Soiling of nests in modified cages for laying hens might be reduced by using a wire mesh floor for the nest. However, use of such a material might be contrary to the preferences of the hens and compromise their welfare. Twenty-four laying hens were housed singly in modified cages which incorporated two nests. One nest had the standard perforated plastic floor whilst the other had one of two types of metal mesh floor. To determine whether hens preferred any one of the floor types for oviposition, the positions of the nest floors were swapped three times during 110 days. The hens showed a dichotomy in their behaviour after the nestfloors were swapped: the majority (12 of those making a consistent choice) continued to lay in the same nest location (ie location conservative) whereas 6-9 hens changed the nest in which they laid (ie floor type conservative). Only one of the floor type conservative hens preferred to lay on metal mesh. These results show that although the majority of hens showed no apparent aversion to laying in nests with metal mesh floors, 57-68 per cent preferred plastic floors and changed location to lay on this substrate.

The olive ridley sea turtle Lepidochelys olivacea is the most abundant marine turtle species in Guatemala, representing > 99% of all nests. Along with other marine turtles, they are important both culturally and ecologically. Conservation efforts rely almost exclusively on an informal system whereby local residents can harvest olive ridley sea turtle nests on the condition they donate 20% of each nest to a hatchery, where the eggs are incubated and hatchlings later released. This system was initiated in the 1970s and, until recently, no effort has been made to determine its sustainability. In a 2020 publication based on tracks on a single beach in Guatemala and 15 years of egg incubation data from Guatemalan hatcheries, it was concluded that the population had increased. Several weaknesses were detected in this research. To verify the validity of the conclusion, we analysed data from 22 years (2 years are missing) and 11 beaches using several statistical models. We used an intraseasonal model of nesting phenology to fill in missing data for monitored periods during a nesting season, and a new method of spatial and temporal aggregation of nesting seasons. Based on our findings, we reject the hypothesis that olive ridley sea turtle nesting activity is increasing. The total nesting activity for these 12 beaches was stable over the 22-year period. Because of inconsistent hatchery management and the financial dependency of local communities on the sale of turtle eggs, the number of incubated eggs cannot be used as an indicator of the population trend of olive ridley sea turtles in Guatemala.

Data about breeding populations of birds in the Antarctica are rare and fragmented. Thus, information about the status of the breeding populations of Antarctic birds is crucial given the current scenario of climate change, which is particularly acute in Antarctica. This paper presents new information about the populations of the Antarctic tern Sterna vittata, the kelp gull Larus dominicanus, the southern giant petrel Macronectes giganteus, the Antarctic skua Catharacta antarctica lonnbergi, the chinstrap penguin Pygoscelis antarctica and the gentoo penguin Pygoscelis papua on Byers Peninsula (Livingston Island, South Shetland Islands). We used line transects counts to estimate both densities and numbers of nests of the different species. We estimate that there are 398.96 birds km-2 of southern giant petrels (2793 individuals), 62.4 birds km-2 of Antarctic tern (3746 individuals) and 269.1 birds km-2 of kelp gull (1884 individuals). Furthermore, we found 15 nests of Antarctic skua in 25 km2, from which we can estimate that 60–91 birds must breed on Byers Peninsula. We also censused two colonies of gentoo penguins (3000 and 1200 pairs) and 50 pairs of chinstrap. Compared to previous estimates, gentoo penguins seem to have increased whereas chinstrap penguin have decreased. Finally, the populations of Antarctic tern, southern giant petrel and kelp gull have stabilized or slightly increased.

Nests of a fungus-growing termite Macrotermes jeanneli discharge all their metabolic gases through a single outlet to the atmosphere. This made it possible to measure the production of metabolic gases, and the rates of water loss, for intact nests in the field. Rates of production of carbon dioxide and methane from isolated nest components (different termite castes and intact fungus combs) were measured. Using previously published nest population data and fungus comb weights in relation to nest size, the expected gas production rates for intact nests were calculated. These estimates were compared with direct observations of the gaseous outflow from intact nests. The rates were in reasonable agreement, but some nests emitted excess carbon dioxide, probably produced by respiration of tree roots and non-termite soil organisms. Large nests may have a total gas outflow of 100,000 to 400,000 1 d–1 including 800 to 1500 1 d–1 of CO2 and 0.5 to 1.3 1 d–1 of CH4. Nests lose water at the rate of up, to 13 1 d–1 gross, but allowing for ambient humidity the net water loss was up to about 5 1 d–1. Some of this is metabolic water, but the larger proportion comes from the soil. Area-based estimates of gas production were made for this and two other species of Macrotermes, but they are not accurate because the field distribution and mound density are not adequately known.

In order to avoid the decrease in the numbers of wild red-legged partridge, Alectoris rufa, observed in several areas, the most appropiate solution is to repopulate using animals from game farms. The nesting place chosen by 30 pairs of red-legged partridge in captivity was studied. There were five different nest types combined in groups of three in 30 cages. Type A nest: made with natural bush plants tied together at one end and placed invertedly forming a cone. Type B: made with the same natural bush plants as the previous type but placed over an internal wire structure and having preformed entrances. Type C: a wooden structure in the form of a roof with two slopes. Type D: similar to the type C but on one of the laterals the opaque material only covers the upper half, and a plastic mesh covers the lower half. Type E: a wooden square box covered with an inclined plank of opaque and waterproof material. Our study shows that the type A nest received significantly (P < 0·05) more eggs than the others, possibly because this type of nest allowed for better vigilance and a better sense of protection for the animals. Type E nest was the second most preferred. In this type, the partridge was able to monitor the surroundings through the space between the walls and the roof and this space could be used as an escape route. From a production and industrial perspective, type E has some advantages over type A, being easy to build, clean and disinfect, and allowing the birds to see through the nest.