Population Biology of Three Satyrine Species (Nymphalidae: Satyrinae) in a Suburban Habitat

ABSTRACT. Decades after the publication of the first population studies on Neotropical butterflies, knowledge of their population biology remains scarce in the literature. Inconspicuous groups like the nymphalid subfamily Satyrinae are often overlooked, and studies that examine the demographics of these neglected groups are paramount for a more comprehensive understanding of insect population dynamics. The present paper addresses this dearth of information by describing the population biology of three common species of Euptychiina (Nymphalidae: Satyrinae) butterflies, Hermeuptychia atalanta, Cissia eous and Malaveria affinis, in a suburban area. A 13-month mark-release-recapture study was carried out in the grass lawns of the University of Campinas, São Paulo State Southeastern Brazil. The results showed that population parameters differ among the three studied species. For example, the population of H. atalanta is about five times that of C. eous, which is four times larger than that of M. affinis. Sex ratios were male-biased in H. atalanta and C. eous, but not in M. affinis (whose sex ratio was 1:1). Hermeuptychia atalanta and C. eous had mean adult lifespans of approximately one week, with no variation between sexes. Malaveria affinis, however, had a lifespan of approximately 11 days for males and just five days for females. Age structures were similar in all three species, with no recruitment peaks detected throughout the year. Sexual dimorphism, based on wing size, was not observed in H. atalanta, but a clear pattern of dimorphism with larger females was observed for the other two species. The present study is the first to describe population parameters for Euptychiina in detail, and one of the few focusing on population biology of butterflies in suburban areas. Indeed, the present results could help to define strategies of lawn management for the campus, aiming to increase local biodiversity and consequently improve ecosystem services.

The first population biology studies for Neotropical butterflies are five decades old (Turner 1971, Ehrlich & Gilbert 1973).Although some progress in the field has been made, our knowledge on population dynamics for most Neotropical butterfly species remains low and many groups of butterflies are understudied or completely ignored (but see Torres et al. 2009, Seixas et al. 2017, Uehara-Prado & Freitas 2019).One such group is the subtribe Euptychiina (Nymphalidae: Satyrinae); with more than 440 described species, the group is distributed from Canada to Argentina, reaching its maximum diversity in the forests and savannas of South America (DeVries 1987, Marín et al. 2011, Espeland et al. 2019, 2023).The group has remained overlooked for decades and thorough studies in taxonomy and systematics in this subtribe are very recent.Apart for taxonomy and systematics, the euptychiines are mostly unknown in terms of hostplants and immature stages, natural history, behavior and ecology (Marín et al. 2011).Moreover, only a few, short-term, studies of population biology of any species of Euptychiina have been published (Emmel 1970, Whittaker 1983, Uehara-Prado & Freitas 2019), meaning that information on basic aspects of population biology for Euptychiina, including longevity, sex ratio and population size, among others, is virtually absent.
Since the pioneering studies of Ruszczyk in Brazil (e.g.Ruszczyk 1986, 1987, Ruszczyk & Araújo 1992, Ruszczyk & Nascimento 1999 and references therein), studies of urban ecology in tropical butterflies have increased considerably, with a strong focus in community ecology (Brown & Freitas 2002, Collier et al. 2006, Iserhard et al. 2019 and references therein).In this respect, studies focusing on population biology of urban tropical butterflies are scarce and restricted to very few groups (Ruszczyk & Nascimento 1999, Vanini et al. 1999, Ruszczyk et al. 2004, Tourinho & Freitas 2009).Studies of urban ecology are especially important in the present day, where urban environments are replacing natural habitats at a fast pace (Byrne 2022).Moreover, the persistence of biological diversity in urban habitats is directly linked with ecosystem services and with human well-being (Bolund & Hunhammar 1999, Naeem et al. 2016).In this sense, studies of urban ecology can provide subsidies to the management of urban landscaping, increase the functional and taxonomic diversities (or at least maintain the current levels of functionality) and mitigate the effects of urbanization (deJong et al. 2012, Iserhard et al. 2019).
Thus, the present study helps to address the two above knowledge gaps, by describing population parameters of three species of Euptychiina in an urban landscape, namely Hermeuptychia atalanta (Butler, 1867), Cissia eous (Butler, 1867) and Malaveria affinis (Butler, 1867).The present study is also the first to census populations of neotropical euptychiines for at least one year, thus providing reliable data on several basic population parameters such as population size, age structure, longevity, sex ratio and wing size variation.

Study Area
A mark-release-recapture (MRR) program was carried out at the campus of the University of Campinas (Unicamp), São Paulo state, southeastern Brazil (22°49'S, 47°4'W).The annual rainfall in the region is about 1,360 mm and mean temperature is 20.6 °C (data from the Instituto Agronômico de Campinas).The climate is markedly seasonal, with a warm wet season from September to April, and a cold dry season from May to August.During the study period, the coldest month was June with a mean temperature of 18.6 C, and the hottest month was March with an average temperature of 25.2 °C.The vegetation of the campus consists of many grass lawns of Paspalum notatum Flüggé (= bahia grass), with sparse trees and some small bushes, with groups of small to medium-sized concrete buildings (Fig. 1A-D).The lawns are mowed on a regular basis (about once a month) as part of the normal landscape maintenance of the campus (Fig. 1).The study area was divided into three contiguous sub-areas with different characteristics: area 1) a large sunny grass lawn with interspersed shrubs and trees (approximately 8,500 m 2 ) (Fig. 1A); area 2) a combination of small lawns among university buildings, resulting in shaded patches at certain times of the day (1,500 m 2 ) (Fig. 1B), and area 3) mostly a sunny lawn, but with a fenced sector near some greenhouses, with little lawn management and periodic watering (in the nearby greenhouses) (3000 m 2 ), allowing the growth and persistence of patches of the large bunch grass Megathyrsus maximus (Jacq.)B. K. Simon & S. W. L. Jacobs (= guinea grass), an introduced African species, as well as other small grass species more dependent of shade and humid conditions, such as Axonopus compressus (Sw.)P. Beauv.(carpet-grass) and Eleusine indica (L.) Gaertn.(goosegrass) (Fig. 3C, D).

Butterfly species and their food resources
The three studied butterflies, Hermeuptychia atalanta (sensu Seraphim et al. 2014) (Fig. 1E), Cissia eous (Fig. 1F) and Malaveria affinis, are widespread species of satyrines that are present in many different open habitats, including forest edges, tree gaps, open secondary forests, savannas, grass fields and lawns in urban areas in the Atlantic Forest (Brown 1992; AVLF, unpublished).Concerning the feeding habits of the adults, these three species are members of the so-called fruit-feeding butterflies, which primarily feed on rotten fruits and other decaying material (in contrast to nectarfeeding butterflies, which primarily visit flowers searching for nectar and pollen) (DeVries 1987).In the study area, all three species were observed feeding on fermenting fallen fruits and other decaying organic material, and H. atalanta was also observed feeding on the wet spikelets of P. notatum on early morning (possibly attracted by fermenting materials).The host plants of all three studied species are all common in the study area: H. atalanta was reported using P. notatum (Cosmo et al. 2014), the dominant grass species; C. eous was observed using A. compressus and E. indica (AVLF, unpublished), two species that grow in humid and partially shaded sectors of the lawns (see above) especially during the wet season; and M. affinis was observed using only M. maximus in the study area (AVLF, unpublished).The three studied butterflies were the dominant species of Euptychiina in the study area; three other species were also present in very low abundances in the study area, namely Taygetis laches (Fabricius, 1793), Paryphthimoides poltys (Prittwitz, 1865) and Yphthimoides ordinaria Freitas, Kaminski & Mielke, 2012.

METHODS
Butterflies were marked-released-recaptured (MRR) between November 4, 1998 andNovember 22, 1999 (1-3 times per week), totaling 117 field days.The sampling sessions were performed at midday and lasted two hours or ended when more than 80% of the individuals captured represented recaptures.Adults were net-captured, numbered on the underside of the forewing using a waterproof felt-tipped pen, and released at the same point of capture.The following data were recorded for each captured individual: age (based on wing wear, divided into four categories: new, intermediate, old, and very old), sex, sub-area (of capture or recapture) and forewing length (in millimeters) (see details in Rosa et al. 2020).
The MRR data were analyzed using the Jolly-Seber (JS) method in MMRWIN_2016 software (Francini 2016).Sexes were analyzed separately for H. atalanta and in most analyses for C. eous; for M. affinis, sexes were combined in some analyses due to the low number of captured individuals.Daily observations were summarized as the number of individuals captured per day (NICD), including recaptures, and the number of individuals present per day (NIPD).To estimate NIPD, recaptured individuals were considered to be present on all previous days since their first capture (as in Rosa et al. 2020).
Individual residence (an indirect measure of lifespan) was calculated as days elapsed between marking and the last recapture (following Brussard et al. 1974).Survival curves followed Ehrlich & Gilbert (1973) and life expectancy (an indirect measure of survival based on the mortality rate) followed Cook et al. (1967).Sex was identified by visual inspection in the field (based on the shape of the tip of the abdomen) and the sex ratio was calculated through the monthly proportions in number of captured individuals of each month (following Ramos & Freitas 1999).Densities were calculated as the quotient of the total number of first captures of each species (both sexes combined) in each of the three subareas by the total area of each sub-area in m 2 .Forewing length (from the insertion on thorax to the wing tip) was measured to the nearest millimeter with a caliper.Movements were based on changes in the three subareas.

Hermeuptychia atalanta
In total, 1,635 individuals were captured and marked (1,149 males and 486 females), with males present on 115 days and females on 112 days.NICD varied from one to 34 for males (mean = 14.0 individuals; SD = 8.69; n = 115 days) and from one to 17 for females (mean = 5.3 individuals; SD = 3.61; n = 112 days).The NIPD varied from one to 39 for males (mean = 17.6 individuals; SD = 11.18;n = 115 days), and from one to 18 for females (mean = 6.4 individuals; SD = 4.19; n = 112 days) (Fig. 2A, B).The estimated population size varied from one to 255 individuals per day for males and from one to 162 for females.For both sexes, the population was somewhat stable from November to May, with a marked decrease in numbers in June and July, a small peak in August and then maintaining low densities from late September to December (Fig. 2A, B, Fig. 3).Males were recaptured from one to six times (464 recapture events) and females from one to five times (107 recapture events); a total of 326 males (28.4%) and 90 females (18.5%) were recaptured at least once.Males were recaptured significantly more often than females (X 2 = 17.5; df = 1; p < 0.0001).The total sex ratio (1149 males and 486 females) was malebiased (χ 2 = 268.04;df = 1; p < 0.0001).Considering the months separately, sex ratios were male-biased in all months but October 1999, when the sex ratio was 1:1 (Fig. 4).
The residence time (based on recaptured individuals) varied from two to 33 days for both sexes, with the average residence time of males (mean = 7.9 days; SD = 5.69; n = 326) higher than that of females (mean = 7.1 days; SD = 6.71; n = 90) (Mann-Whitney U test; U = 11963.5;p < 0.01).Life expectancy (following Cook et al. 1967) was 5.61 days for males and 7.82 days for females.Age structure was stable (both sexes combined), dominated by intermediate individuals in all months (Fig. 5).Survival curves (Fig. 6) were similar for both sexes (Kolmogorov-Smirnov test; p > 0.05; df = 2), approaching a type II survival curve.
Most of the first captures of H. atalanta males were in the area 3 (n = 580 individuals), followed by area 1 (n = 338) and the area 2 (n = 231).For females, the pattern was the same, with most first captures occurring in area 3 (n = 265), followed by area 1 (n = 134) and area 2 (n = 87).The highest density was reported in area 3 (0.27 individuals/m 2 ), followed by area 2 (0.21) and area 1 (0.05).Based on recaptures, changes in sub-areas occurred in 138 males (42%), while 188 were recaptured in the same area of first capture.In females, changes in subareas occurred in 21 individuals (23%), while 69 individuals were recaptured in the same area of first capture.
The forewing length varied from 15 to 20 mm in males and from 15 to 21 mm in females, with the average forewing length of females (mean = 17.1 mm; SD = 0.64; n = 1099) being not significantly different than that of males (mean = 17.2 mm; SD = 0.74; n = 459) (t = -19501; df = 754.08,p = 0.0534).No sexrelated differences in wing size were also reported in monthly samples (Fig. 7).Mean forewing lengths were apparently stable along the year.

Cissia eous
In individuals; SD = 0.94; n = 79 days).The NIPD varied from one to nine for males (mean = 4.0 individuals; SD = 2.11; n = 93 days), and from one to five for females (mean = 1.9 individuals; SD = 1.09; n = 79 days) (Fig. 2C).The estimated population size varied from one to 25 individuals per day for males and from one to eight for females.For males, the population was somewhat stable with two periods of decrease in numbers, the first from June to August and the second in October; females were present in low numbers most of the year, with one peak on mid-July to early September (Fig. 8).Males and females were recaptured from one to five times (94 and 35 recapture events respectively); a total of 65 males (30.7%) and 20 females (18.0%) were recaptured at least once.Males were recaptured significantly more often than females (X 2 = 6.01; df = 1; p < 0.05).The total sex ratio (212 males and 111 females) was malebiased (χ 2 = 31.58;df = 1; p < 0.0001).Considering the months separately, sex ratios were male-biased in all months except April, July and August of 1999, when the sex ratio was 1:1 (Fig. 9).with two periods of increase in new individuals, the first from May to July and the second in October-November, 1999 (Fig. 10).Survival curves (Fig. 11) were similar for both sexes (Kolmogorov-Smirnov test; p > 0.05; df = 2), approaching a type II survival curve.
Most of the first captures of C. eous males were in the area 1 (n = 86 individuals), followed by area 3 (n = 72) and the area 2 (n = 54).For females, the pattern was the same, with most first captures occurring in area 1 (n = 55), followed by area 3 (n = 42) and area 2 (n = 14).The higher density was reported in area 2 (0.05 individuals/m 2 ), followed by area 3 (0.04) and area 1 (0.02).Based on recaptures, changes in sub-areas occurred in 24 males (37%), while 41 were recaptured in the same area of first capture.In females, changes in subareas occurred in 9 individuals (45%), while 11 individuals were recaptured in the same area of first capture.
The forewing length varied from 16 to 21 mm in males and from 16 to 22 mm in females, with the average forewing length of males (mean = 17.6 mm; SD = 0.93; n = 207) significantly smaller than that of females (mean = 18.9 mm; SD = 1.04; n = 110) (t = -11.1627;df = 315, p < 0.0001).In monthly samples, average forewing size of females was significantly greater than that of males in all months except November 1998 and September 1999 (comparisons were not possible in December 1998, June and October 1999 due to the low sampling size) (Fig. 12).Mean forewing lengths were apparently stable through the year.

Malaveria affinis
In total, 78 individuals were captured and marked (44 males and 34 females), with males present on 47 days and females on 32 days.Considering only days with individuals captured (both sexes combined), the NICD varied from one to seven (mean = 2.1 individuals; SD = 1.46; n = 58 days), the NIPD varied from one to nine (mean = 2.6 individuals; SD = 1.75; n = 58 days) (Fig. 2D), and the estimated population size varied from one to 25 individuals per day (both sexes combined).The population remained at low numbers throughout the period, with a small peak from March to early May, reducing to a very low size from May to December (usually with only one individual captured during MRR sessions) (Fig. 2D, Fig. 13).Individuals were recaptured from one to three times (42 recapture events); with 32 individuals recaptured at least once (41%), being 20 males (45.4%) and 12 females (35.3%).The proportion of recaptures were statistically equal in males and females (X 2 = 0.818; df = 1; p = 0.366).The total sex ratio (44 males and 34 females) was not biased (χ 2 = 1.28; df = 1; p = 0.3082).Considering the months separately, due the low individual numbers only November 1998 and March 1999 could be tested, and sex ratio was not different from 1:1 in both months.
The residence time (based on recaptured individuals) varied from two to 26 days in males (mean = 11.0 days; SD = 7.20; n = 20) and from two to nine days in females (mean = 5.4 days; SD = 2.2; n = 12).For both sexes combined, life expectancy (following Cook et al. 1967) was of 10.31 days.Age structure showed a period of predominance of new individuals from November 1998 to January 1999, then intermediate individuals dominate in the following months, with an increase of old individuals from October to November 1999 (but note that this is based on one to three individuals from May to November 1999) (Fig. 14).The survival curve (Fig. 15) approaches a type II survival curve.
Most of the first captures of M. affinis males were in the area 3 (n = 41 individuals), with only three individuals captured in the area 1 (no male individuals were recorded in area 2).The pattern was similar for females, with most first captures occurring in area 3 (n = 31), followed by two in area 1 and a single individual in area 2. The higher density was reported in area 3 (0.013 individuals/m 2 ), followed by area 2 and area 1 (both with less than 0.001 individual/m 2 ).No changes in sub-areas were reported, with all recaptures reported in the area 3.

DISCUSSION
The three studied species showed similarities and differences in the reported population parameters.In terms of population size, H. atalanta was dominant, followed by C. eous and M. affinis.This parameter can be directly related to its host plant use, with H. atalanta using the predominant grass species in the study area, and C. eous and M. affinis using host plants that are less abundant and with restricted distributions in the study area.Concerning the variation in numbers through the year, however, H. atalanta and C. eous exhibited a similar pattern, with somewhat stable populations during the wet season and beginning of the dry season, with a reduction in numbers towards the dry season, while M. affinis showed a single population peak followed by very low numbers during most of the dry season.
Apparently, population decreases are not related to lawn mowing in the wet season, as reported for Eurema elathea (Pieridae) in the same study area (Vanini et al. 1999), except for the five successive mowing events in early June 1999 (dry season), which may have contributed to a pronounced population decrease in all three species (see Fig. 2).Given that the three studied species breed on grasses that are mostly growing in the grass lawns (see above), local mowing likely destroyed their immature stages and possible contributed to adults moving to another sub-areas, and this result is especially critical if mowing occurs in periods of low population numbers or near the periods of population decline, such as during the dry season (Vanini et al. 1999, Tourinho & Freitas 2009).
Male-biased sex ratios were reported for H. atalanta and C. eous, but not for M. affinis.Male-biased sex ratios are usually reported in population studies of tropical and temperate butterflies, including several species of satyrines (see Seixas et al. 2017, Rosa et al. 2020 andreferences therein).Usually, behavioral differences between sexes are argued to be the reason for this pattern, with males and females flying in different parts of the habitat (Ehrlich & Gilbert 1973, Mallet & Jackson 1980, Freitas 1993).In the present study, however, virtually the entire habitat was covered during MRR sampling in the three sub-areas.Females could have larger home ranges, moving to nearby grass lawns searching for better ovipositing sites (a hypothesis supported by the lower recapture rates of females in both species) (Wiklund 1977), and therefore may have a broader home range than males.In contrast, M. affinis presented a sex ratio of 1:1 and the recapture rates were equal for both sexes.This could be explained by the high philopatry of this species, which was basically restricted to a sector of sub-area 3 where its host plant M. maximus thrives, allowing the capture of most individuals in the population (evidenced by the high recapture rate reported in this species compared with H. atalanta and C. eous).Although the low sample size could affect the detection of a male biased sex ratio in this species, sex ratio of M. affinis in laboratory rearing was also 1:1 (AVLF unpublished data).
Age structures of all three species are similar in respect that there are no marked events of recruitment of new individuals in any specific time of the year, which is expected for species that have continuous recruitment throughout the year and overlapping generations (Ramos & Freitas 1999).The average permanence (an indirect measure of lifespan) was similar for H. atalanta and C. eous (about one week, with maximums of nearly a month), and slightly higher for M. affinis (about 11 days for males, but also with a maximum of nearly a month).However, the life expectancy was lower in H. atalanta when compared with the other two species, which can be visually verified in the survival curves: although similar, the survival curve for H. atalanta shows a pronounced decline in adults above the category of 16-20 days of permanence when compared with C. eous and M. affinis.
The mean adult lifespans of about one week reported here are noticeably short in comparison with other tropical butterflies, including Heliconius, some Ithomiini, Papilionidae and even other fruit-feeding nymphalids, including some euptychiines, whose adults present mean lifespans considerably longer, from two weeks to one month or more (Ramos & Freitas 1999, Andrade & Freitas 2005, Seixas et al. 2017, Pedrotti et al. 2019, Lourenço et al. 2022).Although several factors could underly for butterfly longevity, adult feeding has been considered one of the main factors influencing this parameter, especially in fruit-feeding butterflies (Bauerfeind & Fisher 2005, Molleman et al. 2007).Although fruit trees, such as guava (Psidium guajava L.; Myrtaceae) and black mulberry (Morus nigra L.; Moraceae), are present in the campus, these are not abundant and are located near to buildings and fences.Thus, the scarcity of food resources (especially fleshy fruits, see above) throughout most of the year in the study area could explain the short lifespans reported for the three species here studied.However, there are no comparative studies of these same species in forested habitats for comparison, and the low number of population studies with tropical butterflies prevents the identification of general patterns for different groups.
The abundance of each species by sub-area are not related to total area, and only C. eous presented higher abundance in area 1 (the largest sub-area in the present study).Thus, abundances are likely explained by biological factors such as microhabitat and presence of host plants.For example, the M. affinis is mostly restricted to the small, fenced sector inside of area 3 (Fig. 1D), where its host plant M. maximus persist due to the very low management (mechanized mowing was never observed inside the fence).Considering densities, the higher valor for C. eous was reported in area 2, where the shaded conditions imposed by the buildings allowed the persistence of one of its host plants, E. indica, a grass species that is especially common in the contacts of paved areas with the grass lawns, and area 3, where both host plants persist due to the absence of mechanized mowing and shaded conditions.In addition, C. eous is a territorial species (Peixoto andBenson 2008, 2009), and the spatial distribution of males could be partly explained by the distribution of potential defendable territories.Previous studies showed that males of this species establish territories in sunny clearings at forest edges (Peixoto & Benson 2008, 2009), a condition that is absent in the open sunny lawns (explaining the low densities of C. eous in area 1), but present in the area 2 and especially in the fenced sector of area 3.In the case of H. atalanta, however, the host plant P. notatum is the main grass in all studied subareas, and other factors should explain the higher densities in area 3 and area 2, respectively.In this case, high densities could be related to local environmental conditions such as microclimates, presence of adult resources (such as scarce fermenting fruits and other occasional decaying organic material), or more suitable larval host plants.
In the present study, two species, C. eous and M. affinis, present female-biased sexual size dimorphism, while this bias was not reported for H. atalanta.In fact, insects in general present a female-biased sexual dimorphism in size (Stillwell et al. 2010), a feature usually linked with greater fecundity in bigger females (Allen et al. 2011 and references therein).This pattern was also that most frequently reported for butterflies (Allen et al. 2011), with the remarkable exception of species in the genus Heliconius, whose males do not differ in size or are larger than females (Ramos & Freitas 1999, Andrade & Freitas 2005, Seixas et al. 2017, but see Hernández & Benson 1998).Another exception includes territorial butterflies, whose larger males have an advantage in confrontations, resulting in males usually being larger than females (Allen et al. 2011).However, although C. eous is a territorial species, body mass and not wing length was not reported as a reliable predictor of success in territorial contests (Peixoto & Benson 2008), which could explain the larger females in this species.

CONCLUSIONS
Although the present study cannot be considered long-term, this is the first to describe in detail some population parameters of Neotropical euptychiines based on at least a year of censuses.Thus, the present results could be considered reliable in terms of longevity, sex ratio and temporal variation in several studied parameters.Moreover, combined with previous ecological studies of the same area (Vanini et al. 1999, Cogni et al. 2000, Tourinho & Freitas 2009), this study could help to define strategies of lawn management in the campus, aiming to increase local biodiversity and consequent ecosystem services.For example, a plan of management of the grass lawns, with less intensive mowing, is recommended to maintain viable populations of invertebrates throughout the year, resulting in higher abundance and diversity in these groups (e.g.Lerman et al. 2018, Wintergerst et al. 2021), a pattern also reported for grazing systems (Schtickzelle et al. 2007).Such a result could be especially important considering that similar decreases in insect richness and abundances are mirrored by other invertebrates (Gibson et al. 1992, Ausden et al. 2005), especially during the dry season, affecting the available food supply for local populations of birds, small mammals, lizards and frogs in the study area.Finally, studies of population biology should be encouraged, since demographic data are fundamental for several areas of research in the biological sciences, including ecology, evolution and conservation (Lowe et al. 2017).

FIG. 1 .
FIG. 1. Study area and studied species.A. general view of area 1, a large lawn with sparse trees; B. general view of area 2, formed by small lawns near the campus buildings; C, D, general and close view of area 3, respectively, showing the patches of M. maximus (the large grass tufts in both pictures); E. H. atalanta; F. C. eous.
FIG. 3. Population size of adult males (above) and females (below) of H. atalanta.Solid circles number of adult individuals present per day, open circles estimated number (bars = 1 standard error).
FIG. 4. Sex ratio of H. atalanta.Data presented as percent of males (black) and females (white) based totals for each month; NS = non-significant difference (sex ratio = 1:1).
FIG. 8. Population size of adult males (above) and females (below) of C. eous.Solid circles number of adult individuals present per day, open circles estimated number (bars = 1 standard error).

FIG. 13 .
FIG. 13.Population size of M. affinis (both sexes combined).Solid circles number of adult individuals present per day, open circles estimated number (bars = 1 standard error).
FIG. 15.Survival curve for M. affinis (both sexes combined).The frequencies of individuals are plotted on a log10 scale against residence categories.