So, how did Noah manage to gather and load so many animals from so many different distant areas on earth?
Gathering the animals ─ Many believe that God used His special powers
to draw the animals to the ark because God seems to have told Noah,
"Two of every kind... will come unto thee." (Gen 6:20 BSB)
However, the Hebrew word בּוֹא (Strong #935) for
"will come" in verse 20 was translated as "you are to
bring" in verse 19. Translators may have thought it sounded nicer that the
animals would bring themselves to Noah. Assuming God did call the
animals for Noah, questions remain, such as how animals from extremely cold
climates, such as polar bears, survived the trek through hot, arid lands or how
animals such as the koala bear survived a trek through thousands of miles of
eucalyptus-free wilderness. The Bible doesn't mention animal journeys to the
ark. With a top speed of 0.003 MPH, sloths would need to start their
journey many years in advance of the flood. Porting animals across oceans and rivers ─ The children's version of the story includes animals that lived across the ocean from Noah's home such as the lemurs that only live in Madagascar, the kiwis that only live in New Zealand, the Tasmanian devil, the kangaroos, and the duckbilled platypuses that only live in Australia. The Bible doesn't say how such animals cross the oceans and rivers to reach the ark.
Keeping animals until all had arrived ─Noah would have needed a huge wilderness reserve with all the conditions necessary to support the animals as they arrived. He would been too busy building the boat and storing feed and food to keep them in pens. There is nothing in the Bible to suggest that all animals arrived right on loading day.
Preventing animals from killing each other ─ As the animals gathered at the ark, ravenously hungry from their journeys, the urge to eat each other would normally have been irresistible for the carnivores. The Bible doesn't say how Noah managed to prevent this.
Acquiring enough food and feed ─ The Bible says Noah boarded the ark on day 7 of month 2 of his 600th year and disembarked on day 27 of month 2 of his 601st year. So, he had to water and feed all the people and animals for 375 or 376 days. The Saint Louis Zoo, of moderate size, feeds 462 tons of hay, fresh produce, and meat per year. That equates to about 18 loads on 18-wheeler trucks. That's a lot of food for a family eight to raise and store while making a living for themselves and building an ark on the side.
Loading so many animals into the ark ─ As the story is traditionally told, the animals marched up the ramp, into the ark, and right to the correct pens without needing to be sorted and herded one way or the other. The Bible mentions that the ark three stories and rooms. Getting wild animals to happily walk in, down a hall, up a ramp to an upper story, down another hall and into a small cage would normally be near impossible. But the Bible doesn't mention any difficulties. And, if God chose animal families instead of species so that all would fit on the ark, Bible literalists would need to acknowledge accelerated evolution to explain the plethora of genera and species now seen on Earth. Fossil evidence contradicts such fast evolution.
Managing animals onboard ─ Saint Louis Zoo has 6 or 7 keepers who care for the animals, watering, feeding, bathing, and cleaning pens. However, the ark likely did not have indoor plumbing or waste drainage or automation to assist in hauling food or waste. The Bible does not hint at any difficulties caring for the animals for a year and ten days.
Dispersing all animals to their homeland across oceans ─ Unloading
the ark should have been as easy as opening its door and all the internal pens.
But Noah needed some domesticated animals for his livelihood and for
sacrificial offerings to God. The bulk of the animals presumably would
need to be guided to the far regions of the earth where they now live. The
Bible does not say how the animals managed to conquer the vast distances, the
lack of food, the huge rivers, the impassible mountain ranges, and the huge
oceans on the way to their final homes.To make the story feasible and believable, apologists suggest that all the continents and islands of the earth were together during Noah's day, so there were no oceans to cross on the way to the ark. And, either land area was configured without large rivers and impassible mountains or all types of animals lived in Noah's neighborhood and wandered to their current locations after the flood using various land bridges of the day. Also, many species should have been able to survive the flood without access to the ark. Animals such as the koala bear did not need a special diet in Noah's day and the sloth was not too slow to make it back to the Americas back in Noah's day. Such species suffered from post-flood genetic degradation. The saltwater fish survived with a little less salt and the freshwater fish survived with a little more salt so that Noah didn't have to maintain aquariums on the ark. All such theories require the believer to reject virtually all of modern geology and earth physics while still suffering from unanswered questions.
Young-earth creationists have to stretch their imaginations even further to accommodate the various
dinosaurs. If Noah only took genera on board, such as dogs, cats, and so forth, he would also have taken at least 1,245 genera of dinosaurs that later diversified into the various species. (Wiki)
It's likely generalized words used in the translations from the Hebrew text don't have the all-inclusive meanings traditionally ascribed to them. For example, after exiting the ark, "Noah builded an altar unto the LORD; and took of every clean beast, and of every clean fowl, and offered burnt offerings on the altar." Clean beasts include all cud-chewing, split-hooved animals such as sheep, goats, deer, oxen, giraffes, gazelles, bison, etc. (Leviticus 11:3; Deuteronomy 14:6) There are over 10,000 species of birds. The list of clean beasts and fowls is very long. Did Noah actually sacrifice every clean beast and fowl?
So, rather than having Noah save tens of thousands of species of animals, it makes more sense to think of Noah saving the only those types of beasts and birds native to his neighborhood that could be domesticated and managed as livestock or pets.