Projects in Peru

Census of Humboldt penguins at key locations in Peru in 2022

Landau, 20th May 2024


Preliminary note


For over 20 years, ACOREMA, in cooperation with the Saint Louis Zoo (Missouri, USA), has been conducting Humboldt Penguin counts at key sites for the National Service of Federally Protected Natural Areas (SERNANP) and the National Reserve System of Guano Islands, Islets and Rocky Headlands (RNSIIPG). The regular surveys are hardly known as they are not published in any specialist journals. Sphenisco was also unaware of the results until now, despite its long and close collaboration with ACOREMA. During a personal meeting in Pisco, southern Peru, in December 2023, we discovered the knowledge gap and are publishing the last available report from December 2022 with the permission of ACOREMA.


Pisco December 2022


Title: Census of Humboldt penguins at key sites in Peru in 2022


Main Author: Alí Jefferson Altamirano Sierra
                     ACOREMA. Calle San Francisco 253, 201-B, Pisco, Peru.

Co-Author: Julio César Reyes Robles
                      ACOREMA. Calle San Francisco 253, 201-B, Pisco, Peru.

                      Patricia McGill, Ph.D. 

                      c/o Saint Louis Zoo, One Government Drive, St. Louis, Missouri 63110 USA.

                      Anne Tieber,
                      St. Louis Zoo, One Government Drive, St. Louis, Missouri 63110 USA.


Implementing institution: Coastal Areas and Marine Resources (ACOREMA),

Calle San Francisco 253, Office 201-B, Pisco, Peru, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.




The Humboldt penguin (Spheniscus humboldti) census was conducted from January 23 to February 2, 2022 at various locations on the north-central coast of southern Peru. The aim was to determine and evaluate the development of the population of the endangered species. The method essentially consisted of conducting counts during the moulting season according to the 1998 Population and Habitat Viability Assessment (PHVA) method. A total of 15,663 penguins were counted on 34 islands and coasts. The locations with the most penguins were: the piers of the Peru LNG terminal (1,759), the San Juanito Island-North Island-Little Island area (1,827), Punta San Juan (1,621), San Lorenzo Island (1,261), San Gallán Island (731) and La Vieja Island (723). In addition, 2 important locations - the island of Guañape Norte (1,817) and the island of Macabí (1,542) - were identified and taken into account. Data for these two islands were collected by local personnel. The oceanographic conditions for the 2022 survey period were classified as "neutral", within normal parameters. Compared to the moderate to cold conditions of the 2018-19 El Niño event, the difference between 2020 and 2022 is positive: plus 13% compared to the last count. Numbers on Santa Rosa Island remain low and have declined dramatically since their peak in 2014. The use of drones in the counts has proven to be very useful, as it can complement and contrast the counts carried out by observers.




The 2022 annual Humboldt penguin (Spheniscus humboldti) census took place from January 23 through February 22, along several sites in the north-central to southern Peruvian coast. The aim was to continue evaluation of the population trend of this threatened species. Methodology followed the 1998 PHVA methodology that involves penguin count during the molting period. From observation in 34 sites included this year, the number of penguins counted was 15,663. The localities with higher counts were the Peru LNG breakwater (1,759), the group of islote San Juanito‐Isla Norte‐Islote Pequeño (1,827), Punta San Juan (1,621), San Lorenzo Island (1,261), San Gallán Island (731) and Isla La Vieja (723). In addition, two major sites were identified by the resident guards who provided data: isla Guañape Norte (1,817) and isla Macabí (1,542). During the 2022 census, oceanographic conditions were considered “neutral”, within normal parameters. During moderate to cooler conditions since the ENSO in 2018-19, the difference between 2020 and 2022 is positive: +13% compared to the last census. The numbers continue low at Santa Rosa Island, which has experienced a dramatic decline since its peak in 2014 when 4,939 penguins were counted. The use of drones continues to be important to contrast and to complement the direct counts made by the census team.


Description of the project area


The surveys were conducted from January 23 to February 2, 2022 along the coast and on the islands in the central and southern part of the Peruvian coast (approximately between 11° S and 15° S, including two islands off 8° S). Locations, teams and dates are listed in Table 1. The following sites were selected for the 2020 counts: Punta Hornillos promontory and Hornillos Island, the Ocoña area, including Cueva el Saltadero, Punta Atico and Zaragoza Island, Puerto Inka, Punta San Juan, San Juanito Island (in addition to North Island and Small Island), Santa Rosa Island, Pan de Azúcar Island, La Vieja Island, Tres Puertas, Bajada Blanca, San Gallán Island, Punta El Arquillo, Blanca Island, Ballestas, Chinchas, Asia and Los Checos Islands, Pachacamac Island, San Francisco Island, Los Farallones, San Lorenzo Island, Palomino Island, Las Cavinzas, Pescadores Island and the piers of the Peru LNG terminal located in Pampa Melchorita (Figure 1). 


In addition, data from two important sites - Guañape Norte Island and Macabí Island - provided by AGRORURAL and SERNANP staff were included. The counts from February 1 were included as they were very close to the counts from the other sites.




The first Population and Habitat Viability Assessment (PHVA) for Humboldt penguins (Spheniscus humboldti) was conducted in 1998 by researchers from Chile, Peru and the United States (Araya et al. 2000). The PHVA recommended simultaneous censuses in Peru and Chile so that future management decisions can be based on more accurate population models of the status of the species. In contrast to previous studies on this penguin species, the PHVA recommended that surveys be conducted during the moulting season. During the moulting period, the penguins stay in groups on the shore in traditional locations and fast during the 21-day moulting period. Studies on the African penguin (Spheniscus demersus), a species with a similar lifestyle, have shown that counts during the moult provide a better estimate of the total population than counts during the breeding season (Crawford & Boonstra 1994). Although the modified methodology does not allow a comparison in magnitude with previous studies, it provides a better estimate of actual populations, which were stable between Peru and Chile until 2008.

The current distribution area of the Humboldt penguin stretches from the island of Foca (5°12'S) in Peru to the island of Puñihuil (42°73'S) in Chile. Since 1999, the penguins have mainly been counted on the central and southern coast of Peru. As the populations on the north coast were very low at the beginning of the surveys, only two counts were carried out in 2015 and 2018, as information was available from sites with a greater presence of the birds. In general, sites are added to or removed from the survey area because the distribution of moulting animals has changed or because new sites with high concentrations become known. If the number of animals is consistently low, especially if they are remote, they are removed from the annual survey list. The surveys clearly show that both the number and distribution of penguins change from year to year. However, the significance of this observation is not fully understood. For example, between 1999 and 2000 and between 2003 and 2004, the number of moulting penguins increased at some sites, while it decreased at others. The maximum number of penguins was reached at almost all sites in 2014 and 2015. It is not known whether the moulting season (and thus the period during which birds are counted on the coast) changes each year, whether birds have migrated to other areas or whether the numbers have actually changed. During and after El Niño, penguin numbers may decline in key locations. It is not known whether the birds have died or moved to other locations. The decline in total numbers along the coast after a strong El Niño suggests that the former hypothesis is the more likely.

The International Working Group on Penguins of the genus Spheniscus recommended annual surveys until there is a better understanding of trends, annual fluctuations, geographical effects of El Niño and other events. Similarly, a BirdLife International workshop on birds in Peru in 2007 emphasized the importance of developing appropriate methods for counting penguins during the breeding season, but conducting annual counts throughout the range during the moulting season (BirdLife International 2008).

Due to the challenges posed by the Covid-19 pandemic and the tsunami triggered by the volcanic eruption in Tonga, the main objective in 2022 was to monitor the areas that have historically had the highest abundance of Humboldt penguins. Three teams were deployed: in the north from Pescadores to Asia, in the central south from Melchorita (Peru LNG terminal) to Santa Rosa and in the south from San Juanito Island to Punta Hornillos. The teams obtained further data from the monthly counts in January and February 2022, which were carried out by SERNANP and AGRORURAL employees.




1. to determine the current Humboldt penguin populations at the most important sites in Peru using the methods defined in the PHVA and subsequent revisions. These methods are comparable with the surveys carried out since 1999, the results of which are available for comparison with other methods.

2. contribute to improving information on the variation in counts from year to year, particularly at key sites.

3. strengthen collaboration between Peruvian field researchers and biologists from zoological institutions in the United States to improve information and conservation priorities.




The surveys were conducted from January 23 to February 2, 2022 along the coast and on the islands in the central and southern part of the Peruvian coast (approximately between 11° S and 15° S, including two islands at 8° S).

As in previous surveys, penguin colonies on islands and cliffs were approached by fishing boats or tourist sailing boats. Most sites are inaccessible from land, so counts were conducted from a distance of 50 to 100 meters using 10x40 or 10x50 binoculars. At least 2 observers carried out separate counts. The counts were repeated until the observers arrived at approximately equal results (up to 10 %). The counts on land in Punta San Juan were carried out from observation huts or other positions. The distance was such that the birds were not disturbed and their flight was not hindered. On the islet of San Juanito and the neighboring islets, the count was conducted from the shore using binoculars and a telescope. If the swell permitted, the penguins were usually photographed in front of the cave entrances and their numbers were then determined from the photos. This allowed for more accurate counts than trying to count from a moving boat with binoculars and in poor light. Since 2018, the counting team has been using drones, where available, to take photos in places that are difficult to see or access due to the presence of nesting guano birds, the nature of the rocky coastline, the height of the cliffs and platforms used.


Results and discussion 


The total number of penguins counted in 2022 during the survey of 34 islands and coastal sites was 15,663 (Table 2). One additional site, Tres Puertas (Paracas), was visited but no counts were possible due to rough seas and fog. The pier of the Peru LNG terminal was visited for the second time this year. Compared to the counts from 1999 and previous years, 1,759 penguins were counted. Compared to the sites surveyed in 2020, this count showed an increase of 13 %. However, compared to the high numbers in 2014, this result represents a decrease of 49.5 % (only the sites visited in both years are taken into account). The severe El Niño events of 1997-1998 and 2014-2016 were followed by significant declines in populations. This did not play a role in 2022. At the end of 2021 and in January 2022, the month in which the census was carried out, the oceanographic conditions were "neutral" according to reports from the ENFEN Committee, with no extreme phenomena such as El Niño occurring. However, negative temperature anomalies were detected in January 2022 compared to December 2021. This would indicate a short-lived coastal La Niña event in January (ENFEN, 2021, 2022). Thus, there seems to be no correlation with the dynamics of the marine ecosystem that the number of Humboldt penguins remained low at some of the most important sites.

The highest densities of penguins were observed in 2022 at the following locations: the piers of the Peru LNG terminal (1,759), the area of San Juanito Island (North Island), Pequeño Island (1,827), Punta San Juan (1,621), San Lorenzo Island (1,261), San Gallán Island (731) and La Vieja Island (723). Other sites with high concentrations of birds were Guañape Norte Island (1,817) and Macabí Island (1,542). These locations accounted for 70 % of the total number of Humboldt penguins counted in 2022. Figure 2 shows the development of the moulting population at important locations or island groups. Punta San Juan (Ica) had the highest numbers of moulting penguins in 7 of the last 10 surveys. The island of San Juanito with its offshore islets has gained in importance in recent years and has remained relatively stable. Counts on Santa Rosa Island remain low and have experienced a steady decline of almost 97 % since their peak in 2014 (when 4,939 penguins were counted). Of particular note is the pier of the Peru LNG terminal, which has seen a steady increase in penguin numbers since its construction in 2009 (Vélez-Zuazo, 2016). The census team visited the area for the first time in 2020. The area includes two artificial piers that were built as part of the construction of the natural gas plant in Pampa Melchorita. The first penguins were observed in 2012 with around 60 individuals. Before the construction of the jetty, there were no records of penguins in the area, as the natural topography only featured a sandy beach. It is tempting to speculate about the settlement of almost 2,000 penguins at the piers in a period of only 8 years. The closest known penguin colonies exist on the Chincha Islands, about 42 km to the south. Between 2011 and 2014, there were a total of 1,300 to 1,400 Humboldt penguins there, of which around 1,000 were on Chincha North Island. At the northern end of this island is a cave where a large proportion of the penguins lived. In 2015, the number of penguins on North Chincha Island suddenly dropped to 119. One hypothesis is that the sudden and almost complete decline in the penguin population is linked to a comparable increase in the population at the artificial jetties of the Peru LNG terminal. In 2022, 1,759 birds were counted here.

In the 24 years in which the standardized surveys were carried out, the number of penguins in Peru fluctuated between 2,000 and over 20,000 (McGill et al. 2004, 2013; P. McGill, unpublished data). The reasons for the fluctuations are of a methodological and biological nature. In years when two counts were conducted, more penguins were recorded because two separate samples of the moulting population were counted and then combined (see Paredes et al. 2003 for the combination method, which reduces the effect of double counting). Although the PHVA recommended two separate repeat surveys in 1998, this was only possible in Peru in 2000, 2003 and 2004. The recommended method of two counts at each site, three weeks apart, can therefore be of considerable importance in determining the total number. However, it requires a lot of time and resources. In years when it is not possible to conduct a complete count and a double count using the PHVA methods (due to weather or sea conditions, availability of personnel or financial resources), it makes sense to conduct at least one count at key sites where significant concentrations of Humboldt penguins have been detected in the past.  In this way, trends could be observed and threatened locations identified. Another reason for the fluctuations is the moulting period, which varies from year to year. Peak numbers of moulting penguins are recorded at different times due to ecological conditions. Analysis of these patterns suggests that counts in a given year should not be taken as an indicator of conservation status.

Since counts began during the moult in 1999, sites have been added or removed from the count based on information from biologists, park rangers, island rangers and locals, especially fishermen. Including 2022, 31 new sites with a constant penguin presence were added. At the same time, 26 sites were removed from the annual count because the number of penguins was too low, because the penguins were repeatedly absent from year to year, or because access to these sites required a disproportionate amount of time and resources. When the counts began in 1999, the number of penguins found north of Lima was extremely low. In recent years, however, the counting team has received reports of penguins in the north. In 2015, the team visited all sites north of Lima where penguins had been reported in recent years. In 2018, sites in the north were included again, resulting in 13 additional sites being included in the count. Since 1999, a total of 80 sites have been visited to search for and count penguins. Apart from logistical difficulties, 36 sites have been consistently counted to date.

As on San Juanito Island in 2019, drones were also used on San Gallán Island in 2020 and 2022 to search the upper part of the island so that Humboldt penguin locations could be observed at a point on the island that the team could not see from the boats. The drones also proved their worth in inaccessible places where many nesting guano birds live. For example, it was possible to capture penguins in a very remote part of the island. This supports the use of this technique for future surveys in areas that are difficult to access. The figures shown in Table 2 for San Gallán Island, Punta Coles, Punta San Juan, Zaragoza Island and San Juanito Island correspond to the counts carried out using conventional methods, so that they can be compared with those of previous years.




1. the total number of penguins counted during the survey of 34 islands and coastal sites conducted in 2022 amounted to 15,663, with data from the piers of the Peru LNG terminal in Pampa Melchorita included for the 2nd time.

2. the number of Humboldt penguins counted at the same locations in both years increased by 13 % in 2022 compared to 2020.

3. during the 2022 survey period, oceanographic conditions were classified as "neutral" and within normal parameters, with only a slight trend towards negative anomalies in temperature. It is therefore not valid to attribute the increase or decrease in penguin numbers relative to 2020 to oceanographic conditions.

4. eight sites accounted for 70% of all penguins counted in 2022, with the piers of the Peru LNG terminal and San Lorenzo Island standing out. The number of penguins on Santa Rosa Island remains low. It has decreased dramatically since its peak in 2014.

5. the use of drones is proving to be an important advance in the methodology of the counts. Their use enables observations to be made in areas that are difficult to access and otherwise outside the range of observations. However, it is not justified to conduct all counts on the basis of drone photographs, as direct counts are just as accurate and faster.




The Humboldt Penguin surveys conducted in 2022 outside of protected areas were possible under the authorization granted by SERFOR through RD No. D000001-2022-MINAGRI-SERFOR-DGGSPFFS-DGSPFS. For the area of the National Reserve System of Islands, Islets and Guano Points (Reserva Nacional Sistema de Islas, Islotes y Puntas Guaneras - RNSIIPG), we had authorization under Resolution No. 001-2022-SERNANP-RNSIIPG, while Resolution No. 001-2022-SERNANP-RNP/J applied to the Reserva Nacional de Paracas. Our special thanks go to the company Perú-LNG S.R.L., SERNANP and AGRORURAL for providing the data from counts carried out in their facilities or at sites under their jurisdiction.

Field work and logistics were facilitated by the participation of Patricia McGill and Anne Tieber (Saint Louis Zoo, USA) and field teams from ACOREMA, Asociación Yunkawasi and Universidad Cayetano Heredia/Programa Punta San Juan, Centro de Sostenibilidad Ambiental (CSA).

The census was financed and supported by the Saint Louis Zoo (USA).



- Araya, B., D. Garland, G. Espinoza, A. Sanhuesa, A. Simeone, A. Teare, C. Zavalaga, R. Lacy, S. Ellis (Eds.) 2000. Population and Habitat Viability Analysis for the Humboldt penguin (Spheniscus humboldti). Final Report. IUCN/SSC Conservation Breeding Specialist Group: Apple Valley, MN. 

- BirdLife International 2008. BirdLife International/American Bird Conservancy Workshop on Seabirds and Seabird‐Fishery Interactions in Peru. RSPB, Sandy, UK. 

- Crawford, R.J.M. & Boonstra, H.G.v.D. 1994. Counts of moulting and breeding Jackass Penguins ‐ a comparison at Robben Island, 1988‐1993. Marine Ornithology 22: 213‐ 219. 

- ENFEN 2021. Comunicado oficial ENFEN No12‐2021 (diciembre 2021): 1‐5. ENFEN 2022. Comunicado oficial ENFEN No01‐2022 (enero 2022): 1‐5. McGill, P., A. Tieber, J. Reyes Robles, L. Ayala & M. Cardeña. 2013. Fifteen Years and Counting: the status of Humboldt penguins in Peru based on annual censuses. Resumen presentado en el 8th International Penguin Conference, Bristol, UK. McGill, P., M. Roca, R. Paredes, & P. Majluf. 2004. An assessment of the annual census as a conservation tool for Humboldt penguins in Peru. Resumen presentado en la 5th 

- International Penguin Conference, Ushuaia, Argentina. Paredes V, R., C. B. Zavalaga, G. Battistini, P.A. McGill, & P. Majluf. 2003. Status of the Humboldt penguin (Spheniscus humboldti) population in Peru, 1999‐2000. Waterbirds: 

- Journal of the Waterbird Society 26(2): 129‐256. Vélez‐Zuazo, X. 2016. The curious colonization of the Humboldt penguin. Smithsonian Conservation Biology Institute News. 4pp. 



Alí J. Altamirano S. is a veterinarian and member of ACOREMA. He mainly deals with fossils, but also works on ACOREMA projects, e.g. projects on sharks and birds. One of the projects is the penguin census.

Together with other researchers, Alí J. Altamirano S. discovered an almost complete skeleton of the Inkayacu paracasensis (genus of extinct penguins) in the Paracas National Reserve. It was the first fossil found with feathers. The feathers were so well preserved that the researchers Julia Clarke, Liliana D'Alba and Ali J. Altamirano were able to analyze the melanosomes.

Alí J. Altamirano S. did further work in the context of penguin fossils.


Tab 1
Census of Humboldt penguins during the moult, Peru
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Tab 2 Locations recorded during the census on the Peruvian coast (year 2022 compared to the 2019                         and 2020 censuses)
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Fig. 1 The most important locations visited during the 2022 Humboldt Penguin Census
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Fig. 2 Humboldt penguin moulting populations in Peru 1999-2022. The areas included throughout are those that have been assessed in every survey unless conditionsprevent this, or new areas that have been surveyed every year since their initialinclusion
see photos

Fig. 3 Locations with the highest concentrations of Humboldt penguins. 1999-2022
see photos

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