WhenToBird

Melospiza georgiana · Passerellidae

When Do Swamp Sparrows Arrive in New Jersey?

Adult Swamp Sparrow
Photo: Sandra Keller, CC BY 4.0 via iNaturalist

Swamp Sparrows are winter birds in New Jersey: the first arrive in mid September, they are common by late September, peak in mid October (25% of checklists), and most are gone by mid May.

When to look

First arrivalsSep 15-21mid September
Common bySep 22-30late September
PeakOct 15-21mid October
Most gone byMay 15-21mid May

Best: mid October. First arrivals mid September; most are gone by mid May. Peak: on about 25% of New Jersey checklists.

  1. Januncommon
  2. Febuncommon
  3. Maruncommon
  4. Aprcommon
  5. Mayuncommon
  6. Junrare
  7. Julrare
  8. Augrare
  9. Sepuncommon
  10. Octpeak season
  11. Novpeak season
  12. Decuncommon

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

0%10%20%30%Jan 1-7: 5.3% of 28167 checklistsJan 8-14: 5.0% of 20583 checklistsJan 15-21: 4.4% of 19739 checklistsJan 22-31: 4.9% of 24586 checklistsFeb 1-7: 4.3% of 17226 checklistsFeb 8-14: 3.3% of 19567 checklistsFeb 15-21: 2.4% of 26553 checklistsFeb 22-28: 3.1% of 19046 checklistsMar 1-7: 2.8% of 17969 checklistsMar 8-14: 3.1% of 18976 checklistsMar 15-21: 3.8% of 18581 checklistsMar 22-31: 5.0% of 27590 checklistsApr 1-7: 7.3% of 21202 checklistsApr 8-14: 9.5% of 23609 checklistsApr 15-21: 10% of 25056 checklistsApr 22-30: 10% of 36679 checklistsMay 1-7: 8.9% of 38378 checklistsMay 8-14: 6.5% of 44071 checklistsMay 15-21: 3.3% of 34076 checklistsMay 22-31: 3.1% of 32558 checklistsJun 1-7: 3.1% of 18049 checklistsJun 8-14: 3.0% of 15597 checklistsJun 15-21: 2.8% of 14894 checklistsJun 22-30: 2.6% of 17187 checklistsJul 1-7: 2.8% of 13406 checklistsJul 8-14: 2.7% of 12550 checklistsJul 15-21: 2.9% of 12358 checklistsJul 22-31: 2.8% of 18382 checklistsAug 1-7: 2.5% of 13689 checklistsAug 8-14: 1.6% of 14006 checklistsAug 15-21: 1.1% of 14483 checklistsAug 22-31: 1.2% of 23182 checklistsSep 1-7: 1.1% of 17984 checklistsSep 8-14: 1.3% of 18320 checklistsSep 15-21: 2.1% of 20491 checklistsSep 22-30: 6.9% of 26176 checklistsOct 1-7: 17% of 24112 checklistsOct 8-14: 24% of 24603 checklistsOct 15-21: 27% of 24549 checklistsOct 22-31: 24% of 26206 checklistsNov 1-7: 18% of 17469 checklistsNov 8-14: 13% of 15102 checklistsNov 15-21: 11% of 14958 checklistsNov 22-30: 10% of 19447 checklistsDec 1-7: 8.0% of 14017 checklistsDec 8-14: 7.4% of 14625 checklistsDec 15-21: 8.6% of 16937 checklistsDec 22-31: 6.7% of 26651 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

Frequency is the share of complete checklists in New Jersey 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.

JanFebMarAprMayJunJulAugSepOctNovDec
today
Second week of November

Each county is shaded by the share of complete checklists there that listed the bird, blended with the weeks either side. Darker is more often. It follows where people watch birds, not how many birds there are. How to read it.

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Where in New Jersey

Best counties

Share of checklists at the peak
  1. Hudson CountyBest mid October · 392 checklists that week, 21,191 in all39%
  2. Bergen CountyBest mid October · 1471 checklists that week, 73,457 in all34%
  3. Burlington CountyBest mid October · 911 checklists that week, 52,358 in all32%
  4. Cumberland CountyBest late October · 211 checklists that week, 13,927 in all30%
  5. Sussex CountyBest the second week of October · 479 checklists that week, 30,305 in all30%
  6. Warren CountyBest the second week of October · 283 checklists that week, 20,077 in all26%

Best spots

Share of checklists at the peak
  1. Meadowlands Commission Trust ParkBergen County, best late October · 25 checklists that week, 369 in all89%
  2. Wallkill River National Wildlife RefugeSussex County, best late June · 35 checklists that week, 2,362 in all87%
  3. Bishop FarmsteadBurlington County, best late October · 24 checklists that week, 585 in all84%
  4. Newstead NorthEssex County, best early October · 25 checklists that week, 209 in all84%
  5. West Essex ParkEssex County, best mid October · 22 checklists that week, 1,556 in all84%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In New Jersey, the Swamp Sparrow is most often listed on checklists started between 6 and 8 am (11% of those checklists).

0%5%10%15%12 am: too few checklists (746) to judge1 am: too few checklists (640) to judge2 am: too few checklists (606) to judge3 am: too few checklists (755) to judge4 am: too few checklists (1681) to judge5 am: too few checklists (11258) to judge6 am: 11% of 50447 checklists7 am: 11% of 118312 checklists8 am: 9.6% of 123273 checklists9 am: 8.4% of 107783 checklists10 am: 7.0% of 97537 checklists11 am: 5.5% of 82427 checklists12 pm: 5.3% of 72581 checklists1 pm: 4.9% of 71478 checklists2 pm: 5.2% of 69994 checklists3 pm: 5.1% of 66822 checklists4 pm: 5.3% of 55950 checklists5 pm: 5.1% of 41360 checklists6 pm: 3.6% of 28122 checklists7 pm: too few checklists (14727) to judge8 pm: too few checklists (4257) to judge9 pm: too few checklists (1273) to judge10 pm: too few checklists (920) to judge11 pm: too few checklists (693) to judge12a3a6a9a12p3p6p9p
Share of checklists started in each local hour that reported it. It reflects when people go birding as well as when birds are active. Grey hours have too few checklists (under 2% of the state’s, or under 200) to judge.
Week-by-week table
MonthDays 1-78-1415-2122-end
January5.3%5.0%4.4%4.9%
February4.3%3.3%2.4%3.1%
March2.8%3.1%3.8%5.0%
April7.3%9.5%10%10%
May8.9%6.5%3.3%3.1%
June3.1%3.0%2.8%2.6%
July2.8%2.7%2.9%2.8%
August2.5%1.6%1.1%1.2%
September1.1%1.3%2.1%6.9%
October17%24%27%24%
November18%13%11%10%
December8.0%7.4%8.6%6.7%

Neighboring states

  • Delaware: arrives mid September, in the same week than New Jersey
  • Connecticut: arrives mid March, 24 weeks earlier than New Jersey
  • Pennsylvania: arrives the second week of September, 1 week earlier than New Jersey
  • New York: arrives the second week of March, 23 weeks later than New Jersey

Common questions

When do Swamp Sparrows arrive in New Jersey?
Swamp Sparrows are winter birds in New Jersey: the first arrive in mid September, they are common by late September, peak in mid October (25% of checklists), and most are gone by mid May.
When do Swamp Sparrows leave New Jersey?
Most Swamp Sparrows have left New Jersey by mid May, when reports fall below half their usual rate. Stragglers are still reported until early August.
When is the best time to see a Swamp Sparrow in New Jersey?
The Swamp Sparrow is reported most often in mid October, on about 25% of New Jersey checklists.
Where in New Jersey are Swamp Sparrows seen most often?
By county, Hudson County, Bergen County, and Burlington County have the highest peak reporting rates for the Swamp Sparrow (counties with at least 200 checklists).