Multi-Season Regional Analysis of Multi-Species Occupancy: Implications for Bird Conservation in Agricultural Lands in East-Central Argentina

Abstract

Rapid expansion and intensification of agriculture create challenges for the conservation of biodiversity and associated ecosystem services. In Argentina, the total row crop planted area has increased in recent decades with the expansion of soybean cultivation, homogenizing the landscape. In 2003 we started the first long-term, large-scale bird monitoring program in agroecosystems of central Argentina, in portions of the Pampas and Espinal ecoregions. Using data from this program, we evaluated the effect of land use and cover extent on birds between 2003-2012, accounting for imperfect detection probabilities using a Bayesian hierarchical, multi-species and multi-season occupancy model. We tested predictions that species diversity is positively related to habitat heterogeneity, which in intensified agroecosystems is thought to be mediated by food availability; thus the extent of land use and cover is predicted to affect foraging guilds differently. We also infer about ecosystem services provisioning and inform management recommendations for conservation of birds. Overall our results support the predictions. Although many species within each guild responded differently to land use and native forest cover, we identified generalities for most trophic guilds. For example, granivorous gleaners, ground insectivores and omnivores responded negatively to high proportions of soybean, while insectivore gleaners and aerial foragers seemed more tolerant. Habitat heterogeneity would likely benefit most species in an intensified agroecosystem, and can be achieved with a diversity of crops, pastures, and natural areas within the landscape. Although most studied species are insectivores, potentially beneficial for pest control, some guilds such as ground insectivores are poorly represented, suggesting that agricultural intensification reduces ecological functions, which may be recovered through management. Continuation of the bird monitoring program will allow us to continue to inform for conservation of birds in agroecosystems, identify research needed to reduce key uncertainties, and anticipate the effects of changes in agriculture in central Argentina.

Orange River Francolins (Scleroptila levaillantoides) persist in fragmented Highveld farming landscapes, South Africa

“…It has been demonstrated that agricultural activities may provide benefits for the survival of the Orange River Francolin, provided they are managed properly. This is in accordance with the finding of Goijman et al (2015) that a positive relationship exists between bird species diversity and habitat heterogeneity in agricultural landscapes. Aspects which proved beneficial in this regard were a diversity of crops and pastures with patches of natural areas.…”

“…Francolins benefit from arable edges (a product of fragmentation) in a number of ways (Goijman et al 2015); (1) weed, soya bean and maize plants provided cover in the edges of arable land so that the francolins could move into these habitats to feed unhindered by predators; (2) open edges probably provided space for marginal francolins which otherwise would have perished due to competition should they have remained in the grass camps during a time when chicks are growing up; (3) arable edges, especially when ploughed, provide food in the form of pieces of weed plants, corms, bulbs and fallen grain which were not found in grass camps (Little 2016). Since the grass camps were grazed quite heavily by cattle limited grass seeds were available for food during late winter which is a period when the francolins moved into arable edges to supplement their diet; (4) the maize fields between grass camps probably provided a buffer between territorial males as these males are actively attracted towards each other by territorial calls in unvaried grass camps (e.g.…”

The impact of a fox‐ and cat‐free safe haven on the bird fauna of remnant vegetation in southwestern Australia

“…The approach models detection/non-detection data from multiple species pre-and post-treatment (i.e. Russell et al 2009;Goijman et al 2015). Each species is modeled individually (with species-specific parameters) but also related to other species through the model's hierarchical formulation (Goijman et al 2015).…”

“…A site longitude covariate was included in the modeling to account for some of the possible effects of this bias (i.e. Goijman et al ); however, we consider any confounding factors unlikely to be as important as the main treatment effect, given that introduced foxes and cats are known to be major predators of the Australian avifauna (Dickman ; Woinarski et al ).…”

Oil palm and biodiversity: a situation analysis by the IUCN Oil Palm Task Force

“…Another major crop, soy, also has a large negative impact on biodiversity (242), supporting an impoverished bird diversity compared to natural ecosystems in Brazil and Argentina (243,244). Much of the soy production in Brazil has replaced the high-biodiversity Cerrado grasslands, home to many species found nowhere else (162), despite the Soy Moratorium (245,246).…”