Avian Ecology at MU

University of Missouri - Columbia

Kosñipata Ecosystem Project

Introduction

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The Kosñipata Ecosystem Project is a group of researchers studying the ecological diversity and processes in the Kosñipata Valley in Southeastern Peru. The eastern slope of the Andes is one of the most diverse places on earth. Compared to northern temperate regions the ecology of montane regions in the Neotropics is relatively poorly understood. The goal of the Project is to enhance our understanding of this region, altitudinal transects in general, and ecosystem processes through a variety of experimental and descriptive studies of the plants and animals found in the valley.

Collaborators

There are a number of researchers from various institutions actively pursuing research activities in the Kosñipata Valley. We welcome all researchers with interests in the area to join. For more information contact Chris Merkord.

Current Research

Frog diversity, distribution, population trends

Amphibians are declining at alarming rates throughout the world. Many frogs have disappeared from protected or pristine areas in neotropical montane forests. These declines are often associated with the emergence of the fungal disease chytridiomycosis. The montane forests of the Manu Biosphere Reserve are home to more that 40 species of frogs, including several critically endangered, endangered, and vulnerable species. In addition to chytridiomycosis, high-Andean frogs are threatened by deforestation, cattle grazing and fire, and global climate change. What are the current conditions and prospected trends for frog populations along the Kosñipata Valley?

We are collecting data on frog species diversity, altitudinal distribution, density and rates of chytrid infection in high-Andean grasslands and montane forests between 1500 and 3700 m. We will compare contemporary data with similar data collected between 1996-99 (before the emergence of chytridiomycosis in southern Peru) and in 1975 (between 3400-3500 m only) to assess the populations’ conditions and trends. We are also studying the effects of changes in vegetation structure induced by cattle grazing and fire on frog diversity and abundance, by using a combination of survey, analytical (carbon and nitrogen stable isotopes) and experimental approaches.

Understanding forest carbon cycling along an Andean elevation gradient

Tropical montane cloud forest ecosystems are amongst the least studied of terrestrial ecosystems, as well as potentially the most vulnerable to warming climates. As they combine low mean annual temperatures (characteristic of temperate forests) with small temperature seasonality (characteristic of tropical forests), understanding the carbon cycling of these unusual forest ecosystems could yield fundamental general insights into the processes controlling forest systems structure and function. This project aims to examine the effects of mean annual temperature and seasonality on forest ecosphysiology and carbon dynamics, by monitoring key forest processes along an elevational gradient in an Andian tropical cloud montane forest.

Ecosystems Dynamics team, Oxford University Environmental Change Institute

Altitudinal migration of birds

Little is known about the migratory status of many neotropical forest birds, though most are assumed to be sedentary. Chris Merkord and Jill Jankowski are undertaking a series of studies in to determine whether altitudinal migration is actually prevalent among montane forest birds in the Kosñipata Valley. These studies attempt to describe the extent, timing, and duration of altitudinal migration in a number of species.

This study has multiple components, some of which are explained here. First, stable isotope values of feather samples collected at field sites across an elevational gradient will be used to to determine which species are migratory, when they migrate, and what altitudes they migrate to and from. Second, visual/auditory surveys of birds throughout the year will be used to look for changes in abundance of certain species over time.

Both of these strategies involve use exciting new methodological developments in the study of animal movements. With any luck, this project with shed light on what has until now been virtually unstudied on the eastern flank of the Andes. If altitudinal migration is present, it could have important conservation implications in the Andes and elsewhere, especially in the face of deforestation and climate change.

Avian Range Limits and Species Replacements

In contrast to altitudinal migrants, whose range limits vary throughout the year with movement of individuals, other species are believed to have relatively fixed range limits that are maintained by strong species-habitat associations and/or interspecific interactions. Of particular interest are species replacements, where pairs of closely related species (usually congeners, or species in the same genus) have adjacent, non-overlapping altitudinal distributions. Interspecific competition, via interspecific territoriality, may underlie such replacements by preventing coexistence of strong competitors, though community-wide patterns suggesting competition are rarely verified experimentally. Alternatively, species replacements could arise from specialization of congeners to respective habitats separated by abrupt changes in vegetation or habitat structure.

We are testing these two hypotheses for selected species exhibiting altitudinal replacements by 1) conducting interspecific playback experiments in contact zones between congeners to evaluate interspecific aggression and 2) combining species occurrence data from our avian census with vegetation and habitat descriptions to examine species-habitat associations along the altitudinal gradient. This will be an important study for assessing the ways that ecological forces structure tropical avian communities and will increase our understanding of what drives high endemism in Andean landscapes.

Tree Performance & Response to Climate Change

Temperatures in the eastern tropical Andes are predicted to rise 4-5 degrees Celsius in the next century, an equivalent of moving downslope 800 meters in elevation. Since most tree species in Kosñipata Valley of Peru have elevational ranges of less than 800 meters, and many trees live more than a century, most of the trees currently in the forest will experience climatic conditions that are not currently in the norm. How will these trees respond? While only time and careful observation will give a definitive answer, we can make predictions based on the current performance of species across their elevational ranges. To shed light on this question I am investigating how growth, survival, and fecundity change in the tree genus Weinmannia between 1500 meters elevation to tree line at 3500 meters elevation. Weinmannia is a dominant tree genus in tropical montane cloud forests around the world and there are at least a dozen species in the Kosñipata Valley , forming near mono-dominant stands in some places. Since it is ultimately the establishment of new individuals that will determine the composition of future forests, I am also investigating what conditions seedlings need to germinate, grow, and survive to become reproductive adults through surveys and controlled experiments across the elevational gradient.

Comparisons of Diversity Patterns across Taxonomic Groups

Species diversity patterns within landscapes are often described by species richness (alpha diversity or within-habitat diversity) and change in species composition across space (beta diversity or species turnover). While species richness patterns along tropical altitudinal gradients are relatively well documented, the levels of beta diversity and the patterns of species turnover in heterogeneous landscapes are poorly understood. It is also likely that taxonomic groups respond differently to gradients, though there have been very few opportunities to compare these community attributes across taxa in the same landscape.

One goal of our project is therefore to use census data for both avian and tree communities to compare the levels and patterns of species turnover for these taxa along the Kosñipata altitudinal gradient. We expect that these data will be insightful for further investigation of whether the distributions of particular species (e.g., fruiting trees and frugivorous birds) co-vary across heterogeneous landscapes. These taxonomic comparisons will also be useful for regional conservation planning and provide an excellent case study to examine how designs for nature reserves with aims to maximize protection of species diversity might vary with different focal taxa.

Where is Kosñipata?

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The Kosñipata valley is in southeastern Peru, in the Department of Cusco. The valley is reached from Cusco by traveling north on the Cusco-Pillcopata highway. About 100 km from Cusco the highway crosses a pass at Acjanaco (3540m) and descends into the Kosñipata valley, named after the river which forms it. The highway follows the valley for the next 60 km as it winds its way towards the town of Pilcopata, where the Río Kosñipata enters the Río Alto Madre de Dios.

On the map below you can follow the highway north out of Cusco to Acjanaco, where it enters the cultural zone of Manu National Park.

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