Habitat Loss and Fragmentation: The Good, Bad and Ugly

Transcription

1 Habitat Lss and Fragmentatin: The Gd, Bad and Ugly 1 Brief Descriptin: Habitat fragmentatin is visible all ver Michigan. Rads, lawns, buildings, farmland, and ther changes in habitat have turned ur state, and mst thers, int a huge patchwrk quilt f ectypes. Unfrtunately, the lines between thse quilt squares and the small size f thse patches has had a huge impact n the wildlife that call Michigan hme. Cme jin us fr a sessin f active games and prizes. Yu can really see what impacts fragmentatin has by putting yurself in the shes f the critters dealing with the changes we make. Weather permitting we will head utside fr sme fun, s cme dressed fr the chill in the air and be prepared t get active and have fun! Objectives f Lessn: At the cnclusin f the lessn, students will be able t: Explain hw habitat fragmentatin can influence the survival and reprductin f tw cmpeting species Describe the recent, 400 year histry f land use change in the Great Lakes Regin Identify causes and cnsequences f land use change and habitat fragmentatin Understand why it is difficult fr small ppulatins t survive Identify sme key endangered species in Michigan Grade Levels: 6-9 Length f Lessn Sequence: 1 hur Cntent Statements/Standards Cvered: L3.p2B Describe cmmn eclgical relatinships between and amng species and their envirnments (cmpetitin, territry, carrying capacity, natural balance, ppulatin, dependence, survival, and ther bitic and abitic factrs). (prerequisite) L3.p3A Identify the factrs in an ecsystem that influence fluctuatins in ppulatin size. (prerequisite) L3.p4A Recgnize that, and describe hw, human beings are part f Earth s ecsystems. Nte that human activities can deliberately r inadvertently alter the equilibrium in ecsystems. (prerequisite) B3.4C Examine the negative impact f human activities. B3.5C Predict the cnsequences f an invading rganism n the survival f ther rganisms. B3.5d Describe different reprductive strategies emplyed by varius rganisms and explain their advantages and disadvantages. L5.p1C Explain hw extinctin remves genes frm the gene pl. (prerequisite) Materials and Resurces: 20 cntainers with lids fr fd 2 different types f candy r reward (multiple pieces per type)

2 2 20 red flags, 20 blue flags, 20 white flags, 20 yellw flags 45 red eggs, 45 green eggs, 45 blue eggs (Yu may substitute any bject that symblizes an egg) Stp Watch Whistle t signal time Backgrund: Habitat fragmentatin is visible all ver Michigan. Rads, lawns, buildings, farmland, and ther changes in habitat have turned ur state, and mst thers, int a huge patchwrk quilt f ectypes. Unfrtunately, the lines between thse quilt squares and the small size f thse patches has had a huge impact n the wildlife that call Michigan hme. This activity helps t highlight the impacts fragmentatin has by putting yurself in the shes f the critters dealing with the changes we make. The Kirtland s warbler is an endangered bird species that nly nests in yung jack pine frests f central and nrthern Michigan. Tw challenges that limit the ppulatin size f this species is habitat availability and brd parasitism by the brwn headed cwbird, which inhabit pen areas and invaded areas in Michigan after defrestatin and cnversin t agriculture. The cwbirds lay their eggs in the nests f the warblers, and the ffspring ften ut-cmpete the warbler ffspring fr fd and essential resurces. Fr mre infrmatin abut these rganisms, see Michigan Natural Features Inventry summary n the Kirtland s warbler at Students in this activity take the rles f the tw different species, and play a game t find ut which species are mst successful in a fragmented envirnment. Activities f the Sessin Prir t the activity, identify lcatins fr fd cntainers, wintering grunds and nest building materials. Fill 10 cntainers with mstly Life Savers and a few Jlly Ranchers. Place these cntainers in pen areas f the game area, because they cntain mstly Brwn Headed Cwbird fd. In the ther 10 cntainers, fill them with mstly Jlly Ranchers and a few Life Savers. Place these cntainers in the frested areas because they are filled with Kirtland s warbler fd. Yu may chse t fill sme cntainers with nly ne type f fd. Befre beginning the activity, discuss the first 10 slides f the attached pwerpint presentatin with the students regarding land use change in the Great Lakes Regin. Play the game with the students using the rules n the activity sheets belw. Discuss with the students the fllwing questins Which f the three grups was the mst successful at surviving? Which f the three grups was mst successful at reprducing? Why was it difficult fr the Kirtland s warblers t reprduce and find enugh fd? Wuld it have been easier if the frested areas were larger r less fragmented? What advantage did the cwbirds have? Were the resistant warblers mre successful than the susceptible cwbirds? Use the last six slides f the attached pwerpint presentatin t talk abut ther issues regarding land use change. The pwerpint presentatin helps t highlight: The causes and cnsequences f land use change and habitat fragmentatin

3 Why it is difficult fr small ppulatins t survive Endangered species in the great lakes regin 3 Resurces Michigan Natural Features Inventry Kirtland s Warbler Summary Michigan Natural Features Inventry Special Animals List Michigan Natural Features Inventry Special Plants List

4 4 COWBIRDS Yu are a brwn-headed cwbird. Yu are an invasive species in this regin that des very will in disturbed habitats where frests have been cleared. Yu are a nest parasite which means yu d nt make yur wn nest, but instead lay yur slightly larger egg in ther birds nests. T d this yu need t find the nests and sneak in t lay the egg withut being caught. Yu are having an impact n the Kirtland s warblers because they tend t be susceptible t getting their nest parasitized. If yu are successful at getting yur egg int anther nest yur chick will hatch a little sner than the ther eggs and will try t push ut the ther eggs. If ther chicks hatch yur chick will kill the thers either directly r by being slightly larger and taking all the fd. If yur egg hatches, the nest wner will unwittingly care fr it and raise it, leaving yu with less wrk and the ability t lay eggs in ther nests. Here are the rules yu must play by: Yu have 3 eggs but can nly lay ne per parasitized nest Yu must frage in pen areas and need t cllect 15 candies t survive Yu d nt build a nest but have t find cmpleted nests fr yu eggs If a nest wner catches yu in the frested areas, yu must leave immediately KIRTLAND S WARBLERS - susceptible Yu are a Kirtland s warbler. Yu are endangered and ne f the reasns fr yur decline is the nest parasite bird called the brwn-headed cwbird. This bird will sneak in and lay eggs in yur nest. The chicks will then kill yur chicks, s yu end up raising the chick f the cwbird. Yu d nt like pen areas, preferring frested areas where yu frage and nest. Yu need t make a nest, lay yur eggs, and frage fr fd. But watch yur nest because a cwbird may sneak in and parasitize it. Here are the rules yu must play by: Yu have t make a nest Yu have 3 eggs which will all be laid in the nest yu make Yu must frage fr fd in the frested areas and need t cllect 10 candies t survive at least 5 f thse candies must be cllected after yu have made yur nest and laid yur eggs Yu must guard yur nest while yu frage and can stp any cwbirds befre they get t yur nest but have n pwer nce they are at yur nest KIRTLAND S WARBLERS nn-susceptible Yu are a Kirtland s warbler. Yu are endangered and ne f the reasns fr yur decline is the nest parasite bird called the brwn-headed cwbird. This bird will sneak in and lay eggs in yur nest. The chicks will then kill yur chicks, s yu end up raising the chick f the cwbird. Yu d nt like pen areas, preferring frested areas where yu frage and nest. Yu need t make a nest, lay yur eggs, and frage fr fd. But watch yur nest because a cwbird may sneak in and parasitize it. Here are the rules yu must play by: Yu have t make a nest Yu have 3 eggs which will all be laid in the nest yu make Yu must frage fr fd in the frested areas and need t cllect 10 candies t survive at least 5 f thse candies must be cllected after yu have made yur nest and laid yur eggs Yu must guard yur nest while yu frage and can stp any cwbirds in frested areas befre they get t yur nest. If a cwbird parasitizes yur nest yu have 2 ptins Ignre it yu get n ffspring but can spend the time fraging Start building a new nest and mve yur eggs t a new nest, but yu will nt have this time t frage

5 Game Setup and Rules 5 Setup: Use cntainers with lids (Tupperware, Glad-ware, anything plastic) fr the fd. Use tw kinds f candies fr the fd warblers and cwbirds shuld have different kinds f individually wrapped candies (lifesavers, mints, and suckers wrk well). In each f the fd cntainers, place sme fd types fr each bird. Half the fd cntainers will be spread ut n each end f the playing field. All the frested areas cntainers shuld have 2/3 warbler fd and 1/3 cwbird fd. All pen area fd cntainers shuld have 2/3 cwbird and 1/3 warbler fd. Using cntainers with different clr lids r sme ther distinguishable feature will make it easier t see what rati f candies is in the cntainer. Yu will need t decide ahead f time if fd scarcity is ging t be an issue, as we wuld recmmend. If s, nly place enugh candies ut fr the number f players in the game. Fr example, if yu have 15 players, 7 warblers and 8 cwbirds, place ut apprximately 70 warbler candies and 120 cwbird candies ut fr the game, distributed amng all the cntainers. Layut tw large areas ne frested habitat and ne pen habitat. Depending n space available, these areas shuld be as large as pssible but tuching. Outside areas wrk best (play field, part f the playgrund, etc.), but yu can use a gym r hallway t allw traveling time. We suggest that using actual wded and pen areas if they are available will increase the difficulty and give realistic results. Anther ptin is t have the playgrund equipment as the frested area s the warblers have plenty f nesting spts. Flat pen field will wrk just as well thugh. Use string, flags, masking tape, r ther item t shw the line between the frested and pen areas. Mark the cwbird eggs with numbers, letters, clrs, r sme ther marks. There shuld be enugh eggs s that each player has 3 eggs. Each cwbird is assigned a number and must find their eggs, ne at a time, befre they can lay them. Place all the eggs in a single cntainer n lid is needed. Even thugh cwbirds d nt make nests in the wild, they prduce larger eggs and need t put effrt int the egg, s the numbered eggs makes the cwbirds in the game wrk t get their egg. Alng the pen habitat rectangle s far end place the egg cntainers with the numbered eggs. Spread the fd cntainers randmly arund this area. Use the fd cntainers that are have 2/3 cwbird fd. Take advantage f all the areas and spread the fd cntainers ut as much as pssible. The warbler eggs are nt marked and can all be the same clr. They can be placed in ne cntainer r multiple cntainers n lid needed. There shuld be mre than 3 eggs per warbler in the cntainer since sme warblers may abandn their nest and re-nest, therefre they wuld need mre eggs. Alng the frested habitat rectangle s far end place the nesting materials (flags) and the egg cntainer with unnumbered eggs. Place the fd cntainers scattered arund the rectangle, taking advantage f the space available. These shuld be the cntainers with 2/3 warbler fd. Example f layut: FORESTED OPEN Nest Materials

6 6 Rules: Give each play a card with their species infrmatin n it. Fr the first run yu will give ½ the peple cwbird cards, ¼ f the peple susceptible warbler cards, and ¼ f the peple nn-susceptible warbler cards. Give all the warblers a small cntainer that will be the base f their nest (paper cups r ther small cntainers will wrk). Have everyne read the infrmatin within their grups. Make sure all f them knw the rules f the game fr their specific species. In additin tell them these rules that apply t everyne: Yu can nly get ne fd item frm a cntainer at a time and nt frm the same cntainer twice in a rw yu can nly take yur designated candy type. Each play needs t pen the cntainer, take their fd, then reclse the cntainer befre mving n and befre anther bird can access it. Warblers can mve all 3 f their eggs at a time Cwbirds can nly mve ne egg at a time All birds can mve arund the area freely but any cwbird caught near a warblers nest by the nest wner must leave that nest and nt parasitize it. A nest is cmpleted when there are 4 flags in place. N eggs can be laid in a nest befre it is finished. Fr larger grups in small areas, yu can allw multiple cwbirds t parasitize a nest, but the last ne place in the nest is the nly ne that survives. This can be kept track f by having the newest cwbird remving the egg f the ld cwbird and placing it next t the nest. Having cwbird eggs f a different clr than warbler eggs will help keep this prcess clear. Candies must be held nt and cannt be stashed in the nests. Birds can carry the candies in baggies if yu chse, r leave them t deal the with issue while they frage Fr the first run, the playing field shuld be set up as shwn and allw it t run fr 5-10 minutes (depending n the number f players and the size f the field). At the end f the game, have all warblers reprt their number f candies and their nest success (fail r succeed). Any parasitized nests, the adult warbler lives, but all the eggs will die. Any warblers that d nt have 10 candies will die and their nests will nt succeed. Have all cwbirds reprt their number f candies and number f successful eggs. Any cwbird withut at least 15 candies will die and but their eggs will survive if the hst nest survives. If the warbler in the hst nest dies due t a lack f fd, all the eggs, including the cwbird egg, die. Determine the survivrship and number f ffspring prduced by the warblers and the number f survivrs and ffspring frm the cwbirds.

7 Example f data sheet. See attached excel file fr the full size frm RUN #1 Warblers - nn-susceptible Names Candies Nest Success Offspring Prduced 7 Warblers susceptible Names Candies Nest Success Offspring Prduced Cwbirds Names Candies Nest Success Offspring Prduced

8 8 Fr the secnd run change the frested area by placing a rad acrss the frest r expanding the pen area (see diagram fr an example f rad). Rerun the game. The rest f the rules apply the same but the warblers have less area and nt all the warbler fd cntainers are in the frested area. Recrd the results the same way. These results can be graphed in excel t graphically shw hw the ppulatins change ver this time. Yu can als make this an iterative prcess by changing each dead cwbird int a warbler and each dead warbler int a cwbird in each successive run f the game and determine which ppulatin will thrive and which will g extinct. Example f a secnd run layut: FORESTED OPEN Nest Materials Rad Other pssible ptins fr reruns: 1) Leave the habitat the same, d nt increase the pen area r add a rad. Instead at the end f the first run, all warblers that die will becme cwbirds and all the cwbirds that die will becme warblers. Repeat the game at least 3 times, mre if time allws, and see if the cwbird r warbler ppulatin increases. If ne increases, des it get t the pint that there are resurce scarcity issues that then start frcing the ppulatins dwn? Will ne species push the ther t extinctin, and if s hw many generatins des it take? 2) Each run f the game remve a fd cntainer frm each area. Is ne grup better able t survive? Hw d the birds change their behavir because f the decrease in resurces? 3) Make all the warblers nn-susceptible fr the secnd run. Are there changes in the number f warblers surviving and successful? Hw des the cwbird ppulatin change? 4) Start the game with nly 3 warblers and 3 cwbirds. Fr each egg that survives, add that many players t represent that breeding success (births). Remve any adults that die due t a lack f fd. Rerun the game. On the third run, all the riginal birds die ff (deaths = end f their life expectancy), all birds that did nt get enugh fd die, and players are added t represent the successful eggs. Run the game multiple times and see hw the ppulatins change. If yu have multiple classes invlved in this lessn, have the first class start it, then have subsequent classes pick up where they left ff. Keep all cunts n the data table r in a visible place s the students can see the changes ver time. If time allws, restart the game and change the habitat t mre pen areas due t defrestatin r rad cnstructin. Shift fd resurces accrdingly. See hw the ppulatins respnd. Des ne species frce the ther t extinctin? Is there a pint when ne ppulatin gets t big and begins t decline again? Allw the cwbirds t lay mre eggs. Mnitr which cwbirds are mst successful and try t determine why. Which warblers are mre successful and why?

9 Example f data sheet. 9 RUN #1 Warblers - nn-susceptible Names Candies Nest Success Offspring Prduced Warblers - susceptible Names Candies Nest Success Offspring Prduced Cwbirds Names Candies Nest Success Offspring Prduced Fr the secnd run change the frested area by placing a rad acrss the frest (see diagram). Rerun the game but nw the cwbirds are safe frm bring caught by the warblers when they are in the rad. The rest f the rules apply the same. Recrd the results the same way. These results can be graphed in excel t graphically shw hw the ppulatins change ver this time. Yu can als make this an iterative prcess by changing each dead cwbird int a warbler and each dead warbler int a cwbird in each successive run f the game and determine which ppulatin will thrive and which will g extinct. Example f a secnd run layut:

10 10 FORESTED OPEN Nest Materials Rad RUN #2 Warblers - nn-susceptible Names Candies Nest Success Offspring Prduced Warblers - susceptible Names Candies Nest Success Offspring Prduced Cwbirds Names Candies Nest Success Offspring Prduced

11 QUESTIONS: 11 Why did the cwbird need 20 candies versus the warbler s 15 candies? Did the secnd run f the game with the warbler habitat fragmented make things easier n the cwbirds r easier n the warblers? Why? What kinds f management actins wuld be useful fr helping maintain warbler ppulatins? What ther factrs besides nest parasitizing may be playing a rle in the warbler decline in relatinship t habitat fragmentatin? D small parcels f frest land have value t the rganisms that live in the frest r shuld we fcus all ur attentin n the big chunks f habitat?