I have lived in a bushland area of Wamboin for nearly three decades, and over the past few years have noticed a decline in the numbers of many species of birds, lizards and micro-bats.

The common denominator, of course, is that they all feed exclusively or partly on insects. Night-flying insects are now scarcer and what used to be annual invasions of bogong moths and Christmas beetles no longer happen. Habitats such as decaying (but now usually dry) logs and the spaces under tree bark are almost devoid of insects.

Professor Lindenmayer states that we must conserve "entire ecosystems and all the species that live in them". Insects are an essential component of land and water ecosystems and an integral part of the food chain our fauna are dependent on.

Some long-term monitoring of insect populations and the effects on them of decreasing rainfall and increasing temperatures might shed some light on the decline of some insect-eating species.

After so many kangaroos have been killed without halting the decline of insectivores, it would seem to indicate that something other than kangaroo grazing is the problem.

Jo Walker, Wamboin

Journalist James Hall has done a worthy job of quoting the differing viewpoints of three of the scientists engaged in the debate over the ACT government's kangaroo slaughter.

David Lindermayer's views are, of course, well-known and long dismissed by most of the people who oppose the government's slaughter on ecological grounds.

It is refreshing to see some words from Ramp and Newman for a change. Lindermayer chooses to dismiss the inhumaneness of the slaughter, implying that being humane is somehow at odds with protecting the environment.

As both an environmental scientist and an animal advocate myself, I do not know of any situation where that has ever been the case.

In a final quote at the end of the article, an ACT government spokesman pipes up with assurances that "procedure is in place to protect kangaroo young". He neglects to mention that this procedure is to bash them to death or decapitate them.

He also assures us that killing kangaroos in autumn and winter minimises the chance of orphaning dependent joeys.

Anyone who has seen the dozens of orphaned dependent joeys crowding the street edges after a night of shooting between March 1 and July 31 knows just how completely this policy is failing.

Frankie Seymour, Queanbeyan

Isn't Scott Morrison wonderfully tolerant for asserting he has "always respected everybody else's faith and always sought to respect everybody else's view"? ("Treasurer defends anti-gay advocacy", April 24, p3).

How can he be so intellectually lazy? There is a difference between the person and the view. People should be shown respect, even those with offensive views, however difficult that may be.

But all views respected? No view or idea, religious or not, is above criticism and should be examined, debated and critically evaluated. And labelled as offensive, illogical, stupid or plain wrong when they are not supported by evidence.

The views of Eric Metaxas, the keynote speaker at the Australian Christian Lobby conference and whose views Scott Morrison respects, are all of the above: offensive, illogical, stupid and wrong.

Judy Aulich, Giralang

In the article "Turnbull government's mixed messages on middle-class tax cuts" (Sunday CT, April 24, p4), it is mentioned that the government is planning to cut the company tax rate from 30 per cent to 28.5 per cent in a move that will be pitched as necessary to spark more investment.

Investment decisions are usually made by assessing the merits of a proposal and its desirability against a set of criteria. These can include the future benefits in terms of profitability, and determining whether the proposal is the most desirable after allowances are made for the uncertainty of the future and the risk that current estimates and forecasts may be inaccurate.

There are several other issues that are also considered, including the cost of capital, rate of return and a review of the proposal and the assessment of its overall risk.

The Australian company tax rate has fluctuated between 49 per cent in 1987 to 30 per cent in 2001 where it has stayed without any great lift in the rate of investment during that period.

Given the number of Australian companies that do not pay tax, it seems unlikely that a reduction of 1.5 per cent in the company tax rate will start a boom in capital investment in Australia.

Les Brennan, Sunshine Bay, NSW

I was amazed to see the Phillip Business Community ("Plea for Phillip parking crackdown, Sunday CT, April 24) asking the government for special treatment.

In spite of massive rate increases imposed on all Canberrans, the fundamentals are still being overlooked. The Phillip Business Community must sit back, like the rest of us, and just accept the poor quality of management and services offered by this government.

The highly paid CEOs of departments should get out and about with their ministers, inspect the neglect and resolve to develop a plan. Lobby groups can then be directed to a program.

We are all suffering from the poor level of management of the municipal services enjoyed by other cities that have a plan and lower rates.

John Whitty, Hawker

The Pirate Party Boat had 15 holes from corrosion. A consultant said the problem lay with the environment or the shore power stray currents are transferred through the earth line ("Power corrosion could have sunk party boat", Sunday CT, April 24, p6).

Tram lines are the return earth lines for the tram power. The tram lines do generate stray currents which do corrode metal pipes and metal structures in the ground. The internet has numerous reports about the consequences.

In contrast, bus lanes do not create corrosion problems.

John Simsons, Holt

Moya Homan (Sunday CT Letters, April 24) claims that ACL is being denied the right to state their views. The fact that we are aware of these views shows this to be incorrect.

David Grills, Kambah

Email: letters.editor@canberratimes.com.au. Send from the message field, not as an attached file. Fax: 6280 2282. Mail: Letters to the Editor, The Canberra Times, PO Box 7155, Canberra Mail Centre, ACT 2610.

Keep your letter to 250 words or less. References to Canberra Times reports should include date and page number. Letters may be edited. Provide phone number and full home address (suburb only published).