Biological Diversity

Contributed Oral

Rio Campo’s Mammals: An Assessment of Mammalian Diversity and Distribution in a Central African Protected Area
Tiff Degroot, Kristin Brzeski, Jared Wolfe, Luke Powell

Protected areas aim to conserve wildlife while also benefiting local communities. However in tropical forests, wildlife within protected areas are often threatened by habitat degradation and hunting, despite their legally-protected status. In central Africa, wildlife managers often face funding challenges that lead to inadequate protection, though even simply the presence of law enforcement or survey crews can create “passive” protection for wildlife at risk. For example, in Equatorial Guinea in central Africa, the government agency responsible for protected areas management is underfunded, but during their limited wildlife surveys, they have been able to shut down poaching and illegal logging operations. Furthermore, researchers can play a positive role by providing reports directly to wildlife managers that can inform on-the-ground management. With this in mind, we have assessed mammalian distribution and diversity in Rio Campo, a protected area in Equatorial Guinea that has been recognized as an important area for large mammals, using camera trap data collected in 2017 and 2019 by the local government. Our results include a species inventory and detection rates for taxa of importance due to their IUCN Red List status (e.g. mountain gorillas), and/or their importance for local subsistence and commercial hunting (e.g. duikers). With this assessment, we aim to 1) help equip wildlife managers with the tools necessary to efficiently protect wildlife in Rio Campo, by indicating key areas of focus for the protection of Endangered species, and 2) build on previous mammal survey work carried out by researchers in 1999 and 2013, by providing an updated and more comprehensive snapshot of species diversity and distribution for both Endangered species and common, yet extensively hunted species in Rio Campo. 

Mixed Evidence of Lake Effect at PV Solar Energy Projects in Southern California
Karl Kosciuch, Daniel Riser-Espinoza, Cyrus Moqtaderi, Wally Erickson

The development of photovoltaic (PV) utility scale solar energy (USSE) in the desert southwest was anticipated to negatively affect birds through impacts to habitat and collision mortality. The discovery of stranded or dead birds that associate with aquatic habitat was unexpected as PV USSE facilities do not contain water and are not tall vertical hazards to migrating birds. Based on early patterns in fatality monitoring data, the lake effect hypothesis (LEH) was developed and suggested that birds misinterpret PV solar panels for water; however, no explicit tests of predictions of the LEH have been completed. We collected data from five PV USSE facilities and reference areas in three habitat types in southern California to determine if general predictions under the LEH were supported for aquatic habitat birds. We did not find that live aquatic habitat birds occurred more frequently at the PV solar sites than in the paired reference areas of similar habitat to the solar sites. Although the bird community (live and dead) contained aquatic habitat species, bird diversity was 3-4 times higher and standardized use was more than an order of magnitude higher at a small regional lake than measured at the PV USSE facilities. Finally, we did not observe aquatic habitat bird fatalities in the desert/scrub and grassland reference areas, but we did observe aquatic habitat bird fatalities in the agricultural reference area. Thus, the idea of ‘lake effect’ in which birds perceive a PV USSE facility as a waterbody and are broadly attracted is likely an overgeneralization of a nuanced process. We suggest there could be species-specific context dependent attraction to PV solar facilities in place of a generalized ‘lake effect’ and that potential causal mechanisms require further investigation.

Effect of Landscape Fragmentation on the Population Dynamics of Northern Bobwhite
Edwige Bellier, John Yeiser, James Martin

Habitat fragmentation and loss due to humans is identified as one of the most critical factors contributing to the decline and loss of biodiversity worldwide. The response of population dynamics to habitat fragmentation is complex and poorly known; however, predictive models are needed to assist with conservation delivery. Thus, we are developing dynamic and adaptive ecological scenarios to analyze the effects of habitat fragmentation on threatened populations of game birds. The biological model of study is northern bobwhite (Colinus virginianus). The model is based on female population dynamics and incorporates density dependence, different levels of fragmentation, dispersal, stochastic, and realistic vital rates from long-term data. Our simulation model assumes density dependence between population size and fecundity, non-breeding season survival, breeding season survival, emigration rate, immigration rate, but not chick survival. The simulated populations are not influenced by extreme weather events beyond the typical annual variation. The different levels of landscape fragmentation are simulated from a spatially explicit covariance function with different ranges (i.e., Gaussian covariance) that represent the landscape’s pattern. We test the effect of the different levels of fragmentation based on two hypotheses. First, we assume an interaction between the ability to disperse from the covey and the level of fragmentation. Second, we assume interaction between winter survival and habitat fragmentation. We show that increasing fragmentation negatively influenced population growth. When the level of fragmentation is low, populations can persist. We will extend our model to determine the fragmentation and habitat loss thresholds at which populations persist to inform conservation planning. This study shows how using spatially explicit life-cycle models based on long-term data can help us analyze how fragmentation may influence population-level dynamics.

Whiskers in the Water: A Multi-Method Approach to Detect Freshwater Semi-Aquatic Mammals
Glynnis Hood

Freshwater semi-aquatic mammals, despite some variability in habitat use, share a notable degree of habitat overlap and interspecific interactions. For example, the presence of beaver is an important predictor of habitat use by river otter, and muskrat and mink exhibit a similar relationship. Assessing habitat use by water shrews and northern bog lemmings is more difficult because of their cryptic nature. We placed specialized camera boxes, camera rafts, and cameras on beaver dams to assess detectability of riparian mammals. From ~28,000 images, we identified over 2,800 individual animals, including 27 species of birds, 20 species of small mammals, 5 species of medium to large mammals, 2 species of herptiles, and several invertebrates. Muskrats, beavers, and water shrews were the most abundant small mammals detected by the cameras, with shoreline camera boxes being more effective at capturing the highest diversity of species (42 species). Camera data informed locations for subsequent eDNA sampling in ponds within the Beaver Hills Biosphere in east-central Alberta, Canada. In collaboration with InnoTech Alberta, we also developed and tested four DNA assays for the more cryptic species of semi-aquatic mammals (river otters, mink, water shrew, and bog lemming). We also conducted winter field surveys within several protected areas across the study area (1,572 km2) to map the distribution of beaver lodges (2,100+), muskrat push-ups and huts, and mink and muskrat tracks. This research increases our understanding of the efficacy of varied non-lethal sampling methods for the detection of cryptic, but important riparian species.

Mammal Diversity on Great Lakes Islands Supports Theory of Island Biogeography
Nathaniel Wehr, Samuel Wehr, Hailey Boone, Jerrold Belant

The theory of island biogeography suggests the biodiversity of an island should be associated with island size and distance from mainland source populations. This theory has broad support describing oceanic islands, but less for describing freshwater systems. Further, while island size consistently predicts biodiversity, other characteristics of islands including distance to source populations and presence of neighboring islands have not received clear support. Our objective was to assess these aspects of island biogeography theory in a freshwater system addressing present knowledge gaps. We collected data on the presence of meso- and large- mammals on 44 islands across the Laurentian Great Lakes of North America. Presence data was collected via direct communication with resource managers and researchers associated with each island, databases of species distributions (e.g. iNaturalist), and a literature review. As predicted by island biogeography theory, larger islands had greater species richness while islands farther from mainland source populations had lower species richness. However, the effect of distance to mainland was dampened by a stepping stone effect whereby islands in archipelagoes with an island closer to mainland source populations had greater species richness. We also found mammals with larger home ranges (e.g. moose [Alces alces] and gray wolf [Canis lupus]) were more likely to be present on islands, likely due to their dispersal capabilities. Comparatively, winter dormant species (e.g. American black bear [Ursus americanus] and North American porcupine [Erethizon dorsatum]) were less likely to be present on islands, potentially due to their inability to use seasonal ice bridges. In sum, our results largely support the theory of island biogeography and highlight the importance of stepping stone islands for species occurrence, with application beyond geographical islands to ecological islands. Further, our dataset can provide a baseline for future investigations of mammalian distributions and biology in the Great Lakes region.

Insects and Bioblitzes: A Case Study at Alabama Forever-Wild’s Big Canoe Creek
Thomas Franzem, Paige Ferguson

To address the ongoing extinction crisis and preserve the services biodiversity provides, ecologists must identify drivers of population and distributional changes. To accomplish this, biodiversity data is crucial.  However, major gaps in biodiversity data persist and existing data sets tend to be taxonomically and temporally biased.  Insects are often underrepresented in biodiversity data and there are still major gaps in our understanding of the distribution and ecology of many insects.  A popular and cheap method for generating biodiversity data is a bioblitz, where biodiversity data is gathered by volunteers in a short time-frame.  Bioblitzes are often unstructured and taxonomically biased; insects are often overlooked.  The goals of this project were to: 1. implement a new bioblitz framework to generate better insect data, 2. use site-occupancy models to analyze the data, and 3. compare the resulting dataset to an insect dataset generated from a traditional bioblitz. We developed a modification of a traditional bioblitz, that we term a Recurring Expert Bioblitz (R.E.B.) at a recently acquired conservation property; effectively, this sampling design is a temporally replicated bioblitz.  In 2018, we participated in a standard bioblitz and then the following year conducted an R.E.B. that consisted of four, two-day surveys. R.E.B. surveys were spatially and temporally replicated to facilitate data analysis in site-occupancy models.  During the R.E.B. insects were collected via sweep-net transects and aspirator points at seven sampling plots.  Compared to the traditional bioblitz, our follow-up surveys detected significantly more insect taxa.  Moreover, the traditional bioblitz insect dataset was dominated by a two insect orders, while the R.E.B. dataset was not.  Further, our statistical models indicate habitat associations for detected taxa and estimate their distribution across the property.  Our results suggest this approach can be used to generate high-quality insect data in future bioblitz-style surveys.  

Contradictory Effects of Landscape-Level Stressors on Frog and Salamander Richness in Managed Lands of the Midwestern United States
Ethan Kessler, John Crawford, Andrew Kuhns, Christopher Phillips

Species richness and diversity are commonly used as proxies of habitat quality in wildlife conservation. In North America, frogs are often used as such a proxy since, as amphibians, they occupy terrestrial and aquatic habitats due to their biphasic life history, are regarded as sensitive to disturbance, and are relatively easy and cost-effective to survey due to their seasonal breeding choruses. However, taxa are only useful as an indicator of habitat quality if they are sensitive to variation in habitat quality. We sampled wetland-breeding amphibian communities at 37 publicly-owned properties across Illinois to determine frog, salamander, and total amphibian richness of each site. We calculated relative richness as the ratio of site-specific richness and the regional species pool and used quasibinomial regression to model the effects of several landscape-level variables on relative richness at each site. We found that the proportion of agriculture and total area of conservation lands within a buffer (adjusted to the scale of best fit) affected salamander and frog richness in contradictory ways. Frog richness increased with more agriculture and less conservation area, while the opposite relationship was observed in salamanders. We also found that landscape-level effects were stronger for salamanders when sites with surface mining history were removed from the analysis. This suggested a negative effect of surface mining on salamanders which obscured landscape-level effects, although no such effect was seen in frogs. Our results show that while salamander richness varied with landscape variables as predicted, frogs showed a paradoxical increase in richness at sites which are generally considered to be of lower quality. Therefore, measures of frog richness, especially in temperate systems, may be a poor predictor of habitat quality and could lead to inappropriate conservation recommendations and actions.

Contributed Oral
Location: Virtual Date: November 4, 2021 Time: 3:00 pm - 4:00 pm