
...directions. In many birds and mammals, heat...
...Many mammals and birds live in places...
...is important in birds and many mammals....
...many mammals. Some birds have a pouch...
...of the mouth. Birds flutter the pouch...
...Reptiles other than birds also thermoregulate behaviorally....
...thermogenesis, mammals and birds may increase their...
...acclimatize differently. In birds and mammals, acclimatization...
...infections, mammals and birds develop fever, an...
...Penguins, like most birds, do not grow...
...small mammals and birds exhibit a daily...

...amphibians, reptiles (including birds), and mammals. There...
...amphibians, reptiles (including birds), and mammals. According...
...and reptiles (including birds). The evolution of...
...turtles, crocodilians, and birds, as well as...
...not entirely ectothermic. Birds are endothermic, capable...
...later taken by birds; some were insect-eaters,...
...the ancestors of birds. There is continuing...
...gave rise to birds was certainly endothermic,...
...endothermic, like all birds. There is increasing...
...all dinosaurs (except birds) became extinct. It...
...reptiles (apart from birds) alive today. Most...
...tropics and subtropics. Birds evolved as feathered...
...organs. For instance, birds lack a urinary...
...in size. Modern birds are toothless and...
...Flight enables many birds to catch flying...
...It enables many birds to migrate great...
...an active metabolism. Birds are endothermic, using...
...four-chambered heart keep birds’ tissues well supplied...
...and oxygen uptake. Birds have acute vision...
...large brains of birds (proportionately larger than...
...the breeding season, birds engage in elaborate...
...reptilian ancestors of birds were theropods. In...
...closely related to birds had feathers with...
...seen in some birds today. Dinosaurs could...
...Fossils of later birds from the Cretaceous...
...shared by all birds today, including a...
...orders of living birds, arose before the...
...years ago. Most birds can fly, but...
...a few flightless birds, the ratites, which...
...of all flying birds similar. The beak...
...The beak of birds is very adaptable,...
...considerable variation. Various birds use their feet...

...drought. Of 1200 birds, only 180 survived....
...The proportion of birds with large beaks...
...population increased because birds with large beaks...
...two populations of birds remained in Illinois,...
...fewer than 50 birds. The few surviving...
...The few surviving birds had low levels...
...Ten of the birds were collected in...
...brought in 271 birds from neighboring states....
...black-bellied seedcrackers. Larger-billed birds are more efficient...
...seeds, and smaller-billed birds are more efficient...
...on soft seeds. Birds with intermediate bills...
...may make male birds more visible to...
...situations. For example, birds might benefit from...
...four legs. However, birds descended from reptiles...

...influence breeding in birds increased day length...
...of year, parent birds can find an...
...success compared to birds that breed in...
...for feeding young birds, breeding when days...
...is innate in birds. The world provides...
...migratory behaviour in birds are genetically programmed....
...the best-studied migratory birds is the blackcap...
...and auditory signals. Birds are diurnal and...
...and songs of birds than the rich...
...songs of most birds are at least...
...food was stored). Birds can learn that...
...of songs by birds has revealed varying...
...response. The young birds learn the songs,...
...southwest Germany. The birds were caged in...
...paper. As the birds moved around the...
...of wintering adult birds captured in Britain...
...laboratory-reared offspring. Young birds originally from Germany...
...of the young birds. Has the behaviour...
...Most newly hatched birds cannot care for...
...is why most birds are monogamous. Birds...
...birds are monogamous. Birds with young that...

...IN SPECIES NUMBERS (BIRDS) 6Estimating Extinction RatesModel...
...of large ground birds and insectivorous birds...
...birds and insectivorous birds of forest canopy...
...narrow ranges (island birds, freshwater fish) have...
...in Kenya½ OF BIRDS LOST 50 YEARS...
...1000 KM½ OF BIRDS LOST 100 YEARS...

...(IMPORTANT).Megafauna = MAMMALS, BIRDS, REPTILES OVER 44...
...terrestrial vertebrates (especially birds and mammals)More conspicuousWell...
...species)129 species of birds (1.3% of all...
...of extinctions of birds during 25 year...
...of extinction of birds and mammals =...
...example:100 species of birds/mammals went extinct between...
...8000 populations of birds driven to extinction.In...