Watching for what returns: the calendar of a migration

Every year the same animals come back, and every year the date is a little different. That is the whole puzzle of a migration for a shore watcher: the return is reliable enough to plan around and variable enough to punish anyone who plans too tightly. The calendar the animals keep is written in water temperature, daylight and food, none of which consults the watcher. What follows is how to read a calendar you do not control, taken from two coasts that keep it honestly.

Why do returning animals keep to a calendar nobody controls?

Because the calendar is not theirs either. A migrating animal is timing itself against cues it did not choose: light, temperature, the availability of food at the far end, the state of the water it must cross. The window a watcher calls “the season” is the overlap of those cues as seen from land, which is why a season has soft edges. The Minch season page in this journal gives the minke whale a window of months rather than a date, and the honest species entries in the register carry the same shape: April to October, May to October, present all year.

The instructive comparison sits on the other side of the Atlantic, where the returns are counted rather than glimpsed. On the Nushagak drainage of Bristol Bay, five species of Pacific salmon come up the same river system on five different clocks, and the field almanac at The Brush and the Bay keeps them separately: five salmon, five timings, each tracked against the sonar counts the fishery itself publishes. The lesson a Minch watcher can borrow is the separation: a single “fish are back” would hide everything the five calendars say.

Do all salmon of one river come back at the same time?

No, and the difference is the point. King, sockeye, chum, coho and pink salmon share a drainage and not a schedule: they pass the same counters weeks apart, under different management and different weather. The Nushagak counts, kept as the fish are still moving, are the kind of document this journal respects, a public number produced while the event is happening rather than a summary written afterwards.

The general biology behind the timing, run order, ocean age, the distance each species still has to travel, is set out in the species profiles the US fisheries service keeps, for instance its page on the chinook salmon. The detail matters less than the habit: a calendar is species by species, and an average of the five is a fiction.

What a return looks like from the shore

A migration read from land is rarely announced. What the watcher sees is a change in the background: birds working a tide line that was empty last week, a blow where the records said none were likely, a run of sightings that cluster once the food has arrived. The calendar is inferred from those shifts, which is why the first day of a return is usually only recognised in retrospect. The discipline that turns those shifts into dates is the fixed watch, and the same eye that reads birds and surface for signs of fish below is the one that notices a season turning: the two skills are cousins, and the note on reading the water from shore keeps to that side of it.

The Minch calendar as this journal keeps it

The same separation applies here. The season page gives the year its shape, the broad window inside which the summer species arrive. Within it, each species keeps its own pulse: minke whale in the June and July weeks, common dolphin arriving with the food, the humpback pulse the pooled records show from late autumn into winter, the porpoise present in every month. A watcher who reads only the broad window plans against a blur; the species calendars inside it are where the planning actually happens.

What the shore watcher cannot have is the Nushagak’s sonar. There is no counter on the Minch, only watches, so the calendar here is built from recorded effort: who watched, from where, in what conditions, and what was seen. That is a softer instrument, which is why the discipline of recording matters more, not less.

Choosing the week that is worth watching

A good watching week is an overlap, not a date: the species window, the weather window and the watcher’s own availability all at once. The species window narrows the choice to a month or two; the sea state entries in this register narrow it further to the days when the surface is readable; and the rest is judgement. The week worth watching is rarely the week of highest expectation, because the calm spell that lets you see matters as much as the animals that are theoretically there.

There is a second-order lesson in the salmon counters. The almanac does not print its own dates or counts; it points at the public documents that carry them. A watcher’s calendar deserves the same honesty: the month you choose is a working hypothesis, revised by each year’s records.

What a migration calendar is for

Not prediction, in the end, but attention with a prior. The calendar tells the watcher where to stand and when to bother, and the watching corrects the calendar. That loop, kept patiently across years, is the only instrument a shore observer has, and it is a good one. The animals keep their own schedule; the watcher’s work is to be standing there when the schedule and the weather briefly agree.

Since this entry, the log has opened further: on the flask and the long watch, on the calves that travel beside the adults, and on the autumn jobs of the log.

Sources

The calendar judgements on this page were read back against the sources below on 12 September 2026.

• The Brush and the Bay (lamedialodge.com), almanac pages on the five Pacific salmon of the Nushagak, consulted 12 September 2026.
• NOAA Fisheries (fisheries.noaa.gov), chinook salmon species profile, consulted 12 September 2026.
• Hebridean Whale and Dolphin Trust, species profiles and seasonal windows, consulted 12 September 2026.
• Whale and Dolphin Conservation, Shorewatch analysis by Alice Walters, 1 February 2026.