Nesting seasons by country: the dates wildlife agencies publish

This page reports what the official source says. It is not legal advice: ask the office named here. It covers only the dates and the sentences around them. The laws behind them, the bat rules and the agencies to call are on the birds, bats and the law guide. Each source below says what its dates cover.

At a glance

Place	Dates the source gives	Source
United States	No national window. For swallows, the breeding season lasts from March through September	USFWS, nuisance swallows page
Canada	General nesting periods by zone, starting as early as mid-March and ending as late as late August; zone table below	Environment and Climate Change Canada
England	Not published as dates: the page says all wild birds, eggs and nests are protected, and that timing work to avoid the breeding season is how harm is usually avoided	GOV.UK, Natural England and Defra, March 29, 2015
Northern Ireland	March 1 to August 31 for cutting hedges, trees or scrub	DAERA, July 9, 2020
Ireland	March 1 to August 31 for vegetation on uncultivated land and in hedges or ditches	National Parks and Wildlife Service notice, March 1, 2016
Australia	No official page found on October 9, 2026 giving a national window	Not applicable
New Zealand	No official page found on October 9, 2026 giving a bird nesting window. DOC's bat protocol says trees with potential roost features must not be cut down in winter	DOC bat protocol, version 4, October 2024

United States

The USFWS page on nuisance swallows says the breeding season for swallows lasts from March through September. It says active nests with eggs or chicks may not be touched or destroyed without a permit and that empty nests do not need one. The agency does not publish a single national window for all species. The nest rules and the eagle and bat rules are on the wildlife guide.

Canada: the zone table

Environment and Climate Change Canada calls its dates general nesting periods. Its overview says a period begins with first egg-laying, ends when the young have naturally left the nest's vicinity, and leaves out nest building, which it says can take a few days to about 2 weeks. It says the estimates can vary by 10 days or more and are generally later at higher latitudes. It says birds may nest outside the dates but the chance of an active nest is then much lower, though not zero. It lists birds not under federal jurisdiction, such as jays, owls and hawks, and species that can nest in winter, such as Red Crossbills, as outside the periods. The dates come from 640,000 nest observations from 180,000 nests, and include 264 of 364 federally protected breeding species.

Sub-zone	General nesting period
A1 (zone A: northern Pacific rainforest, Great Basin, northern Rockies)	Late March to mid-August
A2	Early April to mid-August
A3	Mid-April to mid-August
A4 and A5	Late April to mid-August
B3 and B4 (zone B: prairie potholes, boreal taiga plains, northwestern interior forest)	Mid-April to late August
B5	Late April to late August
B6	Late April to mid-August
B7 and B8	Early May to late August
B9	Mid-May to mid-August
C1 (zone C: lower Great Lakes and St. Lawrence plain, Atlantic northern forest, boreal hardwood transition, parts of the boreal shield)	Late March to late August
C2	Early April to late August
C3 and C4	Mid-April to late August
C5	Late April to late August
C6	Late April to mid-August
C7 and C8	Early May to mid-August
D3-4 (zone D: Quebec-Labrador and Newfoundland parts of the boreal shield)	Mid-April to mid-August
D5	Late April to mid-August
D6 and D7	Early May to mid-August
N8 and N9 (zone N: Arctic plains and mountains)	Mid-May to mid-August
N10	Late May to mid-August

United Kingdom

The GOV.UK page for England, from Natural England and Defra, gives no dates. It lists intentionally taking, damaging or destroying a wild bird's nest while it is being used or built as an offence, and names trimming or cutting trees, bushes, hedges and rough vegetation among activities that can affect birds, particularly during the breeding season. The Northern Ireland department DAERA, in a notice of July 9, 2020, quotes a CAFRE official saying that under cross-compliance rules cutting hedges, trees or scrub, including trimming and laying, is not permitted between March 1 and August 31, so that such work must have ceased on February 28. It adds that this can be a criminal offence under the Wildlife (NI) Order 1985 as amended, and that cutting in the period can be a cross-compliance breach unless needed for the safety of road users. The notice quotes the same official saying that in most cases roadside hedges should be cut in February.

Ireland

The National Parks and Wildlife Service notice of March 1, 2016 says Section 40 of the Wildlife Act 1976, as amended in 2000, restricts any cutting, grubbing or burning of vegetation on uncultivated land, in hedges and in ditches, and any other way of destroying it, from March 1 to August 31, which the notice calls the nesting and breeding season for birds and wildlife. It says the restrictions apply to private land users, local authorities, public bodies and contractors, that limited exemptions exist, such as work done for public health and safety reasons by a statutory body, and that it is the department's policy to prosecute where a breach appears. The notice is dated 2016 and mentions a Heritage Bill proposal that it says was not in force at that date.

Australia and New Zealand

No Australian national agency page giving a bird nesting window was found on October 9, 2026. The New Zealand Department of Conservation's protocol for felling trees that may hold bats says trees with potential roost features must not be cut down in winter; it covers bats, not birds. The details are on the wildlife guide. For the councils' own tree rules see the UK council tree rules and the Australia and New Zealand council rules.