Some very nice lifers from this batch in April
Mammals
17. Groundhog (Marmota monax)
April 9, seen on campus while walking home after class
18. Eastern Red Bat (Lasiurus borealis) (Lifer)
I've long wanted to see a landed and identifiable bat species. I've seen plenty in flight during summer evenings, but those are often only IDed to family level. I was pleasantly surprised on my walk home, when I passed some flowering trees that I glanced at to admire the flowers. On the tree was an odd fuzzy fruit. Interesting, I thought, and almost continued on my way, until it registered, and I did a double take. An eastern red bat! I snapped a couple photos with my phone, wishing I had my camera to take shots of the amazing and well posed creature, but happy to have found it nonetheless.
Birds
April 4, I surveyed the country roads looking for Smith's longspurs, one of the best annually occurring birds in my area. I tried once unsuccessfully last year and was determined to find one this year. Found many Vesper sparrows in the country and the swallow at Riverbend forest preserve along the way. The male smiths in breeding plumage are really strikingly beautiful.
161. Vesper Sparrow (Pooecetes gramineus)
162. Northern Rough-winged Swallow (Stelgidopteryx serripennis)
163. Smith’s Longspur (Calcarius pictus) (Lifer)
Went with some friends to refind the smiths for them and also check out the 'county line floodle' where we had a large flock of one of my highly wanted species, one of the more common ones I'd been missing.
164. Lesser Yellowlegs (Tringa flavipes)
165. American Golden Plover (Pluvialis dominica) (Lifer)
April 10, my backyard
166. Hermit Thrush (Catharus guttatus)
April 12, one of my other most wanted IL birds was especially showy among the reeds at dusk at Weaver Park
167. Virginia Rail (Rallus limicola) (Lifer)
April 13, A nice pair of thrashers at McKee Marsh in Dupage Co, no county 1st or one of less than 10 state records or anything 
168. Brown Thrasher (Toxostoma rufum)
169. Sage Thrasher (Oreoscoptes montanus) (Wild)
If someone told me I'd have Sage Thrasher this year, I'd believe them but only because I was in northern Arizona in January. Got pretty lucky with this bird as I was in the area and showed up to the spot right as it perched beautifully and then hid until the next day. Did miss out on a well-seen Burrowing Owl at Montrose, however I'll take the thrasher over the owl.
Reptiles
At McKee marsh April 13
3. Common Garter Snake (Thamnophis sirtalis)
Fish
April 8, at Sam Parr state park in Jasper Co, where I went after watching the eclipse. No new species while watching the eclipse but I saw a lot of interesting behavior from Tree Swallows and even heard and saw Soras vocalizing.
3. Western mosquitofish (Gambusia affinis)
Inverts
14. Greater bee fly (Bombylius major) (Lifer)
Also at Sam Parr, bee flies and other mimic flies are always really cool to find
Some very nice lifers from this batch in April
Mammals
17. Groundhog (Marmota monax)
April 9, seen on campus while walking home after class
18. Eastern Red Bat (Lasiurus borealis) (Lifer)
I've long wanted to see a landed and identifiable bat species. I've seen plenty in flight during summer evenings, but those are often only IDed to family level. I was pleasantly surprised on my walk home, when I passed some flowering trees that I glanced at to admire the flowers. On the tree was an odd fuzzy fruit. Interesting, I thought, and almost continued on my way, until it registered, and I did a double take. An eastern red bat! I snapped a couple photos with my phone, wishing I had my camera to take shots of the amazing and well posed creature, but happy to have found it nonetheless.
Birds
April 4, I surveyed the country roads looking for Smith's longspurs, one of the best annually occurring birds in my area. I tried once unsuccessfully last year and was determined to find one this year. Found many Vesper sparrows in the country and the swallow at Riverbend forest preserve along the way. The male smiths in breeding plumage are really strikingly beautiful.
161. Vesper Sparrow (Pooecetes gramineus)
162. Northern Rough-winged Swallow (Stelgidopteryx serripennis)
163. Smith’s Longspur (Calcarius pictus) (Lifer)
Went with some friends to refind the smiths for them and also check out the 'county line floodle' where we had a large flock of one of my highly wanted species, one of the more common ones I'd been missing.
164. Lesser Yellowlegs (Tringa flavipes)
165. American Golden Plover (Pluvialis dominica) (Lifer)
April 10, my backyard
166. Hermit Thrush (Catharus guttatus)
April 12, one of my other most wanted IL birds was especially showy among the reeds at dusk at Weaver Park
167. Virginia Rail (Rallus limicola) (Lifer)
April 13, A nice pair of thrashers at McKee Marsh in Dupage Co, no county 1st or one of less than 10 state records or anything 
168. Brown Thrasher (Toxostoma rufum)
169. Sage Thrasher (Oreoscoptes montanus) (Wild)
If someone told me I'd have Sage Thrasher this year, I'd believe them but only because I was in northern Arizona in January. Got pretty lucky with this bird as I was in the area and showed up to the spot right as it perched beautifully and then hid until the next day. Did miss out on a well-seen Burrowing Owl at Montrose, however I'll take the thrasher over the owl.
Reptiles
At McKee marsh April 13
3. Common Garter Snake (Thamnophis sirtalis)
Fish
April 8, at Sam Parr state park in Jasper Co, where I went after watching the eclipse. No new species while watching the eclipse but I saw a lot of interesting behavior from Tree Swallows and even heard and saw Soras vocalizing.
3. Western mosquitofish (Gambusia affinis)
Inverts
14. Greater bee fly (Bombylius major) (Lifer)
Also at Sam Parr, bee flies and other mimic flies are always really cool to find
Catching up with migration here
Birds
April 15, Moorman Swine ponds
170. Chipping Sparrow (Spizella passerina)
171. House Wren (Troglodytes aedon)
172. Solitary Sandpiper (Tringa solitaria)
173. Chimney Swift (Chaetura pelagica)
April 20, Busey Woods, really odd place for this lifer, as a result got spectacular views!
174. American Bittern (Botaurus lentiginosus) (Lifer)
175. Grey Catbird (Dumetella carolinensis)
Finally got a trio of lost whistling ducks. They're in the area for about a day almost every year, but I missed them in the past. April 27 Target parking lot retention pond.
176. Black-bellied Whistling Duck (Dendrocygna atumnalis) (Lifer)
April 28, Middlefork River Forest Preserve, finally got the Cranes in Champaign Co.
177. Sandhill Crane (Antigone canadensis)
178. Northern Waterthrush (Parkesia noveboracensis)
179. Yellow Warbler (Setophaga petechia)
180. Swainson’s Thrush (Catharus ustulatus)
181. Least Flycatcher (Empidonax minimus)
182. Palm Warbler (Setophaga palmarum)
Busey Woods, looking (unsuccessfully) for a Worm-eating Warbler. The falcon was really nice for the county, though, and I'd never seen one in Illinois.
183. Broad-winged Hawk (Buteo platypterus)
184. Pine Warbler (Setophaga pinus)
185. Peregrine Falcon (Falco peregrinus)
186. Blue-gray Gnatcatcher (Polioptila caerulea)
April 29, I returned to Busey woods for migration
187. Warbling Vireo (Vireo gilvus)
188. Tennessee Warbler (Leiothlypis peregrina)
189. Summer Tanager (Piranga rubra)
190. Black-throated Green Warbler (Setophaga virens)
191. Nashville Warbler (Leiothlypis ruficapilla)
192. Blue-headed Vireo (Vireo solitarius)
193. Blackpoll Warbler (Setophaga striata)
194. Northern Parula (Setophaga americana)
195. Yellow-throated Vireo (Vireo flavifrons)
196. Great Crested Flycatcher (Myiarchus crinitus)
197. Rose-breasted Grosbeak (Pheucticus ludovicianus)
198. Indigo Bunting (Passerina cyanea)
199. Blue-winged Warbler (Vermivora cyanoptera)
200. Golden-winged Warbler (Vermivora chrysoptera)
201. Baltimore Oriole (Icterus galbula)
202. Ovenbird (Seiurus aurocapilla)
203. Hooded Warbler (Setophaga citrina)
204. Prothonotary Warbler (Prothonotaria citrea)
205. Scarlet Tanager (Piranga olivacea)
206. Gray-cheeked Thrush (Catharus minimus)
207. Kentucky Warbler (Geothlypis formosa)
208. Eastern Whip-poor-will (Antrostomus vociferus) (Lifer)
Whippoorwill was a previously heard only species I finally saw after someone flushed it in Busey woods and it landed in a tree. It made up for the Chuck-will's-widow in town that I missed (Would have been heard only though)
209. Eastern Screech Owl (Megascops asio) (Lifer)
A second previously heard only lifer I saw in the night while trying to refind the Chuck
April 30, on the north quad of my campus, surprisingly cooperative warbler spent the day there and gave spectacular views, in sharp contrast to the sulky one I missed at Busey earlier
210. Worm-eating Warbler (Helmitheros vermivorum) (Lifer)
I then saw a family of owls in Urbana after class
211. Barred Owl (Strix varia)
A solid April, putting me over 200. Accidentally included repeat Black-and-white warbler initially because I completely forgot I saw a vagrant one in AZ in Jan.
Inverts
15. Silverfish (Lepisma saccharina)
16. American dog/wood tick (Dermacentor variabilis)
17. Bluegrass billbug weevil (Sphenophorus parvulus)
18. Painted lady (Vanessa cardui)
19. American lady (Vanessa virginiensis) (Wild)
20. Six-spotted green tiger beetle (Cicindela sexguttata)