Birds of a eucaliptos woodlot in interior São Paulo

Abstract

Some 255 birds were recorded between 1982-2001 in and near a 2314-ha "Horto" of old eucalyptus plantations with native understory and a lake, near Rio Claro, in central São Paulo, Brazil. This is close to the 263 recorded in and around a ten-times smaller nearby 230-ha woodlot of semideciduous forest. Different species were 44, for a total of 307 in both areas. One hundred and fifty nonvagrant forest and border species were recorded in 1982-86, a number close to the 152 in the small native woodlot. With dry years and logging of plots in 1985-93, 21 of the 150 species were lost, 42 species decreased in numbers, 49 were stable, 19 increased (15 being border species), and 5 entered (one of dry forest and 4 of borders), so 129 species remained in 1996-2001 compared to 133 in the native woodlot. Open-area birds were 33, versus 50 in better-checked grassy swales in sugar cane near the natural woodlot, for a total of 53. Several species, like some border ones, did not enter the open but isolated and mowed interior lake area, or took years to do so. Water and marsh birds were 46 versus 40 in smaller creeks and ponds near the natural woodlot (total, 55) but many were migrants or infrequent visitors using distant areas, and perhaps should be counted as 0.1-0.9 "local species" rather than "1" species. Use of this more accurate method would reduce waterbird totals by 14 "species" in the Horto and by 11 around the native woodlot. I also recommend longer censusing at the edges in large woodlots or many edge species will be recorded only in small fragments of habitat. Several species increased and others decreased with occasional cat-tail and water-lily cleanups at the lake. A forested corridor between the Horto and natural woodlot is recommended, with old eucalyptus left to provide flowers for hummingbirds.

Questioning the implementation of habitat corridors: a case study in interior São Paulo using ants as bioindicators

“…It is important to cite that our results also contrast with those for the highmobility birds group. While less than 30% of ant species from the three MSJ fragments also occur in FEENA, birds share about 70% of its species between FEENA and MSJ1 (considering strictly forest and border bird species of these two areas) (Willis, 2003;Willis Oniki, 2002).…”

“…Furthermore, the subtle differences in the micro-habitats of FEENA and MSJ would cause some ant species (for example those present in MSJ and not in FEENA) not to adapt in a different environment, which, from this point of view, would turn the corridor useless. Thus we consider that the successional process of FEENA's flora and fauna must occur without this kind of "help" from MSJ, but with the gradual cut of Eucalyptus trees and cultivation of native species, which would certainly be cheaper and more effective than implementing a habitat corridor (opposing Willis, 2003).…”

“…That is because one of the areas (or fragments) may hold exotic or tramp species that could threaten the communities of the other area, outcompeting native species (Williamson and Fitter, 1996;McGlynn, 1999;Schultz and McGlynn, 2000). Since the cited reforestation possesses non-native elements in its vegetation segment (Eucalyptus and Pinus), probably, in additional segments of the biota, it may also hold other species that are not present in the native forest fragments (Bierregaard et al, 1992;Willis, 2003). On the contrary, if the vegetation of the areas in the referred proposal is indeed similar, other segments of the biota are also expected to be similar, like birds, mammals or insects communities.…”

“…But, until present, the dynamic of movement of the biota between native Atlantic Forest remnants and non-native reforestations that occur in such close proximity has been poorly studied (but see Willis and Oniki, 2002;Willis, 2003). The older reforestations generally possess a considerable number of native species, in view of the time that they have been in process of ecological succession (Moura, 1998).…”

“…This proposal rose from concise suggestions in scientific articles (e.g. Willis, 2003) and from a lot of informal communications between researchers and decision-makers. The incipient debate culminated in a concern of the state forest administration, due to the lack of technical-scientific information showing the viability, efficiency and real importance of those corridors (FEENA administration, pers.…”