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 pertains to Adelie 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 dataset captures annual measurements of body mass for Adelie penguin chicks at Signy Island, from 1997 until 2020. Between 50 and 100 chicks are measured on beaches immediately prior to their departure, with 3-5 weighing sessions carried out annually per species in the period before fledging is complete. This monitoring contributes to the CCAMLR Ecosystem Monitoring Program (CEMP) and is part of the annual seabird Long Term Monitoring Science carried out by the British Antarctic Survey at Signy Island. 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 captures information on the diet composition and mass of Adelie 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 (Commission for the Conservation of Antarctic Marine Living Resources) Ecosystem Monitoring Program (CEMP) Standard 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.