EcoRoad Reseach Paper final
- 1. Senior Seminar Research Project University of North Florida Biology Department University of North Florida 1 UNF Dr. Jacksonville, Florida 32224 Jorge Jamie Gomez Dr. Anthony Rossi Determining the efficacy of the University of North Florida Eco-‐Road to reduce animal road mortalities.
- 2. Jorge J. Gomez/Dr.Rossi Eco Road Research 2 Determining the efficacy of the University of North Florida Eco-‐Road to reduce animal road mortalities. Abstract The effects of roadways on animal populations are often overlooked. Initially animal road mortalities were seen as an indicator of animal population health although roads have been a problem for diversity and conservation efforts since their introduction and with the rapid increase in automobile use they are now more detrimental than ever. Effects include animal vehicle collisions resulting in animal mortality, habitat fragmentation, chemical pollution, changes in hydrology and the introduction of invasive species. With such alarming rates of animal mortality on roadways, it is necessary to take appropriate measures to reduce the mortality rate. The purpose of this study is to evaluate the efficacy of the University of North Florida Eco-‐road at reducing animal mortalities on the Sawmill-‐Slough Preserve. Animal mortalities were counted on the University of North Florida Eco-‐road and on an adjacent stretch of standard roadway two days per week from September 2011 through August 2012. The rate of animal mortalities on the UNF Eco-‐road was significantly lower than that of the standard road. Although there is evidence supporting the efficacy of the Eco-‐road, future studies need to address ways to reduce animal mortalities of specific animal species. Introduction An often-‐overlooked aspect affecting biodiversity are roads. Not only do roads reduce biodiversity but they also reduce usable habitat, just as importantly
- 3. Jorge J. Gomez/Dr.Rossi Eco Road Research 3 they cause habitat fragmentation and species isolation (Lode, 2000). Interestingly, Lode (2000) found that vehicles release an array of toxic pollutants that are soluble in fatty tissue including heavy metals that accumulate and are detrimental to the fitness of animal populations by specifically affecting the reproductive cycles. Additionally roads may facilitate the introduction of a variety of invasive species into a habitat (Hawbaker et al., 2006). Aside from the effect roads have on animal and plant populations, they also alter hydrologic flows including an increase in erosion and the introduction of chemical pollutants caused by roads when intersecting rivers and streams (Forman and Alexander, 1998). A Study by Roe et al (2009) on the movement of water turtles, Chelodina longicollis, showed that a single wetland was not the minimum habitat of C. longicollis and that in some instances specimens traveled more than 5.2 km into other wetlands. Roe et al (2009) also showed that the inter-‐patch networks and interactions between species are fundamentally altered by wetland degradation and segmentation. Specifically, local population dynamics may be altered when roads intersect critical resource patches because they reduce inter-‐patch movements of individuals that would disperse in order to exploit interconnected resource patches (Roe et al., 2009). In a study by Hawbaker et al (2006) it was shown that in Wisconsin, mean patch area decreased from 121 hectares in 1937 to only 20 hectares in 1999. Hawbaker et al (2006) also showed that road density more than doubled in the same time frame form 1.7 Km Km-‐2 to 3.5 km km-‐2. There are also probable genetic consequences due to the fragmentation of habitats from road construction (Forman and Alexander, 1998 and Lode, 2000). Roads cover about 1%
- 4. Jorge J. Gomez/Dr.Rossi Eco Road Research 4 of North America, which is approximately an area the size of Austria (Forman and Alexander, 1998). It has been documented that roads can aid invasive species, for example in New York, the spread of the invasive plant, Lythrum salicaria, was facilitated by roadside ditches (Forman and Alexander, 2009). While birds, insects, amphibians and mammals are likely to be crushed by automobiles, small animals, such as worms, are almost always killed by automobiles but many die due to desiccation on the road surface (Pickles, 1942). High road mortality rates in New York have not only posed an increased threat to local amphibian and reptile population but they have had an indirect effect on the safety of humans using the roads (Langen et al, 2006). It is estimated that 159,000 birds and 633,00 mammals die in the Netherlands every year; 7 million birds in Bulgaria; 5 million frogs and reptiles in Australia and in the United States of America there are approximately 1 million vertebrate deaths per year (Forman and Alexander, 1998). Danger to motorist and pedestrians presents itself when motorist have to inadvertently swerve in order to avoid a collision with an animal (Langen et al, 2006). Although high mortality rates on highways has been interpreted as sign of healthy animal populations, high numbers of road animal deaths is a rising concern for conservation ecologists (Langen et al., 2006). Species that have high mortalities resulting from vehicle-‐wildlife collisions are populations of white-‐tailed deer (Odocoileus virginianus), black bears (Usrus americanus) and the Florida Panther (Puma concolor coryi) the later which is an endangered species (Clevenger et al., 2001). It is believed that high mortality rates for amphibians and reptiles occur
- 5. Jorge J. Gomez/Dr.Rossi Eco Road Research 5 because they seek out roadways to raise their body temperature (Lange et al., 2006). Ways to reduce the high numbers of animal mortality along roads includes mitigation fencing, tunnels and bridges. A study in the Banff National Park in Alberta, Canada showed that wildlife mortalities were reduced by over 50% after mitigation fencing was installed despite annual increases in traffic volume (Clevenger et al., 2001). The University of North Florida Eco-‐Road (UNFER) has two features, which are intended to reduce animal mortality by motor vehicles. The two features of the UNFER designed to reduce animal mortality are three sections of tunnels that connect both sides of the Saw Mill Slough Preserves that are separated by the UNFER and mitigation fencing that lines the length of the road. The goal of the current study is to monitor road mortality using the techniques of Pickles (1942), Caro et al. (2000), Langen et al. (2007) and Lode (2000) to compare the ability of the UNFER to reduce animal deaths compared to an adjacent standard roadway referred to as the Loop road also on the University of North Florida campus. Materials and Methods Two stretches of road completely situated on the UNF campus were chosen to perform the animal mortality counts. These included the UNF Eco-‐road as well as an adjacent stretch of standard road referred to as the Loop Road. A .33-‐mile section of road was selected from each road. Deceased animals were counted on both roads, twice a week and recorded at approximately the same time of day. Animal mortalities were classified by the road where they were found and by type
- 6. Jorge J. Gomez/Dr.Rossi Eco Road Research 6 (vertebrate or invertebrate). Data was analyzed using a Chi-‐Square test with Yates’ correction. Results The total animal counts for both the Eco-‐road and the Loop Road was 92 total deceased animals with 34 on the Eco-‐road and 58 on the Loop Road (see table 1). Table 1 Total number of deceased animals found. Road Count Totals Loop and Eco-‐road combined totals (Total=92) Raccoon 4 Coleoptera 7 Toad/toad 35 Squirrel 3 Hymenoptera 3 Lizard 1 Armadillo 2 Odonoata 9 Unidentified Vertebrate 5 Opossum 2 Orthoptera 1 Unidentified Invertebrate 3 Turtle 3 Lepidoptera 1 Annelida 5 Bird 4 Eco-‐road (total=34) Raccoon 1 Coleoptera 6 Toad/toad 13 Squirrel 1 Hymenoptera 1 Lizard 0 Armadillo 1 Odonoata 2 Snake 2 Opossum 2 Orthoptera 1 Unidentified Vertebrate 2 Turtle 0 Lepidoptera 1 Unidentified Invertebrate 1 Annelida 0 Bird 0 Loop Road (total=58) Raccoon 3 Coleoptera 1 Toad/toad 22 Squirrel 2 Hymenoptera 2 Lizard 1 Armadillo 1 Odonoata 7 Snake 2 Opossum 0 Orthoptera 0 Unidentified Vertebrate 3 Turtle 3 Lepidoptera 0 Unidentified Invertebrate 2 Annelida 5 Bird 4
- 7. Jorge J. Gomez/Dr.Rossi Eco Road Research 7 Total number of animals killed on the Eco-‐road was significantly lower than the number of deceased animals on the Loop Road. (χ2 = 6.272; P < .025, df = 1). In every month that count data was analyzed, the number of deceased animals was higher on the Loop Road compared to the Eco-‐road except for November of 2011 (Figure 1). Figure 1 Comparison of animal mortality on the Eco-‐road and Loop road. Figure 1 Animal mortality on both roads peaked in the May, which may coincide with spring migration patterns or the passing of Tropical Storm Beryl, which Jul Month - Year Numberofdeadanimals 0 2 4 6 8 10 12 14 16 18 20 Eco-road Loop road Sep O ct N ov D ec M ar Apr M ay Jun Aug 2011 2012
- 8. Jorge J. Gomez/Dr.Rossi Eco Road Research 8 dropped a large amount of rain resulting in animals leaving adjacent habitats to seek high ground. This supposition is supported by the dramatic increase in amphibians. These trends were consistent even when number of dead animals per month was divided by the number of sampling days (sampling effort; Figure 2). Figure 2 Comparison of animal mortality on the Eco-‐road and Loop road using sampling effort. The number of animal mortalities on the Eco-‐road was significantly lower than the animal mortality rate on the Loop road (Statistical analysis; Fig.3). Jul Month - Year Numberofdeadanimals/days 0.0 0.5 1.0 1.5 2.0 2.5 Eco-road Loop road Sep O ct N ov D ec M ar Apr M ay Jun Aug 2011 2012
- 9. Jorge J. Gomez/Dr.Rossi Eco Road Research 9 Figure 3 Statistical comparison of animal mortality rates of the Eco-‐road with the Loop road. Figure 3 Statistical Analyses shows that the animal mortality rates of the Eco-‐road are significantly lower than those of the Loop road (χ2 = 6.272; P < .025, df = 1). Even though the results show that the Eco-‐road is lowering the mortality rate it does not a significant trend for animal type. There is not a significant difference in mortality rates between invertebrates and vertebrates on either road (Contingency table; Fig. 3) Numberofanimals 0 10 20 30 40 50 60 70 Eco-road Loop road 2 = 6.272 df = 1 p < .025
- 10. Jorge J. Gomez/Dr.Rossi Eco Road Research 10 Figure 4 2X2 contingency table comparison of animal mortality rates of invertebrates and invertebrates on both roads . Figure 4 The 2X2 contingency table did not show a significant difference in the rates of invertebrate mortality rates compared to vertebrate mortality rates on either of the roads. Discussion The use of tunnels under the Eco-‐road is an effective way to reduce animal mortality rates. This is especially vital to protected wildlife areas such as The Sawmill Slough Preserve on the University of North Florida campus. According to Inbar and Mayer (1999), animal mortality is a serious problem to species such as Puma corii concolor, Daspus novemcinctus, which is the only member of the Vertebrates Animal group Numberofanimals 0 10 20 30 40 Eco-road Loop road Invertebrates c2 =.4041 df = 1 p > 0.5 (NS)
- 11. Jorge J. Gomez/Dr.Rossi Eco Road Research 11 Dasypodidae found in the US. Connectivity was highly altered in the Sawmill Slough Preserve by the construction of the Eco-‐road and the break in connectivity can have a detrimental effect on the biota (Roe et al, 2009). These problems include the genetic isolation of certain species (Forman and Alexander, 1998 and Lode, 2000). The tunnels and mitigation fencing that are characteristics of the University of North Florida Eco-‐road have shown significant decreases in animal road mortality. Since the results support the use of eco-‐roads, it should be considered in all future road construction, especially in areas that are set aside for conservation such as state and national parks. The results of the this study are consistent with the results of a study done in the Banff national Park in Alberta, Canada by Clevenger et al, (2001) which showed that the used mitigation fencing reduce animal road mortalities. Clevenger et al, (2001) also provides evidence that road signs are functional methods for reducing animal mortalities on roads. This approach could be easily implemented on existing roads. According to Inbar and Mayer (1999) there appears to be a stronger correlation between traffic related animal mortalities and phenology than traffic volume thus mitigation fences, tunnels and signage should be taken into account even on roads that are considered low traffic volume roads. Some problems that need to be addressed with the study include the faster disappearance of carcasses of smaller animals compared to larger animals (Caro et al, 2000) and counts are not as accurate when they are performed from a moving automobile compared to counts done while walking (Pickles, 1942). In conclusion the measures taken to reduce animal mortalities on the University of North Florid
- 12. Jorge J. Gomez/Dr.Rossi Eco Road Research 12 Eco-‐road have been shown to reduce animal road mortalities and provided evidence that supports the implementation of these mechanisms in future road construction. References Adams, C E. 1983. Road-‐Killed Animals as Resources for Ecological Studies. The American Biology Teacher. 45(5): 256-‐261. Caro, T M, Shargel, J A and Stoner, C J. 2000. Frequency of Medium-‐Sized Mammal Road Kills in an Agricultural Landscape in California. American Midland Naturalist. 144(2): 362-‐369 Clevenger, A P, Chruszcz., B and Gunson, K E. 2001. Highway Mitigation Fencing Reduces Wildlife-‐Vehicle Collisions. Wildlife Society Bulletin. 29(2): 646-‐653 Forman R T and Alexander, L E. 1998. Roads and Their Major Ecological Effects. Annual Review of Ecology and Systematics. 29: 207-‐231+C2. Hawbaker, T J, Radeloff V C, Clayton, M K, Hammer, R B and Gonzalez-‐Abraham, C E. 2006. Road Development, Housing Growth, and Landscape Fragmentation in Northern Wisconsin: 1937-‐1999. Ecological Applications. 16(3): 1222-‐1237. Inbar, M and Mayer, R T. 1991. Spatio-‐Temporal Trends in Armadillo Diurnal Activity and Road-‐Kills in Central Florida.Wildlife Society Bulletin. 27(3): 865-‐872 Langen, T A, Machniak, A, Crowe, E K, Mangan, M, Marker, D F, Liddle, N and Roden, B. 2007. Methodologies for Surveying Herpetofauna Mortality on Rural Highways. The Journal of Wildlife Management. 71(4): 1361-‐1368 Lodé, T. 2000. Effect of a Motorway on Mortality and Isolation of Wildlife Populations. Ambio. 29(3): 163-‐166 Pickles, W. 1942. Animal Mortality on Three Miles of Yorkshire Roads. Journal of Animal Ecology. 11(1): 37-‐43 Roe, J H, Brinton, A C and Georges, A. 2009. Temporal and Spatial Variation in Landscape Connectivity for a Freshwater Turtle in a Temporally Dynamic Wetland System. Ecological Applications. 19(5): 1288-‐1299.