Wednesday, 29 October 2014

Costa Rica, progress and highlights

Last year on the 28th October, Wendy and I completed our 40th and final standard banding session of the 2013 Fall season here on the Caribbean coast in Costa Rica.
Our final session was at our Tortuga Lodge site, which funny enough is where we were banding today.
An adult female Slaty-tailed Trogon we banded today..
....she has a bite !!

Last Fall season Wendy and I captured 1568 birds of 72 species in 40 continuous days banding based here in Tortuguero. A look back to our blog for this day last year here

 A Swainson's Thrush... 502 captured in 2013,  94 so far in 2014...

This year I started banding a day earlier, on the18th September, after nine days (26th September) we left the Caribbean coast and banded in the Highlands for 14 days returning here and recommenced banding on the 16th October.
Therefore our data is not directly comparable but I will do some comparisons when home !

Our total to date....409 captured of 59 species in the 22 days here at Tortuguero, and we are planning to band here until the 14th November. Another 17 more 6 hour visits to the five standard banding sites here at Tortuguero.. 

A bit of time to highlight some of the species we haven't caught before at Tortuguero..
.....or are just awesome birds !
This White-eyed Vireo was an excellent discovery on the 26th, I'm sure the second edition of Garrigues & Dean, Birds of Costa Rica (due, Dec 2014) will have updated the status from rare, four have been caught on this project now - first in 2012.

This a Plain-brown Woodcreeper...found at Cano Palma  on the 20th.
One of the largest, with subtle head and neck markings. Only the second I've seen - amazed it was a retrap !
From 46.8g - the weight of tha above Woodcreeper.... to 2.4g !!
The weight of this Stripe-throated Hermit, Cano Palma on the 20th. We don't see much of these bee size hummingbirds, or we mistake them for insects...

During banding sessions time to learn too,
Adult and first (hatch) year Red-eyed Vireo wings being compared.

I've seen a couple in Canada,and banded quite few here.
 Prothonatory Warbler, along with Northern Waterthrushes, provide a good percentage of re-wintering recaptures. Figures when home, but c10 % of each species maybe returning site-faithful birds.

A couple of shots to finish tonight....our boat leaves at 5am to take us to Cano Palma !
At Cano, our banding station, is in the crows nest above the boat dock ! 

The outstanding birds,....
Collared Aracaris, and this Chestnut-colored Woodpecker.

See a couple of previous postings below for more details on these...

Monday, 27 October 2014

Burry Inlet Oystercatchers

This weekend three of the group went to Whiteford Burrows on the North Gower coast to help with the annual visit to ring Oystercatchers in the Burry Inlet.

This long running project, started in 1990, provides data on survival rates and body condition at this important site. The Burry Inlet contains the largest continuous area of saltmarsh in Wales and vast areas of intertidal sand.
With equiment from the SCAN wader ringing group and Steve Dodds, we had a successful catch of 175 Oystercatchers. One was a very old bird, ringed across the estuary at Burry Port in 1991.
A beautiful if rather windswept site at which to spend the morning.
Although one of the team seemed to enjoy sitting in the windiest spot!
 Once ringed, and aged,a set of standard measurements were taken by two processing teams
and moult score was recorded

Thanks to Dave Coker, Steve and Rachel for an interesting and enjoyable weekend. 

The National Trust bunkhouse at Cwm Ivy was an excellent base and highly recommended for a group stay
For further reading on this work on Oystercatchers see this interesting paper from 2010
Analyses of Oystercatcher body condition and survival on the Burry Inlet SPA
( Burton, N.H.K., Wright, L.J., Coker, D. & Dodd, S.G. 2010.  CCW Contract Science Report No:
952, 28pp, CCW/BTO.)

Hopefully the wind will drop sometime this week to enable us to get out ringing on the Teifi Marsh.



Saturday, 25 October 2014

Tongues Part Two: The Woodpecker !



We couldn't be more lucky.

We caught a Chestnut-colored Woodpecker today during standard banding at Cano, the day immediately after having discussed woodpecker tongues during the writing of the Toucan Tongue post.

So today, we wish to follow this fascinating theme of tongues.

The tongue of the woodpecker is extremely long, far longer than their bill.  So what do they do with all that tongue?  Well, the answer is simple.  They wrap it around the back of their skull.

Or at least, that's what is commonly thought.

In actuality, the tongue is connected to a complex called the hyoid bone, and it is this which extends around the back of the skull and helps protect the brain of the woodpecker when it is doing what woodpeckers do best.


SPECIALIZED: A curving complex of cartilage and bone within a woodpecker’s head permits the bird to extend and store its exceptionally long tongue. Illustration by Denise Takahashi, from Bird Watching Daily

A very interesting study was conducted that examined the structure of the woodpecker's skull, and their complex of tongue, cartilage, and hyoid bone. You can read it here: “Why Do Woodpeckers Resist Head Impact Injury: A Biomechanical Investigation,

We also noticed that the tip of the tongue is slightly feathered similarly to that of a toucan. Bit difficult to see in the picture below, but how interesting !


 ~ Author Pauline Pearse

Friday, 24 October 2014

Toucan Tongues...and bill development

An almost embarrassing number of Collared Acararis; four ! have landed themselves in our nets in the past week of standard banding for Costa Rica Bird Observatory.  Our initial excitement has now dwindled to self-preserving musings of how best to extract and keep that snapping bill away from flesh at the same time.

We have been quite lucky to be able to closely examine a broad range of ages, from juveniles, almost surely straight out of the nest, to the beautiful adult below.


With such a run, it has been easy to observe the differences in bill development between the ages.  It is quite interesting to see and compare the development of structure, colour, and even strength, so up-close and personally. 


Adults also have far better bill-eye-hand coordination. 
 
 

Amidst requests to "take that thing off my finger, pleease" during processing, we have had many opportunities to see the amazing appendage-like tongue that is possessed by these creatures. 

Juveniles, likely not long fledged.  Note the dull colour of the bill and smoothness of the edge. 

And this feathery tongue!  Apparently used for helping push food down the throat, and loaded with taste receptors to decide whether its worth the effort or not.

This juvenile is developing bill serrations and colour, and that tongue is even more feathered.  Curving of the bill is becoming more pronounced.

The ultimate adult.  Strongly coloured bill.  Tongue is very feathered. 

Serrations are verified.

And this little guy.  Not caught in Tortuguero.  Didn't show his tongue. But Richard didn't want this to end on him being bitten. 
Emerald Toucanet, caught at Madre Selva, CRBO standard banding site in the Highlands.

~ Author Pauline Pearse (Richard's Aracari-bill opener when the bites hurt)

Wednesday, 22 October 2014

An early start for thrushes...CR style

Pauline joined me in San Jose and we are banding together until mid November...
What a start at InBIO, our standard banding site in San Jose, Tropical Kingbird. We see many every day, but never before in the hand
Yesterday our standard banding site was at our base at The Sea Turtle Conservancy, here in Tortuguero. This view of Tortuguero including four of our standard banding sites from the Cerro after a recent climb..
Here we can catch large numbers of migrants, as well as the resident species, and yesterday we were successful in banding over 70 Catharus thrushes.
Here a selection of other species caught yesterday too.
 Chestnut-sided Warbler, a regular species around the sites.
 
Ovenbird, we don't catch many, six in our last two visits to Costa Rica compared to 59 Northern, and four Louisiansa Waterthrushes

Streak-crowned Woodcreeper, the lowland equivalent of the Highland Spot-crowned Woodcreeper.

The final bird of yesterday, our friendly grosbeak. We catch many Rose-breasted Grosbeaks at Long Point Bird Observatory in Canada, but this is my first in Costa Rica,...
Behaviour in the hand still the same !

What a day, planned and  hoped for...but unexpected..
101 birds captured of 21 species, of which 15 species were migrants.

This followed an amazing previous day  standard banding at Parq. In particular one amazing net round....
I was vis mig counting Chimney Swifts pouring over, when Pauline appeared from the forest with three bags full !
The photos say it all...
A young Semiplumbaceous Hawk..
 and two very juvenile Collared Aracari..
Though almost certainly siblings, interesting to compare the rate of development.

Twenty days since my last notes and some highlights, mainly species not mentioned before will follow on a blog.....if not too busy at our Aeropuerto site.....
Yes !
A standard banding site at the end of the airstrip...not primary forest, but coastal woodland regenerating and can be full of migrants too..

Saturday, 11 October 2014

A First and a Second

A last-minute decision to get out of bed and put in a few hours on the Marshes between showers this morning was rewarded by a first for the Group and a first for me (though other TRG members have ringed them with other groups elsewhere) in the shape of a passing Whinchat. Also unexpected was only the second Meadow Pipit that we have ever caught on the Marshes.

This, according to Svensson, is a juvenile female
The supporting cast gracing the nets this morning, among Blue Tits so numerous that I'm trying to blank them from my memory, were a Jay, another new Kingfisher, two more new Cetti's, Blackcaps, Bullfinches, Goldfinches, Goldcrests, Long-tailed Tits, Great Tits, Wrens, a Robin, and four more new Reed Buntings recruited to our colour-ringed RAS project.

Tuesday, 30 September 2014

Costa Rica - rufous-tailed to steely-vented...

Today we were banding at InBioparque in the capital San Jose. A standard CES type site, within a park with objectives much like Regents Park in London but smaller. Migrants in evidence here, with a Canada Warbler, several Chestnut-sided and a great surprise to see a Worm-eating Warbler
The above photo of a Canada Warbler was taken at our Tortuguero site, more on banding there later...
...back to InBioparque...
I don't associate this inner city site with good hummingbirds...today I was proved wrong. Following a regular Rufous-tailed, show below..
A  new species for me, a Steely-vented Hummingbird with a different but equally stunning tail.
In some hummingbirds males perform at a lek, where tails may have a role. These two species don't lek but are very aggressive towards others. As well as the steely-tail in the photo below, note the standard wing measuring technique taught and used across the Americas...
Agustin doing the biometrics, and below with a House Wren, a wren species found in many different sub-species across North and South America.
Agustin is a local Costa Rican and we are banding together across all our sites in the coming weeks.

A final warbler from our first week's banding in Tortuguero, our Caribbean coastal base. We will return to Tortuguero in about 2 weeks after a spell at our Highland sites.
This a juvenile Mourning Warbler, a species not easy to see though apparently a common Fall migrant, we only caught two last Fall, so a pleasing start.!