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Funding: manuscript preparation was supported by BBSRC grant BB/G023913/2 (C.R). Here, we report an observation of a Eurasian nuthatch Sitta europaea foraging with a tool in a public park in Greater London, UK. This record is of significance, as it provides the first photographic evidence (to our knowledge) of nuthatch tool use, reveals an unusually wide phylogenetic and geographic distribution of tool behaviour within the Sittidae, and constitutes a rare example of animal tool use in an urban environment. To improve our understanding of nuthatch tool behaviour, we are building a global database of relevant anecdotal field observations—submissions are most welcome. Postprint

Here we describe the modification and use of a new tool type in the woodpecker finch (Cactospiza pallida). This species is known to habitually use twigs or cactus spines to extract arthropods out of tree holes. We observed an adult and a juvenile bird using several barbed twigs from introduced blackberry bushes (Rubus niveus) which the adult bird had first modified by removing leaves and side twigs. The barbs of blackberry tools provide a novel functional feature not present in tools made from native plants and de-leafing of twigs never has been observed before. Both birds were observed using several of these tools to extract prey from under the bark of the native scalesia tree (Scalesia penduculta). They oriented the twigs such that the barbs pointed towards themselves; this rendered the barbs functional as they could be used to drag prey out of a crevice. The juvenile bird first watched the adult using the tool and then used the tool that the adult bird had left under the bark at the same location and in the same way as the adult. Our observation highlights the fact that opportunities for the transmission of social information do occur in the wild and indicates that woodpecker finches are flexible in their choice of tool material and tool modification.

The use and manufacture of tools has been considered to be cognitively demanding and thus a possible evolutionary driving factor of intelligence. Animal tool use provides the opportunity to investigate whether the use of tools evolved in conjunction with enhanced physical cognitive abilities. However, success in physical tasks may simply reflect enhanced general learning abilities and not cognitive adaptations to tool use. To distinguish between these possibilities, we compared general learning and physical cognitive abilities between the tool-using woodpecker finch, Cactospiza pallida, and its close relative, the small tree finch, Camarhynchus parvulus. Since not all woodpecker finches use tools, we also compared tool-using and nontool-using individuals, predicting that domain-specific experience should lead tool-using woodpecker finches to outperform nontool-users in a task that is similar to their natural tool use. Contrary to our predictions, woodpecker finches did not outperform small tree finches in either of the physical tasks and excelled in only one of the general learning tasks, and tool-using woodpecker finches did not outperform nontool-using woodpecker finches in the physical task closely resembling tool use. Our results provide no evidence that tool use in woodpecker finches has evolved in conjunction with enhanced physical cognition or that domain-specific experience hones domain-specific skills. This is an important contribution to a growing body of evidence indicating that animal tool use, even that which seems complex, does not necessitate specialized cognitive adaptations.

Zusammenfassung 1. Nahrungssuche und einige soziale Verhaltensweisen des Mangrovefinken von Albemarle werden beschrieben. 2. Wie der Spechtfink setzt der Mangrovefink ein Stockchen ein, um im Holz verborgene Insekten hervorzustochern. Dieser Werkzeuggebrauch bestatigt die enge Verwandtschaft beider Finken und zeichnet sie vor allen anderen Geospizidae aus. Es ist eine offene Frage, ob alle Individuen beider Arten den Brauch ausuben. 3. Ahnlich dem Spechtfinken bereichert der Mangrovefink seinen hauptsachlich aus Insekten, Spinnen, ihren Eiern und Larven bestehenden Speisezettel durch pflanzliche Kost, indem er Mangroveblattstuckchen verzehrt. 4. Einige Probleme der okologischen Differenzierung beider Arten werden vorgefuhrt. Summary 1. The feeding habits and some of the social behaviour patterns of the mangrove finch, Cactospiza heliobates, on Albemarle Island, are described. 2. Like the woodpecker finch, Cactospiza pallida, the mangrove finch uses a stick for poking insects from dead wood which are out of reach of its bill. This use of a tool confirms the close relationship of the two species and, at the same time, distinguishes them from all other Darwin's Finches. It remains an open question whether the stick probing habit is universally present in all individuals of either species. 3. Like the woodpecker finch the mangrove finch feeds mainly on insects, spiders, their eggs, and larvae; additionally it incorporates vegetable matter in its diet, i. e. pieces of mangrove leaves. 4. Some of the problems of ecological differentiation of the two species are briefly considered.

We investigated seed predation and dispersal by nine Darwin's finch (Geospizinae) species, including species previously regarded as seed predators or insectivores. All nine ate fruit. Eight commonly discarded seeds, acting as short-distance dispersers. Seven defecated viable seeds, being therefore potential longer-distance dispersers. Fruit comprised the majority of dietary items in all four Geospiza species and Small Tree Finch (Camarhynchus parvulus). All except Common Cactus Finch (G. scandens) defecated intact seeds. The highest proportions of feces containing viable seeds were of Small Ground Finch (G. fuliginosa) and the “insectivorous” species Woodpecker Finch (Camarhynchus pallidus) and Warbler Finch (Certhidea olivacea). These two may be more important endochorous dispersers than other species that eat more fruit but are better seed predators. Intact seeds were found in 23% of fecal samples; 50% of the samples with intact seeds had viable seeds. The most frequently encountered intact see...

Insects, mammals and birds are known to use tools, but empirical evidence of the ecological importance of tool-use is scarce. Here, we present the first ecological study of tool-use by a bird species. Woodpecker finches use twigs or cactus spines to pry arthropods out of tree-holes. We compared tool-use during wet and dry seasons in two different vegetation zones: the Arid Zone and the humid Scalesia Zone. In the Scalesia Zone, where food was abundant and easily accessible, woodpecker finches rarely used tools. In contrast, in the Arid Zone, where food was limited and hard to access, they obtained half of their prey using tools during the dry season. Tool-use enabled the birds to reach particularly large and otherwise inaccessible prey hidden in tree-holes. Our data suggest that tool-use in the woodpecker finch has evolved in response to the dry and

The similarities between the genes of humans and those of birds are reflected in their cognition capacity. Birds are capable of advanced forms of behaviour and can surmount difficult situations surpassing mammals in many respects.

The trap tube is a classic test of causal reasoning abilities in animals in the physical domain. Recently, a modified version of this task improved its diagnostic capacity and allowed testing of non-tool-using animals. We used this modified two-trap tube task to compare the cognition of two Darwin’s finch species: the woodpecker finch, Cactospiza pallida, a tool-using species, and the small tree finch, Camarhynchus parvulus, a closely related non-tool-using species. Not all woodpecker finches use tools in nature, and we therefore also tested non-tool-using individuals to assess the effect of experience on trap tube performance. No small tree finches and only two non-tool-using woodpecker finches solved the initial task which was operated using a pre-inserted piston. One tool-using woodpecker finch solved the task when allowed to use its own tool instead of the pre-inserted piston. The fact that none of these subjects transferred their knowledge when the features of the task changed, suggests that in this species, neither experience using tools nor the genetic composition of a tool-user are associated with the general physical cognitive skills required to solve the trap tube task.

Woodpecker finches are famous for their spontaneous tool use behaviour in the wild. They use twigs or cactus spines to pry arthropods out of crevices and use this ability more than any other tool-using species known. We experimentally investigated the cognitive abilities related to tool use. We chose three experimental designs that have been used to test several primate species (trap tube task and modification task) and New Caledonian crows (tool length task). One of six woodpecker finches was able to solve the trap tube task, and several individuals modified tools and chose twigs of appropriate length. Most subjects mastered these new tasks quickly, but we found no evidence that they were able to assess the problems in advance. These findings resemble those obtained for primates in these tasks.

The 13 species of finches found on the Galapagos Islands, and the one species from Cocos Island, together collectively known as Darwin's finches, are one of the better-studied groups of birds. Much has been learned about their ecology, behavior, and the short-term effects of natural selection (Lack 1947, Bowman 1961, Grant 1999). The four species of tree finch (Camarhynchus), six species of ground finch (Geospiza), the tool-using Woodpecker Finch (Cactospiza pallida), the Vegetarian Finch (Platyspiza crassirostris), the Warbler Finch (Certhidea olivacea), and the finch on Cocos Island (Pinaroloxias inornata) appear to fill different ecological roles via differentiation of bill size and shape (Grant and Grant 2002). In fact, most authors consider Darwin's finches to be a classic example of an adaptive radiation, owing to the great diversity in bill form and ecological habit that presumably evolved in a relatively short time. For example, Petren et al. (1999:321) noted, "Species in this group show adaptive variation in beak size, beak shape and body size that is more typical of differences among [taxonomic] families of birds... (boldface added). Taxonomic History.-Darwin originally collected the finches from the Galapagos, not realizing what an evolutionary gold mine they would become (Sulloway 1982). In fact, he was not careful about labeling specimens as to the island from which a specimen was obtained, thus obscuring taxonomic boundaries. Subsequent work with better-labeled specimens revealed taxonomically significant patterns of variation. Gould (1837) recognized that different species existed in the collections from the Darwin expedition. However, Gould was unable to produce a stable classification. Since Gould's time, many of the major figures in avian taxonomy have published differing classifications. The succession of revisionary efforts attests to the difficult nature of classifying phenotypic variation among the finches. Although the species show considerable morphological diversity, many in fact are notoriously difficult to identify in the field (especially females and immatures). Populations from different species and islands overlap in morphometric space (Grant 1981).

An integrative approach to managing host–parasite interactions that threaten species communities will benefit from identifying variation in parasite impact across host species, and host–parasite responses to annual climatic variation. We examine interannual, inter- and intraspecific variation in Philornis downsi intensity – an introduced blood sucking fly that causes high fitness costs in Darwin’s finches on the Galapagos Islands. We sampled 131 nests of six finch species (with nestling survival ⩾6 days post-hatching) between 1998 and 2005 on Santa Cruz Island. P. downsi total (per nest) and mean (per nestling) intensity differed across species and years. The woodpecker finch (Cactospiza pallida), and the large tree finch (Camarhynchus psittacula) had the highest total parasite intensity. Both species had comparatively large adult body mass, and we found a positive association between adult body mass and total parasite intensity among nestlings. P. downsi total and mean intensity was highest during the El Nino year of 1998. Surprisingly, despite a threefold difference in rainfall across lowland and highland habitats in other than the El Nino year, there was no difference in parasite intensity per nest between habitats. However, species composition of hosts and intraspecific brood size vary across habitats. Highland nests with larger broods and lower mean (per nestling) parasite intensity had higher fledging success. There was no significant effect of total parasite intensity on fledging success for intraspecific analyses. The percentage of nests with nestling mortality in each habitat ranged between 40% and 100% for all six host species.

Four isosporan species are described from the small tree finch, Camarhynchus parvulus from Isabela Island on the Galapagos Archipelago. Isospora exigua n. sp. oocysts subspheroidal, one-layered, smooth, yellow-brown color, 20.4 X 20.1 (20-23 X 18-23) microns, with no micropyle, residuum, or polar body. Sporocysts ovoidal, 14 X 9.5 (13-15 X 8-10) microns, with small Stieda and substieda bodies and irregular-shaped residuum. Isospora rotunda n. sp. oocysts subspheroidal, single-layered, smooth, yellow-brown wall with large polar body and no micropyle or residuum, 20.9 X 20.8 (20-24 X 19-23) microns. Sporocysts ovoidal, 15 X 9.7 (13-16 X 9-10) microns with knob-like Stieda bodies, prominent substieda bodies and round residuum. Isospora fragmenta n. sp. oocysts subspheroidal with no micropyle or residuum but with many splinter-like polar granules and a smooth, colorless, single-layered wall, 25.3 X 24.2 (24-27 X 23-25) microns. Sporocysts piriform 15.4 X 11.5 (14-17 X 11-12) microns with knob-like Stieda bodies, prominent substieda bodies, and irregular-shaped residuum. Isospora temeraria n. sp. oocysts ellipsoidal with one polar body, no micropyle or residuum, and wall of a single layer, smooth, yellow-brown color, 25.4 X 21.1 (21-30 X 17-23) microns. Sporocysts piriform, 15 X 10 (14-15 X 9-11) microns with knob-like Stieda bodies, prominent substieda bodies, and a round residuum. One woodpecker finch, Cactospiza pallida, was found to be infected with I. exigua, and a warbler finch, Certhidea olivacea was infected with I. fragmenta.

THE use of natural objects as tools by free-living vertebrates has, so far as we know, been reported for four species only—the chimpanzee, Pan troglodytes; the gorilla, Gorilla gorilla; the Californian sea otter, Latax lutris; and the Galapagos woodpecker finch, Camarhynchus pallidus. Chimpanzees have been observed to use rocks to break open hard food1; to insert sticks into honey2, to use sticks and stems for feeding on termites and ants3, and to use leaves for sopping up water to drink3 and also for wiping their bodies3,4. A gorilla is reported to have pulled fruit towards it with a crooked stick5. The sea otter uses rocks for breaking open shell fish6, and the woodpecker finch probes insects from their holes with spines or short twigs7.