14 de octubre de 2021

Differentiating Tasmanian Scrubwren and Tasmanian Scrubtit

I find this one tricky, and I don't think I have it 100% yet. Please comment any extra tips you have for differentiating these two Tassie bb's!

Side-by-side comparison

Left image Tasmanian Scrubwren by Michael Hatton from observation https://www.inaturalist.org/observations/46495230
Right image Tasmanian Scrubtit, by margot_oorebeek from observation https://www.inaturalist.org/observations/46695320

Tasmanian Scrubwren

The features I look for:

  • Staring (angry-looking) eyes
  • Face framed with pale triangular lines
  • Dark lores (the region between the eye and bill on the side of the bird's head)
  • Slim black-white-black-white lines on the wing
  • Dark throat and chest

These features are clear in the following observations:

Left image by Michael Hatton from observation https://www.inaturalist.org/observations/46495230
Right image by jsatler from observation https://www.inaturalist.org/observations/5360699

Tasmanian Scrubtit

The features I look for:

  • Soft (kind-looking) eyes
  • Pale lores and/or pale eye-brow (in addition to or more-so than the pale triangular lines of the Scrubwren)
  • White spots on the wing (rather than the black-white-black-white slim lines of the Scrubwren)
  • Very pale throat and chest

These features are clear in the following observations:

Left image by margot_oorebeek from observation https://www.inaturalist.org/observations/46695320
Right image by Brendan Costello from observation https://www.inaturalist.org/observations/94092352


Left image by Jan Ebr from observation https://www.inaturalist.org/observations/71971256
Right image by lowch from observation https://www.inaturalist.org/observations/41024403

Anotado en 14 de octubre de 2021 a las 11:25 PM por tamika_lunn tamika_lunn | 0 comentarios | Deja un comentario

27 de abril de 2021

Differentiating Ducks - Native, Mallard and Mallard hybrids

I find Mallard ducks very confusing - they can be patterned, darker or lighter, all white or all black, and even larger than normal or much smaller. What I find even more confusing is that they hybridize readily with the Pacific Black Duck (PBD), making it difficult to know if a PBD is a pure native or a Mallard hybrid.

These are notes to keep track of main identifying features of confusing ducks. Please comment if you have any extra hot-tips. I focus on Mallard x PBD because these are the main hybrids I see in Tasmania.

Pacific Black Duck
Identifying features of PBDs include grey bill, dark legs and feet, black lines through face (widest through eye) and a dark brown body with buff feather margins:

Image by fritzu from observation https://www.inaturalist.org/observations/25345332

Mallard hybrids
There are a number of physical variants that can be expressed in Mallard x PBD hybrids. These can be subtle to very obvious. These include:

Orange legs
Bright orange legs is a Mallard trait and is a very commonly expressed trait in hybrids. While PBD can have an orange hue, bright orange is distinctive of Mallard genes:

Image by Roy Lowry from observation https://www.inaturalist.org/observations/45056622

Discolouration of bill
Discolouration to bill is also indicative of Mallard genes. Bill discolouration can be any colour (i.e. not necessarily orange):

Left image by Graeme Rigg from observation https://www.inaturalist.org/observations/45241779
Right image by Athas from observation https://www.inaturalist.org/observations/72357925

Light feather colouration
Light colouring (lighter than normal for a PBD) is indicative of a Mallard x PBD hybrid. Some examples:

Light variant:

Left image by Catalina Tong from observation https://www.inaturalist.org/observations/39354902
Right image by Anna Lanigan from observation https://www.inaturalist.org/observations/25652293

Very light variant:

Left image by naturego1 from observation https://www.inaturalist.org/observations/61539055
Right image by Tamika Lunn (me) from observation https://www.inaturalist.org/observations/75140373#activity_comment_faaf79bc-df3c-4f6a-bd84-f0d3f53264b5

Light neck and breast:

Image by Geoffrey Cox from observation https://www.inaturalist.org/observations/13660337

Curly tail
Curly tails are another Mallard trait, and is a very commonly expressed trait in hybrids:

Image by Antoni Camozzato from observation https://www.inaturalist.org/observations/30089284

Non-uniform ducklings
Another sign of hybrids is that the ducklings have different markings. See above photo by Catalina Tong. Another example:

Image by Catalina Tong from observation https://www.inaturalist.org/observations/39354911

Pure Mallard
Physical features of mallards are enormously variable, so I won't include many photos of these. Northern Mallard males have a green head, white neck-ring, brown body and bright bills/legs. Females look similar to a PBD but very pale and without strong face markings. As mentioned, Domestic Mallards could range from anything between entirely black to entirely white. I tend to err that, if they don't look like anything else (including other domestic breeds) they're probably a Domestic Mallard. When looking at the many variations, watch for bright bill/legs and little curled feathers above the tail. The curled tailed in particular is diagnostic of a male Mallard.

Male:

Image by Allan Lugg from observation https://www.inaturalist.org/observations/66999481

Female (left):

Image by Bay Reeson from observation https://www.inaturalist.org/observations/63748297

Anotado en 27 de abril de 2021 a las 07:50 AM por tamika_lunn tamika_lunn | 0 comentarios | Deja un comentario

Differentiating Tasmanian thornbill and brown thornbill

You've seen a thornbill in Tasmania? Neat! Is it a Tasmanian thornbill? Not necessarily...

The two thornbills in Tasmania are hard to differentiate. I go by these tips published by the Australian Bird Study Association (ABSA):

Colour of leading edges of primary feathers - brown/rufous on Tasmanian thornbill (left) & cream/off-white on brown thornbill (right):

Tasmanian thornbill (left) by James Bailey from observation https://www.inaturalist.org/observations/18528637
Brown thornbill (right) by paulstanchurcher from observation https://www.inaturalist.org/observations/72605592

Colour of undertail coverts - white on Tasmanian thornbills (left) and brown on brown thornbills (right) (though this may depend on age or time of year). If this isn't super clear in these photos, see link below for better comparison photos.

Tasmanian thornbill (left) by Geoff Walker from observation https://www.inaturalist.org/observations/66760594
Brown thornbill (right) by Jeff Melvaine from observation https://www.inaturalist.org/observations/71857812

Extent of forehead scalloping & breast streaking - stronger on brown thornbills (right) than Tasmanian thornbills (left):

Tasmanian thornbill (left) by Alan Melville from observation https://www.inaturalist.org/observations/18795985
Brown thornbill (right) by Anthony Katon from observation https://www.inaturalist.org/observations/72887582

Eye colour - this is illustrated as different in Morcombe's guide but isn't a reliable diagnostic feature. Eye colour could be generally darker in Tasmanian thornbills, but it is very variable in brown thornbills (and possibly age related).

Other useful comparative photos of the two species here, made by Catherine Hamilton Young: https://www.instagram.com/p/BejxatKHiXk/?igshid=1p4w6rzbpv4mz

Anotado en 27 de abril de 2021 a las 03:39 AM por tamika_lunn tamika_lunn | 1 comentario | Deja un comentario

Differentiating Myiagra flycatchers

Some notes on differentiating features of the Myiagra flycatchers - please comment if you have extra tips.

Broad-billed Flycatcher
Defining features from the other myiagra flycatchers include pale lores (the area between the eye and bill) and obviously gradated tail feathers (i.e. being of different lengths giving a distinctly 'stepped' appearance). Broad-billed Flycatchers are also mangrove specialists (generally speaking).

Pale lores:

Image by Graham Winterflood from observation https://www.inaturalist.org/observations/57891741

Gradated tail feathers:

Image by Andrejs Medenis from observation https://www.inaturalist.org/observations/67450795

Satin Flycatcher & Leaden Flycatcher
These can be harder to differentiate. Glossiness/dullness of males can be a diagnostic feature. Male Satin Flycatchers have glossy blue-black feathers (left), whereas male Leaden Flycatchers have dull blue-black feathers (right). This is not a reliable diagnostic feature for females.


Satin image by Jeff Melvaine from observation https://www.inaturalist.org/observations/72881173
Leaden image by julieoconnor3 from observation https://www.inaturalist.org/observations/73095161

Feather margins (edging) on the lower wing can be a diagnostic feature. Satin Flycatchers have brown/buff feather margins (left) and Leaden Flycatchers have silvery-grey feather margins (right).

Females:

Satin image by Rebecca Ludstrom from observation https://www.inaturalist.org/observations/61088536
Leaden image by Rachael Jones from observation https://www.inaturalist.org/observations/71785137

Males:

Satin image by James Peake from observation https://www.inaturalist.org/observations/55870977
Leaden image by crazybirdman from observation https://www.inaturalist.org/observations/69128310

Young flycatchers can have a more broadly brown wing, which can be mistaken as buff margins/edging. Be careful that edging refers to the edges of the feathers on the lower wing, not the overall wing colour.

Shining Flycatcher
Distinct from other flycatchers. Males are entirely blue (left) and females have a bright rufous back-tail:

Male image by sbarton16 from observation https://www.inaturalist.org/observations/69754075
Female image by seanpai from observation https://www.inaturalist.org/observations/63074057

Restless Flycatcher
Distinct from other flycatchers. Breast is white (not blue). Females may have a slight buff tint to breast (right)

Male image by Daniel Townend from observation https://www.inaturalist.org/observations/72080449
Female image by aussiecreature from observation https://www.inaturalist.org/observations/63155441

Anotado en 27 de abril de 2021 a las 01:06 AM por tamika_lunn tamika_lunn | 2 comentarios | Deja un comentario

15 de abril de 2021

Differentiating Lesser Sand-Plover and Greater Sand-Plover

Breeding and non-breeding plumage is similar for these species. Lesser Sand-Plover is proportionally smaller-headed and has a shorted bill (less than 1/2 the width of the head). The bill has a slight bulge at the tip. It also has darker and shorter legs.

Lesser Sand-Plover:

Image by lcwoo from observation https://www.inaturalist.org/observations/69696611

Greater Sand-Plover:

Image by Amanda Johnston from observation https://www.inaturalist.org/observations/70305628

Anotado en 15 de abril de 2021 a las 02:00 AM por tamika_lunn tamika_lunn | 1 comentario | Deja un comentario

Differentiating ravens and crows

Learned from this observation https://www.inaturalist.org/observations/73204495 and this podcast https://www.alieward.com/ologies/corvid-thanatology.

As a general rule of thumb only, may not apply to all species

  • Australian crow species have white down under their feathers, ravens have grey down under their feathers.
  • Species have different sheens to their outer feathers: Australian Raven - purple/green/grey sheen; Forest Raven & Little Raven - deep black; Little crow & Torresian Crow - blue/violet sheen.
  • Audible and visible aspects of the call are important - ravens typically have more prominent throat hackles than crows (but these can be smoothed down when not calling).
  • There can be species specific behavioural aspects - e.g. Little Raven wiggles its wings

Australian Raven (long throat hackles):

Image by johncull from observation https://www.inaturalist.org/observations/73929919

Australian Raven (grey down):

Image by namack from observation https://www.inaturalist.org/observations/70477316

Torresian Crow (short throat hackles):

Image by Natasha Taylor from observation https://www.inaturalist.org/observations/73277623

Torresian Crow (white down):

Image by deborod from observation https://www.inaturalist.org/observations/69762255


Image by Richard Yank from from observation https://www.inaturalist.org/observations/69770865

Anotado en 15 de abril de 2021 a las 01:49 AM por tamika_lunn tamika_lunn | 0 comentarios | Deja un comentario

Differentiating Bar-tailed Godwit and Black-tailed Godwit

Learned from this observation: https://www.inaturalist.org/observations/73373704

Non-breeding plumage looks very similar between the species. Tail tip is barred and wingtips are black for Bar-tailed Godwit, while wingtips and tail tip are all black for Black-tailed Godwit.

Black-tailed Godwit (black wing tips):

Image by Andrew Thompson from observation https://www.inaturalist.org/observations/73426202


Image by Анна Голубева from observation https://www.inaturalist.org/observations/72916471

Bar-tailed Godwit (barred wing tips):

Image by Graham Winterflood from observation https://www.inaturalist.org/observations/73373704


Image by leo_in_merimbula from observation https://www.inaturalist.org/observations/73088962

Anotado en 15 de abril de 2021 a las 01:23 AM por tamika_lunn tamika_lunn | 0 comentarios | Deja un comentario

Differentiating Grey-tailed Tattler and Wandering Tattler

Learned from this observation: https://www.inaturalist.org/observations/73302509. Also see P34 in Paulson (1986). Identification of juvenile tattlers, and a gray-tailed tattler record from Washington. Western Birds 17: 33-36.

Plumage of both species is very similar. Can look to the bill groove to reliably differentiate the species - "Nasal groove is shorter in Gray-tailed. The deep groove on each side of the bill into which the nostril opens is shorter in Gray-tailed, not reaching one-half the bill length; in Wandering it reaches to somewhat over one-half the bill length."

Wandering Tattlers are also much less common in Australia, and are visitors to NE and N only (visitation to N very rare)

Grey-tailed Tattler (groove <1/2 of bill length):

Image by Malcolm Tattersall from observation https://www.inaturalist.org/observations/73469129


Image by andrewpavlov from observation https://www.inaturalist.org/observations/72352041

Wandering Tattler (groove >1/2 of bill length):

Image by toddburrows from observation https://www.inaturalist.org/observations/70311925


Image by docprt from observation https://www.inaturalist.org/observations/73680449

In noting this, while looking for photo examples in INaturalist there seems to be inconsistency here - i.e. many Research Grade Wandering Tattlers with short grooves and Research Grade Grey-tailed Tattlers with long groves. Please comment if you know why or know of other identifying features to look out for.

Anotado en 15 de abril de 2021 a las 01:07 AM por tamika_lunn tamika_lunn | 0 comentarios | Deja un comentario

14 de abril de 2021

Hot tip - differentiating sex in Swift Parrots

Hot tip from Dr Dejan Stojanovic (tweeted: https://twitter.com/teamswiftparrot/status/1379952684011114501)

You can tell the sex of a swift parrot by the colour of the feathers underneath the tail - red for males, light red/salmon for females:

Male:

(photo by Jeff Melvaine, observation here: https://www.inaturalist.org/observations/65846833)

Female:

(photo by Dejan Stojanovic, tweeted here: https://twitter.com/teamswiftparrot/status/1379952684011114501)

Anotado en 14 de abril de 2021 a las 06:21 AM por tamika_lunn tamika_lunn | 0 comentarios | Deja un comentario

Archivos