Check List 9(2): 391–399, 2013 © 2013 Check List and Authors Chec List ISSN 1809-127X (available at www.checklist.org.br) Journal of species lists and distribution Observations of the under-described avifauna of the PECIES S Mostardas Peninsula, Rio Grande do Sul, Brazil OF Nancy M. Harrison 1*, Michael J. Whitehouse 1 and Lauro A. S. P. Madureira 2 ISTS L 1 Anglia Ruskin University, Animal [email protected] and Environmental Research Group, Department of Life Sciences, East Road, Cambridge CB1 1PT, UK 2 Federal University of Rio Grande, Laboratory of Fisheries Technology and Hydroacoustics. Av. Itália km 8. CEP 96201-900. Rio Grande, RS, Brazil. * Corresponding author. E-mail: Abstract: The Mostardas Peninsula on the east coast of Rio Grande do Sul state, Southern Brazil is important for migratory that the Peninsula is bereft of terrestrial birds relative to similar habitat in Rio Grande do Sul. We used rapid assessment methodsshorebirds to that evaluate depend terrestrial upon the bird wetlands diversity in the and Lagoa note do observations Peixe National of migratory Park. However, birds previousat the western surveys margin have suggested of Lagoa indo fragmented Peixe National woodland. Park between We discuss 11 theFebruary reasons 2007 for theand discrepancy 25 March 2007.between We our recorded observations fourteen of thespecies terrestrial not previously avifauna andreported previous for this reports, area, andincluding the possibility several new that breeding the Mostardas records, Peninsula and detail is a the passerine occurrence migratory of mixed-species route that remainsforaging poorly flocks documented. Introduction species, however the survey effort has not been extensive, and it is possible that the avifauna is under-sampled. seaward side of the Mostardas Peninsula in Rio Grande do Here we report observations of birds on the Mostardas Sul,Lagoa Brazil (Figuredo Peixe 1A) National is recognized Park (LPNP),as being internationallylocated on the Peninsula, notably terrestrial birds in and near the important for migrant shorebirds (Nascimento 1995; western margins of LPNP. We used rapid assessment et al. 2006); it is a Ramsar site and is highlighted methods – ‘10-species lists’ – which are of growing interest as a conservation tool (Roberts et al. 2007), our Bencke(WHSRN 2009) as one of South America’s most outstanding purpose to reassess the species richness of this region of refugesby the Western for thousands Hemisphere of long distanceShorebird migrants. Reserve Following Network the Mostardas Peninsula. Using this method we document species diversity and abundance of the community of birds Sul (Belton 1984, 1985, 1994), Nascimento (1995) documentedBelton’s landmark the occurrence study of ofthe 181 birds bird of species Rio Grande for LPNP. do A further 49 species have been documented as occurring Althoughin the arboreal the marismas and scrubby (i.e. restingassalt marshes) and floodedand lagoons forests, of theand LPNPdescribe were mixed-species not systematically foraging surveyed flocks observed as part ofthere. the present investigation, we document the shorebirds and in the park up until 2010 (Lara-Resende and Leeuwenberg waterfowl we observed over the period of study. Finally, we Mohr1987; 2004;Nascimento Mohr unpublishedet al. data; Maurícioet al. 2007; and BenckePereira comment on the reasons for the discrepancy between our 2000; Mohr 2003 as cited in Pereira and Poerschke 2010; observations of the avifauna of the Mostardas Peninsula few species when compared 2005; with Bencke the total of 661 that have and Poerschke 2010). This total of 230 is still relatively et al. 2010). Of these 230 species, ~53% are water birds and previous reports, and the likelihood that with further (bothbeen recordedmarine and in thefreshwater) state of Rio and Grande the rest do (107 Sul (Bencke species Materialeffort the list and of Methodsbirds is likely to increase considerably. including 16 raptors and owls) are terrestrial birds. With the majority of interest lying with the wetland 31°13’12” S, 50°58’12” W, part of a fazenda on the western birds, there are relatively few reports on the terrestrial marginOur surveyof LPNP focused (Figure on 1A an and area 1B). of ~2 The sq majority km centred of our on main survey area was arboreal and scrubby restingas the peninsula as being ‘interesting because of its paucity which was consistent with the description in Belton ofbirds passerine of the Mostardas species’. However, Peninsula. he Belton based (1984) this assessment identified (1984) as comprising ‘members of the laurel (Lauracea) on a total of 13 days of survey on the Mostardas Peninsula and myrtle (Myrtaceae) families and impressively large between 1972-1981 during the months of January, May, Ficus spp.) with enormous spreading branches July and October (Belton 1985), relatively few periods of bearing a spectacular burden of epiphytes’. This habitat observation in a seasonal environment that one would fig trees ( expect to be characterised by the passage of migrants. coast and is typical of the once more extensive littoral The low number of species of passerines, hummingbirds forest.runs in To a stripthe east (~1 of km this, broad an escarpment, at this point) with parallel an elevation to the and other terrestrial birds reported for the Mostardas Peninsula is surprising. The peninsula may be isolated biogeographically and genuinely have few terrestrial forestfall from and about swamps. 15 m Further to 5 m, eastmarks are the the western grazed marismasboundary of LPNP and a transition from dry restingas to flooded 391 Harrison et al. | Avifauna of the Mostardas Peninsula, Brazil and then the lagoon. Water levels on much of this wetland species had not been reported previously for the area, and are not controlled by the tides, but instead vary over short we document a further 31 species whose status is unclear time scales with rainfall and changes of wind direction. or ambiguous. Our rapid assessment surveys elucidate the Areas with juncos and sedges are scarce and fragmented, sometimes thin as the result of grazing, and nowhere as comment on migration through the area. expansive as seen at Taim or Pelotas areas further south. status and flocking habits of many forest birds and we also To the west of the restingas there is an expanse of sparsely Rapid assessment (10-species lists). In the survey of restinga and forest habitat we completed a total of with invasive Pinus species. The western border of the 126 ‘10-species’ lists. While completing this systematic fazendavegetated is formedsandy habitat, by the RST101 susceptible road tothat flood runs and the dottedlength survey we observed 94 species (Table 1). From the species of the Mostardas Peninsula. accumulation curve we are able to assess whether our Observations were made between 15 February and survey appears to have documented all species in the study 1 March 2007 then again 17 to 24 March 2007. We used rapid assessment methods to evaluate the diversity of say that no new birds are being found, and our list probably birds on 13 of these days; we did not conduct systematic showsarea (Figure the full 2); diversity if the accumulation of birds. In curvefact we flattens continued we can to surveys during rainy or windy weather. The marismas observe new species until the end of the study. were not systematically surveyed as part of this ‘rapid The rapid assessment showed a step in which a number assessment’, but we report here on our observations of of new birds were observed towards the very end of the shorebirds and waterfowl, and changes evident over the survey. This ‘step’, visible on the species accumulation period of our visit (spanning the end of summer and the beginning of fall migration for many species). In particular and onset of fall migration. The Mostardas Peninula has curve (Figure 2), would appear to reflect the end of summer extending east from the main study area across the grazed of terrestrial migrants, but our observations, including marismaswe note counts to the made lagoon. on 23 March along a 2.2 km transect not been identified as anCoccyzus important americanus area for the(Linnaeus, passage The rapid assessment method requires the Yellow-billedA Cuckoo (Poulsenidentification et al.of all1997). birds Weencountered compiled as‘10-species’ observers movelists, identifyingaround a defined all species study by site, sight using and pathssound whereuntil a possible total of of10 adifferent list using species a GPS hadunit been(Garmin observed; see Figure and identified,1B for an marking the geographic position at the start and the finish example of a typical survey track). After the tenth species newhad beenspecies. identified, Graphing a newthe ‘species10-species accumulation list was started, curve’ provideswith some an repetition indication of of birds species from diversity. the first The list, higher as well the as diversity, the more new species will appear in lists through time. Also, the proportion of lists on which a species occurs (List Reporting Rate; LRR) is proportional to its abundance (Roberts et al. 2007). et al. 1984; RidgelyIn the and field Tudor we 1989,used 1994;a comprehensive de la Peña andselection Rumboll of 1998;guides Remold for the identification 2001; Mata et of al. species 2006). (HaymanFor a few species we B also collected sound recordings (Edirol R-09 MP3 recorder with a Sennheiser e.g. internet sites such as Xeno-canto FoundationMKH8070 shotgun(2005-2011), microphone) and Remold for (2001).comparison However, with knownas we did songs not and systematically calls ( photograph or collect specimens, any potentially new records for the area can only be considered hypothetical. Taxonomy and Brasileiro de Registros Ornitológicos (2011). nomenclatureFisher’s exact follows tests the were classification used for ofbasic the testsComitê of probability. Analyses were carried out using R, version Figure 1. study site. B. Aerial photograph of the study site showing a typical route A.