Cease livestock grazing: Forest, open woodland & savanna
Overall effectiveness category Awaiting assessment
Number of studies: 5
Background information and definitions
Grazing by livestock reduces vegetation height and ground cover, alters plant abundance and diversity, creating openings for seed growth and preventing reed or shrub growth. These changes can have beneficial (Tesauro & Ehrenfeld 2007) or detrimental effects (Howland et al. 2014) on reptile populations depending on the reptile species, grazing intensity, timing and conjunction with burning regimes. Studies included in this intervention measure the impact of ceasing grazing on reptiles. Studies that compare the effects of varying intensities of grazing or different types of grazing regimes on reptiles are included under the intervention Modify grazing regime.
For interventions that aim to reduce the detrimental effects of grazing by wild herbivores see Threat: Invasive or problematic species - Remove or control invasive or problem herbivores and seed eaters.
Howland B., Stojanovic D., Gordon I.J., Manning A.D., Fletcher D. & Lindenmayer D.B. (2014) Eaten out of house and home: impacts of grazing on ground-dwelling reptiles in Australian grasslands and grassy woodlands. PLoS One, 9, e105966.
Tesauro J. & Ehrenfeld D. (2007) The effects of livestock grazing on the bog turtle [Glyptemys (=Clemmys) muhlenbergii]. Herpetologica, 63, 293–300.
Supporting evidence from individual studies
A paired, controlled study in 1991 of tropical deciduous forest ranchland in Baja California Sur, Mexico (Romero-Schmidt et al. 1994) found that lizard abundances tended to be higher in ungrazed sites compared to grazed sites. Results were not statistically tested. Thirty-two lizards were observed in ungrazed sites and seven in grazed sites. Five species were observed in both ungrazed and grazed sites: spiny lizard Sceloporus hunsakeri (ungrazed: 6 individuals, grazed: 2), Baja California brush lizard Urosaurus nigricaudus (16, 2), orange-throated whiptail Aspidoscelis hyperythrus hyperythrus (7, 1), spiny lizard Sceloporus licki (2, 1), and Baja blue rock lizard Petrosaurus thalassinus thalassinus (1, 1). Five 25 x 5 m transects at 5 m intervals were established in a 2,400 m2 exclosure with no grazing since 1989. The same survey set up was established in a grazed area 35 m outside the exclosure on a livestock ranch. Lizard abundance was measured by counting the number of lizards observed/time spent looking.Study and other actions tested
A replicated, site comparison study in 1994–1998 in woodland savanna near Santo Domingo, Argentina (Leynaud & Bucher 2005) found that 25 years after cattle were excluded, overall snake and lizard abundances and diversity tended to be similar to adjacent grazed ranchland. A total of 82 snakes of 15 species and 136 lizards of 12 species were captured in ungrazed land compared to 71 snakes of 16 species and 182 lizards of 10 species in grazed land (results were not statistically tested). Species diversity was similar between ungrazed restored and grazed land (Shannon Wiener Diversity index of snakes ungrazed: 2.4, grazed: 2.4; lizards: 1.7, 1.6). One lizard and one snake species were more abundant in ungrazed land, and two lizards and one snake species were more abundant in grazed land (see paper for details). Reptiles were monitored in an area fenced in 1976 to exclude cattle and allow woodland regeneration (10,000 ha) and an adjacent overgrazed ranchland (7,500 ha). Surveys were carried out in six plots of each habitat type (>7 km apart) using drift fences with funnel traps (‘arrays’, 6 traps/array, one array/plot) in March 1994–March 1998 (152 non-consecutive days).Study and other actions tested
A replicated, site comparison study in 2001 in savanna woodland in Queensland, Australia (Kutt & Woinarski 2007) found that overall reptile abundance and the abundance of five of 18 species was higher in ungrazed than grazed plots. Overall reptile abundance was higher in ungrazed (18.5–19.6 individuals/plot) than grazed plots (12.3–14.0), regardless of fire history. Of 32 reptile species observed, 18 were included in analysis (appeared in high enough numbers). Five species abundances were higher in ungrazed than grazed plots (eastern bearded dragons Pogona barbata ungrazed: 0.6–0.7 individuals/plot vs grazed: 0–0.1; variable fat-tailed geckoes Diplodactylus conspicillatus: 0.8–1.0 vs. 0.1–0.2; stout ctenotus Ctenotus hebetior: 2.6–4.3 vs. 2.0–2.3; leopard ctenotus Ctenotus pantherinus: 1.4–4.4 vs. 0–1.3, red-earth ctenotus Ctenotus rosarium: 1.9–2.0 vs. 1.0–1.3). Dwarf skink Menetia greyii abundance was lower in ungrazed (0–0.3) than grazed plots (1.0–1.3). The abundance of the remaining 12 species was similar in ungrazed and grazed plots. In January 2001, reptiles were monitored on three cattle stations (>20,000 ha each) in 29 one-ha plots that were either ungrazed (paddocks where cattle were excluded) or grazed (4–8 cattle/ha). Plots were also either recently burned (within 2 years) or unburned (last burnt >2 years ago). Reptiles were sampled using cage traps and pitfalls supplemented by day and night log rolling and litter raking.Study and other actions tested
A site comparison study in 2006 of cattle pasture in Corrientes, Argentina (Cano & Leynaud 2010) found that overall reptile diversity, species richness and abundance were similar in ungrazed sites (with annual fires or no fire for three or 11 years) and grazed sites with annual prescribed fires. Overall reptile species richness, abundance and diversity were similar in ungrazed sites that had either annual fires or no fires for three or 11 years (richness: 3–4; abundance: 22–44, Shannon diversity index: 0.8–1.1) compared to grazed sites with annual prescribed fires (richness: 4; abundance: 17, Shannon diversity index: 1.1). Species composition was most similar in sites that were ungrazed with annual fires and sites that were grazed with annual fires (result reported as similarity index). Four areas (≥ 400 ha) were monitored: ungrazed and no fires for three years; no grazing or fires for 11 years; ungrazed with annual fires (August–September); grazed (3 ha/cattle unit) with annual fires. Monitoring was undertaken using drift-fencing with pitfall traps in January–April 2006 (80 survey days).Study and other actions tested
A replicated, site comparison study in 1997–2007 in open woodland in south eastern Australia, Australia (Haby & Brandle 2018) found that following removal of domestic livestock, combined reptile and small mammal species richness, but not abundance, increased. Over 11 years, overall reptile and small mammal species richness increased after livestock removal in woodland (0.04 species/100 trap nights/year) compared to areas with livestock (0.01 species/100 trap nights/year). Over the same time period, livestock removal did not affect the change in overall reptile and small mammal abundance over time (no livestock: −0.40 individuals/100 trap nights/year; with livestock: −0.31). In 1997–2007, reptiles and small mammals were surveyed in two woodland sites (open mulga Acacia aneura woodland) with historical but no current domestic livestock grazing and two sites with livestock (sheep and/or cattle) grazing in the Flinders Ranges. Reptiles were surveyed using pitfall traps one–three times/year (23 surveys).Study and other actions tested