Research Article |
Corresponding author: Leroy Soria-Díaz ( leroysoriadiaz@gmail.com ) Academic editor: Jorge Salazar-Bravo
© 2021 Carlos A. Contreras-Díaz, Leroy Soria-Díaz, Yuriana Gómez-Ortiz, Rogelio Carrera-Treviño, Claudia C. Astudillo-Sánchez, Julio C. Chacón-Hernández, Luis F. Martínez-García.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Contreras-Díaz CA, Soria-Díaz L, Gómez-Ortiz Y, Carrera-Treviño R, Astudillo-Sánchez CC, Chacón-Hernández JC, Martínez-García LF (2021) Temporal and spatial segregation of top predators (Felidae) in a Mexican tropical Biosphere Reserve. Zoologia 38: 1-10. https://doi.org/10.3897/zoologia.38.e63231
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Jaguars, Panthera onca (Linnaeus, 1758), and pumas, Puma concolor (Linnaeus, 1771) are the largest felids in the neotropics. Both can overlap in niche axes (time, space and prey), and are therefore potentially competing species. Segregation mechanisms presented by a low overlap in one of these axes of niche can facilitate the coexistence. Our aim was to analyze jaguar and puma temporal and spatial overlap for understanding their segregation mechanisms. Between 2015 and 2017, twenty-six camera trap stations were located in five habitat types of El Cielo Biosphere Reserve (ECBR) in northeastern Mexico. Temporal activity was analyzed using circular statistics and time overlap analysis. Spatial overlap was calculated with the Pianka index and a selectivity habitat analysis. Our results showed that jaguars and pumas were nocturnal and that the temporal overlap was high (∆4 = 0.77). We found an intermediate spatial overlap (Pianka index = 0.61). Jaguars were more selective and preferred the deciduous forest. In comparison, pumas preferred oak-pine forest, but also used oak and deciduous forest. Our results indicate that spatial segregation best explains the coexistence of jaguars and pumas in our study area, probably due to both habitat diversity in the reserve and the generalist habits of the puma.
Camera trap, coexistence, El Cielo Biosphere Reserve, northeastern Mexico, Panthera onca, Puma concolor
Activity patterns and habitat use are important components that describe the ecology and behavior of species and may facilitate coexistence between species or individuals that experience intra-guild competition (
Jaguars, Panthera onca (Linnaeus, 1758), and pumas, Puma concolor (Linnaeus, 1771), constitute a large mammalian predator guild that can affect the structure and pattern of associated ecological communities (
Some authors suggest that competition between jaguars and pumas is low due to differences in diet (
Generally, jaguars consume larger prey than pumas, and pumas have a more diverse diet (
Other studies of overlapping temporal activity in populations of sympatric jaguars and pumas, noting that both felids can change their behavioral patterns when exposed to anthropogenic pressures such as agricultural burning, poaching, and logging (
The Sierra Madre Oriental of northeastern Mexico represents one limit of the geographical distribution where jaguar and puma populations occur simultaneously (
Given the variety of habitat types and the status of conservation of the ECBR, we hypothesized temporal and spatial segregation would be important mechanisms mediating the coexistence between jaguars and pumas. Our aim was to analyze temporal and spatial overlap between jaguars and pumas in the ECBR to help understand the segregation mechanisms that ensure their coexistence.
We conducted our study in ECBR, which is in northeastern Mexico and is part of the state of Tamaulipas (Fig.
We established 26 study camera trap stations in five habitat types from January 2015 to December 2017. The mean distance between stations was approximately 6 ± 3 km. The number of stations in each habitat were chosen in proportion to the area of habitat it represented in the reserve: OF (414.6 km2, n = 9 stations), DF (329.7 km2, n = 8 stations), MCF (191.5 km2, n = 5 stations), OPF (80.3 km2, n = 2 stations), and SDF (69.6 km2, n = 2 stations) (Fig.
We installed two camera traps (Scoutguard HCO SG565) at each of the 26 sampling stations along unpaved roads and man-made trails to maximize the detection probability of jaguars and pumas (
Photographs were classified as independent events to avoid autocorrelation. We define these independent events as: a) consecutive photographs of different individuals of the same species; b) consecutive photographs of individuals of different species; c) each individual in a group photograph; d) one hour between photographs only when it was not possible to identify individuals (
We grouped independent photographic events into 24 one-hour categories starting at 00:00 h. Daily activity patterns for each species were further broken down into day, night, and crepuscular (dawn and dusk). We determined the exact time of dawn and dusk by using Sun Times software v. 7.1 (Kay and Du Croz 2008,
Temporal activity patterns for each species were analyzed using circular statistics implemented with the Oriana v. 4.02 software (Kovach Computing Services, UK). Rayleigh’s Uniformity Test (
We also compared the activity pattern of the jaguar and puma between years (2015, 2016, and 2017) and seasons (dry and wet) using parametric or nonparametric circular tests depending on whether or not the data showed a von Mises distribution. This distribution can be regarded as the circular analogue of the normal distribution on the line (
We calculated the temporal coefficient of overlap (∆) and its 95% confidence interval from 10,000 bootstrap samples between jaguar and puma activity patterns (
We grouped independent events of jaguars and pumas into the five habitat types (DF, SDF, OF, OPF, MCF), and spatial overlap was subsequently calculated with the Pianka index. This index ranges from 0 (no overlap) to 1 (complete overlap) and was performed in EcoSim 7.0 software (http://www.garyentsminger.com/ecosim) (
We also performed a selectivity habitat analysis to determine if the jaguars and pumas used or avoid some habitat types of the ECBR according to availability. We used satellite imagery (Google Earth) and ArcGIS 10.2 to digitize the five habitat types of the reserve and calculated the percentage of available area for each habitat (DF [30.37%], SDF [6.41%], OF [38.19%], OPF [7.40%], MCF [17.64%]). We used the index of selectivity (Ei) according to
Further, to know on a fine scale if both felids share the same space, we determined the percentage of camera trap stations where jaguars and pumas were photographed at the same site, but at different times.
From January 2015 to December 2017, we had 28,220 camera trap days of survey effort and 1,063 photographs of jaguars and pumas, 553 of which were identified as independent events (371 jaguars; 182 pumas).
The activity pattern of jaguars was mainly nocturnal; 80% of independent events at night and activity peaks at 21:00, 22:00, and 02:00 h (Fig.
Jaguar and puma activity patterns did not show a Von Mises distribution (U2) in some years (jaguar: 2015 U2 = 0.23, p < 0.05; 2016 U2 = 0.04, p > 0.05; 2017 U2 = 0.32, p < 0.05; and puma: 2015 U2 = 0.05, p > 0.05; 2016 U2 = 0.02, p > 0.05; 2017 U2 = 0.03, p < 0.05). Based on these results we use a Mardia-Watson-Wheeler (W) nonparametric multisample test to compare jaguar and puma activity patterns among sampling years, and no significant differences were found (jaguar: W = 1.63, p > 0.05; and puma: W = 5.1, p > 0.05).
We also compared the activity pattern of the jaguar between seasons (dry and wet) using the Watson-Williams (F) parametric test (two samples) and the Von Mises distribution (wet season: U2 = 0.41, p > 0.05; dry U2 = 0.14, p > 0.05). For pumas we use Mardian-Watson-Wheeler (W) nonparametric test (two samples), because the season did not show a Von Mises distribution (wet: U2 = 0.04, p < 0.05; dry: U2 = 0.03, p < 0.05). However, there were also no significant differences in activity between wet and dry seasons (jaguar: F = 0.16, p > 0.05; and puma W = 0.89, p > 0.05), so we did not consider those variables in the time overlap analysis.
Time overlap analysis showed a high coefficient of overlap between jaguars and pumas (∆4 = 0.77) with confidence intervals of 0.71–0.84 (Fig.
Circular histograms of activity patterns for jaguar (Panthera onca) and puma (Puma concolor) in El Cielo Biosphere Reserve, Tamaulipas, Mexico. Each bar is a discrete 1-hour time interval and is centered on the hour. The dependent variable (inner circles) is number of times jaguars or pumas appeared in photographs at each time interval.
Time overlap analysis of activity patterns between jaguar (Panthera onca) and puma (Puma concolor) in El Cielo Biosphere Reserve. Time overlap is shown by the shaded area. The solid line represents the activity pattern of jaguars and dashed line shows the activity pattern of pumas (∆4 = 0.77 is the result of the overlapping coefficient between jaguar and puma activity).
The habitat use analysis showed that jaguars mostly used DF with 90% of independent records found in this habitat types, while pumas mostly used three different types of habitats in ECBR: OF (35%), DF (31%), and OPF (24%). The Pianka index indicated an intermediate spatial overlap (0.61) between jaguars and pumas. Therefore, pumas show behaviors of a generalist species by using a greater number of habitat types, which is a potential strategy to avoid encounters with jaguars, and for both to coexist in the same landscape with similar habitats. We also recorded a low percentage (22.5%) of co-occurrence (sites where we photographed jaguars and pumas in the same space but at different times).
Habitat selectivity analysis (Ei) showed segregation in relation to habitat use. The jaguar selects the DF (Ei = 0.48), uses the SDF in proportion to availability (Ei = −0.08), and avoids using the MCF (Ei = −1), OF (Ei = −0.84), and OPF (Ei = −0.39). In comparison, puma prefers the OPF (Ei = 0.41), uses the OF (Ei = −0.04), DF (Ei = 0.09) and SDF (Ei = −0.18) in proportion to availability, and avoids using the MCF (Ei = −0.51). Based on the results of this analysis we believe that jaguars are more selective than pumas (Fig.
Jaguars and pumas are sympatric top predators across the entire jaguar range, share a remarkably similar morphology, and are obligate carnivores (
Our results showed a high temporal overlap between jaguars and pumas in the ECBR (∆4 = 0.77). These observations concur with results of studies conducted in the Venezuelan llanos (
Jaguars were nocturnal in the ECBR (80% of the independent photographs) and did not show uniformity in their daily activity and were not considered cathemeral. The jaguar activity in this study is similar to that described in other studies (
Pumas showed a greater tendency to be nocturnal but showed activity at different times throughout the day; however, were not considered cathemeral. Other authors mention that puma activity during the day is common and may be due to low human activity and the availability of prey during the day (
The reasons for nocturnal activity of jaguars and pumas are variable, but some authors hypothesize that hunting at night is advantageous because the two felids can get closer to their prey without being detected (
Understanding how large felids use habitat is essential to allow us to identify whether habitat use is a strategy for coexistence in species that are potential competitors (
Based on our results of spatial overlap (Pianka index = 0.61), habitat use, and low percentage of co-occurrence in shared sites, we believe this is the mechanism that best explains the coexistence of jaguars and pumas in ECBR. Of course, this statement should be taken with caution until the diet of these two felids can be analyzed in a future study. Jaguars showed a strong preference for DF, used three other habitats sparingly, and were absent from the MCF. Pumas preferred OPF but used the four other types of habitats (albeit some sparingly). Because of the ECBR’s variety of habitat types, high heterogeneity, and low disturbance by humans (
Additionally,
Our results yielded interesting conclusions of temporal and spatial interactions between jaguars and pumas and improves our knowledge about the ecology of these Neotropical felids within a protected area (ECBR). We suggest that temporal segregation is not the main coexistence mechanism between these two felids because our temporal overlap results were high. Temporal segregation may only be a secondary strategy in the jaguar and puma interaction. Instead, we suggest that spatial segregation may be the mechanism that best explains the coexistence of the jaguar and puma in the ECBR. We believe that the presence of different habitat types allows these felids to avoid each other and coexist. In addition, the puma’s generalist habits are an important factor to consider. In this study, pumas used a wider array of time and space. Finally, we recommend in a future study in ECBR, to determine the diet of the jaguar and puma (scats analysis) to include an analysis of trophic niche overlap between those two felids, and then, analyze the temporal overlap of the felids and their main prey. This last analysis is essential, because it would help to corroborate the coexistence of the jaguar and puma in the ECBR.
We thank the Programa para la Conservación de Especies en Riesgo de la Comisión Nacional de Áreas Naturales Protegidas (CONANP); the owner of the lands, and volunteers of the wildlife laboratory of the Faculty of Veterinary Medicine and Zootechnics of the Autonomous University of Nuevo Leon, Mexico. We also thank the Autonomous University of Tamaulipas for funding the project UAT/PFI2015-15, and to the Program for Professional Development for Higher Education (PRODEP) through the project UAT-PTC-221/511-6/17-8212. We also thank to two anonymous reviewers for their comments and to R.J. Smith for copyediting English version.