Purple Finch

Juvenile is washed brown and has streaking on the throat and loosely textured undertail coverts. Juv M=F.

This HY in September is undertaking its preformative molt with median (MCs) and greater coverts (GCs) in sheath. GCs molt proximally (towards the birds body) and when all GCs are molted, the innermost (GC10) is normally the last of these feathers replaced. This however was not the case with this bird which appeared to have replaced the innermost GCs first!

PUFIs often don’t replace all their GCs in their preformative molt with molt limits then appearing within the GCs in which case this innermost feather (GC10) is often a retained or skipped feather.

Notice also the narrow, tapered outer primary coverts with indistinct, narrow, pale buff edging and fresh retained juvenal remiges (primaries and secondaries).

This HY in August is undertaking its preformative molt. Notice that only a single median covert (red arrow) has so far been replaced and that again rather than having replaced the greater coverts proximally in sequence, this bird has replaced the outermost and innermost GCs first and unlike the bird above the carpal covert which is normally replaced after the GCs complete.

Notice again the very narrow, tapered outer primary coverts with indistinct, narrow, pale buff edging and fresh retained juvenal remiges (primaries and secondaries).

This HY in August is also undertaking its partial preformative molt. Notice this time that the outer greater covert (GC1) has been skipped, the molt limit in the making between GC1 and GC2 in sheath (red arrow).

Notice again the narrow, tapered outer primary coverts with indistinct, narrow, pale buff edging and fresh retained juvenal remiges (primaries and secondaries).

This HY in August is also undertaking its partial preformative molt. Notice this time that all of the greater coverts are being replaced, the molt limit in the making between GC1 in sheath and the innermost retained primary covert (red arrow).

Notice again the narrow, tapered primary coverts with no pale buff edging and fresh retained juvenal remiges (primaries and secondaries).

This HY in October has completed its preformative molt replacing lesser coverts and inner median and greater coverts only (red arrows). Notice the thin, tapered primary coverts and alula with little or no pale buff edging. Although the primaries and secondaries are retained juvenal feathers they are still fresh and quite broad and rounded.

This HY in September has completed its preformative molt replacing all lesser coverts and median coverts and the inner greater coverts, the molt limit shown between GCs 6 and 7 (red arrow). Notice the thin, tapered outer primary coverts and alula with little pale buff edging and again, still fresh and quite broad and rounded retained juvenal primaries and secondaries.

Another HY in October showing a clear molt limit within the greater coverts (red arrow). Notice the tawny, olive edged inner greater coverts and obvious ‘step-in’ between the replaced and retained feathers on this bird.
Notice also the thin, tapered and worn outer primary coverts and alula with little or no pale buff edging.

Tail shape is helpful in ageing many species being tapered and more abraded on retained juvenal feathers in first year birds (HY/SY) and broad and truncate with a corner to the inner web and relatively fresh in adults (AHY/ASY). The outer retrices (R4-R6) generally show the greatest age specific differences.
However, it is important not to use tail shape alone as it is generally not very reliable because of a) individual variation and b) the possibility of accidental loss and replacement (adventitious molt). For this reason and the fact that tail feathers are frequently lost and replaced between normal molts tail feather shape must be used with great caution by banders, and only with other supporting characters (e.g., molt limits), when determining the ages of birds in hand.

The tail of this HY in August is showing very narrow, tapered and abraded rectrices. Notice the sharp points to the tips of these feathers and compare with the adult birds below.

Although Purple Finches have delayed plumage maturation mentioned above some birds can be sexed like this SY male in October showing a clear molt limit within the greater coverts between the retained brownish outer GCs and distinctive pinkish replaced inner GCs.
Notice the skipped innermost greater covert (GC10) referenced above and the thin, tapered and worn outer primary coverts and alula with little or no pale buff edging.

This SY in May is showing a clear molt limit within the greater coverts (red arrow). Notice the glossy and tawny edged replaced inner greater coverts contrasting with the retained outer greater coverts.

This SY in January shows the variability in extent of replaced feathers in the preformative molt in Purple Finches with all lesser, median and greater coverts replaced, the molt limit between the replaced outer covert and inner primary covert (red arrow). Notice the glossy and tawny edged replaced greater coverts contrasting with the retained primary coverts and thin, tapered and worn outer primary coverts and alula with no pale buff edging.

As mentioned above it is sometimes possible to sex SY birds based on plumage like this SY male in May with strongly purple washed coverts This bird replaced all lesser, median and greater coverts and the carpal covert in its preformative molt following the breeding season last year, molt limits indicated with red arrows between the replaced outer greater covert and retained inner primary covert and between the alula covert and main lower alula feathers.

Notice the contrast between the greater alula covert (A1) and lower main alula feathers and thin, tapered and worn primary coverts and alula.

This SY in July has replaced lesser and median coverts (red arrow) but only some inner greater coverts. Notice the glossy replaced inner greater coverts (red arrow) but skipped (retained juvenal) GC 8 (green arrow).

This SY male in August is also in flight feather molt – there can be no doubt as to the age of this bird – a second year male replacing brownish contour and flight feathers with the purple washed feathers diagnostic of adult males.

As mentioned above Purple Finch males have delayed plumage maturation meaning they do not acquire male plumage traits until they are more than one year old (i.e., at the time of their definitive prebasic molt, which is their first complete post-breeding molt).

Until this time they resemble the brown-streaked females. Thus, a male that is replacing brown juvenal and first basic feathers with new raspberry-coloured feathers is an SY, while one replacing old purplish feathers with new ones is an ASY.
This SY in August is just such an example replacing very worn and brown juvenal and formative feathers with new raspberry coloured adult feathers in its first definitive adult prebasic molt in its second year.

This ASY female in February is showing uniformly adult wing coverts tinged pinkish, with no discernible molt limits among the coverts or alula but notice the longer outer primaries and darker rachises on these feathers (?).

This AHY female in August is in the early stages of replacing all of its wing feathers. The definitive adult prebasic molt in passerines starts with the lesser and median coverts, then tertials and innermost primaries, primary replacement proceeds distally towards the outermost primary, primary coverts molt with the corresponding primary as can be seen here and greater coverts molt shortly after the start of the primaries which is the stage at which this photo was taken.

Although aged as an after hatch year (AHY) this bird was almost certainly a second year bird based on the thin, tapered and very worn, as yet to be replaced outer primaries, secondaries and alula.

This ASY male wing in January is a prime example of what definitive adult male plumage, with no discernible molt limits among the coverts or alula, looks like in the winter. Notice the uniformly adult, reddish edged wing coverts and broad, truncate primary coverts not contrasting in wear with the greater coverts. Notice also the broad, truncate visible primaries and secondaries, the overall glossiness and quality of these feathers with very little wear to the tips.

This ASY male wing in May is another example of what definitive adult male plumage, with no discernible molt limits among the coverts or alula, looks like in the spring. Notice again the uniformly adult, reddish edged wing coverts and broad, truncate primary coverts not contrasting in wear with the greater coverts. And notice again the broad, truncate visible primaries and secondaries, the overall structure and quality of these feathers with little or no wear to the tips.

Another ASY male in May showing definitive adult male plumage, with no discernible molt limits among the coverts or alula. Notice again the uniformly adult, reddish edged wing coverts and alula and broad, truncate primary coverts with a corner to the inner web, not contrasting in wear with the greater coverts.

This ASY male tail in May is a prime example of what definitive adult rectrices look like in the spring. Notice the very broad, truncate rectrices with a corner to the inner web (red arrow) and distinct reddish edging with very little wear.

As mentioned above tail feather shape must be used with great caution by banders, and only with other supporting characters (e.g., molt limits), when determining the ages of birds in hand. This AHY female in October is a good example that not all adult rectrices are as broadly truncate as the male above.