100 nests in designated Adelie and Chinstrap penguin colonies are marked and then regularly monitored. Data are collected on when eggs are laid in each nest, when they hatch, when eggs or chicks are lost, and when chicks become unguarded. Data exist from 1996 onwards. For Adelie penguins, 100 nests in a colony designated A41 was monitored between 1996 and 2002, from 2003 onwards 100 nests in a colony designated A39 were monitored. For Chinstrap penguins, 100 nests in a colony designated A69 were monitored between 1996 and 2015, from 2016 onwards, 100 nests in a colony designated C66 were monitored. No data were collected in the 1997-98, 1999-2000 and 2010-2011 seasons. To calculate the annual hatching date a binomial model was fitted using the proportion of nests containing one or more chicks as the response variable and the date in days after 1 Oct as the explanatory variable. This model was fitted for each species and year separately. The dose.p function in the MASS package in R was used to derive the day when 50% of nests contained one or more chicks to produce the mean hatching date for each species-year combination. Mean laying dates were back-calculated from the mean hatching dates by subtracting the average incubation periods for each species (35 days for Adelies and 36.4 days for chinstraps, which are relatively constant between years). This has been calculated for data from 1996 to 2016.

This datasets captures the annual measurements of body mass for chinstrap penguin chicks at Signy Island, from 1997 to 2020. Between 50 to 100 chicks are measured, with 3-5 weighing sessions carried out in the period before fledging is complete. This monitoring contributes to the CCAMLR Ecosystem Monitoring Program (CEMP) and is part of annual monitoring carried out by the British Antarctic Survey. This work was funded by Natural Environment Research Council (UK) core funding to the British Antarctic Survey.

100 nests in designated Adelie and Chinstrap penguin colonies are marked and then regularly monitored. Data are collected on when eggs are laid in each nest, when they hatch, when eggs or chicks are lost, and when chicks become unguarded. Data exist from 1996 onwards. For Adelie penguins, 100 nests in a colony designated A41 was monitored between 1996 and 2002, from 2003 onwards 100 nests in a colony designated A39 were monitored. For Chinstrap penguins, 100 nests in a colony designated A69 were monitored between 1996 and 2015, from 2016 onwards, 100 nests in a colony designated C66 were monitored. No data were collected in the 1997-98, 1999-2000 and 2010-2011 seasons. To calculate the annual hatching date a binomial model was fitted using the proportion of nests containing one or more chicks as the response variable and the date in days after 1 Oct as the explanatory variable. This model was fitted for each species and year separately. The dose.p function in the MASS package in R was used to derive the day when 50% of nests contained one or more chicks to produce the mean hatching date for each species-year combination. Mean laying dates were back-calculated from the mean hatching dates by subtracting the average incubation periods for each species (35 days for Adelies and 36.4 days for chinstraps, which are relatively constant between years). This has been calculated for data from 1996 to 2016.

This dataset comprises the annual count of chinstrap penguins arriving to Signy Island each breeding season, from 1996 to 2020. Penguins arriving at the beach in mid to late November (the austral summer) were counted. This monitoring contributes to the CCAMLR (Commission for the Conservation of Antarctic Marine Living Resources) Ecosystem Monitoring Program (CEMP) and is part of the annual seabird Long Term Monitoring carried out by the British Antarctic Survey at Signy Island. Ecosystems component of BAS Polar Science for Planet Earth Programme, funded by NERC.

This dataset pertains to chinstrap penguin breeding success at selected colonies on Signy island from 1978 to 2020. It comprises annual ground counts of occupied and incubating nests, eggs (proxy for breeding pairs), chicks hatched, and chicks expected to fledge. The GPS locations for surveyed sites are also included. From the 1996-1997 season onwards, this dataset conforms to CCAMLR data collection standards and contributes to the CCAMLR Ecosystem Monitoring Program (CEMP). Ecosystems component of BAS Polar Science for Planet Earth Programme, funded by NERC.

This datasets captures the body mass, bill length and bill depth of adult chinstrap penguins immediately after their arrival to Signy Island at the start of the annual breeding from 1996 to 2020. Penguins arriving at the beach were measured for bill length, depth, and body mass before being released where they were captured. These measurements were made in mid/late November, as chinstrap penguins arrive for the austral summer. This monitoring contributes to the CCAMLR (Commission for the Conservation of Antarctic Marine Living Resources) Ecosystem Monitoring Program (CEMP) and is part of the annual seabird Long Term Monitoring carried out by the British Antarctic Survey at Signy Island. Ecosystems component of BAS Polar Science for Planet Earth Programme, funded by NERC.

This dataset captures information on the diet composition and mass of chinstrap penguin stomach contents at Signy Island, from 1997 to 2020. The monitoring period occurred over four weeks each year and involved sampling adults returning to feed their chicks during the creche period. Sampling took place approximately every five days. Numbers of birds sampled on each occasion varied over the entire period of the dataset from a maximum of eight to a minimum of six, equating to an annual maximum of forty birds and an annual minimum of thirty, depending on the year. All adult penguins were sampled on their return to the colony using the stomach lavage methodology specified in CCAMLR CEMP Standards Methods A8A. The stomach samples were then weighed and categorised into krill, cephalopods, fish and non-food and identified to species level where possible. Krill carapaces and otoliths were removed and measured. Ecosystems component of BAS Polar Science for Planet Earth Programme, funded by NERC.

Numbers of nesting birds were manually counted from images collected by low-altitude aerial photography from multirotor Un-crewed Aerial Vehicles (UAVs). Three species were included in this study; gentoo (Pygoscelispapua) and chinstrap (Pygoscelis antarctica) penguin and South Georgia shag (Leucocarbo atriceps georgianus). Data were collected in the 2016/17 and 2017/18 field seasons.

Images of bird colonies on Signy Island, South Orkney were collected by low-altitude aerial photography from multirotor Un-crewed Aerial Vehicles (UAVs). Three species were included in this study; gentoo (Pygoscelis antarctica) and chinstrap (Pygoscelis papua) penguin and South Georgia shag (Leucocarbo atriceps georgianus). Data were collected in the 2016/17 and 2017/18 field seasons. Mosaic images were created for colonies surveyed with multiple frames by stitching together individual images.