WhenToBird

Osprey · Pandion haliaetus

When Do Ospreys Arrive in Maine?

Adult female Osprey
Photo: Bill Levine, CC BY 4.0 via iNaturalist

Ospreys reach Maine in early April, are common by the second week of April, peak in mid August (19% of checklists), and most are gone by late September.

When to look

First arrivalsApr 1-7early April
Common byApr 8-14the second week of April
PeakAug 15-21mid August
Most gone bySep 22-30late September

Best: mid August. First arrivals early April; most are gone by late September. Peak: on about 19% of Maine checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marrare
  4. Aprcommon
  5. Maycommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Seppeak season
  10. Octuncommon
  11. Novnot usually seen
  12. Decnot usually seen

Darker months: more checklists report it. Outlined: peak month.

Ospreys in Maine, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
OspreyApr 1-7Apr 8-14Aug 15-21Sep 22-3019%
0%5%10%15%20%OspreyJanFebMarAprMayJunJulAugSepOctNovDec
  • Osprey
Share of complete checklists reporting each species, by week (4 per month). Gaps: fewer than 10 checklists that week.

Frequency is the share of complete checklists in Maine that listed the bird, 2016–2025. It is not a head count, and it follows where and when people go birding. How to read it.

Where in Maine

Best counties for Osprey

Share of checklists at the peak
  1. Sagadahoc CountyBest early August · 424 checklists that week, 21,736 in all35%
  2. Lincoln CountyBest the second week of August · 1147 checklists that week, 59,429 in all35%
  3. Knox CountyBest late August · 1175 checklists that week, 34,453 in all32%
  4. Waldo CountyBest late August · 860 checklists that week, 33,433 in all29%
  5. Kennebec CountyBest the second week of August · 947 checklists that week, 48,185 in all23%
  6. Cumberland CountyBest late August · 3830 checklists that week, 169,501 in all22%

Common questions

When do ospreys arrive in Maine?
Ospreys reach Maine in early April, are common by the second week of April, peak in mid August (19% of checklists), and most are gone by late September.
When do ospreys leave Maine?
Most Ospreys have left Maine by late September, when reports fall below half their usual rate. Stragglers are still reported until the second week of October.
When is the best time to see ospreys in Maine?
The Osprey is reported most often in mid August, on about 19% of Maine checklists.