The southern right whale cavorting in the harbour for nearly a fortnight earlier this month captivated Wellingtonians.

People find these great creatures, once hunted to the verge of extinction, endlessly fascinating.

And whales in our coastal waters and harbours are likely to become much more common sights.

The number of humpbacks migrating from Antarctic waters through Cook Strait to their breeding grounds in the South Pacific has increased dramatically.

The Department of Conservation and a group of former whalers have recorded an increase from 25 just over a decade ago to 187 last year.

Commercial whaling ended in New Zealand in 1964 when it was deemed no longer economic.

Humpbacks and right whales were the major species killed.

Fur seals are also on the comeback in a big way.

Commercial sealing was banned in 1894. The estimated population around the country at numerous colonies has now grown to at least 50,000 but perhaps double that.

Gannets – spectacular hunters that plunge into the sea like missiles – were nearly wiped out on the mainland in the late 19th century, their eggs a delicacy to Maori.

Cape Kidnappers was the sole refuge for about 50 surviving birds but is now home to about 5000. At least another 12 nesting sites have become established from Northland to Farewell Spit in the last century, home to an estimated 100,000 birds.

We commonly hear hundreds of New Zealand animal species are in danger of extinction but some natives are clearly headed the other way, becoming more numerous.

Former DSIR scientist, cartoonist and current Dominion Post columnist Bob Brockie is among those who believe some conservationists sounding alarms overstate their case.

He has assiduously counted roadkill for nearly 60 years as one means of assessing populations.

In the 1950s he rarely saw a squashed pukeko.

“These days some roads look like pukeko bowling alleys,” he says.

The last creature to be recorded as becoming extinct in New Zealand was the bush wren in 1972, according to Brockie.

No marine species have been listed as being lost.

The only known fish species to disappear is the freshwater grayling, last seen in the early 1930s, which succumbed to destruction of its lowland river habitat.

Tui birdsong, absent for decades, is now common in places like Hamilton thanks to determined pest control and more planting of food trees.

The Zealandia reserve in Wellington has had a profound effect on birdlife.

A national count last year of our handsome native pigeon, the kereru, put numbers at 15,459. Their distinctive heavy wingbeat is again being heard in some city margins.

In the marine environment the fishing industry is a popular whipping boy but the often alarmist claims of its impacts do not withstand scientific scrutiny.

That is not to deny there is some small endangered species bycatch but the industry is taking numerous steps to reduce or eliminate that.

The yellow-eyed penguin (hoiho), a sub-Antarctic species, has recolonised on the mainland, as have sea lions.

That has brought the problem of one threatened species harming another.

Mammal scientists studying prey remains on the Otago peninsula believe female sea lions may be eating as many as 20-30 penguins a year.

Sharks, barracouta and fur seals are also penguin predators.

Seabird numbers are generally stable, although there is real concern about the Antipodean albatross, which forages as far as Chile.

Ornithologist Colin Miskelly was quoted in last Saturday’s Dominion Post that “Asian fishing fleet crews are so starving we think they’re deliberately catching albatross to eat… that is probably the greatest threat to New Zealand albatross”.

Overall, there is no cause for complacency but the fact remains a number of our species are doing relatively well, decline is not inevitable.