A brief great summary of our talks at the British Ecological Society meeting in Edinburgh (UK) this week, by CoDisperse. The summary of the tweet feed is here. This was the thematic topic on Tuesday afternoon, focusing on “Dispersal Processes Driving Plant Movement: Challenges for Range Shifts in a Changing World” and organized by Cristina García, Etienne Klein and myself. Big thanks CoDisperse!
This is the California gull, Larus californicus (Lawrence, 1854). It is subs. californicus.
Here we see the white mirrors in P9 and P10, which are characteristic, and the white trailing edge to inner wing. This (both photos of same individual) is an adult (at least 4cy) with the winter plumage (hindneck has dense brown streaks). These first three photos were taken at Wilder Ranch State Park, Santa Cruz, along the coast line.
A detail of the wonderful head of this gull (same individual in these two photos, an ad). Note the dark iris, and the color pattern in the bill ring (black with red-orange tinted patch in the lower mandible). The bill is characteristically 4-colored: yellowish at the base, black ring, red-orange dot and ivory tip- this separates it from Ring-billed and Herring. The leg color is also characteristic (green-bluish) but apparently is very variable. I saw other ad birds with very yellow legs. These two photos were taken in San Lorenzo Park, Santa Cruz, CA.
This is a 3cy bird, finishing molt to 3rd winter. The bill ring is wholly black; there are no white patches on P feathers, nor white mirrors. The bill is longer than in Ring-billed and the head is more massive. The photo was taken at Moss Landing, Elkhorn Slough, CA.
This is a 1cy bird (juvenile molting into 1st winter plumage), with characteristic black-tipped bill with pale pink in the base. It has not yet started te molt of the scapulars, yet some grayish ones seem to be apparent- the median coverts look worn and faded, creating pale midwing-panel; so the bird is a bit delayed in its molt.
These are some shots of my recent trip to California, last October, where I had the opportunity to do a whale watching trip offshore Monterrey Bay, from Moss Landing. I’ll be posting more photos soon…
Heermann’s (Larus heermanni (Cassin, 1852) is one of my favorite gulls, with a beautiful plain grey plumage in the adult, contrasting with the white patches and the coral-red bill, and a smooth dark brown plumage of the immature birds. They were common birds along the coast up to Santa Cruz, quite often in large flocks. The population size is estimated in ca. 150000 pairs.
The adult birds here seem to be starting with the winter plumage, with paler grey heads.
This is a typical juvenile bird facing its 1st winter. The head is very dark grey, with a creamy base of the bill.
I like the broad white trailing edge of the wing. It’s a very elegant gull in flight (well, as all the gulls). I’m getting a gull-addicted, even for the commonest species, which pose very nice identification problems when you try to get to the details of the plumage patterns and molt. Even the most common species (i.e., the yellow-legged here in S Spain) pose amazing identification challenges, especially in winter.
And here, with the Humpback whale…
The photos were taken with the Nikon D7000, AF-S VR Zoom-Nikkor 70-300mm f/4.5-5.6G IF-ED, f8, 1/1000, ISO 400.
Muriquis (Brachyteles arachnoides) are the largest neotropical primates and the largest mammal endemic to Brazil, reaching more than 12 kg (Reis et al., 2006). They are endemic to the SE Brazil.
Previously recorded as different subspecies, muriquis are currently recognized as two distinct species, the northern muriqui B. hypoxanthus and southern muriqui B. arachnoides (Rylands et al., 1997). Aguirre (1971) estimated that before the arrival of Europeans there were about 400,000 muriquis in the Atlantic rainforest, distributed from southern Bahia to northern Paraná, and in 1971 there were no more than 3,000 individuals. Currently the northern muriqui occurs in southern Bahia, Espirito Santo and Minas Gerais and the southern muriqui occurs in southern Rio de Janeiro, São Paulo and northern Paraná (Melo and Dias 2005, Hirsch et al., 2006).
The muriquis live in groups of more than 30 individuals present social fission-fusion system where the group is divided into independent sub-groups of variable size. When in pristine areas they have a higher home ranges, ca. 1000ha, within daily displacements more than 5 km. I was fortunate enough to watch a group of 10-11 muriquis in Intervales, relatively close to the Carmo base. They were 3 males, 2-3 juveniles and 3 females, two of them carrying babies. Some of the individuals were feeding on the catkins of Cecropia glazeouvi. I approached them on a very steep slope and observed them for ca. 30 min. They were moving slowly among the canopies of the trees but with an extraordinary agility, always helping themselves with the tail. After a period close to me they moved quickly uphill.
Muriquis are herbivores, adapted to the handling, chewing and digestion of leaves or fleshy fruits, and they also consume flowers, seeds and bamboo (Strier 1991; Talebi et al., 2005). In relation to frugivory, muriquis have lower consumption of fruits (21% to 33%) in semi-deciduous Atalantic forest (Strier 1991, Martins 2006, 2008), but more intense consumption (35% to 71%) in ombrophilous Atlantic rain forests (Petroni 1993, 2000, Carvalho et al ., 2004; Talebi et al., 2005).
My friend Rafael Bueno did his master project (finished in 2010) on this species and tapirs [Frugivoria e efetividade de dispersão de sementes dos últimos grandes frugívoros da Mata Atlântica: a anta (Tapirus terrestris) e o muriqui (Brachyteles arachnoides)]. He did a great job showing the relevance of these frugivores for the dynamics of the Atlantic forest. Many tree species (at least 28 species) critically depend on their service for seed dispersal. Rafael recorded daily movements of muriqui groups ranging between 0.5 and 5.4 km. He estimated that on average, individual muriquis may disperse ca. 11,000 seeds/year. These amazing data show how relevant plant-animal mutualistic interactions are for the maintenance of tropical forests.
I’m just arrived from the field course in Brazil. Everything run very well and we really enjoyed this edition. Here is a photo of Aburria jacutinga in a Cecropia glazouvi tree. I’ve uploaded more photos in my FB portal.
Back from the very interesting workshop organized in Madrid by Juanjo Robledo-Arnuncio. We focussed on long-distance dispersal events (LDD) and their importance to understand the potential responses to climate change. Changes in the environment will force adaptations or long-distance migration and range expansion in plants. Thus a key question is, are the LDD services provided by animal frugivores potentially allowing this environmental tracking.
We have been advancing a lot in understanding the local, stand-level patterns of dispersal and their consequences. Yet there are numerous conceptual and methodological challenges to understand migration among patches or fragments. LDD events > 500 km will be extremely difficult to assess in a robust way with current techniques, given the tremendous logistic challenge of sampling all the potential available pollen and seed sources. However, LDD events @100 km scale are probably affordable to estimate with a combination of mechanistic models (i.e., relying on high-precision satellite tracking of animal movement combined with physiological models) and genetic tools. Large scale sequencing and cheaper DNA analysis will help to genotype massive amounts of samples and allow the identification of rare immigrants, even when migration rates are low. Some lasting conceptual challenges include the estimation of 2D dispersal kernels that accommodate the complex reality of natural landscapes and the complexities of animal movement, which is quite often markedly directional and anisotropous.
The program of this interesting and thought-provoking workshop is here:
Long distance dispersal (LDD): perspectives and new directions
December 2nd, 2010
Sala Javier Palacios
Centro de Investigación Forestal (CIFOR)
Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)
Ctra. de la Coruña km 7,5