Circadian preferences of birdwatchers in Poland: do “owls” prefer watching night birds, and “larks” prefer daytime ones?

Introduction

Many factors influence human attitudes to animals, including animal traits such as colour, size, rarity and popularity and human traits such as gender, age, education level and even food preferences (reviewed in: Prokop & Randler, 2018). Obviously, both animal and human perception have co-evolved, and the latter changes due to life experience and education (Prokop, Kubiatko & Fančovičová, 2008; Prokop & Randler, 2018). Recently, dealings with animals have not necessarily been linked just to a targeted use (e.g. food source, guard role, beast of burden), but simply watching animals for fun, of which birdwatching is one example, is increasing worldwide (Kronenberg, 2016; Callaghan et al., 2018). Bird species differ in many ecological traits and these can also affect human behaviour, for example searching for information on particular species (Żmihorski et al., 2013; Correia et al., 2016, 2017) and even willingness to pay for their conservation (Raab, Randler & Bogner, 2018). However, people watching birds, and other taxa, differ in many psychological and physical traits and one very marked behavioural difference is their particular morningness–eveningness spectrum of activity (Werner, Geisler & Randler, 2015). In the case of bird observation, this can affect not only intellectual and physical peak performance during the day (Pica et al., 2015; Randler, Faßl & Kalb, 2017; Arrona-Palacios & Díaz-Morales, 2018), but also punctuality (Werner, Geisler & Randler, 2015) and risk-taking (Wang & Chartrand, 2015), which can be useful in finding and watching rare birds, which is a particularly focussed activity of some birdwatchers (Żmihorski, Sparks & Tryjanowski, 2012; Callaghan et al., 2018).

The morningness–eveningness preference may change in relation to age, gender and even seasons (Pica et al., 2015; Randler, Faßl & Kalb, 2017), which also makes this interesting to study in terms of the potential relationship between humans and birds. Birds are a very variable taxonomical group. There are more than 10,000 species, they live in different habitats and they have different seasonal and daily activities mainly related to breeding, wintering and seasonal migrations (Del Hoyo, Elliott & Sargatal, 1992–2011; Jetz et al., 2012), all of which combine to strongly affect people who watch and study birds (Callaghan et al., 2018). Because people have different financial resources, time availability, personal preferences, skills, knowledge and commitment, they may focus on different bird species/taxonomic groups (Lee & Scott, 2004; Prokop, Kubiatko & Fančovičová, 2008; Yarwood, Weston & Garnett, 2014). Furthermore, the psychological terminology on circadian preference and morningness–eveningness has always been linked to bird behaviour, as shown by use of the classical phrase ‘owls vs. larks’ (Pica et al., 2015; Putilov, Donskaya & Verevkin, 2015). Furthermore, differences in daily patterns of data collection and a focus on particular bird species may attach a bias to obtained results. Given the current debate on the importance of data quality (La Sorte & Somveille, 2020) this is a very pertinent issue, also in the context of bird monitoring schemes (Snäll et al., 2011).

However, we do not know of a single study that has linked morningness–eveningness to preferences of particular bird species or groups and therefore it is difficult to specify exact testable hypotheses. However, we hazard a guess that people with stronger morningness than eveningness will prefer morning rather than nocturnally active bird species and vice versa. Therefore, based on an e-mail questionnaire to birdwatchers, we attempted to answer whether: (1) if there is a relationship between observer morningness–eveningness and favourite bird species; (2) if there are differences between amateur birdwatchers and professional ornithologists in this human trait; (3) if potential differences are influenced by other factors (age and gender).

Methods

Results

Favourite bird species

A total of 204 species were identified as favourite birds, of which 184 (90.2%) were classified as daytime birds. A full table of species indicating their daytime/nighttime category is given in Supplemental Material 1. The 34 species mentioned by five or more respondents are listed in Table 1. Only two species, the common crane Grus Grus and the Eurasian pygmy owl Glaucidium passerinum, were mentioned by more than 10% of respondents. Only the 12 species that were mentioned 10 or more times were subject to further analysis. This additional analysis suggested that the white stork Ciconia ciconia was more popular with professionals than non-professionals (13% cf. 3%) and the swift Apus apus less popular (3% cf. 12%). No significant gender preferences were detected in this subset of species. There was a significant difference in the circadian preference categories for swift which was not mentioned by any of the category A respondents.

Table 1:

The 34 most popular species (those with n ≥ 5) reported by respondents.

In addition to the overall number and percentages, percentages are also given by professional status (NP nonprofessional, P professional), gender (F female, M male) and circadian preference (categories A–D, see main text). Significance (indicated by *) tested using chi squared or Fisher exact tests for the 12 species with n ≥ 10. Species in grey shading were categorised as nighttime; all others as daytime.

Species	n	%	NP%	P%		F%	M%	A%	B%	C%	D%
Grus grus	28	19.6	23.3	15.9		23.3	18.6	20.0	29.3	15.2	6.3
Glaucidium passerinum	16	11.2	12.3	10.1		10.0	11.5	10.0	14.6	9.1	12.5
Alcedo atthis	14	9.8	11.0	8.7		10.0	9.7	12.0	7.3	9.1	12.5
Upupa epops	14	9.8	11.0	8.7		10.0	9.7	8.0	12.2	12.1	6.3
Turdus merula	13	9.1	11.0	7.2		6.7	9.7	14.0	2.4	9.1	12.5
Aegithalos caudatus	12	8.4	8.2	8.7		16.7	6.2	8.0	9.8	9.1	6.3
Ciconia ciconia	11	7.7	2.7	13.0	*	3.3	8.8	12.0	4.9	9.1	0.0
Vanellus vanellus	11	7.7	8.2	7.2		6.7	8.0	2.0	9.8	9.1	18.8
Apus apus	11	7.7	12.3	2.9	*	10.0	7.1	0.0	14.6	12.1	6.3	*
Merops apiaster	11	7.7	9.6	5.8		10.0	7.1	10.0	2.4	12.1	0.0
Haliaetus albicilla	10	7.0	8.2	5.8		6.7	7.1	8.0	9.8	0.0	6.3
Lanius collurio	10	7.0	5.5	8.7		6.7	7.1	10.0	2.4	9.1	6.3
Strix aluco	9	6.3	9.6	2.9		6.7	6.2	6.0	12.2	3.0	0.0
Circus pygargus	9	6.3	8.2	4.3		6.7	6.2	6.0	9.8	3.0	6.3
Corvus monedula	9	6.3	2.7	10.1		10.0	5.3	8.0	7.3	6.1	0.0
Ciconia nigra	8	5.6	8.2	2.9		6.7	5.3	6.0	7.3	3.0	6.3
Corvus frugilegus	8	5.6	4.1	7.2		6.7	5.3	10.0	0.0	6.1	6.3
Corus corax	8	5.6	8.2	2.9		13.3	3.5	4.0	7.3	0.0	12.5
Galerida cristata	8	5.6	6.8	4.3		3.3	6.2	8.0	4.9	3.0	6.3
Erithacus rubecula	7	4.9	6.8	2.9		3.3	5.3	8.0	4.9	3.0	0.0
Bucephala clangula	7	4.9	4.1	5.8		3.3	5.3	6.0	2.4	6.1	6.3
Sturnus vulgaris	6	4.2	5.5	2.9		3.3	4.4	8.0	0.0	6.1	0.0
Parus major	6	4.2	1.4	7.2		3.3	4.4	6.0	0.0	6.1	6.3
Lyrurus tetrix	6	4.2	5.5	2.9		0.0	5.3	2.0	7.3	6.1	0.0
Athene noctua	6	4.2	4.1	4.3		10.0	2.7	0.0	0.0	9.1	18.8
Aquila chrysaetos	6	4.2	8.2	0.0		6.7	3.5	2.0	9.8	0.0	6.3
Limosa limosa	6	4.2	5.5	2.9		3.3	4.4	2.0	7.3	3.0	6.3
Tyto alba	5	3.5	4.1	2.9		0.0	4.4	6.0	0.0	6.1	0.0
Milvus milvus	5	3.5	4.1	2.9		3.3	3.5	6.0	0.0	3.0	6.3
Tetrao urogallus	5	3.5	2.7	4.3		3.3	3.5	0.0	7.3	6.1	0.0
Sylvia nisoria	5	3.5	2.7	4.3		0.0	4.4	2.0	4.9	6.1	0.0
Coracias garrulus	5	3.5	2.7	4.3		3.3	3.5	4.0	2.4	0.0	12.5
Strix nebulosa	5	3.5	2.7	4.3		6.7	2.7	4.0	0.0	3.0	12.5
Clanga pomarina	5	3.5	6.8	0.0		3.3	3.5	4.0	2.4	0.0	12.5

DOI: 10.7717/peerj.8673/table-1

There were no significant Spearman correlations between age, response times and percentage of favourite birds that were categorised as daytime birds (all P > 0.297).

Binary logistic regression on the proportion of favourite birds categorised as daytime produced an overall significant model (${\chi }_9^2=23.47$, P = 0.005) with one significant main effect (gender: ${\chi }_1^2=5.09$, P = 0.024) and one significant interaction (gender × circadian preference: ${\chi }_3^2=14.26$, P = 0.003). In addition, circadian preference was very close to significance (${\chi }_3^2=7.80$, P = 0.0503). This interaction is shown in Fig. 1 where female respondents in category A reported fewer favourite daytime birds than their male counterparts and in contrast to the pattern in other categories.

Discussion

The number of participants may appear lower than expected in western European countries such as the Netherlands, Germany and especially the UK (Cocker, 2012). But in reality we asked a large proportion of bird observers that usually participate in national citizen science projects in Poland, such as Common Birds Monitoring Scheme, Winter Bird Counts and BirdFeeder Project. These schemes usually attract only 100–180 people. We used an e-mail based questionnaire, with an overall response rate of 35.6% which may appear low, but is similar to the average rate in other studies using similar methods in psychology (Cook, Heath & Thompson, 2000; Sheehan, 2001). We also noted with great interest the few complaining e-mails where respondents, mainly professionals, expressed concerns over the aims and methodology of the study. It may seem obvious that a significantly greater rate of complaint would derive from professional ornithologists rather than amateur birdwatchers, because professionals focus much more on science than simply gaining pleasure from watching birds (Yarwood, Weston & Garnett, 2014; Yarwood, Weston & Symonds, 2019 and see also below).

The study also suggests that watching birds is still more popular among men than women, similar to other studies in Poland, but which were based on a much smaller sample size (Sklodowski & Jurkowska, 2015). However, it is interesting to note that women participating in our study were significantly younger than men, which is a sign of an encouraging (probably global) trend that birdwatching has recently become more popular with women (Cooper & Smith, 2010). The most represented circadian preference was the ‘early morning type,’ a finding similar to that found by Raab, Randler & Bogner (2018). Moreover, those authors even suggested that students with a morningness preference were more likely to be protective of and appreciative towards, nature, including birds. Furthermore, early morning (lark type) people more often participated in voluntary activities, shared information, were open to new ideas, were faster and more punctual (Song & Stough, 2000; Werner, Geisler & Randler, 2015). On the other hand, if we compare birders with the general Polish population (Jankowski, 2013; Tęgowska, Sobocińska & Maliszewska, 2014) there is still apparent a visible bias to the early morning type. In a correlative-type study like ours it is impossible to determine if early morning types are more likely to take up an ornithological career, or indeed if they just have to get up early to watch more bird species. This can only be resolved if a representative sample of Polish people was surveyed and matched for gender and age, because there are significant age effects in circadian preference in the adult population (Randler et al., 2016).

The 143 respondents mentioned 204 species as favourite birds with great variation between respondents, but some patterns are worth noting. Only two species, the common crane and the Eurasian pygmy owl, were mentioned by more than 10% of respondents. We did not ask why people decided on their particular species, but Eurasian pygmy owl was a surprise to us. The common crane is a more obvious choice because it is a big charismatic bird with a characteristic call, an increasing population size and is also represented in Polish culture and art (Wąs, 2013). Interestingly, the white stork was a more popular choice with professionals than with non-professionals but the swift showed an opposite pattern. The white stork is a Polish icon, well recognised, easy-to-spot even by beginners and very popular in both scientific studies and the cultural life of Poland (Kronenberg, Andersson & Tryjanowski, 2017). There are long term-data on white storks that permit advanced statistical analyses and so it is often chosen as a study species by ornithologists, although it is not very attractive to classical birdwatchers because it is still common, but is more exciting to visitors to Poland rather than local birdwatchers (Kronenberg, 2016; Kronenberg, Andersson & Tryjanowski, 2017). In choosing study species, ornithologists follow different criteria, based on the probability of obtaining a good sample size, conservation status and even size and behaviour (Yarwood, Weston & Garnett, 2014; Yarwood, Weston & Symonds, 2019). After some years of study, they know much about the biology of the species, including its secrets and are fascinated by the species which then also becomes a favourite bird (personal experience of the authors). It is likely that preferences change over time and are sensitive to mass-media information making species more or less charismatic in recent years (Żmihorski, Sparks & Tryjanowski, 2012; Correia et al., 2016, 2017). In our sample, swift is perhaps an indicator of changes in recent times, because the species is an object of recent debate focused on bird conservation in urban areas and information has been promoted on this species biology, ecology and importance to humans (Luniak & Grzeniewski, 2011). It is interesting that this species was not suggested as a favourite bird by any of the ‘early morning’ respondents, which fits especially well with the late afternoon and early evening activity of swifts.

A number of other interesting patterns appear evident in Table 1 but failed to achieve either significance or sufficient sample size for testing. A study based on a larger sample would be needed to confirm or refute any of these apparent patterns. Probably a more advanced study should compare species choice with other factors, for example how much attention she/he pays to that particular bird species, how many publications are dedicated to that particular species and even a measure of emotional attachment. Similar studies could be useful for understanding the choice of different outdoor activities between people, as well as a deeper understanding of the variability of other groups of passionate recreationalists (e.g. anglers, hunters, mountain climbers, cf. Wałęga, Wałęga & Graczyk, 2017). Given that much of the data used to estimate species population sizes and geographical distributions and to produce bird guides, originate from recorders of which our respondents were a sample, it is important to know if their behaviour may subconsciously influence their records. Furthermore, a better understanding of the reasons for the popularity of species could help enormously in planning for and funding, their conservation. One important aspect that chronobiology may contribute to bird research is the influence on citizen science programs. Citizen science programs, such as eBird rely heavily on the submissions of many volunteer birdwatchers (Wiersma, 2010). However, the reporting of given species may be significantly influenced if the chronotype of the birdwatchers and the circadian rhythms of specific species do not map. Early morning bird species may go underreported if most birdwatchers are not morning oriented themselves. In a similar manner, a higher proportion of ‘owls’ in birdwatchers may lead to a better registration of owls in these databases. Of course, these assumptions need further study based on larger samples.

Conclusion

Although much is known about birds and the importance of citizen science, only scarce evidence is available about the nature of birdwatchers, both professional and amateur. These data, especially about their morning or evening preference, may severely influence data collection behaviour but, in this study, we were able to show that there is only a weak influence of circadian preference on leisure birdwatching; thus, we assume a minimal or even absent influence of circadian preference on birdwatching.

Supplemental Information