The beak of the finch - Impressions from two
Shelley's crimsonwing finch (Cryptospiza shelleyi) skins at the
Alexander König Museum Bonn, Germany
I visited the ornithological section of the Natural History Museum
"Alexander König" in Bonn to take photographs of
two skin specimens of Cryptospiza shelleyi that I knew were present
in one of the most comprehensive bird skin collections world-wide.
What was my motivation? Having read about this elusive bird at the
RFCG homepage and blog, I eventually wanted to see the bird with
my own eyes and hold it in my hands. Of course, a living bird would
be much more thrilling, but knowing that this is something to fancy
for the future this was a compromise for the presence. Apart from
these feelings of a finch enthusiast, it was scientific curiosity
that urged me to see these museum specimens: I always felt uncomfortable
when looking at the two known fotos of Shelley's (the one taken
by the www.gorilla.org-group in 2008 and the other published in
1974 in the Zaire bird book by Lippens & Wille) and at drawings
in books, such as in the "Handbook of the Birds of the World"
(HBW) Vol. 15, in "Birds of Africa" Vol. 7, or in "Finches
& Sparrows"(by Clement, Harris, and Davis). They all look
a bit different in terms of colour and habitus. For instance, in
HBW, the colours are much lighter than in Birds of Africa. Which
one is more realistic? Looking at the gorilla.org-foto, which seems
to be the best quality picture of a living bird that we have in
our hands, it looks as if the lighter drawing in HBW might capture
it more realistically. But we all know that fotos can be misleading
because a large number of possible combinations of environmental
influences (in particular intensity of light) and camera settings
can produce significantly different impressions of the bird. By
looking at the museum skins, I therefore hoped to get a more unbiased
impression of Shelley's plumage colour and to compare it to the
other crimsonwing finch species. I had previously written in the
RFCG blog that when comparing the four Cryptospiza species, Shelley's
looked like a phenotypic outlier to me. If this was true and if
it was reflected in the genetic relatedness to the other three species,
one might also speculate about possible differences in life style
and habitat requirements. This might be an interesting step towards
identifying the factors responsible for Shelley's apparent decline
and the reason why C. reichenovii and C. jacksoni, who share their
habitat with Shelley's, seem to be doing fine under the same environmental
influences.
The two specimens (1,1) at the Bonn museum were collected 45 years
ago by Dr. Peter Kunkel, a German ornithologist who was the director
of a research institute in the Kivu highlands (Dem. Rep. Congo)
from the 1960s to the beginning 1970s. Besides the two Shelley's
crimsonwing finches, the collection holds a considerable number
of C. reichenovii and C. salvadorii, as well as a few specimens
of C. jacksoni. The Shelley's pair was obviously collected at Mt.
Kahuzi, located southwest of the Virunga and Bwindi Impenetrable
Forest National Parks in the Eastern part of the DR Congo. The area
was converted into a national park (Kahuzi-Biéga National
Parc) in 1970.
Museum specimen No. 66.912
Cryptospiza shelleyi, 1,0; notes on the tag (English translation
in red):
Kahuzi, 20.04.1966, 2300 m
gest. (died) 29.04.1966
adult male, Gonade:
16 g
Auge braun (eye brown)
Schnabel blutrot, Wurzel weiss (beak blood-red,
basis white)
Füße braungrau (feet brown-grey)
Museum specimen No. 66.913
Cryptospiza shelleyi, 0,1; notes on the tag (English translation
in red):
Kahuzi, 17.03.1966
adult female, Gonade: 5,2 x 1,8 mm
Gewicht (weight) 17 g
Auge braun (eye brown), Füße
braun-schwarz (feet brown-black)
Schnabel, 29.06.1966, rötlichschwarz, zu den Schneiden hin
rot, Spitze rot (Beak, 29.06.1966, reddish-black,
red towards the edges, red tip)
Overall appearance of the skins
Compared to fotos of the Durban museum specimens shown on the RFCG
website, the Bonn specimens appear to be in a less good condition,
in particular the female (Figure 1). The museum is planning to subject
them to restauration.
![](images/news-7-2011-fig1.jpg)
Figure 1: Side view of a pair of Cryptospiza shelleyi, 1,0
on the left (for size comparison, a centimeter scale and a Euro
coin)
My overall impression was that the colour of the birds is darker
than shown in HBW, on the Gorilla.org- foto and possibly also darker/less
bright than the Durban specimens. It seemed to be closer to the
drawing in Birds of Africa and Finches & Sparrows. It is unclear
whether the colour of the skins might have changed over the past
45 years. However, the colour of the skins of C. reichenovii and
C. salvadorii, which were stored under the same conditions and which
have a similar age, appeared completely natural to me. In their
case, I can compare to living birds, as I have seen a number of
both species which used to be quite common in aviculture until the
EU import ban of 2007.
I found the difference in beak colour between male and female quite
remarkable and more pronounced than depicted in drawings. Unfortunately,
the red pigment of the beak is not preserved in the museum specimens.
The male's beak is blood-red, as can be seen on the gorilla.org
foto. Unfortunately, there is no known foto of a female and thus
no documentation of the natural appearance. Dr. Kunkel described
the female's beak as reddish-black, successively turning red towards
the edges and tip of the beak. The dark pigments are preserved in
the Bonn specimen.
From the tags on the skins, one can assume that Dr. Kunkel kept
the birds for a couple of days (male) to several weeks (female).
Unfortunately, although Dr. Kunkel published about his observations
on a regular basis during the 1960s, I am not aware of any publication,
fotos or else about the Shelley's finches that he kept. I am currently
trying to make contact with Dr. Kunkel.
Shelleys crimsonwing finch in visual comparison to the other
Cryptospiza species
First of all, please note that the skin sizes do not necessarily
reflect the true size of the birds because of differences in skin
preparation. The C. reichenovii specimen depicted in Fig. 2-4 is
certainly too small compared to the other species. According to
the literature, Shelley's is supposed to be the largest species
of the genus (13 cm length), followed by C. jacksoni (11 cm) and
C. reichenovii and C. salvadorii (both 10-11 cm).
When I actually saw the skins of all four Cryptospiza species next
to each other, the systematic relatedness became more obvious than
from drawings and individual fotos alone (Figs. 2-4). Especially
the dorsal view (Fig. 3) reveals pronounced similarities in colour
and plumage patterns. The red is very similar, small differences
may be the result of different basis pigments that interfere with
the red. Wing feathers and tail are always black.
What I found very interesting was that the green of the chest feathers
is very similar between C. shelleyi and C. reichenovii. This was
not clear to me from known drawings and fotos.
![](images/news-7-2011-fig2.jpg)
Figure 2: Side view of all four members of the genus Cryptospiza
(all males). From left to right: C. shelleyi, C. jacksoni, C. reichenovii,
C. salvadorii.
![](images/news-7-2011-fig3.jpg)
Figure 3: Dorsal view of all four members of the genus Cryptospiza
(all males). From left to right: C. shelleyi, C. jacksoni, C. reichenovii,
C. salvadorii.
Differences in beak size and shape
The most surprising observation to me was the size and shape of
Shelley's beak. The beak appears to be much larger than the ones
of Jackson's and especially Reichenov's and Salvadori's. This becomes
very obvious in the ventral view (Fig. 4) where I noticed how broad
(at the base) the beak is compared to the other species. If you
compare to Jackson's which is of similar body size, the difference
is quite pronounced and does not seem to be simply proportional
to the relatively small size difference. In C. reichenovii, the
beak appears much more pointed.
I am clearly not an expert on the interpretation of beak shapes,
but I know that specialists can make predictions regarding food
preferences based on beak measurements. In the case of Shelley's,
could the broad beak give rise to fruit being a substantial portion
of its diet (with possible consequences for habitat requirements,
location of the birds within their habitat, i.e. possibly not coming
to the edges of the forest too often, etc.)? Although analysis of
the crop content of a very limited number of Shelley's crimsonwing
finches (Birds of Africa, Vol. 7) did not find evidence for fruit
-they contained mainly unripe seeds of Impatiens spec.- other important
parts of Shelley's diet might have been missed so far. Together
with scientists of the Königs museum, we are trying to find
experts who might be able to comment on this.
It is clear that the number of Shelleys that are available for
beak measurements is very limited and may prevent reliable conclusions
that can be drawn from these data. At least in Durban, there is
another pair of Shelley's where the beak size could be measured.
Is the RFCG aware of other natural history museums that might have
Shelley's skins in their collections?
![](images/news-7-2011-fig4.jpg)
Figure 4: Ventral view of all four members of the genus Cryptospiza
(all males). From left to right: C. shelleyi, C. jacksoni, C. reichenovii,
C. salvadorii.
Acknowledgement:
I would like to deeply thank Dr. Renate van den Elzen, Kathrin Schidelko
(M.Sc.), and Darius Stiels (M.Sc.) for giving me access to the ornithological
collections of the Alexander König museum and for very helpful
and stimulating discussions.
Sven Cichon, Bonn, July 2011
Please refer to the RFCG Blog site on rarefinch.wordpress.com
for the very latest news . The RFCG Blog was activated in September
2010 and is updated approximately 2 to 3 times a month.
Rare Finch Conservation Group (
RFCG ) progress report June 2009 to July 2010
Searching for Shelley's Crimsonwing finches amongst Africa's
Mountain Gorilla's
The following is a brief account of the various activities pertaining
to the current field work undertaken by the RFCG in Uganda.
The RFCG is extremely grateful to the Hans Hoheisen Charitable
Trust who provided most of the funding required for this very important
phase of the project .The in situ field work by the RFCG has, for
the moment , been completed in the Bwindi Impenetrable National
Park ( BINP ). This tropical rainforest park is situated in South
Western Uganda and covers an area of approximately 330 square kilometres.
( By way of size comparison the Kruger National Park in South Africa
is approximately 18,000 square kilometres )
The BINP is designated as a UNESCO world heritage sight, the forest
is considered as one of the richest ecosystems in Africa. The park
is only accessible on foot and is one of the last two remaining
strongholds for the threatened Mountain Gorilla's( Gorilla beringei
beringei ) , with an estimated population of 340 of the worlds last
remaining 600 odd Mountain Gorilla's residing in the Bwindi Impenetrable
Forest.
In addition to the gorillas the park provides habitat for some
120 mammal species and 346 bird species ( 44 finch species )
The altitude in the park varies between 1190 m and 2607 m above
sea level, although 60 percent of the park has an elevation of greater
than 2000 metres.
The parks diversity in species is partly attributable to the large
variations in altitude along with the diverse habitat types which
have evolved due to the extreme age of the area.
As access to the area is on foot only it has been due to the efforts
of the RFCG field team led by Benson Bumutura that we have managed
to access and catalogue the species which we have thus far netted.
During the field work we have endeavoured to cover as wide a spectrum
of the ecosystems within the park as possible, and as can be imagined
given the topography of the area this has at times been a huge challenge
for our field team.
The RFCG team, with permission from the Ugandan Wildlife Authority
as well as the Ugandan National Council for Science and Technology,
has been deployed to mist net within the various identified areas,
and make observations pertaining to the species, gender, location,
and time of capture. All species were also photographed.
As the capture method is non selective we have netted a fairly broad
spectrum of species during our work .The diversity in species will
soon all be displayed in the new RFCG photo gallery section that
is currently being prepared for this website .
During the work in the BINP area, we have consistently encountered
two of the four crimsonwing finch species, the Dusky crimsonwing(Crytospiza
jacksoni) and the Red faced crimsonwing (Cryptospiza reichenovii)
with very sporadic reports of the Abysinnian crimsonwing(Cryptospiza
salvadorii), but to date none of our targeted species the elusive
Shelley's Crimsonwing ( Cryptospiza shelleyi ).
All captured crimsonwings are banded by the team, and the details
of the specimen are recorded along with the ring numbers.
This data ,when the bird is renetted , allows us to establish how
much movement occurs by any given individual within the species.
Currently the technology to monitor, by means of radio telemetry
is prohibitively expensive and all indications are that given the
nature of the terrain in which we are operating this method would
not be successful and also, we do not possess sufficient data on
this means of tracking to state unequivocally that such telemetry
equipment does not hamper the bird in any way and thus making it
more vulnerable to predation.
All field requests for equipment and supplies etc. plus daily operational
matters are managed by means of cellular communications between
Benson in Uganda and RFCG directors Eelco Meyjes ( Operations )
and Simon Espley ( Strategy ) in South Africa.
The RFCG management team, who are based in South Africa, at all
times have a reasonably up to date indication on the exact whereabouts
of the field team.
All field work data including information sheets, photographs etc.
pertaining to the crimsonwing species research are filed and sent
to the RFCG, through the kind facilitation of the Institute of Tropical
Forest Conservation ( ITFC ) who are based in Ruhija in the South
Eastern part of the Bwindi Impenetrable Forest
The RFCG receives monthly postal reports from Uganda and the field
data is then collated and formatted by Professor Ernst Kruger, and
the RFCG website is updated by William van Rijn and all finances
are managed by Mark Stewart.
In conclusion given the nature of the terrain and the limited resources
at our disposal, the group has managed to build through these endeavours
a foundation of practical experience that we would not have been
able to acquire by any other means.
Despite the extensive efforts in this regard, we have as yet been
unable to fulfil our primary goal for this initial project and that
would be the successful netting, photography and census of a population
of Shelley's crimsonwing finches. The RFCG after much consideration
believe we have by the means at our disposal done all we can , for
the moment, within Bwindi to find this species.
Obviously there now exists a far greater degree of awareness of
the rarity of the Shelley's , probably than ever before , both in
the Bwindi area among the professional bird guides, who are in the
field almost daily with international birders, as well as amongst
finch enthusiasts throughout the world.
The RFCG in February 2010 decided to relocate our field research
team to the Mgahinga Gorilla National Park , which is in the very
southern part of Uganda , the park is contiguous with the Virunga
National Park in the Democratic Republic of the Congo to the west
and the Volcanoes National Park in the Republic of Rwanda to the
south.
Benson our head field researcher has a confirmed sighting of the
Shelley's in this park, prior to him being part of the RFCG field
project, and hence we are filled with optimism for our new venture
in this area.
Finding this finch remains our first goal, but we do not want to
lose sight of the fact that the RFCG was established, in 2005, in
an attempt to assisting in the plight of all rare and endangered
finch species and we continue to direct our efforts towards this
goal.
The Rare Finch Conservation Group is a registered non profit organisation.
Should you wish to become a donor contributions can be made to :
The Rare Finch Conservation Group . Nedbank. Account number 1933
198885, SWIFT NEDSZAJj Sandown Branch 193 305 . South Africa . All
contributions will be acknowledged on the RFCG website and in Africa
Birds and Birding magazine ( official media sponsors to the project
)
For more information contact : Eelco Meyjes editor@avitalk.co.za.
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