Project

REFAUNA

Goal: The Refauna project intends to restore ecological interactions that were lost in defaunated forests by reintroducing medium and large mammals in the Atlantic forest fragments of Rio de Janeiro, southeastern Brazil. We have started in 2010 by reintroducing the red-humped agouti Dasyprocta leporina in Tijuca National Park. In 2015 we have released the first group of brown howler monkeys Alouatta guariba in the same location. This year we intend to reintroduce the first couple of lowland tapirs in the Ecological Reserve of Guapiaçu.

Date: 1 February 2010

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Project log

Pedro Mittelman
added 2 research items
en The aim of animal reintroductions has mainly been species recovery; only few reintroduction initiatives focus on ecosystem restoration. Therefore, reintroduction consequences on ecological interactions are seldom assessed. We used the interaction between a reintroduced population of agoutis (Dasyprocta leporina) and a vulnerable tropical endemic tree (Joannesia princeps) to examine reintroduction effects on seed dispersal and seedling establishment. To test the outcomes of this interaction, we tracked seeds of J. princeps in two adjacent forest areas with and without reintroduced agoutis. We also assessed if dispersal distances affected seedling survival. To determine seed fate and dispersal distance, we used spool‐and‐line tracking, together with camera traps to identify dispersers. Agoutis were the only species removing J. princeps seeds, thus dispersal only occurred where agoutis had been reintroduced; in the area without agoutis, all seeds remained intact on the soil, even one year after the experiment's beginning. At the reintroduction area, most seeds were preyed upon by agoutis but 7% remained dispersed and 2% germinated after ten months. Only seeds buried by agoutis were able to germinate. Most dispersed seeds were dispersed 15 m or farther and longer dispersal distances benefited J. princeps, since seedlings farther from a conspecific adult tree had greater survival probability. Agoutis were also seen burying seeds of two other plant species; these mammals have the potential to benefit dozens of large‐seeded species in our study system. Agouti reintroduction thus exemplifies the value of trophic rewilding programs to re‐establish ecological interactions and restore ecosystem functioning. Abstract in Portuguese is available with online material Resumo es O objetivo das reintroduções animais tem sido principalmente a recuperação de espécies ameaçadas e apenas poucos projetos de reintrodução focam na restauração de ecossistemas. Portanto, as consequências das reintroduções nas interações ecológicas são raramente estudadas. Aqui, usamos a interação entre uma população reintroduzida de cutias (Dasyprocta leporina) e a cutieira (Joannesia princeps), uma árvore tropical vulnerável e endêmica, para examinar os efeitos da reintrodução na dispersão de sementes e estabelecimento de plântulas. Para testar os resultados dessa interação, nós acompanhamos o destino de sementes de J. princeps em duas áreas florestais adjacentes com e sem cutias reintroduzidas usando o método de carretel e linha, junto com armadilhas fotográficas para identificar os animais dispersores. Também verificamos se a distância de dispersão influenciava na sobrevivência das plântulas de cutieira. A dispersão de sementes de J. princeps só ocorreu onde as cutias foram reintroduzidas; na área sem cutias, todas as sementes permaneceram intactas no solo, mesmo um ano após o início do experimento. Na área de reintrodução, a maioria das sementes foi predada por cutias, mas 7% permaneceram dispersas e 2% germinaram após dez meses. Apenas sementes enterradas pelas cutias germinaram. A maioria das sementes dispersas foi levada a 15 metros ou mais de sua origem e distâncias de dispersão maiores beneficiaram a planta, uma vez que plântulas de J. princeps mais distantes de uma árvore adulta coespecífica tiveram maior probabilidade de sobrevivência. As cutias também foram vistas enterrando sementes de outras duas espécies de plantas e têm o potencial de beneficiar mais dezenas de espécies com sementes grandes. A reintrodução de cutias exemplifica o valor dos programas de resselvajamento trófico para restabelecer interações ecológicas e restaurar o funcionamento de ecossistemas.
Bruno Cid
added a research item
The consumption of the carrion of a tapiti by a reintroduced female Dasyprocta leporina was observed in the wild. Herein, besides describing this event, we reviewed other evidence of vertebrate consumption by agoutis. Most of the studies describing this behaviour have been carried out in captivity. The preyed animals included birds and small rodents, which were sometimes killed by agoutis. This pattern suggests that this is not an anomalous behaviour for the genus, reflecting its omnivorous habits. This behaviour can be a physiologically sound feeding strategy, so new studies should focus on the temporal variation in the consumption of this resource, possibly related to food scarcity periods or to reproductive seasons, when the need for high-quality food tends to increase.
Carlos H. Salvador
added a research item
Pigmentation polymorphism occurs in many mammals but is considered rare in natural populations. Here, we report the first record of pigmentation polymorphism in a Neotropical squirrel, Guerlinguetus ingrami , at a private reserve in southern Brazil. The number of records for leucistic squirrels was approximately half that for brown squirrels. We also tested the differences in activity patterns between the leucistic and the brown squirrels. Both phenotypes were diurnal, but there was temporal segregation between the two. Further studies are needed to elucidate the occurrence of leucism in G. ingrami , and the possible ecological and behavioral outcomes.
Luísa Genes
added a research item
The use of radio-telemetry provides crucial information for evaluating population dynamics and for primate conservation. However, tracking methods must be balanced in their risks, costs and benefits. We conducted 12 trials; testing three different customized devices on reintroduced brown howler monkeys and compared the outcomes in terms of animal welfare and monitoring effectiveness. Our trials suggest that the use of metal string coated with plastic tube attached with metal sleeves provides lower risk of injuries. We emphasize the need for testing the equipment in captivity and in the field before release and for publishing outcomes of different tracking methods. Resumo: Lidando com radio-telemetria: efeitos no bem-estar de bugios (Alouatta guariba clamitans Atelidae-Primates) e na eficácia do monitoramento. A rádio-telemetria fornece informações essenciais para avaliar dinâmicas populacionais e para conservação de primatas. Entretanto, métodos de rastreamento precisam ser balanceados em seus riscos, custos e benefícios. Nós conduzimos 12 experimentos, testando três tipos diferentes de aparelhos customizados em bugios-ruivos e avaliando tanto o bem-estar animal como a efetividade do monitoramento. O cabo de metal preso por braçadeiras de metal, revestido por tubo plástico, promove o menor risco de ferimentos. É essencial testar o equipamento em cativeiro e em campo antes da soltura de animais. Recomendamos que se publiquem resultados com testes de métodos de rastreamento.
Luísa Genes
added a research item
Rewilding has been an increasingly popular tool to restore plant-animal interactions and ecological processes impaired by defaunation. However, the reestablishment of such processes has seldom been assessed. We investigated the restoration of ecological interactions following the reintroduction of the brown howler monkey (Alouatta guariba) to a defaunated Atlantic forest site. We expected the reintroduction to restore plant-animal interactions and interactions between howlers and dung beetles, which promote secondary seed dispersal. We estimated the number of interactions expected to be restored by the reintroduction to provide the baseline interaction richness that could be restored. We followed the reintroduced howler monkeys twice a week for 24 months (337 hours total) to assess their diet. We used howler monkey dung in secondary seed dispersal experiments with 2484 seed mimics to estimate the removal rates by dung beetles and collected the beetles to assess community attributes. We compared the potential future contribution of howler monkeys and other frugivores to seed dispersal based on the seed sizes they disperse in other areas where they occur. In 2 years, howler monkeys consumed 60 animal-dispersed plant species out of the 330 estimated. Twenty-one dung beetle species were attracted to experimentally provided dung; most of them were tunnelers, nocturnal, and large-sized (>10 mm). On average 30% (range 0-100%) of the large seed mimics (14 mm) were moved by dung beetles. About 91% of the species consumed by howlers (size range 0.3-34.3 mm) overlapped in seed size with those removed by dung beetles. In our study area, howler monkeys may consume more large-seeded fruit species than most other frugivores, highlighting their potential to affect forest regeneration. Our results show reintroductions may effectively restore ecological links and enhance ecological processes.
Carlos H. Salvador
added a research item
We present a novel and simpler way to measure human influence: the cellphone coverage. Besides, we also evaluated its influence in the probability of occurrence of medium and large wild mammals in Brazilian Atlantic Forest, as a study case. As a first step, we have demonstrated the correlation between cellphone coverage and human footprint globally, using a database of > 23 million antennas. Then, we have carefully studied the correspondence between the presence of a species and the cellphone coverage for 45 species of medium and large mammals of the Brazilian Atlantic Forest. We recorded 18,211 points of presence of mammals, and their probability of being under cellphone coverage was on average very low (18%). Most of the species showed a clear negative relationship with cellphone coverage, and threatened species presented an even lower probability, of at least 4% when compared with non-threatened ones. The strong positive relationship between cellphone coverage and the Human Footprint gradient at a global scale corroborated our a priori hypothesis that cellphone coverage can act as a surrogate for human presence, even in forested areas were no other footprint evidence is easily detectable.
Luísa Genes
added a research item
The loss or reduction of animal populations and consequent extinction of ecological interactions in Neotropical forests demand urgent conservation initiatives to reverse these trends. One of the rainforests with the highest levels of mammal defaunation is the Brazilian Atlantic Forest. Local mammalian extinctions in the biome were evaluated to set out priorities. Researchers, reserve managers and ex situ animal keepers throughout the Atlantic Forest were connected through a reintroduction network. From 2010 to 2017, we reintroduced two important seed dispersers, the red-humped agouti and the brown howler monkey, in Tijuca National Park, Rio de Janeiro, with other species on their way. We monitored the reintroduced populations regarding demography, spatial patterns, diet and their effect on ecological interactions. They interacted with several plant species, including large-seeded ones. We found 25 dung beetles' species interacting with howlers' feces. As TNP lacked medium and large sized frugivores, the increased dispersal can have a disproportional effect on forest regeneration. Among the main constraints for refaunation programs we pointed out delays to obtain environmental licenses, scarcity of source populations and difficulties regarding quarantine, release and monitoring of the animals. Refaunation has shown promise as a low-cost, effective way to restore ecological processes in defaunated Neotropical forests.
Luísa Genes
added a research item
As defaunation spreads through the world, there is an urgent need for restoring ecological interactions, thus assuring ecosystem processes. Here, we define the new concept of credit of ecological interactions, as the number of interactions that can be restored in a focal area by species colonization or reintroduction. We also define rewiring time, as the time span until all the links that build the credit of ecological interactions of a focal area have become functional again. We expect that the credit will be gradually cashed following refaunation in rates that are proportional to (1) the abundance of the reintroduced species (that is expected to increase in time since release), (2) the abundance of the local species that interact with them, and (3) the traits of reintroduced species. We illustrated this approach using a theoretical model and an empirical case study where the credit of ecological interactions was estimated. This new conceptual framework is useful for setting reintroduction priorities and for evaluating the success of conservation initiatives that aim to restore ecosystem services.
Caio Kenup
added a research item
This repository contains supplementary information regarding the paper "Walking on their own legs: unassisted population growth of agoutis reintroduced to restore seed dispersal in an Atlantic Forest reserve", authored by Caio Fittipaldi Kenup, Raissa Sepulvida, Catharina Kreischer and Fernando Antonio dos Santos Fernandez Contained here are: R Scripts and Functions used to carry out the analyses (.R) Full carried-out analyses (.RData) Raw data files used as input (.csv). Supplementary Tables as Published (.xlsx) Abstract from the paper: Reintroduction of locally extirpated species populations is an increasingly popular conservation tool. However, few initiatives are made focusing on the restoration of ecological processes. In addition, many reintroductions fail to conduct post-release monitoring, hampering both assessment of its success and implementation of adaptive management actions. A reintroduction effort to reestablish a population of the red-humped agouti (Dasyprocta leporina), a scatterhoarding rodent known to be an important large-sized seed disperser, started in 2009 with the aim of restoring ecological processes at Tijuca National Park, Southeast Brazil. To assess the successful establishment of this reintroduced population, we monitored it through mark-resighting from late 2013 to early 2015. Population size and survival were estimated using a robust design Poisson-log-normal mixed-effects mark-resight model. By March 2015, wild-born individuals fluctuated around 30 individuals and overall growth of the population was positive. As the reintroduced population is capable of unassisted growth, we conclude that the reintroduction has been successful on the medium-term. We suggest that releases should be ceased and efforts redirected to continued monitoring, investigation and management of possible threats to persistence, and to quantification of the reestablishment of ecological processes. Reintroduction of D. leporina populations can be a highly cost-effective tool to restore ecological processes, especially seed dispersal, in Neotropical forests. Disclaimer: For data protection reasons, the photographic records .csv sheet has been truncated to two stations and 12 days of sampling, providing only a toy example. Nevertheless, the summarised data and analysis present on the .RData files represent the full set of records.
Caio Kenup
added 3 research items
A etologia é uma ferramenta importante na detecção do efeito ambiental sobre o animal. Um adequado estudo etológico permite reconhecer os comportamentos de estresse e outros estados anormais do animal, causados por elementos externos nocivos, o que é indispensável para determinar pautas básicas no manejo dos indivíduos. Cutia vermelha (Dasyprocta leporina) são grandes roedores diurnos, principalmente frugívoros que se distribuem desde o sul de México até o norte da Argentina. Foram realizadas observações em cativeiro em cercados de aclimatação de 12 indivíduos no Parque Nacional da Tijuca, antes da soltura deles. O catalogo de comportamento de Dasyprocta leporina (Linnaeus, 1758) foi realizado em 12 horas, caracterizando 63 atos comportamentais, agrupadas em três categorias comportamentais, através das amostragens animal focal e ad libitum. Embora não foi possível registrar as frequências pelo motivo de tempo, pode se observar uma coesão inicial dos indivíduos machos com as fêmeas, mas não entre machos pelo motivo do comportamento territorial incluso deslocando aos outros machos.
Reintroduction of extirpated populations is an increasingly popular conservation tool. However, success rate of reintroduction efforts is low, and only recently careful monitoring of outcomes has become common. Reintroduction efforts have two main goals: first, to increase ranges of threatened species, and improve their long-term viability on the global scale; second, to restore lost interactions and ecosystem process to how they were before the species' extirpation. The red-humped agouti (Dasyprocta leporina) is a scatterhoarding rodent, known to be a good large-sized seed disperser. A reintroduction effort to reestablish a population of this species to Tijuca National Park (RJ) started in 2009 with the aim of restoring ecological interactions such as seed dispersal and thus im- proving tree recruitment. Thirty one individuals were released from semi-captive stocks in Rio de Janeiro from 2009 to 2014. Twenty of these survived the first 12 weeks after release, contributing to population growth. To assess the successful establishment of this reintroduced population, we monitored it through mark-resighting from November 2013 to November 2015. Individuals were captured using Tomahawk traps, and marked indi- vidually with fur bleaching and freeze-branding. Resighting was carried out through 30 days of camera trapping after each capture session. Population size and survival were estimated using a robust design Poisson-log-normal mixed-effects mark-resight model. Population recruitment and growth were derived from those estimates through parametric bootstrapping. We caught a total of 17 individuals, including 13 wild-born ones. Survival was lower for young individuals than for adults. Estimated survival was also lower than previously reported post-release survival of reintroduced animals. Recruitment was low throughout the study, with a peak on August 2014. However, overall growth of the wild-born population was positive, with estimated population size going from 10.63 to 29.31, with a peak of 82.66 on August 2014. The density increase may have increased mortality through competition for resources, higher intraspecific aggression or predation by domestic dogs (Canis lupus familiaris), especially after the latter developed a search image for agoutis. During our study, few released individuals were recorded alive. Therefore, most of the growth observed is due to the reproductive success of the wild population. Because the reintroduced population is capable of unassisted growth, we conclude that the reintroduction has been successful on the medium-term. Thus, releases should be ceased and efforts redirected to continued monitoring and investigation of possible threats to persistence, such as predation from domestic dogs as was observed during the study for 12.5% of released animals. Monitoring should also be directed to quantifying the reestablishment of ecological processes such as seed dispersal by D. leporina. Success criteria at the ecosystem level can be derived from such monitoring. Because agouti reintroductions are able to succeed with low release numbers, management of this species provides a useful laboratory for understanding the dynamics of reintroductions and their effects on ecosystem restoration.
Reintroduction of locally extirpated species is an increasingly popular conservation tool. However, few initiatives focus on the restoration of ecological processes. In addition, many reintroductions fail to conduct post-release monitoring, hampering both assessment of their success and implementation of adaptive management actions. In 2009 a reintroduction effort was initiated to re-establish a population of the red-rumped agouti Dasyprocta leporina , a scatter-hoarding rodent known to be an important disperser of large seeds, with the aim of restoring ecological processes at Tijuca National Park, south-east Brazil. To assess whether this reintroduced population established successfully we monitored it using mark–resighting during November 2013–March 2015. Population size and survival were estimated using a robust design Poisson-log normal mixed-effects mark–resight model. By March 2015 the number of wild-born individuals fluctuated around 30 and overall growth of the population was positive. As the reintroduced population is capable of unassisted growth, we conclude that the reintroduction has been successful in the medium term. We recommend the cessation of releases, with efforts redirected to continued monitoring, investigation and management of possible threats to the species’ persistence, and to quantification of the re-establishment of ecological processes. Reintroduction of D. leporina populations can be a cost-effective tool to restore ecological processes, especially seed dispersal, in Neotropical forests.
Marcelo Lopes Rheingantz
added a project goal
The Refauna project intends to restore ecological interactions that were lost in defaunated forests by reintroducing medium and large mammals in the Atlantic forest fragments of Rio de Janeiro, southeastern Brazil. We have started in 2010 by reintroducing the red-humped agouti Dasyprocta leporina in Tijuca National Park. In 2015 we have released the first group of brown howler monkeys Alouatta guariba in the same location. This year we intend to reintroduce the first couple of lowland tapirs in the Ecological Reserve of Guapiaçu.