Project
© Gonzalo Pardo
© Hernán Povedano
Podiceps gallardoi
Scope of the project
The main threats to Hooded Grebe are invasive species (Rainbow Trout, American Mink and Black-bellied Gull), infrastructure works (street lighting, cities, Santa Cruz River dams) and global climate change.
© maría del castillo
© hernán povedano
© miles brengle
© sergio moya
Project Hooded Grebe arose in 2010 as a conservation emergency due to the increasing difficulty in finding the species and a notable population reduction. Since 2010, with the incorporation of researchers from CONICET and the Laboratory of Ecology and Animal Behavior (Faculty of Exact and Natural Sciences – University of Buenos Aires), we began to work on generating information on their behavior, reproductive biology, genetic structuring and mainly on the effect of their threats.
These research actions provided the first tools for the project to begin conservation actions and direct management of the Hooded Grebe populations as early as 2011. The first step was the establishment of the “Colony Guardians” program, which sought to maximize the survival of nests (protecting them from the impact of the American Mink) and minimize the effect of predation of adults and juveniles by the American Mink. In those early years, we began to add CONICET researchers from other institutions, including institutes such as CADIC, in Ushuaia, and IPEEC-CENPAT, in Puerto Madryn, to address problems in a more comprehensive way, thus generating the American Mink control plans and the rainbow trout management plan to restore lagoons of importance for the macaque macaw.
At the same time, Project Hooded Grebe has been gaining support from numerous national (governmental and private) and international institutions. Since then, this project has continued with conservation and research actions. The main achievements have been to reduce the impact of the main threats, as well as to generate protected areas for the conservation of this critically endangered species.
Macá tobiano project
patagonia in action program
Kini Roesler
Completed
The general objective of this project was to study the factors that affect the viability of the Hooded Grebe populations. It was framed within the need to generate scientific knowledge to implement an integral management plan for the Hooded Grebe population, generating conservation and management actions, both in situ and ex situ. The particular objectives were to study: 1) little known aspects of its general biology; 2) population numbers, trends, reproductive success and the factors that affect it; 3) migratory behavior, the existence of philopatry and, as a result, the possible genetic structuring of the populations; and 4) biotic factors that affect the populations, mainly the effects of invasive species. These objectives were based on the hypothesis that Hooded Grebe populations have a population and genetic structure throughout their distribution. This structure is determined by philopatric migratory behavior and by threat factors of different origins that affect reproductive success and adults. To cover all these objectives, techniques, methodologies and conceptual frameworks will be combined.
To cover all these objectives we combined techniques, methodologies and conceptual frameworks from different disciplines, such as ethology, population ecology, population genetics, population ecology, community ecology and spatial ecology. We developed it throughout the summer and winter distribution of the species, including the localities where it was recorded in Chile.
- Juan Carlos Reboreda & Bettina Mahler - Laboratorio de Ecología y Comportamiento Animal (LEyCA) del IEGEBA-CONICET, FCEN-Universidad de Buenos Aires.
- Marcel Van Tuinen - University of North Carolina at Wilmington.
- Claudia Gray - EDGE of Existence Programme, Zoological Society of London.
All the results of this line of research are reflected in the doctoral thesis presented in 2016 at FCEN-University of Buenos Aires and in publications from 2012 to the present, as well as numerous abstracts of national and international congresses.
© Gonzalo Pardo
© Gonzalo Pardo
© belen dri
© ugo mellone
Gabriela Gabarain
Active
The objective of this line of research is to develop an ex situ rearing program to increase the number of Hooded Grebe juveniles that arrive at the time of migration annually, through the recovery of ecologically lost eggs (i.e. eggs that do not hatch in the wild). The ultimate goal is to boost population strengthening through the release of captive-bred individuals. As part of this project we also seek to deepen our knowledge of aspects of the reproductive biology and behavior (e.g. parental care) of Hooded Grebe in the wild to allow us to adjust the protocols under evaluation; develop protocols for breeding, including transport conditions, incubation, hatching, feeding, swimming and environmental conditions necessary for development; and monitor the survival of released individuals (recruitment to migration and effective recruitment).
To study the reproductive biology and behavior of Hooded Grebe we made observations of the breeding colonies to record, during incubation, the frequency of parental turnover in the nest and how often the adults place the eggs with the beak inside the nest. We also monitored families (two parents and a chick or juvenile) to record the frequency of feeding, amount of prey delivered, how often the parents throw the chick into the water and how long the chick remains in the water. Ex situ rearing: We collect eggs in lagoons on the plateaus and transport them in a cooler with hot water bottles as a heat source. Once at the rearing center, located at the "Juan Mazar Barnett" Biological Station, we labeled them, weighed them and put them in an incubator. We weigh the eggs daily and every three days we carry out a control candling. The last two days of incubation we transferred the eggs to a hatcher. After hatching, we leave the chicks for a minimum of two hours in the hatcher to facilitate the drying of the down. We then keep the chicks in a thermal pen. We weigh them daily, at the same time, as a growth control. Every 30 minutes, 24 hours a day, we offer them food and put them in pools for drinking, defecation and short swims. The work is carried out throughout the reproductive distribution of Hooded Grebe, which includes the high plateaus of the west of the province of Santa Cruz.
The first advances in this line of research are those presented in Gabriela Gabarain's master's thesis in 2021. Since the beginning, we have obtained more than 500 h of colony observations (incubation) and more than 115 h of family observations (feeding). We have also improved the egg collection methodology, which is efficient and does not interfere with the reproductive success of the colony, as well as the egg transport methodology, which is efficient, even in long trips, which widens the range of potential ponds where to collect eggs. After evaluating different incubation protocols (temperature and humidity), we consider that we have arrived at an effective protocol that allows the hatching of chicks with an adequate level of maturity and development. Throughout the seasons we tested different chick care strategies (e.g.: feeding frequencies) and found that regular chick care seems to be fundamental to avoid digestive problems (gas accumulation) frequent in macaques. Likewise, early stimulation seems to be important for the chicks to start eating and thus avoid the "hunger syndrome", cause of early death in chicks in the first week of life. With this we managed to increase the life span of the chicks. So far we have reached a maximum survival for chicks of Hooded Grebe of 24 days, but we have already raised and released individuals of grebe Silver-collared species close to Hooded Grebe, with similar life habits and living in the same environment.
- Will Costa - Wildfoul and Wetland Trust (UK).
- Bettina Mahler - Laboratorio de Ecología y Comportamiento Animal (LEyCA) del IEGEBA-CONICET, FCEN-Universidad de Buenos Aires.
© Gonzalo Pardo
© Valeria Aspinall
© Gonzalo Pardo
© Gonzalo Pardo
Emilia Giusti
Active
As Hooded Grebe is an endangered bird with migratory habits, we need to outline conservation strategies that take into account the sites used throughout its life cycle. This includes breeding sites, wintering sites, and sites used along migratory routes. The identification of conservation units (CUs) is an essential first step in the conservation of this species, and can be carried out using molecular markers. This is based on the identification of demographically independent populations, with a significant divergence of their allele frequencies in nuclear or mitochondrial loci. The molecular techniques, to identify the CUs, will allow to know the most important sites for conservation in a current and historical temporal context of Hooded Grebe, fundamental for this critically endangered species. The general objective of the project is to study the population structuring and the migratory and local movements of Hooded Grebe to understand the spatio-temporal dimension of the life cycle of the species.
We work on genetic analysis of blood samples obtained from individuals captured in three high altitude plateaus (Siberia, Strobel Lake and Buenos Aires Lake). With these samples, molecular analyses are carried out to know the population structure by estimating the variation at genomic level. Telemetry techniques are used to learn about migratory behavior and local movements, including the capture of individuals from Hooded Grebe on the same three plateaus and the subsequent placement of transmitters (GPS-UHF and GPS-satellites). The satellite GPS transmitters store information and the downloading is remote, allowing the study of migratory routes. These also make it possible to know the seasonality of the use of the lagoons by the Hooded Grebe during the pre- and post-reproductive periods (from October until the formation of the first colony and from April until their departure) in order to identify if there is a differential use of the water bodies according to the moment in the reproductive season, the size of the lagoons and the geographic location with respect to the center of the plateau (altitude). The placement of rings and repeated censuses as recaptures of adults and juveniles provides information related to the dispersion of individuals, both to know if there is site fidelity at the reproductive or natal level. In addition, it will also provide information on the seasonality of the species during the winter, so we will also work by visiting the estuaries it uses (estuaries of the Chico and Santa Cruz rivers, Coyle and Gallegos). This last objective aims to deepen our knowledge of how macaes are distributed in the three estuaries during the winter. The objective is to know if there is a differentiated use of the wintering sites and thus re-direct conservation efforts for this endangered species.
- Bettina Mahler - Laboratory of Ecology and Animal Behavior (LEyCA) of IEGEBA-CONICET, FCEN-University of Buenos Aires.
The progress of this line of research can be seen in the numerous presentations at congresses. Also in 2023 Roxana Falconer presented her graduate thesis within the framework of this line of research.
© Patricia Mancilla
© Darío Podestá
© Emanuel Tiberi
© Patagonia Program
Technical team
Active
This project arises as the need to evaluate the effect of the active management actions that have been carried out since 2011 is fundamental to be able to adapt and improve them in the future. Therefore, we seek to evaluate the effects of the "colony guardians" on the reproductive success and survival of adults of Hooded Grebe to study the effect of the management actions applied on the American mink populations in the high altitude ponds: to study the effect of trout removal from the lagoons on waterbird populations and, in particular, on the reoccupation of Hooded Grebe, to know the effect of the management of the Cook's Gull populations and the consequences on its impact on the colonies of Hooded Grebe and, finally, to study the effect of artificial nesting platforms and windbreak systems on the survival of Hooded Grebe. We also seek to know the impact on the social perception of the " Hooded GrebeProject" in Santa Cruz.
- Colony Guardians: We analyzed the data collected from 2011 (with the first protected colony) to the present, with the idea of evaluating the effect of the presence of colony guardians in the lagoons on the reproductive success and survival of adults of Hooded Grebe.
- American mink trapping: The work with this species is focused on evaluating the effect of control actions carried out in the lagoons and watercourses adjacent to the plateau of Lake Buenos Aires where the presence of this predator is permanent. Since 2013, mink populations are controlled based on a strategy that combines systematic trapping from December to May, and since 2019 with search dogs (specially trained to search for individuals and mink burrows) for selection of localized trapping points (close to active burrows).
- Rainbow Trout Removal.
- Control of populations of the Black-headed Gull: The Lesser Black-backed Gull was mentioned as one of the main threats to the conservation of Hooded Grebe by preying on eggs and chicks. Favored by human activities, the Lesser Black-backed Gull managed to establish itself in the vicinity of the breeding lagoons of grebe. The gull colony is located on the plateau of Lake Buenos Aires, in the "El Gaviotero" lagoon. This lagoon has three rocky islets, where a gull colony has settled.
- Artificial platforms and windbreaks: Artificial platforms and windbreak systems are one of the newest management actions being undertaken to improve the status of Hooded Grebe. For this reason, we compared the success of colonies from 2011 to the present by contrasting the success of those colonies without management against those in which platforms and/or windbreaks/windbreaks systems were applied.
- Social perception: Knowing the social impact of the management actions carried out by a conservation project is fundamental to understand and improve the relationship with local society. For this we used social science strategies, mainly interviews and surveys focused on the age groups and social groups represented in the towns and rural areas of the region.
This project is dynamic and its objective is to generate information that will allow us to adapt the conservation and management actions carried out. An important progress is to generate a doctoral project that will allow for systemic monitoring of actions.
© Ugo Mellone
© Hernán Povedano
© Julián Márquez
© Ugo Mellone
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