Beryl Fraser, of Crocodile Nest B&B, submitted a great sequence of photos of a Spectacled Weaver pair that raised two broods in the same nest. This is unusual as Spectacled Weavers will usually build a new nest when one brood has been raised.

See all Beryl's PHOWN records here: click on each thumb-nail to see the full record details (right click and open each thumb-nail in a new tab or page, starting with record 1845; or see the thumb-nails at the bottom of each record page and click on the successive record numbers). Beryl did not know about PHOWN initially, but had photos that she could use to submit earlier records.

On 13 January 2012 Rory McDougall found a dead bird on the Great North Road in Zambia at 9h30. The road kill was an adult male Thick-billed Weaver with ring 4A46849. Rory forwarded the details to Zambian birders and Pete Leonard sent it to SAFRING. Rory wrote: "I was unaware these birds moved so far and wonder where it was ringed? I have found them breeding on Colin Streets farm on a dam on the Kaleya River approx 30kms as the crow flies from where this bird was killed, but I have never known anyone ring this species in the area? I am sure it will be an interesting recovery."

This bird was ringed as an immature on 7 July 2008 by Lizanne Roxburgh on Huntley Farm, 111km from the ring recovery site. As Rory pointed out, this is an interesting recovery, being the second longest movement known for the species. The longest was by an immature with ring 64308136 - it had moved 130 km along the Eastern Cape Coast in South Africa.

Related news items:
To read about the oldest Thick-billed Weaver, see here
To read about range expansion in the Thick-billed Weaver, see here

The next ADU seminar will take place next week on Wednesday 25 January. Thanks to the work happening on the Gylcol System in Zoology, the venue for the seminar will be Lecture Theatre D in the RW James Building. The seminar will be from 13:15 to 14:15, to fit around the ADU’s course at the UCT Summer School.

Our speaker will be Dr James D Nichols, Senior Scientist at the U.S. Geological Survey's Patuxent Wildlife Research Center in Laurel, M.D. He is visiting the ADU during January and will give a seminar entitled "On Valuing Patches: Estimating Contributions to Metapopulation Systems".

Abstract: Forty years ago, Richard Levins (1969, 1970) introduced the concept of the metapopulation, formalizing the relevance of dispersal among local populations, both to those local populations and to the entire system. Ron Pulliam (1988) later considered the relative values of interacting local populations with his definitions of sources and sinks. Here, I follow the framework developed by Runge et al. (2006) and define contribution metrics reflecting the relative and absolute importance of each specific local population to population growth of (1) every other local population and (2) the entire system. I then describe reverse-time multistate capture-recapture models as a natural framework for drawing inferences about these contributions. Finally, I apply these models to a system of 8 local populations of the banner-tailed kangaroo rat (Dipodomys spectabilis) studied by Peter Waser in Arizona. The analysis yields contribution matrices for the entire system, with elements expressing the contributions of young and adults from each local population to adult population change in every other local subpopulation. The modeling permitted inferences about potential sources of variation in these contributions: (1) age, (2) general location of the local population in the system (central vs. peripheral), and (3) relative metapopulation size (years of high density and low density). I also present estimates of the relative contributions of each local population, and of extra-system immigration, to the entire metapopulation system.

Various aspects of weaver demography are being studied on the Cape Peninsula. The key factors are survival (and movements), which is being studied by ringing, and breeding which is being studied by monitoring colonies and ringing chicks. In the course of ringing weavers, other birds are caught too, like this juvenile Pied Crow (photo: Gabriel Jamie). To obtain data on survival and movements a large number of recaptures is needed, with ringing at a network of nearby sites. A full species list with numbers ringed and recaptured on the Cape Peninsula during 2011 may be seen here.

To see weaver colonies in PHOWN, (Photos of Weaver Nests) see here - choose one of the 4 species to see a map of records.

ADU postdoc Fitsum Abadi Gebreselassie, ADU postdoc currently on a year's "leave of absence" in France, has co-authored another paper on Swiss birds; this time it is Hoopoes and Wrynecks. Fitsum's research interests lie in building population models, making use of all the different sources of information available through monitoring methods: ringing and retrap data, population counts, breeding productivity, etc. This form of population modelling is therefore known as "Integrated Population Models." For his postdoc in the ADU, Fitsum is building integrated population models for South African species such as the African Penguin, Cape Gannet and Peregrine Falcon. Fitsum is off in France learning new skills, sponsored by the Swiss National Science Foundation, and then in 2013 the Claude Leon Foundation will continue their support for his ongoing postdoc in the ADU.

The full reference for this newly published paper is. Schaub S, Reichlin TS, Abadi F, Kery M, Jenni L, Arlettaz R. 2012. The demographic drivers of local population dynamics in two rare migratory birds. Oecologia 168: 97–108.

Abstract: The exchange of individuals among populations can have strong effects on the dynamics and persistence of a given population. Yet, estimation of immigration rates remains one of the greatest challenges for animal demographers. Little empirical knowledge exists about the effects of immigration on population dynamics. New integrated population models fitted using Bayesian methods enable simultaneous estimation of fecundity, survival and immigration, as well as the growth rate of a population of interest. We applied this novel analytical framework to the demography of two populations of long-distance migratory birds, Hoopoe Upupa epops and wryneck Jynx torquilla, in a study area in south-western Switzerland. During 2002–2010, the hoopoe population increased annually by 11%, while the wryneck population remained fairly stable. Apparent juvenile and adult survival probability was nearly identical in both species, but fecundity and immigration were slightly higher in the hoopoe. Hoopoe population growth rate was strongly correlated with juvenile survival, fecundity and immigration, while that of wrynecks strongly correlated only with immigration. This indicates that demographic components impacting the arrival of new individuals into the populations were more important for their dynamics than demographic components affecting the loss of individuals. The finding that immigration plays a crucial role in the population growth rates of these two rare species emphasizes the need for a broad rather than local perspective for population studies, and the development of wide-scale conservation actions.

Copies of the pdf of the paper can be obtained from Les Underhill.