Visitor presence and a changing soundscape, alongside environmental parameters, can predict enclosure usage in captive flamingos

Abstract

The sound environment of a zoo animal is a complex milieu of animal and human‐generated sounds; coming from the species itself, other species, visitors, keepers and other zoo‐users. Research determining how different components of the sound environment affect animal behaviour is surprisingly lacking but could have real‐world impacts for animal welfare and zoo enclosure design. The current study investigated the effects of the sound environment on two flocks of flamingos housed in open‐air enclosures at British zoos. Measures of how each flock used its enclosure (as a response variable) and environmental variables (Inband Power and Peak Frequency were recorded as characteristics of the sound environment, as well as temperature, humidity and cloud cover, and finally visitor presence—all as potential predictor variables) were made over a 2‐month period. Assessment of space use by zoo animals is often used as a measure of the appropriateness of an exhibit and to understand welfare. Given that flamingo activity is influenced by weather and that the sound environment of the zoo is likely to be influenced by the number and the presence of visitors, it was assumed that these predictor variables would influence where the flamingos were located at different times of the day. As expected, there was a complicated relationship between enclosure use and Inband Power (average spectral density, a measure of sound energy) in both flocks; visitors generated salient sound but other visitor characteristics such as their physical presence may have impacted the movement of the birds around their enclosures. Results show a complex picture where environmental conditions influence flamingo enclosure usage as well as visitor presence and sounds around/in the enclosure. Findings are not consistent between the two flocks, with one flock demonstrating distinct temporal change to enclosure zone occupancy and the other responsive to humidity and cloud cover variation. We believe enclosure use can provide a valuable indication of how birds react to their soundscape; however, our findings suggest more work is needed to unpick the components of captive sound environments, and their relative effects on how animals use their space.

Bold Frogs or Shy Toads? How Did the COVID-19 Closure of Zoological Organisations Affect Amphibian Activity?

“…Overall, the total visibility for all amphibians significantly decreased once visitors returned in August and September, and this may suggest that without visitors, these amphibians felt more comfortable being out of or away from cover. The results of visitor presence influencing individuals' enclosure usage has been reported for other taxa [18], and therefore, the measurement of time spent within specific enclosure zones (alongside the number of of 16 visitors at the enclosure) would be useful. Figure 1 indicates that with the introduction of a small number of people, amphibian visibility maintained the same level or increased, and this may be helpful information for zoos to manage visitor flow and number around amphibian enclosures in the future.…”

“…An overlooked area of amphibian wellbeing in the zoo is the presence of visitors and their potential effects on behaviour and welfare. Visitor presence has been recorded as influencing enclosure usage in other taxa [18], but any "visitor effect" needs to be measured and evaluated alongside other environmental influences occurring at the same time, e.g., weather conditions [19,20]. Visitor presence may reduce the amount of usable space in the captive environment and consequently reduce the animal's ability to perform a full behavioural repertoire [21].…”

Conducting Behavioural Research in the Zoo: A Guide to Ten Important Methods, Concepts and Theories

“…As animals in the zoo are exposed to the presence of numerous people on a daily basis, consideration of any related impacts on behaviour should be measured when attempting to infer a welfare state [100]. The visitor effect is highly influenced by other variables (e.g., weather, temperature, pres-ence of animal care staff, season and time of day [32,101,102]), and it is important for these variables to be recorded at the same time as the animal's behaviour to provide context to any potential influence of visitors. Comparative analysis of independent contrasts can also be used to help analyse species differences in behavioural responses [103] by controlling for non-independence caused species' evolutionary relatedness.…”

“…The results generated from both SPI equations should be considered descriptive statistics, with a result of 0 suggesting equal occupancy of all zones and a result of 1 identifying highly uneven zone occupancy. Further inferential analysis of SPI values can be used to identify potential predictors of zone occupancy, e.g., environmental, social, anthropogenic or husbandry influences [32].…”

“…Differences in habitat structure and quality can be useful starting points for assigning zones (e.g., deep pool, shallow pool, mature trees, open grassland), but too many zones can impact the quality of the final enclosure usage measurement. Zoning a large enclosure into many small zones can artificially inflate the chances of finding unequal, biased enclosure usage when using the modified SPI [21,32]. Google Earth Pro [45] is useful for mapping out enclosure zones in medium to large open enclosures where boundaries are known and not obscured by buildings or vegetation.…”